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Takahiro KUBA Last modified date:2018.06.11

Professor / Water and Material Cycles System
Faculty of Engineering


Graduate School
Undergraduate School


E-Mail
Homepage
http://www.doc.kyushu-u.ac.jp/kk_staff.html
Dept. of Civil Engineering Course WP .
http://www7.civil.kyushu-u.ac.jp/toshi/en/entop2.html
Urban and Enviroment Eng. Lab. WP .
http://book.geocities.jp/activatedsludge6/
G30 Classes WP .
http://book.geocities.jp/activatedsludge6/
G30Classes WP .
Phone
092-802-3426
Academic Degree
Doc. of Eng.
Country of degree conferring institution (Overseas)
No
Field of Specialization
Environmental Eng., Sanitary Eng., Wastewater Eng.
Total Priod of education and research career in the foreign country
03years00months
Outline Activities
(5)Algal Growth Inhibition Allelochemical released from Aquatic Macrophytes: In eutrophicated semi-closed water areas, extraordinary growth of blue-green algae (cyanobacteria) has been an increasing serious problem. Many papers have been published on the biosynthesis of liver toxin, microcystin, by cyanobacterium, Microcystis aeruginosa, and on the occurrence of taste and odor due to 2-MIB or geosmin released by Oscillatria agardhii, a dominant species of water-blooms. To purify eutrophicated waters, some aquatic macrophytes have been accepted to absorb nutrients, such as nitrogen and phosphorus. All plants release some biochemical substances, so-called Allelochemical, into ambient environment, and these substances will affect other plants, insects and bacteria as an inhibitor or promoter. These phenomena are called Allelopathy. In addition to the nutrients removal, if aquatic macrophytes show allelopathic inhibition effects on cyanobacteria, it can be a useful method of controlling the eutrophication. The purpose of this paper is to examine allelopathic effects of aquatic macrophytes, Eichhornia crassipes and Cyperus alternifolius L., on cyanobacterium growth inhibition, and to identify algicidal allelochemical. Research results are as follows:
1) Two living macrophytes, E.crassipes and C.alternifolius L completely lysed the cells of M.aeruginosa within a few days after the coexistence. The supernatant after cultivation of the macrophytes showed also strong inhibition on the growth. These results were obtained under no limitation of nutrients as well as light irradiation. This means E.crassipes and C.alternifolius L. released algicidal allelochemical into ambient environment.
2) The algicidal allelochemical isolated from water-extracts of E.crassipes was a kind of Condensed Tannin. Polyphenols, like Tannin, are reported as a typical algicidal allelochemical. It was suggested Tannin released from these macrophytes inhibited the growth of M.aeruginosa.

(6)Isolation of the Denitrifying Phosphate-Accumulating Organisms Utilize Acetate as a Sole Carbon Source: A screening work using new screening equipment was carried out to isolate the denitrifying phosphate-accumulating organisms under alternating anaerobic-anoxic conditions. Acetate as a sole organic matter and nitrate as a final electron acceptor were added in the medium for the anaerobic and the anoxic phase, respectively. Since the inside of equipment was washed with distilled water at the shifting phase from each condition to the other condition, acetate and nitrate did not exist simultaneously during the work. As a result of an screening-isolation work using activated sludge in a municipal waste water treatment plant, three kinds of pure cultures were obtained. By microscopy with staining methods, it was proved that all of isolated bacteria had the activities of polyphosphate and PHB accumulation under the alternating anaerobic-anoxic conditions. It is suggested qualitatively that all of isolated organisms posesses characteristics representative of the behaviour of phosphate-accumulating organisms in activated sludge.

(7)Some Aspects on Pollutant Load to the River Basins in the Itoshima Area: The New Campus of Kyushu University is under construction in the Itoshima area which has four municipalities; Maebaru City, Nijo Town, Shima Town and western part of Fukuoka City. Although a part of wastewater in the area is treated in the Seibu sewage treatment plant at present, which is located out of the area, a new sewage treatment plant, which will discharge the treated wastewater to the semi-closed bay at the north-eastern Itoshima area, the Imazu Bay, is also planed. In future, pollutant load discharged into the bay may increase by the construction of the new campus and regional development. The retarding function, in addition, will deteriorate with the construction and the regional development. These will significantly affect ecosystems, especially in the Imazu bay and the Kahuri bay locating at the estuaries of the Zuibaiji river and the Raizan river, respectively. The objectives of the present work are to create a database on the unit of pollution load and various kinds of statistical data, and to examine the point/non-point pollutant loads to each river basin in the area, by using GIS. Research results indicate that the pollutant loads to the Zuibaiji river basin and the Raizan river basin are more than those in the other basins, and pollutant load from live-stock waste/waste water is the largest in almost all river basins. In order to conserve aquatic environment in the Imazu bay and the Kahuri bay, it will be necessary to control and maintain sewer, to make further improvement for advanced treatment, to convert the Jokaso (septic tank for night soil) into other types of highly efficient sewage treatment systems, and to reduce pollutant lord from live-stock waste/waste water with appropriate treatment. Added to these, it will be extremely important to reduce pollutant lord from the non-point sources.

(8)The influence of starvation phase on the properties and the development of aerobic granules: The current study was to evaluate the influence of starvation phase on surface negative charge, relative hydrophobicity, extra-cellular polymer substances (EPS) and the formation mechanism of aerobic granules. Granules with encouraging settling properties occurred in the reactor about 7 days after the inoculation. The surface negative charge decreased from 0.203 to 0.023 meq g VSS−1 and the relative hydrophobicity increased from 28.8 to 60.3% during the granulation period. Concentrations of protein and carbohydrate decreased from 18.0 to 7.1 and 7.0 to 2.9 mg g VSS−1, respectively in the first period. And from day 13, those values were observed in the range of 5.8–8.6 and 2.9–5.6 mg g VSS−1, respectively. The EPS especially protein concentrations well correlated with surface charge and relatively hydrophobicity. It was concluded that a reasonable amount of EPS should be controlled to form and maintain aerobic granules. It was proposed that aerobic granulation was initiated by starvation phase and then enhanced by anaerobic metabolism.

(11) “Highly dissolved oxygen water system” will be applied for the prevention of oxygen-depleted water occurrence. There are two purposes for the utilization of this kind of system or technique supplying the highly dissolved oxygen water to the bottom layer. The first purpose is to reproduce the barrier oxidative layer at the bottom, in order to control the elution of nutrients from the anaerobic sediment. Another one is to stimulate aerobic microorganisms such as zooplankton and the aerobic bacteria, in order to restructure the aquatic ecosystem, which leading to sustainable water environment.
Water quality measurement and biota investigation were conducted in several important water areas of the Lake Taihu, i.e., the East Lake Taihu area and the Meiliang Bay area. Temporal and spatial variation trends of the water quality and biota in these areas of the Lake Taihu were clarified in the 2010 and 2011. The results of identification and quantification showed that there were many species of aquatic macrophytes in the East Lake Taihu, while they were seldom distributed in the Meiliang Bay. In the East Lake Taihu, pen culture covers a large part of the lake surface, which leads to an increase of the organics and nutrients loading. Eutrophication phenomena characterized with cyanobacteria water-bloom are becoming seriously, especially in the Meiliang Bay. According to these results, an aquatic environmental improvement strategy was proposed. "Ecological Dam” (Eco-engineering Dam Barrier Structure, EDBS) based on the biomanipulation techniques, seems to be available from the ecological engineering point of view.

(12) In order to recover the energy from the sewage, how to advancely treat the secondary effluent is investigated.

(13) Application Possibility of Bamboo Charcoal and Sewage Sludge Slag as Cesium Ion Adsorbent ~Effect of Carbonization Temperature and Coexisting Cations~
Research
Research Interests
  • Control the overgrowth of phytoplankton using LED light in closed water bodies
    keyword : LED light, light wave length, photosynthesis, phytoplankton, water-bloom, Microcystis aeruginosa、Nitzschia sp.
    2016.03.
  • The basic research about removal capability of water-bloom toxin, microcystin using fresh water bivalves
    - Kinetics of microcystin accumulation and detoxification in their body -
    keyword : Microcystis aeruginosa, micricystin, Aoko, water blooms. Anodonta woodiana, Hyriopsis cumingii
    2014.04~2017.03.
  • Cultivation of useful plants over the water surface receiving treated sewage
    keyword : Glycyrrhiza glabra, Vetiveria zizanioides, treated effluent from sewage treatment plant, nitrogen, phosphorus
    2015.04.
  • ECOPHYSIOLOGICAL STUDIES OF A SUBMERGED MACROPHYTE VALLISNERIA ASIATICA FOR THE ECOLOGICAL RESTORATION OF EUTROPHIC LAKE TAIHU, CHINA
    keyword : Lake Taihu, submerged macrophytes, Vallisneria asiatica
    2011.10~2015.03.
  • Polyphosphate Recovery from Sewage Sludge as Magnesium Ammonium Phosphate and its Forming Ability
    keyword : Polyphosphate (Poly-P), magnesium ammonium phosphate (MAP), HEATPHOS, seed crystal
    2014.04.
  • Water Purification Technologies of Ecological Engineering in Closed Water Area -Controlling the Water Bloom Using Biofilm Carriers-
    keyword : Water blooms, Aoko, Biofilm, Field mesocosm experiment
    2013.04.
  • A comparative study of the removability of water blooms by freshwater bivalves ~The physiological energetics method~
    keyword : SFG (Scope for growth), Anodonta woodiana, Sinanodonta lauta, Hyriopsis cumingii, bivalves, water blooms, Aoko, microcystin
    2014.04.
  • Basic research of resource recovery from water bloom
    keyword : Water blooms, Aoko, phosphorus recovery, reduction/removal of internal pollutant loadings
    2014.04~2016.03.
  • Adsorptive Removal of Cesium Ions by Sewage Sludge Slags

    keyword : Cs, non-point source pollution, sewage sludge slags
    2013.04.
  • Application Possibility of Bamboo Charcoal as Cesium Ion Adsorbent ~Effect of Carbonization Temperature and Coexisting Cations~

