剩余活性污泥中的微生物利用实际废液合成聚羟基烷酸酯
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摘要
塑料制品是人们日常生活和工农业生产的必需品。广为使用的石油基塑料造成了严重的环境污染,消耗了大量不可再生资源。聚羟基烷酸酯(Polyhydroxyalkanoates, PHA)是一种生物制备型的环境友好塑料,可完全生物降解,具有和传统塑料相近的物化性质和加工特性,所需底物为可再生有机质。因此PHA是石油基塑料的理想替代品,具有广阔应用前景。纯菌种合成PHA是目前工业化制备PHA的主流。高昂的生产成本制约了PHA作为日常用品得到广泛应用。此外,市政废水处理厂每天产生大量剩余污泥,污泥处置费用高。选择廉价的、可再生且来源广泛的废物作为PHA合成用底物、利用活性污泥中的混合菌群作接种体合成PHA、优化PHA合成工艺的运行条件,都有利于大幅降低PHA生产成本,实现废物和剩余污泥的减量化和资源化。
     本研究的目的即为同时实现PHA生产低成本化,以及废物及剩余污泥资源化。主要研究内容和结论如下:
     通过剩余污泥利用人工废水合成PHA的小试研究,考察了影响PHA产量、底物转化率和PHA单体组分含量的工艺参数。结果表明,好氧、高碳氮比、多次投加碳源底物、弱碱性条件有助于提高PHA产量。在此条件下,活性污泥合成PHA的产量与纯菌种合成PHA的产量及物化性质接近,且PHA合成产率高于纯菌种。通过工艺调控,活性污泥可以合成含有特定单体组分的PHA。好氧时,短链脂肪酸中碳原子的数目决定聚(-β-羟基丁酸-co-β-羟基戊酸)(Poly(β-hydroxybutyrate-co-β-hydroxyvalerate),PHBV)中的单体组分。溶解氧浓度(dissolved oxygen, DO)降低、pH值升高,PHBV共聚物中的羟基戊酰含量(hydroxyvalerate%, HV%)会增加,且与碳源类型无关;污泥来源、碳源与氮磷浓度比的变化会影响羟基烷酸(hydroxyalkanoate, HA)单体组分的含量。
     结合上述试验结果,采用批式好氧动态底物投加工艺,对剩余污泥作为接种体利用污泥消化液中的挥发性有机酸(volatile fatty acids, VFAs)以及食品废液合成PHA进行了工艺优化研究。通过投加镁盐形成鸟粪石沉淀,污泥消化液中过量的氮磷得到去除和回收,以提高污泥消化液的碳氮比。碱性条件和较高的消化温度可以提高污泥消化液中的VFAs产量以及氨氮去除率。污泥消化液中VFAs的主要成分是乙酸。利用剩余污泥消化液中的VFAs合成的PHA的最大产量可达到56.5%(占VSS比重)。活性污泥和纯菌种利用麦芽废物作碳源合成的PHA产量比其它种类的食品废液都高。随后对剩余污泥利用实际废液合成的PHA产物进行了物化加工性质分析。
     为了优化活性污泥合成PHA的单体组分,在总结了纯菌种合成PHA的代谢机理的基础上,模拟了活性污泥合成PHA的生化代谢途径。为了预测活性污泥合成PHA的产量和产率,通过改进活性污泥三号模型(Activated Sludge Modeling 3, ASM3模型)和优化PHA合成工艺参数,建立了活性污泥合成PHA的反应动力学模型。并通过小试试验验证了该模型的准确性。研究结果表明,污泥在厌氧时摄取乙酸会合成HV的代谢机理是,通过“琥珀酰-CoA→丙酰-CoA”反应,部分乙酸转化为丙酰-CoA,成为PHBV中HV的前体物。外界工艺条件改变,会影响活性污泥中的混合菌群的结构和代谢途径,进而改变活性污泥合成的HA单体组分。通过试验验证,活性污泥合成PHA的动力学模型可以较为准确地预测PHA的产量、产率、底物转化率和细胞生长量。
     剩余污泥利用污泥消化液合成PHA工艺的工业化,有助于实现实际废液和剩余污泥的资源化,推动PHA作为普通包装材料得到应用,具有良好的经济效益和社会价值。相对于纯菌种以及活性污泥利用人工废水合成PHA,剩余污泥利用污泥消化液合成PHA工艺,可以节约的成本包括:合成PHA的碳源成本、PHA合成反应构筑物建造和运行成本、剩余污泥处置成本、微生物筛选/富集培养成本,同时得到鸟粪石结晶沉淀副产品。
Plastic product is applied widely in the daily life and industrial and agricultural manufacture. In response to the problem and harmful effects of the plastic wastes on the environment, there is considerable interest in the development of biodegradable plastics. Among the various biodegradable polymer materials, polyhydroxyalkanoates (PHA) provide a good fully degradable alternative to petrochemical plastics. The properties of PHA are very similar to those of polyethylene (PE) and polypropylene (PP). PHA is fully biodegradable, and transformed from renewable raw materials. Thus, PHA is a kind of environmental- friendly plastics and a good substitute to the traditional plastics, therefore having the potential to be widely applied in the future.