    keyword : Cs, non-point source pollution, bamboo charcoal
    2012.04.
  • Development of "Eco-engineering Dam Barrier Structure" (EDBS)
    keyword : Biomanipulation, Lake Taihu、Aoko (Water-bloom), "Ecological Dam” (Eco-engineering Dam Barrier Structure, EDBS)
    2011.04Phosphorus Resources Circulation and the Recoverable Potential in Itoshima Region: Phosphorus is limited resources and the available amount of phosphate rock would be run out within a century. Unfortunately, in Japan, most of the phosphate rock is imported. On the other hand the amount of 20-30% phosphorus imported into Japan is included in sewage and livestock wastewater. This study evaluates (i) the circulation of phosphorus in Itoshima region (Nishi ward of Fukuoka city, Maebaru city, Shima town, Nijo town) that is agricultural area adjoining urban area, (ii) the potential of phosphorus recovery from sewage/sewage-sludge by the MAP (Magnesium Ammonium Phosphate) crystallization method or composting, and (iii) effect on SPA (Self-sufficiency of Phosphorus in Agriculture) by reduction of fertilizer. The results of the evaluation are as follows: (i)70% phosphorus imported to the Itoshima region is for animal husbandry, and 60% phosphorus exported from the Itoshima region is by food distribution. (ii) By the MAP method, at present the phosphorus recovery ratio is only 2.9% in a wastewater treatment plant. If all wastewater treatment plants had the same recovery ratio in the Itoshima region or in both the region and Fukuoka city, the SPA would be 1.7% or 13.2%, respectively. By the composting method, at present the recovery amount of phosphorus is 10.2t-P・yr-1, and the SPA is 6.8%. To raise SPA to 100%, 48,000t of sewage sludge is annually needed, and it is almost equal to half the sludge produced in Fukuoka city. It is, therefore, possible to supply the sludge for the composting in the Itoshima region. (iii)10% or 30% of fertilizer reduction, together with the MAP method (2.9% recovery), brings in increasing 1.5% or 5.7% of SPA, respectively, while together with the composting, brings in increasing 0.7% or 2.9% of SPA. In conclusion, it is important to circulate the phosphorus resources not only in agricultural area but also in adjoining urban area, e.g., through the sewerage system. It should also be added that the reduction of fertilizer directly brings rising SPA..
  • A Relationship between the Water Quality and the Odor in a Dam Resrervor
    keyword : Water Quality, Odor, Dam resrervor
    1984.04~1985.03.
  • Anarobic Wastewater Treatment in a Fluidized Bed Reactor
    keyword : Anarobic wastewater treatment, Fluidized bed reactor, Methane generation
    1986.04~1993.03Anarobic wastewater treatment in a fluidized bed reactor..
  • Sewage treatment with denitrifying phosphate removing organisms and nitrifiers
    keyword : Sewage treatment, Denitrifying phosphate removing organisms (DPB, DPAO), Nitrifiers
    1991.04Sewage treatment with denitrifying phosphate removing organisms and nitrifiers..
  • Increase in rate of biological nitrification with NIPAAm gel as immobilizing media
    keyword : Biological nitrification, NIPAAm gel, Immobilizing media, light-stimulus-responsive gells
    1996.04~2001.03Increase in rate of biological nitrification with NIPAAm gel as immobilizing media. Application of light-stimulus-responsive gells to immobilized media..
  • Allelopathic Effects of Macrophyte on Growth of Microcystis aeruginosa
    keyword : Allelopathic Effects, Macrophyte, Microcystis aeruginosa
    2000.04Allelopathic Effects of Macrophyte on Growth of Microcystis aeruginosa: In eutrophied closed waters, it is a very serious problem that blue-green algae (cyanobacteria) are increasing abnormally. Many reports have been published that cyanobacterium Microcystis aeruginosa which is a dominant species of water-blooms, is responsible for biosynthesis of the potent liver toxin microcystin. The purpose of this paper is to examine allelopathic effects of aquatic macrophytes, Eichhornia crasssipes., Cyperus alternifolius L. and Nasturtium officinale R.Br., on the cyanobacterium growth inhibition. The growth of M. aeruginosa was inhibited by the addition of the macrophyte fragments or liquid-extracts into the culture media. The strong inhibition effects with E. crasssipes and root parts of C. alternifolius L. were observed, and the lysis of M. aeruginosa cells occurred. It was also confirmed that these two living macrophytes completely lysed the cells within a few days after the species coexistence. Furthermore, the supernatant solution itself after the macrophytes were cultivated, showed strong growth inhibition. Overall these results obtained under no limitation of nutrients concentration and light irradiation, lead to the conclusion that E. crasssipes and C. alternifolius L. produce some allelochemicals and these materials inhibit the growth of M. aeruginosa..
  • Isolation of the Denitrifying Phosphate-Accumulating Organisms Utilize Acetate as a Sole Carbon Source
    keyword : Denitrifying phosphorus removing bacteria, Sewage treatment, Advanced treatment
    2000.03~2008.04Isolation of the Denitrifying Phosphate-Accumulating Organisms Utilize Acetate as a Sole Carbon Source: A screening work using new screening equipment was carried out to isolate the denitrifying phosphate-accumulating organisms under alternating anaerobic-anoxic conditions. Acetate as a sole organic matter and nitrate as a final electron acceptor were added in the medium for the anaerobic and the anoxic phase, respectively. Since the inside of equipment was washed with distilled water at the shifting phase from each condition to the other condition, acetate and nitrate did not exist simultaneously during the work. As a result of an screening-isolation work using activated sludge in a municipal waste water treatment plant, three kinds of pure cultures were obtained. By microscopy with staining methods, it was proved that all of isolated bacteria had the activities of polyphosphate and PHB accumulation under the alternating anaerobic-anoxic conditions. It is suggested qualitatively that all of isolated organisms posesses characteristics representative of the behaviour of phosphate-accumulating organisms in activated sludge..
  • Some Aspects of the Pollutant Load to the River Basins in the Itosima Area
    keyword : Pollutant load, River basins, Itosima Area, Water cycle
    2003.04~2013.03Some Aspects of the Pollutant Load to the River Basins in the Itosima Area: The New Kyushu University Campus is building in the Itoshima area including four municipalities; Maebaru City, Nijo Town, Shima Town and a west part of Fukuoka City. Although a part of the waste water is treated in the Seibu sewage treatment plant at the moment, which is located out of the area, construction of a new sewage treatment plant which will discharge the treated waste water to a semi-closed waters at the north-western Itoshima area, the Imazu Bay, is also being planed. In future, there's a strong suspicion that the pollutant loads flowing into the water area are increased by the construction of the New Campus and the regional development such as the construction of the new sewage treatment plant. The retarding function, in addition, will deteriorate with the construction and the regional development. These significantly affect the ecosystems, especially in the Imazu Bay and the Kahuri Bay locating at the estuary of the Zuibaiji River and the Raizan River, respectively. The objective of the present work is to create a database on primitive unit of pollution load and various kinds of statistical information, and to examine the point/non-point pollutant load to each river basin in the Itoshima area, by using GIS (Geographic Information System). The investigation indicated that the pollutant load to the Zuibaiji River Basin and the Raizan River Basin is more than that in the other basins, and the pollutant load of live-stock waste or wastewater is the largest in almost all river basins. In order to conserve the water environment in the Imazu Bay and the Kahuri Bay, it will be necessary (i) to organize and maintain sewerage, (ii) to make further improvements for the advanced treatment, (iii) to convert the single type Johkaso (individual treatment tanks for night soil) into other types of highly efficient sewage treatment systems, and (iv) to reduce the pollutant lord from the live-stock waste/waste water with proper treatment. Added to these, it will be extremely important to reduce the pollutant lord from the non-point source..
  • Development of the Aerobic Granules and the stability
    keyword : Aerobic granulation, Aerobic granules, Extraceller polyomer substances, Wastewater treatment
    2003.10~2007.03The influence of starvation phase on the properties and the development of aerobic granules: The current study was to evaluate the influence of starvation phase on surface negative charge, relative hydrophobicity, extra-cellular polymer substances (EPS) and the formation mechanism of aerobic granules. Granules with encouraging settling properties occurred in the reactor about 7 days after the inoculation. The surface negative charge decreased from 0.203 to 0.023 meq g VSS-1 and the relative hydrophobicity increased from 28.8 to 60.3% during the granulation period. Concentrations of protein and carbohydrate decreased from 18.0 to 7.1 and 7.0 to 2.9 mg g VSS-1, respectively in the first period. And from day 13, those values were observed in the range of 5.8ミ8.6 and 2.9ミ5.6 mg g VSS-1, respectively. The EPS especially protein concentrations well correlated with surface charge and relatively hydrophobicity. It was concluded that a reasonable amount of EPS should be controlled to form and maintain aerobic granules. It was proposed that aerobic granulation was initiated by starvation phase and then enhanced by anaerobic metabolism..
  • Phosphorus Resources Circulation and the Recoverable Potential in Itoshima Region:
    keyword : Phosphorus recovery, Phosphorus rock, Phosphorus resources, Excess Sludge
    2008.04Phosphorus Resources Circulation and the Recoverable Potential in Itoshima Region: Phosphorus is limited resources and the available amount of phosphate rock would be run out within a century. Unfortunately, in Japan, most of the phosphate rock is imported. On the other hand the amount of 20-30% phosphorus imported into Japan is included in sewage and livestock wastewater. This study evaluates (i) the circulation of phosphorus in Itoshima region (Nishi ward of Fukuoka city, Maebaru city, Shima town, Nijo town) that is agricultural area adjoining urban area, (ii) the potential of phosphorus recovery from sewage/sewage-sludge by the MAP (Magnesium Ammonium Phosphate) crystallization method or composting, and (iii) effect on SPA (Self-sufficiency of Phosphorus in Agriculture) by reduction of fertilizer. The results of the evaluation are as follows: (i)70% phosphorus imported to the Itoshima region is for animal husbandry, and 60% phosphorus exported from the Itoshima region is by food distribution. (ii) By the MAP method, at present the phosphorus recovery ratio is only 2.9% in a wastewater treatment plant. If all wastewater treatment plants had the same recovery ratio in the Itoshima region or in both the region and Fukuoka city, the SPA would be 1.7% or 13.2%, respectively. By the composting method, at present the recovery amount of phosphorus is 10.2t-P・yr-1, and the SPA is 6.8%. To raise SPA to 100%, 48,000t of sewage sludge is annually needed, and it is almost equal to half the sludge produced in Fukuoka city. It is, therefore, possible to supply the sludge for the composting in the Itoshima region. (iii)10% or 30% of fertilizer reduction, together with the MAP method (2.9% recovery), brings in increasing 1.5% or 5.7% of SPA, respectively, while together with the composting, brings in increasing 0.7% or 2.9% of SPA. In conclusion, it is important to circulate the phosphorus resources not only in agricultural area but also in adjoining urban area, e.g., through the sewerage system. It should also be added that the reduction of fertilizer directly brings rising SPA..
  • Energy recovery with the treated wastewater
    keyword : Energy recovery, Advanced treatment
    2009.04~2011.03Phosphorus Resources Circulation and the Recoverable Potential in Itoshima Region: Phosphorus is limited resources and the available amount of phosphate rock would be run out within a century. Unfortunately, in Japan, most of the phosphate rock is imported. On the other hand the amount of 20-30% phosphorus imported into Japan is included in sewage and livestock wastewater. This study evaluates (i) the circulation of phosphorus in Itoshima region (Nishi ward of Fukuoka city, Maebaru city, Shima town, Nijo town) that is agricultural area adjoining urban area, (ii) the potential of phosphorus recovery from sewage/sewage-sludge by the MAP (Magnesium Ammonium Phosphate) crystallization method or composting, and (iii) effect on SPA (Self-sufficiency of Phosphorus in Agriculture) by reduction of fertilizer. The results of the evaluation are as follows: (i)70% phosphorus imported to the Itoshima region is for animal husbandry, and 60% phosphorus exported from the Itoshima region is by food distribution. (ii) By the MAP method, at present the phosphorus recovery ratio is only 2.9% in a wastewater treatment plant. If all wastewater treatment plants had the same recovery ratio in the Itoshima region or in both the region and Fukuoka city, the SPA would be 1.7% or 13.2%, respectively. By the composting method, at present the recovery amount of phosphorus is 10.2t-P・yr-1, and the SPA is 6.8%. To raise SPA to 100%, 48,000t of sewage sludge is annually needed, and it is almost equal to half the sludge produced in Fukuoka city. It is, therefore, possible to supply the sludge for the composting in the Itoshima region. (iii)10% or 30% of fertilizer reduction, together with the MAP method (2.9% recovery), brings in increasing 1.5% or 5.7% of SPA, respectively, while together with the composting, brings in increasing 0.7% or 2.9% of SPA. In conclusion, it is important to circulate the phosphorus resources not only in agricultural area but also in adjoining urban area, e.g., through the sewerage system. It should also be added that the reduction of fertilizer directly brings rising SPA..
  • Biomanipulation by the highly dissolved oxygen water
    keyword : Biomanipulation, dissolved oxygen, Lake Taihu、Aoko (Water-bloom), "Ecological Dam” (Eco-engineering Dam Barrier Structure, EDBS)
    2009.04~2016.03Phosphorus Resources Circulation and the Recoverable Potential in Itoshima Region: Phosphorus is limited resources and the available amount of phosphate rock would be run out within a century. Unfortunately, in Japan, most of the phosphate rock is imported. On the other hand the amount of 20-30% phosphorus imported into Japan is included in sewage and livestock wastewater. This study evaluates (i) the circulation of phosphorus in Itoshima region (Nishi ward of Fukuoka city, Maebaru city, Shima town, Nijo town) that is agricultural area adjoining urban area, (ii) the potential of phosphorus recovery from sewage/sewage-sludge by the MAP (Magnesium Ammonium Phosphate) crystallization method or composting, and (iii) effect on SPA (Self-sufficiency of Phosphorus in Agriculture) by reduction of fertilizer. The results of the evaluation are as follows: (i)70% phosphorus imported to the Itoshima region is for animal husbandry, and 60% phosphorus exported from the Itoshima region is by food distribution. (ii) By the MAP method, at present the phosphorus recovery ratio is only 2.9% in a wastewater treatment plant. If all wastewater treatment plants had the same recovery ratio in the Itoshima region or in both the region and Fukuoka city, the SPA would be 1.7% or 13.2%, respectively. By the composting method, at present the recovery amount of phosphorus is 10.2t-P・yr-1, and the SPA is 6.8%. To raise SPA to 100%, 48,000t of sewage sludge is annually needed, and it is almost equal to half the sludge produced in Fukuoka city. It is, therefore, possible to supply the sludge for the composting in the Itoshima region. (iii)10% or 30% of fertilizer reduction, together with the MAP method (2.9% recovery), brings in increasing 1.5% or 5.7% of SPA, respectively, while together with the composting, brings in increasing 0.7% or 2.9% of SPA. In conclusion, it is important to circulate the phosphorus resources not only in agricultural area but also in adjoining urban area, e.g., through the sewerage system. It should also be added that the reduction of fertilizer directly brings rising SPA..
Academic Activities
Books
1. Takayuki Shimaoka, Takahiro KUBA, Hirofumi Nakayama, Toshiyuki Fujita, Nobuaki Hori, Basic Studies in Environmental Knowledge, Technology, Evaluation, and Strategy: Introduction to East Asia Environmental Studies, Springer, Part II Environmental Technology
8 Water Purification by Reducing the Pollution Burden
 Hiroshi KUMAGAI and Takahiro KUBA
 pp.105-121, 2016.03, [URL].
Reports
1. Water Reuse.
2. T. KUBA・M. van Loosdrecht・J.J. Heijnen, Delft final report: Biological Phosphorus Removal from Waste Water by Anaerobi-Anoxic or Anaerobic-Aerobic Sequencing Batch Reactors, NOVEM (Netherlands Agency for th Environment and Energy) No.51120/1610, 1992.01.
Papers
1. Shahjalal Khandaker, Yusaku Toyohara, Seiya Kamida, Takahiro Kuba, Effective removal of cesium from wastewater solutions using an innovative low-cost adsorbent developed from sewage sludge molten slag, Journal of Environmental Management, 222, 304-315, 2018.09, [URL], This study investigates the effective removal of cesium (Cs) from aqueous solution using sewage sludge molten
(SSM) slag that has undergone the surface modification with alkali (NaOH) hydrothermal treatment. The raw
and modified slags were characterised systematically using the BET method, the FESEM, the XRF, the XRD
spectroscopy and the CEC analysis to understand the physicochemical changes of the materials, and its sensitivity
to Cs ions adsorption. Batch adsorption experiments were carried out to investigate the effects of adsorbent
dose, contact time, solution pH, different initial Cs concentrations, temperature and the effect of competitive
ions on Cs adsorption. The adsorption isotherm, kinetic and thermodynamic studies were also evaluated based
on the experimental results. A higher Cs removal efficiency of almost 100% (for 20–100 mg/L of initial concentration)
was achieved by the modified SSM slag, and the maximum adsorption capacity was found to be
52.36 mg/g. Several types of synthetic zeolites such as zeolite X, zeolite Y, zeolite A, and sodalite were formed on
surface of the modified slag through the modification process which might be enhanced the Cs adsorption
capacity. Kinetic parameters were fitted by the pseudo-second order model. The adsorption isotherms data of
modified slag were well-fitted to the Langmuir (R2=0.989) and Freundlich isotherms (R2=0.988). The
thermodynamic studies indicated that the adsorption process by the modified slag was spontaneous and exothermic.
In the competitive ions effect, the modified slag effectively captured the Cs ion in the presence of Na+
and K+, especially at their lower concentrations. Moreover, the modified slag was reused for several cycles after
the successful elution process with an appropriate eluting agent (0.5MH2SO4), without deterioration of its
original performance. Therefore, the SSM modified slag could be effectively used as a low-cost potential adsorbent
for high Cs adsorption from wastewater..
2. Shahjalal Khandaker, Yusaku Toyohara, Seiya Kamida, Takahiro Kuba, Adsorptive removal of cesium from aqueous solution using oxidized bamboo charcoal, Water Resources and Industry, https://doi.org/10.1016/j.wri.2018.01.001, 19, 35-46, 2018.06, [URL], In this study, the air oxidized bamboo charcoal (BC) was investigated for cesium (Cs) adsorption from aqueous solution. The physicochemical properties of the adsorbent were evaluated systematically using the different techniques including BET, FESEM, FTIR, XPS and also the pHpzc value. Batch adsorption experiments were conducted to determine the effect of contact time, solution pH, initial Cs concentrations, temperature and also the presence of competitive ions on adsorption. The adsorption kinetic parameters confirmed the better fitting of pseudo-second order kinetic model. The isotherm data could be well described by the Langmuir isotherm model and the maximum monolayer adsorption capacity was 55.25 mg g-1. The high specific surface area and the porous structure with some acidic functional groups on the surface were obviously responsible for high Cs adsorption onto oxidized-BC. Thermodynamic parameters such as standard enthalpy, entropy, and Gibbs free energy were evaluated and it had been found that the adsorption process was favorable, spontaneous and endothermic in nature. In the competitive ions study, the presence of Na and K with their concentrations up to 12mM did not strongly affect the removal of Cs by oxidized-BC. Therefore, the experimental results suggested that the oxidized-BC could be used as an effective adsorbent for significant Cs removal from aqueous solution considering the high adsorption capacity, short adsorption time and selective removal of Cs ions..
3. Zhifan Ni, Xiaogang Wu. Lingfang Li, Zhe Lv, Zhenjia Zhang, Aimin Hao, Yasushi Iseri, Takahiro Kuba, Xiaojun Zhang, Wei-Min Wu, Chunjie Li, Pollution control and in situ bioremediation for lake aquaculture using an ecological dam, Journal of Cleaner Production, https://doi.org/10.1016/j.jclepro.2017.11.185, 172, 2256-2265, 2018.01, [URL], Aquaculture has become one of the major sources of lake eutrophication, due to the lack of direct and efficient technologies for pollution control and remediation. This study proposes a novel ecological dam (Eco-dam) system, which consists of biofilter floating beds and plant floating beds that form an enclosure (the test zone) around the breeding area that allows lake water to pass through. A pilot-scale test was conducted to test pollution control and in situ bioremediation during breeding of Chinese mitten crab (Eriocheir sinensis) in Yangcheng Lake, China. The results showed slight improvement of water quality in the test zone compared with the breeding zone. The biofilm that formed on the biofilter played a major role in removal of organic pollutants and nitrogen (0.609 kg COD/(m2·d), 0.512 kg NH4+-N/(m2·d), 0.482 kg NO2−-N/(m2·d), and 0.112 kg NO3−-N/(m2·d)). Both proteins and volatile suspended solids (VSS) in the Eco-dam biofilm decreased from the water surface towards the lake bottom, especially below 0.5 m depth. The average ratio of VSS to suspended solids in the biofilm was 0.337 ± 0.025 g/g. Analysis with the Illumina MiSeq System confirmed the presence of a diverse microbe population in the biofilm, performing organic carbon removal and nitrification and denitrification, with limited photosynthesis near the lake surface and methane oxidation near the lake bottom..
4. S. Khandaker, T. Kuba, Y. Toyohara, S. Kamida, Y. Uchikawa, Development of ion-exchange properties of bamboo charcoal modified with concentrated nitric acid, IOP Conf. Series: Earth and Environmental Science, 82, 2017.09, [URL], The surface chemistry and the structural properties of activated carbon can be altered by the acidic modification. The objective of this study is to investigate the changes occurring in bamboo charcoal (BC) during activation with concentrated nitric acid. Low temperature (500˚C) carbonized BC has been prepared and oxidized with 70% concentrated boiling nitric acid (BC-AC). The porous properties of the BC are analyzed with nitrogen adsorption isotherm at 77 K. The surface structure is observed by Field emission scanning electronic microscope (FESEM) and the surface functional groups are examined by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and the pH of the point of zero charge (pHPZC). The results reveal that severe oxidation with HNO3 considerably decreases the surface area of BC with enhanced pore widening and FESEM observation demonstrates the erosive effect of oxidation. The FTIR analysis detects that some absorption bands are assigned for carboxyl, aldehyde and ketone groups on BC-AC. The XPS analysis also clearly shows that the ratio of oxygen and acidic functional groups has been enriched significantly on the BC-AC. The low pHPZC value of BC-AC confirms that the surface is highly acidic for the fixation of acidic functional groups on surface. In general, the existence of the abundant amount of acidic functional groups on adsorbents enhances the sorption of heavy metals ions in aqueous solution. Therefore, it is strongly expected that the modified BC, activated under the proposed conditions would be a promising ion exchanger in aqueous solution and can be applied for the adsorption of different heavy metal ions and radioactive materials from effluent..
5. Shahjalal Khandaker, Takahiro KUBA, Seiya Kamida, Yuji Uchikawa, Adsorption of Cesium from Aqueous Solution by Raw and Concentrated Nitric Acid-modified Bamboo Charcoal, Journal of Environmental Chemical Engineering, http://dx.doi.org/10.1016/j.jece.2017.02.014, 5, 2, 1456-1464, 2017.06, [URL], The study is conducted to explore the potential of bamboo charcoal (BC) as an adsorbent to remove cesium from aqueous solution. Low temperature carbonized BC (500°C) is prepared and the surface of the BC is modified with 70% concentrated boiling nitric acid (BC-AC). Specific surface area, field emission scanning electron microscope (FESEM), fourier transform infra-red (FTIR) spectroscopy, and point of zero charge (pHpzc) of BC and BC-AC have been investigated in this study. The results demonstrate that BC-AC is enriched with oxygen-containing functional groups but its porous structure and surface area are decreased when compared with the raw BC. Optimum cesium adsorption conditions onto BC and BC-AC have been determined by investigating the contact time, pH of solution, adsorbent dosage and initial solution concentration in batch adsorption process. It has been observed that maximum cesium adsorption capacity is 0.17 and 45.87 mg/g for BC and BC-AC, respectively. It has also been observed that almost 100% cesium could be removed from water at up to 400 mg/L concentrated cesium solution by BC-AC whereas the removal capacity of cesium by BC is very poor. The experimental adsorption data of both BC and BC-AC follows the pseudo-second-order kinetic. The Freundlich adsorption equilibrium isotherm data is more appropriate than the Langmuir isotherm for adsorption of cesium by BC. However, adsorption isotherm data for BC-AC is a better fit with Langmuir isotherm than the Freundlich isotherm model. Furthermore, the separations factor (RL) and the surface coverage (θ) for Langmuir isotherm confirms that the proposed adsorption process is the most suitable for BC-AC. This study suggests that BC-AC could be effectively used for the removal of cesium from environmental water..
6. WATER PURIFICATION BY LED IRRADIATION IN DECOMPOSING WITHERED MICROCYSTIS
.
7. The purpose of this study is to identify whether the released Poly-P can be crystallized as MAP and to evaluate its forming ability..
8. Yuxian LIU, Aimin HAO, Yasushi ISERI, Chunjie LI, Zhenjia ZHANG, Takahiro KUBA, POSSIBLE SURVIVAL MECHANISMS OF SINANODONTA WOODIANA EXPOSED TO MICROCYSTIN, Journal of JSCE, Division G: Environmental Systems and Engineering (土木学会論文集), 3, 259-267, 2015.09, [URL], This study aims to figure out the selective feeding mechanism and to deduce the possible detoxification mechanism to the high concentrations of MCs, based on the phenomena found in the long-term grazing experiment..
9. Caixia KANG, Takahiro KUBA, Hao AIMIN, Yasushi ISERI, Antioxidant Responses of Vallisneria asiatica to Eutrophic Sediments in Lake Taihu, China, Bulletin of Environmental Contamination and Toxicology, http://dx.doi.org/10.1007/s00128-015-1579-4, 95, 194-199, 2015.06, [URL], Results indicated eutrophic sediment was a contributing factor in the disappearance of V. asiatica in Western Lake Taihu..
10. MingYang ZHANG, JianWei DU, Takahiro KUBA, Yong WEN, Comprehensive Evaluation of Poly-Phosphate Release from Sewage Sludge with Thermal Treatment, Applied Mechanics and Materials, 476-483, 2015.04, [URL], Phosphorus is a necessary nutrient element to all lives in the world. Distribution and phosphate rock reserves in the world disclose shortage crisis of phosphorus. Thus phosphorus recovery has been a research hot spot in the world. Mr.Ohtake’ group [1] recommended a new method to recover phosphorus from sewage sludge during heating process. It seems that nearly 90% of the poly-phosphate (poly-P) and 87% of total phosphate (T-P) can be released from cultivated sludge by heating at 70˚C for 1 hour. Meanwhile, released poly-P can precipitate with Ca in neutral condition without any pH adjustment. Sewage sludge was used in this research to identify its performance during thermal treatment. With the increase of temperature and heating time, release of poly-P and T-P increased obviously. However, poly-P would be hydrolyzed when temperature was higher than 80 ˚C. With addition of EDTA, release of poly-P increased nearly 100%. Migration of metal cations during thermal treatment can provide indirect evidence which kinds of metal cations would make impediment on poly-P release. A novel phenomenon was observed poly-P mixed with ortho-phosphate can precipitate with NH4+ and Mg2+ as struvite at pH 8.5..
11. CaiXia KANG, Takahiro KUBA, AiMin HAO, Yasushi ISERI, ChunJie LI, ZhenJia ZHANG, Oxidative stress responses of submerged macrophyte Vallisneria asiatica to different concentrations of cyanobacteria, CHINESE JOURNAL OF OCEANOLOGY AND LIMNOLOGY, 10.1007/s00343-015-4084-z, 33, 2, 364-371, 2015.04, In a 10-day aquarium experiment, this investigation examines macrophyte restoration in eutrophic Lake Taihu, the physiological effects of different plant biomass levels and of increasing natural cyanobacterial concentrations on a submerged macrophyte, Vallisneria asiatica. Cyanobacterial stress suppressed the superoxide dismutase (SOD) activity of the plant’s leaves and induced the catalase (CAT) and peroxidase (POD) activities of its roots. The soluble protein content in V. asiatica decreased with an increase in natural cyanobacterial concentrations, whereas the malonaldehyde (MDA) increased significantly at Chl.a concentrations of 222 and 262 µg·L−1 in water. V. asiatica adapted to the stress caused by cyanobacterial concentrations by adjusting its antioxidant defense system to remove the excessive reactive oxygen species when the algal Chl.a concentration was >109 µg·L−1. Additionally, high biomass of V. asiatica (2,222 g FW·m-2) can inhibit the reproduction of cyanobacteria more significantly than low biomass (1111 g FW·m-2). High biomass of V. asiatica increased the oxidative stress in an individual plant when the initial Chl.a concentration in the water reached 222 and 262 µg·L−1, as expressed by the increased MDA in leaves, compared with low biomass of V. asiatica. This provides a basis for controlling cyanobacterial concentrations and V. asiatica biomass for the recovery of V. asiatica in eutrophic Lake Taihu..
12. MingYang ZHANG, JianWei DU, Takahiro KUBA, Yong WEN, Comprehensive Evaluation of Poly-Phosphate Release from Sewage Sludge with Thermal Treatment, The 9th International Conference on Waste Management and Technology, 476-483, 2014.10, Phosphorus is a necessary nutrient element to all lives in the world. Distribution and phosphate rock reserves in the world disclose shortage crisis of phosphorus. Thus phosphorus recovery has been a research hot spot in the world. Mr.Ohtake’ group [1] recommended a new method to recover phosphorus from sewage sludge during heating process. It seems that nearly 90% of the poly-phosphate (poly-P) and 87% of total phosphate (T-P) can be released from cultivated sludge by heating at 70˚C for 1 hour. Meanwhile, released poly-P can precipitate with Ca in neutral condition without any pH adjustment. Sewage sludge was used in this research to identify its performance during thermal treatment. With the increase of temperature and heating time, release of poly-P and T-P increased obviously. However, poly-P would be hydrolyzed when temperature was higher than 80 ˚C. With addition of EDTA, release of poly-P increased nearly 100%. Migration of metal cations during thermal treatment can provide indirect evidence which kinds of metal cations would make impediment on poly-P release. A novel phenomenon was observed poly-P mixed with ortho-phosphate can precipitate with NH4+ and Mg2+ as struvite at pH 8.5..
13. CaiXia KANG, AiMin HAO, Tasushi ISERI, Takahiro KUBA, Metabolic and Antioxidant Responses of Vallisneria asiatica to Different Concentrations of Dissolved Inorganic Nitrogen and Phosphorus, 日本水処理生物学会, 50, 3, 105-112, 2014.09, To clarify the mechanism of submerged macrophytes disappearance and supply the necessary theory for the phytoremediation in eutrophic Lake Taihu, effects of the moderate nutrients concentration, high NH4+-N concentration and high PO43--P concentration in the water column on the antioxidant defense system in submerged macrophyte, Vallisneria asiatica, were studied with the 20-day aquarium experiments. The results showed that the moderate concentration of nutrients can promote the metabolism of V. asiatica. Either high concentrations of NH4+-N or PO43--P could cause the oxidative stress to cells of V. asiatica, expressed as decreased contents of chlorophyll a (Chl.a) and protein, and the enhancement of catalase (CAT) activities in leaves of V. asiatica. In addition, 0.6 mg·L-1 of PO43--P caused more oxidative damages to V. asiatica than 3.5 mg·L-1 NH4+-N. The results indicated that the antioxidative protection mechanisms could be activated but still could not prevent the damage of the metabolism system in V. asiatica exposed to either high concentrations of NH4+-N or PO43--P. Therefore, it is necessary to establish a dual control strategy of N and P for the restoration of V. asiatica in eutrophic Lake Taihu..
14. Takahiro KUBA, MingYang ZHANG, Inhibitory effect of metal ions on the poly-phosphate release from sewage sludge during thermal treatment, ENVIRONMENTAL TECHNOLOGY, 35, 9, 1157-1164, 2014.05, [URL], The purpose of this study was aimed at identifying the influence of metal cations such as Mg2+, Ca2+, Al3+ and Fe3+ on poly-phosphate (poly-P) and total phosphate (T-P) release from sewage sludge collected from wastewater treatment plant during thermal treatment at 70 degrees C for 80 min. With the addition of chelating reagent such as EDTA, release of poly-P and T-P was improved obviously during thermal treatment. Inhibitory effect of metal cations on phosphorus release was apparent by adding metal cations into sludge sample. Most of Ca, Al and Fe inside of cell could be released into the supernatant, but captured in extracellular polymeric substance (EPS); oppositely, large quantity of Mg could be released into the supernatant directly and not concentrated in EPS. Performance of sewage sludge on phosphorus release in summer and winter was different; different precipitation and temperature possibly result in this phenomenon..
15. Yuxian LIU, Aimin HAO, Yasushi ISERI, Takahiro KUBA, Zhenjia ZHANG, A Comparison of the Mussel Anodonta woodiana’s Acute Physiological Responses to Different Algae Diets, Journal of Clean Energy Technologies (JOCET), 2, 2, 126-131, 2014.04, The bivalve Anodonta woodiana is widely distributed throughout Chinese freshwaters and is an important economic pearl mollusk. Recently, A. woodiana as a biomanipulation tool in Chinese lakes due to its strong suppression of phytoplankton, has been attracted increasingly more attention. In order to examine whether A. woodiana can exert grazing pressure on Microcystis and to evaluate the different effects of each algae diets on mussels’ potential growth, a comparative study was carried out on the acute physiological responses to variable microalgae diets including toxic MC-producing cyanobacteria and non-toxic Scenedesmus obliquus green algae. The values of filtration rate, absorption efficiency, oxygen consumption rate and ammonia excretion rate of A. woodiana were measured and finally the SFG (scope for growth) value as a measure of metabolic energy balance for A. woodiana was calculated and compared. The results showed that the mussel A. woodiana has a higher grazing ability on the toxic Microcystis aeruginosa compared with the green algae S. obliquus; Furthermore, the effects of different algae diets on SFG of A. woodiana demonstrated that the toxic M. aeruginosa may supply more energy for A. woodiana’s potential growth. These results indicated that A. woodiana has strong adaptation ability when they were exposed to toxic Microcystis solution in this study, which implied that there is high application feasibility of A. woodiana as a toxic Microcystis-blooming controller in practice..
16. Caixia KANG, Takahiro KUBA, Aimin HAO, Yasushi ISERI, Chunjie LI, Zhenjia ZHANG, Effects of Macrophyte Vallisneria asiatica Biomasses on the Algae Community, World Academy of Science, Engineering and Technology, 7, 12, 217-221, 2013.12, [URL], To improve the water quality of lakes and control algae
blooms, the effects of Vallisneria asiatica which is one of aquatic
plants spread over Lake Taihu, with different biomasses on the water
quality and algae communities were researched. The results indicated
that V. asiatica could control an excess of Microcystis spp. when the V.
asiatica biomass was larger than 50g in the tank with 30L solution in
the laboratory. Planktonic and epiphytic algae responded differently to
V. asiatica. The presence of macrophyte V. asiatica in eutrophic
waters has a positive effect on algae compositions because of different
sensitivities of algae species to allelopathic substances released by
macrophyte V. asiatica. That is, V. asiatica could inhibit the growth of
Microcystis spp. effectively and was benefited to the diatom on the
condition in the laboratory..
17. Yuxian LIU, Aimin HAO, Yasushi ISERI, Takahiro KUBA, Chunjie LI, Zhenjia ZHANG, The Evaluation of Sinanodonta woodiana Application Feasibility as a Microcystis-Blooming Removal Tool in Microcosm Experiments, 土木学会論文集G (環境) (環境工学研究論文集 第50巻), 69, 7, III_45-III_53, 2013.11, The bivalve is widely distributed throughout Chinese freshwaters and is an important economic pearl mollusk. Recently, Sinanodonta woodiana as a tool in biomanipulation of lakes in China due to its strong suppression of phytoplankton, has been attracted increasingly more attention. In order to evaluate the application feasibility of Sinanodonta woodiana as a Microcystis-blooming removal tool, microcosm experiments were performed with naturally blooming pond water and the bivalves in laboratory for 6 days. In this experiment, phytoplankton abundances and community structure were analyzed on 0-day and 6-day for both control and treatment microcosms; also, filtration rate, absorption efficiency, oxygen consumption rate and ammonia excretion rate of S. woodiana were measured on the 0-day and 6-day and finally the scope for growth (SFG) value as a measure of metabolic energy balance for S. woodiana was calculated and compared. The results showed that Microcystis spp. of colony and unicell were reduced obviously on the 6-day; meanwhile, after six days’ exposure to Microcystis-blooming pond water, the SFG value as a measure of metabolic energy balance for S. woodiana increased. This phenomenon indicates that Microcystis spp. in natural eutrophic water can be removed greatly by S. woodiana; moreover, the bivalves themselves have strong adaptation ability when they were exposed to natural eutrophic water and could grow well after 6 days’ exposure to this eutrophic water. Therefore, it can be inferred that there is high application feasibility of S. woodiana as a Microcystis-blooming controller in practice..
18. Yuxian LIU, Aimin HAO, Yasushi ISERI, Chunjie LI, Zhenjia ZHANG, Takahiro KUBA, Application Feasibility of Anodonta woodiana as a Biomanipulation Tool in Lake Taihu, Proc. of The 7th International Symposium on the East Asian Environmental Problems, 58-67, 2013.11.
19. Caixic KANG, Aimin HAO, Yasushi ISERI, Chunjie LI, Zhenjia ZHANG, Takahiro KUBA, Restoration Conditions of Submerged Macrophyte Vallisneria asiatica in Eutrophic Lake Taihu, China, Proc. of The 7th International Symposium on the East Asian Environmental Problems, 68-73, 2013.11.
20. DISTRIBUTION CHARACTERISTICS OF WATER QUALITY AND AQUATIC VEGETATION IN A EUTROPHIC SHALLOW LAKE: TAIHU, CHINA

In order to find practical strategy for controlling eutrophication in Lake Taihu, in this study, water quality and biota were investigated in East Lake Taihu, Meiliang Bay and West Lakeshore. Compared with the lower nutrients concentrations in East Lake Taihu, the values of Chl.a, turbidity, T-N and T-P showed significant fluctuations with eutrophication level in different places of Meiliang Bay and West Lakeshore. There was significant positive correlation among each value of Chl.a, T-N and T-P in Meiliang Bay, which indicated that the occurrence of water bloom was related to the concentration of nutrient. According to the result of identification, there were totally twelve species of aquatic macrophytes in the investigated area, of which two species were found in Meiliang Bay, one species was found in the southwest coastal zone, and twelve species were found in East Lake Taihu including six species as dominant submerged plants. There were ten species of Cyanophyta during the water bloom in East Lake Taihu and Meiliang Bay, of which Microcystis aeruginosa was found with large quantities of biomass as dominant species. Apart from the Cyannophyta, 21 species of diatom and 20 species of Chlorophyta were identified in East Lake Taihu and Meiliang Bay, of which 41 species were spread in East Lake Taihu. The relatively richer phytoplankton indicated the higher biodiversity conditions in East Lake Taihu..
21. Mingyang Zhang, Takahiro KUBA, Aimin HAO, The Crystallization of Struvite by Recycling Poly-Phosphate Released from Sewage Sludge after Thermal Treatment, Advanced Materials Research, 10.4028, 781-784, 1963-1967, 2013.07, Because of the shortage crisis of phosphorus element and environmental problems caused by excess discharge of phosphorus compounds into nature water bodies, phosphorus recovery had been research hotspot. Poly-phosphate (poly-P) released from sewage sludge after thermal treatment could be recovered successfully as magnesium ammonium phosphate hexahydrate (MgNH4PO4•6H2O) commonly known as struvite in present study. This phenomenon was the first time to be found in phosphorus recovery from sewage sludge. The parameters affected struvite formation with poly-P had been tested. Poly-P indicated better characteristics in phosphorus recovery compared with ortho-phosphate (Pi) because it can be precipitated at lower pH condition even neutral condition, with less addition of magnesium element..
22. Hiroshi SAKAI, Aimin HAO, Yasushi ISERI, Song WANG, Takahiro KUBA, Zhenjia ZHANG, Hiroyuki KATAYAMA, Occurrence and Distribution of Microcystins in Lake Taihu, China, The Scientific World Journal, Article ID 838176, 2013, 2013.06.
23. MingYang ZHANG, HAO AIMIN, Takahiro KUBA, Extraction of Poly-Phosphate from the Activated Sludge with Thermal Treatment for Phosphorus Recovery, Advanced materials research, Vols.610-613, pp.2268-2274, 2013.01, Fast consumption of high quality phosphorus mines and uneven distribution in the world
result in the shortage crisis for phosphorus, meanwhile lots of phosphate compounds which are
discharged into nature water bodies by human beings have already induced many environmental
problems. Because of this situation, phosphorus recovery from sewage sludge working in the aeration
tank of wastewater treatment plant (WWTP) has been researched in the present study.
Poly-phosphate (poly-P) and total phosphate (T-P) accumulated inside activated sludge could be
released by thermal treatment at low temperature, 30% poly-P and 29% T-P could be released from
sludge by heating at 70˚C. Different kinds of pretreatments had been tested to improve phosphorus
release from activated sludge in thermal treatment; addition of chelating reagent at final concentration
of 2 mM before thermal treatment could improve the phosphorus release obviously, 68% poly-P and
53% T-P could be released into liquid phase. Approximately 85% T-P could be precipitated with
calcium at pH 11; it was interesting to find precipitation occurred in neutral condition without pH
adjustment..
24. ChumJie LI, ZhenJia ZHANG, HAO AIMIN, Yasushi ISERI, CaiXia KANG, Takahiro KUBA, In situ Remediation of Contaminated Water of Crab Culture by Ecological Dam in Yang Cheng Lake, Proc. of EAEP2012 (The 6th International Symposium on the East Asian Environmental Problems), pp.90-94, 2012.11, Yang Cheng Lake, which is famous with the crab culture, now faces the deterioration of water quality. Ecological dam is designed for in situ remediation of contaminated water of crab culture. The device of ecological dam consists of ecological floating bed with the dimension of 2m long and 1m wide, and immobilized biological media with about 1.8m long which is fixed on the floating bed with one side and immersed in the lake water with another side. In this study, two in situ demonstration areas with dimension of 20m long and 10m wide are constructed in the crab culture farms to investigate the change of water quality. Each area is surrounded by seine to avoid crabs climbing into. In one demonstration area, 36 devices of ecological dam are connected and laid in surrounding, which are planted with water spinaches. The other demonstration area is established in contrast, in which there is no device of eco-dam. It is concluded that during three months’ operation, ecological dam shows a significant effect on the turbidity improvement. However nutrient removal in eco-dam area is not improved, especially for TN. On the contrary, TN shows an obvious increment because of the release of organic nitrogen from the sediment under the condition of weak water exchange. It needs a long time to observe the remediation effect of ecological dam on the contaminated crab culture water..
25. YuXian LIU, HAO AIMIN, Yasushi ISERI, ChumJie LI, ZhenJia ZHANG, Takahiro KUBA, Improvement of Water Quality in Lake Taihu with Aquatic Plants and the Relationship between Cyanobacteria Bloom and Aquatic Plants, Proc. of EAEP2012 (The 6th International Symposium on the East Asian Environmental Problems), pp.96-101, 2012.11, The bivalve Sinanodonta woodiana is widely distributed throughout Chinese freshwaters and is an important economic pearl mollusk. Recently, S. woodiana as a tool in biomanipulation of lakes in China due to its strong suppression of phytoplankton, have been attracted increasingly more attention. In order to evaluate the impact of Microcystis-blooming pond water on the physiological behavior in a bioenergetic method, microcosm experiments were performed with natural eutrophic pond water and bivalves in laboratory for six days. In this experiment, filtration rate, absorption efficiency, oxygen consumption rate and ammonia excretion rate of S. woodiana were measured on the 0-day and 6-day, also the percentage changes of phytoplankton with different size scale were measured every two days for both control and treatment microcosms. The results indicated that after 6 days exposure to Microcystis-blooming pond water, the SFG (scope for growth) value as a measure of metabolic energy balance for S. woodiana increased and microplankton (>20 µm, including colony-forming Microcystis spp.) percentage was reduced obviously on the 6-day. This phenomenon indicates the percentage of phytoplankton with different size scale was obviously changed by the bivalves and meanwhile the bivalves themselves could grow well after six days’ exposure to this eutrophic water. Therefore, it can be concluded that S. woodiana can be used as an effective biomanipulation tool in eutrophic water..
26. CaiXia KANG, HAO AIMIN, Yasushi ISERI, ChumJie LI, ZhenJia ZHANG, Takahiro KUBA, Improvement of Water Quality in Lake Taihu with Aquatic Plants and the Relationship between Cyanobacteria Bloom and Aquatic Plants, Proc. of EAEP2012 (The 6th International Symposium on the East Asian Environmental Problems), pp.102-107, 2012.11, Serious eutrophication is appearing in the Lake Taihu which is the third largest freshwater lake in China. Therefore, the water quality in Lake Taihu should be improved immediately. To improve water quality of the lake and control algae bloom, the effect of Vallisneria asiatica which is one of the macrophytes spread over Lake Taihu, with different biomass on water quality and algae was researched. The results showed that in the laboratory experiments, DTN, DTP, and turbidity decreased and the biomass of Microcystis sp. reduced with the increase of biomass of Vallisneria asiatica. Therefore, it was expected that Vallisneria asiatica could control an excess of Microcystis sp. in Lake Taihu. Furthermore, we discovered that during experimental period, lots of diatom (Nitzschia sp.) appeared in the Microcystis sp. community resulting in settling down of algae in case of small quantity of Vallisneria asiatica by microscopy. This may be one of the important reasons which resulted in the sharp decrease of the biomass of Microcystis sp. At the same time, epiphytic Cocconeis sp. appeared while Nitzschia sp. lessened in the tanks with large quantity of Vallisneria asiatica, which indicated that there was competition between epiphytic Cocconeis sp. and Nitzschia sp..
27. Influence of Copper Ion on Antioxidant Function of Vallisneria asiatica.
28. Yuxian Liu, Aimin Hao, Yasushi Iseri, Shunsuke Kurokawa, Zhenjia Zhang and Takahiro Kuba, PRELIMINARY STUDY ON ECOLOGICAL ENGINEERING METHODS OF WATER QUALITY IMPROVEMENT IN THE LAKE TAIHU, Proc. of EAEP2011 (The 5th International Symposium on the East Asian Environmental Problems), pp.101-106, 2011.11, The results of in situ surveys conducted in our study indicated that eutrophication characterized with cyanobacteria water-bloom coupled with significantly high TP and TN value, is still serious, especially in the Meiliang Bay. Although water quality in the East Lake Taihu is comparatively better, the pen culture of the Chinese mitten crab (Eriocheir sinensis) which covers a large part of the lake surface, results in an increase of the organics and nutrients loading. Aimed to solve the mentioned problems, the laboratory experiments were performed with the macrophyte Vallisneria asiatica and the local economic pearl bivalve species Anodonta woodiana, separately. The results showed that Vallisneria asiatica can absorb the nutrients such as N and P effectively, meanwhile this kind of macrophyte is also the crab’s main food. Furthermore, the bivalve Anodonta woodiana showed an effective role in the water quality improvement through its feeding behavior. As a result, the ecological engineering methods were proposed, using the macrophyte Vallisneria asiatica and the pearl bivalve species Anodonta woodiana inside the Lake Taihu, which can not only bring significant economic value to the local residents but also improve water quality..
29. Mingyang Zhang, Aimin Hao and Takahiro Kuba, THE EFFECT OF CHELATING REAGENTS ON THE RELEASE OF PHOSPHORUS FROM SEWAGE SLUDGE DURING HEATING PROCESS, Proc. of EAEP2011 (The 5th International Symposium on the East Asian Environmental Problems), pp.95-100, 2011.11, Activated sludge working in the aeration tank can accumulate large phosphorus mainly as poly-phosphate (poly-P) inside bodies. They can release the phosphorus into liquid phase easily during the heating process at 70˚C for 80 minutes. With the addition of chelating reagents, the performance of phosphorus release from sewage sludge can be improved obviously. Through the comparison, citrate can make the best improvement on the phosphorus release from sewage sludge during heating process in four kinds of chelating reagents. Many kinds of mineral elements such as Mg2+, Fe2+, Al3+ and Ca2+ can be released into liquid phase accompany the phosphorus release during heating process with the addition of chelating reagent. Thus the existence of mineral elements possibly prevents phosphorus release from sewage sludge during heating process..
30. Chunjie LI, Hongmei LIU, Zhenjia Zhang, Yasushi ISERI, Takahiro KUBA, Aimin HAO, Phosphorus Removal Ability Intensified by Calcium Silicate Hydrates (CSH) in Ecological Technologies, Proc. of EAEP2011 (The 5th International Symposium on the East Asian Environmental Problems), pp.113-117, 2011.11.
31. Yuxian LIU, Yaping YE, Takahiro KUBA, Aimin HAO, Multiple Criteria Assessment of Ecosystem Services Sustained by Qinhuai River in Nanjing, Proc. of International Conference on Water Resources Management and Engineering (ICWRME 2011),, pp.158-163, 2011.08.
32. YuXian LIU, Takahiro KUBA, Aimin HAO, Yasushi ISERI, ZhenJia ZHANG, Biomanipulation method for aquatic environment conservation in the in Lake Taihu, The 2nd International Symposium on Aquatic Environment and Biodiversity Conservation in the Lake Taihu Basin, Proc. of the 4nd International Symposium on Aquatic Environment and Biodiversity Conservation in the Lake Taihu Basin, 2010.11.
33. ZhenJia ZHANG, Takahiro KUBA, Yasushi ISERI, Aimin HAO, Introduction of reduction technology with wastewater pollution from electroplating enterprise in the basin of Lake Taihu, The 2nd International Symposium on Aquatic Environment and Biodiversity Conservation in the Lake Taihu Basin, Proc. of the 4nd International Symposium on Aquatic Environment and Biodiversity Conservation in the Lake Taihu Basin, 2010.11.
34. Aimin HAO, Yasushi ISERI, YuXian LIU, MingYang ZHANG, ZhenJia ZHANG, Takahiro KUBA, Effect of Water Environment on Biota in Lake Taihu, The 2nd International Symposium on Aquatic Environment and Biodiversity Conservation in the Lake Taihu Basin, Proc. of the 4nd International Symposium on Aquatic Environment and Biodiversity Conservation in the Lake Taihu Basin, 2010.11.
35. Ming-Yang ZHANG, Takahiro KUBA, Aimin HAO, Yu-Xian LIU, Phosphorus Recovery from Sewage Sludge with Heating Method, The 4th International Symposium on the East Asia Environmental Problems (EAEP2010), Proc. of the 4th International Symposium on the East Asia Environmental Problems (EAEP2010), pp.9-14, September 2010, 2010.10.
36. Yu-Xian LIU, Y. YE, Takahiro KUBA, Aimin HAO, Economic Valuation of Ecosystem Service sustained by Qinhuai River in Nanjing, The 4th International Symposium on the East Asia Environmental Problems (EAEP2010), Proc. of the 4th International Symposium on the East Asia Environmental Problems (EAEP2010), pp.167-171, September 2010, 2010.10.
37. Yasushi ISERI, Takahiro KUBA, Aimin HAO, Yu-Xian LIU, Ming-Yang ZHANG, Zhen-Jia ZHANG, Control of Freshwater Cyanobacterial Bloom using Eco-Engineering Methods, The 4th International Symposium on the East Asian Environmental Problems (EAEP2010), Proc. of the 4th International Symposium on the East Asia Environmental Problems (EAEP2010), pp.179-184, September 2010, 2010.10.
38. Aimin HAO, Yasushi ISERI, Yu-Xian LIU, Ming-Yang ZHANG, Zhen-Jia ZHANG, Takahiro KUBA, Interaction of Biota and Water Environment in Lake Taihu, The 4th International Symposium on the East Asian Environmental Problems (EAEP2010), Proc. of the 4th International Symposium on the East Asia Environmental Problems (EAEP2010), pp.173-178, September 2010, 2010.10.
39. Takahiro KUBA, Masayuki BANNO, Kousuke SANO, Naoya KAWAMURA, Shumpei ICHIKAWA and Yusuke SAKAI, Bamboo Charcoal as an Adsorbent for the Removal of Non-Point Pollutants, The 3rd International Symposium on the East Asian Environmental Problems (EAEP2009), 2009.12.
40. Zhi-Hua Li, Takahiro Kuba, Tetsuya Kusuda, Xiao-Chang Wang, Effect of extended feeding time on aerobic granulation in SBR, Technology and Sustainable Development, 6, 2/3/4, 104-114, 2009.06.
41. Zhi-Hua LI, KUBA Takahiro, Tetsuya KUSUDA, Xiao-Chang WANG, Effect of Extended Feeding Time on Aerobic Granulation in SBR, World Review of Science, Technology and Sustainable Development, 6, 2/3/4, 104 - 114, 2009.06.
42. V. Torrico, T. Kuba, T. Kusuda, Optimization of Internal Bypass Ratio for Complete Ammonium and Phosphorus Removal in a Dephanox-type Two-Sludge Denitrification System, Journal of Environmental Engineering, ASCE, Vol.134, No.7, pp.536-542, 2008.07.
43. Zhi-Hua LI, KUBA Takahiro, Tetsuya KUSUDA, Xiao-Chang WANG, A Comparative Study on Aerobic Granular Sludge and Effluent Suspended Solids in a Sequence Batch Reactor, Environmental Engineering Science, Vol.134, No.7, pp.577-584, 2008.05.
44. Education and Learning Improvement by Introduction of an Evaluation System to Graduation Research.
45. Z.H. Li, T. Kuba, T. Kusuda, Effect of Rotifers on the Stability of Aerobic Granules, Environmental Technology, Vol.28, No.2, pp.235-242, 2007.02.
46. V. Torrico, T. Kuba, Effect of Anaerobic SRT on Complete Phosphate Removal in a Post-denitrification System, 環境工学研究論文集, Vol.43、pp.327-332, 2006.11.
47. Z.H. Li, T. Kuba, T. Kusuda, Aerobic Granular Sludge: A Promising Technology for Decentralized Wastewater Treatment, Future of Urban Wastewater Systems -Decentralisation and Reuse-, Xiaochan C. Wang, Rong Chen (editors), Proceedings of the International Water Association (IWA) Conference 2005, Xi'an. pp.269-275. Xi'an International Center, Xi'an, China, 18-20 May, 2005.5, Proceedings of the International Water Association (IWA) Conference 2005, Xi'an. pp.269-275

Water Science & Technology, Vol.53 (9), pp.79-85, 2006.09.
48. K. Hamada, T. Kuba, V. Torrico, M. Okazaki, T. Kusuda, Comparison of Nutrient Removal Efficiency between Pre- and Post-denitrification Wastewater Treatment, Future of Urban Wastewater Systems -Decentralisation and Reuse-, Xiaochan C. Wang, Rong Chen (editors), Proceedings of the International Water Association (IWA) Conference 2005, Xi'an. pp.269-275. Xi'an International Center, Xi'an, China, 18-20 May, 2005.5, Proceedings of the International Water Association (IWA) Conference 2005, Xi'an. pp.269-275

Water Science & Technology, Vol.53 (9), pp.169-175, 2006.09.
49. V. Torrico, T. Kuba, T. Kusuda, Effect of Particulate Biodegradable COD in a Post-denitrification Enhanced Biological Phosphorus Removal System, Journal of Environmental Science and Health, Part A Toxic/Hazardous Substance & Environmental Engineering, Vol.A41 (8), pp.1715-1728, 2006.08.
50. Education and Learning Improvement by Introduction of an Evaluation System to Graduation Research.
51. Z.H. Li, T. Kuba, T. Kusuda, The Influence of Starvation Phase on the Properties and the Development of Aerobic Granules, Enzyme and Microbial Technology, Vol.38(5), pp.670-674, 2006.05.
52. Z.H. Li, T. Kuba, T. Kusuda, Selective Force and Mature Phase Affect the Stability of Aerobic Granule: An Experimental Study by Applying Different Removal Methods of Sludge, Enzyme and Microbial Technology, Vol.39, pp.976, 2006.05.
53. Activities of Enhanced Biological Nutrient Removal by the UCT Process in Low-Temperature Terms.
54. T. Kuba, V. Torrico, K. Hamada, T. Kusuda, Recycling Technology of Water -Biological Sewage Treatment and Prevention of Eutrophication-, First International Workshop on Sustainable Habitat Systems -Concept and Technology-, December 10, 2004, ACROS Fukuoka Conference Hall, pp.63-68, 2004.12.
55. Lin-Jiang Yuan, T. Kusuda, T. Kuba, Promoting Nitrification by Using Functional Gel as Immobilizing Medium under Different Temperature Stimulation Patterns, Proc. of Strong N and Agro 2003. IWA specialty symposium on strong nitrogenous and agro-wastewater Conference, Souel. 2, 621-632. Journal of Environmental Science and Health, Part A., Vol.A39, No.7, pp.1787-1796,2004, 10.1081/ESE-120037877, 39, 7, 1781-1790, Journal of Environmental Science and Health, Part A., Vol.A39, No.7, pp.1787-1796, 2004.01.
56. Isolation of the Denitrifying Phosphate-Accumulating Organisms Using Alternating Anaerobic-Anoxic Screening Method.
57. K. Hamada, T. Kuba, T. Kusuda, Development of an Activated Sludge Model with Denitrifying Dephosphatation, 第3回IWA国際水質会議, Melbourne Convention Centre, 2002, 第3回IWA国際水質会議, Melbourne Convention Centre, 2002
No.e211335a, pp.1-8, Enviro 2002 & IWA 3rd World Water Congress, Australlia, 7-12 April, 2002, 2002.04.
58. K. Kumabe, M. Etoh, T. Kuba, T. Kusuda, Application of Light-Stimulus-Responsive Gells to Immobilized Media, Proc. of Asian WATERQUAL 2001, First IWA Asia-Pacific Regional Conference, Vol.II, pp.639-644, 2001, Dec., Proc. of Asian WATERQUAL 2001, First IWA Asia-Pacific Regional Conference, Vol.II, pp.639-644, 2001, Dec., 2001.12.
59. T. Kuba, M.C.M. van Loosdrecht, J.J. Heijnen, Biological Dephosphatation by Activated Sludge under Denitrifying Conditions: pH Influence and Occurrence of Denitrifying Dephosphatation in a Full-scale Waste Water Treatment Plant, Asian Waterqual ヤ97, 6th IAWQ Asia-Pacific Regional Conf. in Seoul, 1997 May) Wat. Sci. Tech., Vol.36, No.12, pp.75-82, 1997 Dec., 10.1016/S0273-1223(97)00713-0, 36, 12, 75-82, Asian Waterqual ヤ97, 6th IAWQ Asia-Pacific Regional Conf. in Seoul, 1997 May)
Wat. Sci. Tech., Vol.36, No.12, pp.75-82, 1997 Dec., 1997.12.
60. E. Murnleitner, T. Kuba, M.C.M. van Loosdrecht, J.J. Heijnen, An Integrated Metabolic Model for the Aerobic and Denitrifying Biological Phosphorus Removal, Biotechnology and Bioengineering, Vol.54, No.5, pp.434-450, 1997 Jun., Biotechnology and Bioengineering, Vol.54, No.5, pp.434-450, 1997 Jun., 1997.06.
61. B. Warinpaisan, T. Kuba, M. Irie, T. Kusuda, Increase in Rate of Biological Nitrification with NIPAAm Gel as Immobilizing Media, Asian Waterqual '97, 6th IAWQ Asia-Pacific Regional Conf. in Seoul, 1997 May, Asian Waterqual '97, 6th IAWQ Asia-Pacific Regional Conf. in Seoul, 1997 May, 1997.05.
62. T. Kuba, M.C.M. van Loosdrecht, E. Murnleitner, J.J. Heijnen, Kinetics and Stoichiometry in the Biological Phosphorus Removal Process with Short Cycle Times, Water Research, Vol.31, No.4, pp.918-928, 1997 Apr., Water Research, Vol.31, No.4, pp.918-928, 1997 Apr., 1997.04.
63. T. Kuba, M.C.M. van Loosdrecht, F.A. Brandse, J.J. Heijnen, Occurrence of Denitrifying Phosphorus Removing Bacteria in Modified UCT-type Waste Water Treatment Plants, Water Research, Vol.31, No.4, pp.777-786, 1997 Apr., Water Research, Vol.31, No.4, pp.777-786, 1997 Apr., 1997.04.
64. A. Wachtmeister, T. Kuba, M.C.M. van Loosdrecht, J.J. Heijnen, A Sludge Characterization Assay for Aerobic and Denitrifying Phosphorus Removing Sludge, Water Research, Vol.31, No.3, pp.471-478, 1997 Mar., Water Research, Vol.31, No.3, pp.471-478, 1997 Mar., 1997.03.
65. M.C.M. van Loosdrecht, G.J. Smolders, T. Kuba, J.J. Heijnen, Metabolism of Micro-organisms Responsible for Enhanced Biological Phosphorus Removal from Wastewater: Use of Dynamic Enrichment Cultures, Antonie van Leeuwenhoek, Vol.71, No.1-2, pp.109-116, 1997 Feb., Antonie van Leeuwenhoek, Vol.71, No.1-2, pp.109-116, 1997 Feb., 1997.02.
66. M.C.M. van Loosdrecht, T. Kuba, H.M. van Veldhuizen, F.A. Brandse, J.J. Heijnen, Environmental Impacts of Nutrient Removal Process: Case Study, Journal of Environmental Engineering, Vol.123, No.1, pp.33-40, 1997 Jan., Journal of Environmental Engineering, Vol.123, No.1, pp.33-40, 1997 Jan., 1997.01.
67. T. Kuba, E. Murnleitner, M.C.M. van Loosdrecht, J.J. Heijnen, A Metabolic Model for the Biological Phosphorus Removal by Denitrifying Organisms, Biotechnology and Bioengineering, Vol.52, No.6, pp.685-695, 1996.12.
68. T. Kuba, M.C.M. van Loosdrecht, J.J. Heijnen, Phosphorus and Nitrogen Removal with Minimal COD Requirement by Integration of Denitrifying Dephosphatation and Nitrification in a Two-Sludge System, Water Research, Vol.30, No.7, pp.1702-1710, 1996.07.
69. T. Kuba, M.C.M. van Loosdrecht, J.J. Heijnen, Effect of Cyclic Oxygen Exposure on the Activity of Denitrifying Phosphorus Removing Bacteria, Wat. Sci. Tech., Vol.34, No.1-2, pp.33-40, 1996.01.
70. T. Kuba, A. Wachtmeister, M.C.M. van Loosdrecht, J.J. Heijnen, Effect of Nitrate on Phosphorus Release in Biological Phosphorus Removal Systems, Wat. Sci. Tech., Vol.30, No.6, pp.263-269, 1994.06.
71. T. Kuba, G. Smolders, M.C.M. van Loosdrecht, J.J. Heijnen, Biological Phosphorus Removal from Wastewater by Anaerobic-Anoxic Sequencing Batch Reactor, Wat. Sci. Tech., Vol.17, No.5-6, pp.241-252, 1993.09.
72. Takahiro KUBA, Hiroaki FURUMAI, Tetsuya KUSUDA, A Kinetic Study on Methanogenesis by Attached Biomass in a Fluidized Bed, Water Research, 10.1016/0043-1354(90)90155-Y, 24, 11, 1365-1372, Vol.23, No.11, pp.1365-1372, 1990.11.
73. Hiroaki FURUMAI, Takahiro KUBA, Tsuyosi IMAI, Tetsuya KUSUDA, Transient Responses of Wastewater Treatment and Biomass Developement in a Methanogenic Fluidized Bed, Water Science and Technology, 23, 7-9, 1327-1336, Vol.23, Kyoto, pp.1327-1336, 1990.08.
74. Evaluation of Methanogenic Activity Test using Glass Vials.
75. An Estimation Method of Active Biomass Concentration of Acetate utilizing Methanogen in Anaerobic Mixed Cultures.
76. Characteristcs of Volatile Fatty Acid Decomposition in Anaerobic Fluidized Bed.
Presentations
1. S. Khandaker1, T. Kuba, Y. Toyohara, S. Kamida and Y. Uchikawa, Development of ion-exchange properties of bamboo charcoal modified with concentrated nitric acid, The 3rd International Conference on Water Resource and Environment (WRE 2017), 2017.06, [URL], The surface chemistry and the structural properties of activated carbon can be altered by the acidic modification. The objective of this study is to investigate the changes occurring in bamboo charcoal (BC) during activation with concentrated nitric acid. Low temperature (500˚C) carbonized BC has been prepared and oxidized with 70% concentrated boiling nitric acid (BC-AC). The porous properties of the BC are analyzed with nitrogen adsorption isotherm at 77 K. The surface structure is observed by Field emission scanning electronic microscope (FESEM) and the surface functional groups are examined by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and the pH of the point of zero charge (pHPZC). The results reveal that severe oxidation with HNO3 considerably decreases the surface area of BC with enhanced pore widening and FESEM observation demonstrates the erosive effect of oxidation. The FTIR analysis detects that some absorption bands are assigned for carboxyl, aldehyde and ketone groups on BC-AC. The XPS analysis also clearly shows that the ratio of oxygen and acidic functional groups has been enriched significantly on the BC-AC. The low pHPZC value of BC-AC confirms that the surface is highly acidic for the fixation of acidic functional groups on surface. In general, the existence of the abundant amount of acidic functional groups on adsorbents enhances the sorption of heavy metals ions in aqueous solution. Therefore, it is strongly expected that the modified BC, activated under the proposed conditions would be a promising ion exchanger in aqueous solution and can be applied for the adsorption of different heavy metal ions and radioactive materials from effluent..
2. Cultivation of useful plants over the water surface receiving treated sewage.
3. Phosphorus recovery by heating extracted polyphosphate from activated sludge.
4. Development of cesium ion adsorption material using sewage sludge molten slag
―The effect of component of the slag, surface treatment and coexisting ion ―.
5. Research of preventing water blooms through destructing Microcystis colonies by diatom.
6. WATER PURIFICATION BY LED IRRADIATION IN DECOMPOSING WITHERED MICROCYSTIS, [URL].
7. POLYPHOSPHATE RECOVERY FROM SEWAGE SLUDGE AS MAGNESIUM AMMONIUM PHOSPHATE AND ITS FORMING ABILITY.
8. MingYang ZHANG, JianWei DU, 久場 隆広, Yong WEN, Comprehensive Evaluation of Poly-Phosphate Release from Sewage Sludge with Thermal Treatment , The 9th International Conference on Waste Management and Technology, 2014.10, Phosphorus is a necessary nutrient element to all lives in the world. Distribution and phosphate rock reserves in the world disclose shortage crisis of phosphorus. Thus phosphorus recovery has been a research hot spot in the world. Mr.Ohtake’ group [1] recommended a new method to recover phosphorus from sewage sludge during heating process. It seems that nearly 90% of the poly-phosphate (poly-P) and 87% of total phosphate (T-P) can be released from cultivated sludge by heating at 70˚C for 1 hour. Meanwhile, released poly-P can precipitate with Ca in neutral condition without any pH adjustment. Sewage sludge was used in this research to identify its performance during thermal treatment. With the increase of temperature and heating time, release of poly-P and T-P increased obviously. However, poly-P would be hydrolyzed when temperature was higher than 80 ˚C. With addition of EDTA, release of poly-P increased nearly 100%. Migration of metal cations during thermal treatment can provide indirect evidence which kinds of metal cations would make impediment on poly-P release. A novel phenomenon was observed poly-P mixed with ortho-phosphate can precipitate with NH4+ and Mg2+ as struvite at pH 8.5.

Keywords: Thermal treatment; Sewage sludge; Metal ions; Release; Struvite.
9. Caixia KANG, Takahiro KUBA, Aimin HAO, Yasushi ISERI, Chunjie LI, Zhenjia ZHANG, Effects of Macrophyte Vallisneria asiatica Biomasses on the Algae Community, World Academy of Science, Engineering and Technology Conference, International Science index Issue 84, 2013.12.
10. Yuxian LIU, Aimin HAO, Yasushi ISERI, Chunjie LI, Zhenjia ZHANG, Takahiro KUBA, The Evaluation of Sinanodonta woodiana Application Feasibility as a Microcystis-Blooming Removal Tool in Microcosm Experiments, 環境フォーラム, 2013.11.
11. Water Pollution of Lake Taihu and Solutions for Environmental Problems.
12. Chunjie LI, Zhenjia ZHANG, HAO AIMIN, Yasushi ISERI, Caixia KANG, Takahiro KUBA, Ecological Dam for In-situ Remediation of Polluted Aquaculture Water in Yang Chen Lake: Experience and Prospect, EAEP2013, The 7th International Symposium on the East Asian Environmental Problems, 2013.11.
13. CaiXiaKANG, HAO AIMIN, Yasushi ISERI, Chunjie LI, Zhenjia ZHANG, Takahiro KUBA, Restoration Conditions of Submerged Macrophyte Vallisneria asiatica in Eutrophic Lake Taihu, China, EAEP2013, The 7th International Symposium on the East Asian Environmental Problems, 2013.11.
14. YuXian LIU, HAO AIMIN, Yasushi ISERI, Chunjie LI, Zhenjia ZHANG, Takahiro KUBA, Application Feasibility of Anodonta woodiana as a Biomanipulation Tool in Lake Taihu, EAEP2013, The 7th International Symposium on the East Asian Environmental Problems, 2013.11.
15. Yuxian LIU, Aimin HAO, Yasushi ISERI, Takahiro KUBA, Zhenjia ZHANG, A Comparison of the Mussel Anodonta woodiana’s Acute Physiological Responses to Different Algae Diets, 2013 4th International Conference on Environment Engineering and Applications (ICEEA 2013), 2013.08.
16. ZHANG MingYang, HAO AIMIN, Takahiro KUBA, The Crystallization of Struvite by Recycling Poly-Phosphate Released from Sewage Sludge after Thermal Treatment, 3rd/2013 International Conference on Chemical Engineering and Advanced Materials (ICCEAM 2013), 2013.07.
17. Impact of Human Activities on the water Environment of Lake Taihu Watershed and Solution for Environmental Problems
(Our Lakes: From the Present towards a Future Perspective).
18. CaiXiaKANG, HAO AIMIN, Yasushi ISERI, Chunjie LI, Zhenjia ZHANG, Takahiro KUBA, Improvement of Water Quality in Lake Taihu with Aquatic Plants and the Relationship between Cyanobacteria Bloom and Aquatic Plants, EAEP2012, The 6th International Symposium on the East Asian Environmental Problems, 2012.11, Serious eutrophication is appearing in the Lake Taihu which is the third largest freshwater lake in China. Therefore, the water quality in Lake Taihu should be improved immediately. To improve water quality of the lake and control algae bloom, the effect of Vallisneria asiatica which is one of the macrophytes spread over Lake Taihu, with different biomass on water quality and algae was researched. The results showed that in the laboratory experiments, DTN, DTP, and turbidity decreased and the biomass of Microcystis sp. reduced with the increase of biomass of Vallisneria asiatica. Therefore, it was expected that Vallisneria asiatica could control an excess of Microcystis sp. in Lake Taihu. Furthermore, we discovered that during experimental period, lots of diatom (Nitzschia sp.) appeared in the Microcystis sp. community resulting in settling down of algae in case of small quantity of Vallisneria asiatica by microscopy. This may be one of the important reasons which resulted in the sharp decrease of the biomass of Microcystis sp. At the same time, epiphytic Cocconeis sp. appeared while Nitzschia sp. lessened in the tanks with large quantity of Vallisneria asiatica, which indicated that there was competition between epiphytic Cocconeis sp. and Nitzschia sp..
19. YuXian LIU, HAO AIMIN, Yasushi ISERI, Chunjie LI, Zhenjia ZHANG, Takahiro KUBA, Impacts of Microcystis-Blooming Pond Water on Feeding Behavior and Metabolic Energy Balance of Sinanodonta woodiana in Microcosm Experiments, EAEP2012, The 6th International Symposium on the East Asian Environmental Problems, 2012.11, The bivalve Sinanodonta woodiana is widely distributed throughout Chinese freshwaters and is an important economic pearl mollusk. Recently, S. woodiana as a tool in biomanipulation of lakes in China due to its strong suppression of phytoplankton, have been attracted increasingly more attention. In order to evaluate the impact of Microcystis-blooming pond water on the physiological behavior in a bioenergetic method, microcosm experiments were performed with natural eutrophic pond water and bivalves in laboratory for six days. In this experiment, filtration rate, absorption efficiency, oxygen consumption rate and ammonia excretion rate of S. woodiana were measured on the 0-day and 6-day, also the percentage changes of phytoplankton with different size scale were measured every two days for both control and treatment microcosms. The results indicated that after 6 days exposure to Microcystis-blooming pond water, the SFG (scope for growth) value as a measure of metabolic energy balance for S. woodiana increased and microplankton (>20 µm, including colony-forming Microcystis spp.) percentage was reduced obviously on the 6-day. This phenomenon indicates the percentage of phytoplankton with different size scale was obviously changed by the bivalves and meanwhile the bivalves themselves could grow well after six days’ exposure to this eutrophic water. Therefore, it can be concluded that S. woodiana can be used as an effective biomanipulation tool in eutrophic water..
20. Chunjie LI, Zhenjia ZHANG, HAO AIMIN, Yasushi ISERI, Caixia KANG, Takahiro KUBA, In situ Remediation of Contaminated Water of Crab Culture by Ecological Dam in Yang Cheng Lake, EAEP2012, The 6th International Symposium on the East Asian Environmental Problems, 2012.11, Yang Cheng Lake, which is famous with the crab culture, now faces the deterioration of water quality. Ecological dam is designed for in situ remediation of contaminated water of crab culture. The device of ecological dam consists of ecological floating bed with the dimension of 2m long and 1m wide, and immobilized biological media with about 1.8m long which is fixed on the floating bed with one side and immersed in the lake water with another side. In this study, two in situ demonstration areas with dimension of 20m long and 10m wide are constructed in the crab culture farms to investigate the change of water quality. Each area is surrounded by seine to avoid crabs climbing into. In one demonstration area, 36 devices of ecological dam are connected and laid in surrounding, which are planted with water spinaches. The other demonstration area is established in contrast, in which there is no device of eco-dam. It is concluded that during three months’ operation, ecological dam shows a significant effect on the turbidity improvement. However nutrient removal in eco-dam area is not improved, especially for TN. On the contrary, TN shows an obvious increment because of the release of organic nitrogen from the sediment under the condition of weak water exchange. It needs a long time to observe the remediation effect of ecological dam on the contaminated crab culture water..
21. ZHANG MingYang, Takahiro KUBA, HAO AIMIN, Extraction of Poly-Phosphate from the Activated Sludge with Thermal Treatment for Phosphorus Recovery, 2nd/2012 International Conference on Energy, Environment and Sustainable Development (EESD 2012), 2012.10, Fast consumption of high quality phosphorus mines and uneven distribution in the world
result in the shortage crisis for phosphorus, meanwhile lots of phosphate compounds which are
discharged into nature water bodies by human beings have already induced many environmental
problems. Because of this situation, phosphorus recovery from sewage sludge working in the aeration
tank of wastewater treatment plant (WWTP) has been researched in the present study.
Poly-phosphate (poly-P) and total phosphate (T-P) accumulated inside activated sludge could be
released by thermal treatment at low temperature, 30% poly-P and 29% T-P could be released from
sludge by heating at 70˚C. Different kinds of pretreatments had been tested to improve phosphorus
release from activated sludge in thermal treatment; addition of chelating reagent at final concentration
of 2 mM before thermal treatment could improve the phosphorus release obviously, 68% poly-P and
53% T-P could be released into liquid phase. Approximately 85% T-P could be precipitated with
calcium at pH 11; it was interesting to find precipitation occurred in neutral condition without pH
adjustment..
22. Phosphorus Removal Ability Intensified by Calcium Silicate Hydrates (CSH) in Ecological Technologies.
23. PRELIMINARY STUDY ON ECOLOGICAL ENGINEERING METHODS OF WATER QUALITY IMPROVEMENT IN THE LAKE TAIHU.
24. THE EFFECT OF CHELATING REAGENTS ON THE RELEASE OF PHOSPHORUS FROM SEWAGE SLUDGE DURING HEATING PROCESS.
25. Proposal of an Eco-Emgineering Environmental Improvement Strategy in the Lake Taihu, China: A Concept based on the Water Quality and the Biota.
26. Japanese Society for Agricultural, Biological, and Environmental Engineers and Scientists
Annual Meeting 2011 Sapporo (JSABEES)
Hokkaido University, September 6-8, 2011
.
27. Multiple Criteria Assessment of Ecosystem Services Sustained by Qinhuai River in Nanjing.
28. Present Aquatic environment and the conservation in the Lake Taihu.
29. Bamboo charcoal was examined to determine the adsorption capacity of nitrate anion and the mechanism in aqueous solution. Added to these, reduction of non-point pollutant load, such as roadway runoff, using the adsorption ability of bamboo charcoal was estimated by a simple one-dimensional laminar model. The bamboo charcoal (BC) was manufactured from Moso bamboo (Phyllostachys heterocycla) at the carbonization temperature of 800°C (BC800). Effect of acid and alkali post-treatment for the BC800 on the nitrate anion adsorption capacity was investigated. The BC800 post-treated with acid (hydrochloric acid) following alkali (sodium hydroxide) had higher adsorption capacity than that post-treated oppositely. It was concluded that the nitrate anion adsorption mechanism onto the bamboo charcoal was ion-exchange chemical adsorption, i.e., the BC800 with partially-substitution of chlorine ion for hydroxide ion easily adsorbed the nitrate anion. From the model estimation with a simple adsorption tank system, the breakthrough time of the BC800 turned out to be more than a year. These results lead to the conclusion that the effective utilization of the bamboo charcoal as an adsorbent could reduce and prevent non-point pollution..
Educational
Educational Activities
・『Biological Water Quality Control Engineering』
『Environmental Solution Analysis』
『Semiar 1 in Urban and Environmental System Engineering』
『Field Work』
『Environmental Problems in Asian Region』

・『Fundamentals of Environmental Engineering』
 『Environmental Protection Engineering』(~2015)
『Harmonization of Development and Conservation of Environment』(2016~)
 『Graduation Research』
Other Educational Activities
  • 2015.03.
  • 2015.01.
  • 2014.03.
  • 2012.08.
  • 2012.03.
  • 2011.08.
  • 2011.06.
  • 2010.08.
  • 2009.08.
  • 2008.08.
  • 2007.08.
  • 2006.09.
  • 2006.08.
  • 2005.12.
  • 2005.12.
  • 2003.05.
  • 2000.04.
Social
Professional and Outreach Activities
Lake Taihu Project
SPIRIT 21.