     Recently, PHA has been industrially produced mainly by pure cultures as inoculation. Wider use of PHA is prevented mainly by their high production cost compared with the oil-derived plastics. Otherwise, the excess sludge generated from the world-wide municipal wastewater treatment plants is plenty and the disposal cost for the excess sludge is very high. Choosing cheap, reusable and common waste material as the carbon source, using the populations in the activated sludge as inoculation, and optimizing the PHA production process parameters is attractive to produce PHA with significant reduced cost, to reduce and reuse waste material, and to decrease both the environment harm and the consumption of the non-renewable resource resulting from the traditional plastics.
     The aim of this study is to realize the reduction of both costs for PHA production and the amount of real waste, as well as the reuse of excess sludge. The main content and results are listed as following:
     The PHA production by excess sludge process parameters influencing the PHA yield, PHA productivity, carbon source transform rate and the copolymer composition was discussed from the lab-scale experiments utilizing synthesized wastewater. Results showed that, adjusting these process parameters is essential for increasing PHA yield and regulating the monomer composition of the PHA copolymer. Aerobic, high ratio of carbon to nitrogen and dynamic feeding pattern was helpful to increase the PHA yield. Under these conditions, the yield of PHA produced by activated sludge was similar to that obtained from pure culture. Moreover, the specific PHB production rate was one order of magnitude higher than that reported for pure cultures. Certain monomer composition of PHA could be obtained by control the process operation parameters. Aerobically, the fraction of the hydroxyvalerate monomer in Poly(β-hydroxybutyrate-co-β-hydroxyvalerate) (PHBV) depends on the carbon atom number of the short chain fatty acids. The variation of dissolved oxygen (DO) concentration influenceed the metabolic pathway of PHA production by activated sludge significantly. The increase of pH value and the decrease of DO led to the increase of HV% in PHBV, which was independent of the type of carbon source. The sludge source as inoculation and the ratio of carbon to nitrogen also influenced the composition of PHBV.
     According to the experiment results of the above studies and the mechanism analysis of both metabolic and kinetic modeling for PHA production by activated sludge, a new process was developed to optimize the yield of PHA and the monomer composition using real wastewater as carbon source. One of the real wastewater was excess sludge fermentation liquid generating from alkaline anaerobic thermophilic sludge digestion, and the other was food waste. The excess sludge as inoculation was not acclimated before being used to synthesize PHA. To increasing the ratio of carbon to nitrogen in the sludge fermentation liquid, the excess ammonia and phosphate was recovered by adding Mg2+ to form the deposition of strive. Alkaline and thermophilic condition could enhance the yield of volatile fatty acids (VFAs) and the removal rate of the ammonia in the excess sludge fermentation liquid. The main component of the VFAs in the sludge fermentation liquid was acetate. The maximum yield of PHA produced by excess sludge from sludge fermentation liquid was 56.5% (fraction of the Volatile Suspended Sludge, wt%). Malt waste was the most popular carbon source for PHA production by excess sludge and the pure culture, which means malt waste led to the maximum PHA yield by these bacterial. The PHA product generated from real waste by excess sludge was analysized to penetrate their physical-chemical characteristics.
     To regulate the PHA copolymer composition, the metabolic pathway for PHA synthesis by activated sludge was simulated based on the metabolic mechanism analysis of PHA synthesis by pure culture. To optimize and forecast the yield and productivity of PHA produced by activated sludge, based on the modification of the Activated Sludge Modeling Number 3 (ASM3), a simple kinetic mathematical model was developed for PHB production process by mixed cultures with sufficient accuracy for supporting model-based optimization studies. The mechanism for the acetate uptaken from the outside was transformed anaerobically to be form hydroxyvalerate (HV) was explained as such: intracellular acetate was metabolized through a converse reaction in TCA cycle as“succinyl-CoA→propionyl-CoA”to become propionyl-CoA, which is the prior of HV in PHBV. The change of process operation conditions influenced the community structure and metabolic pathway of the mixed cultures in the activated sludge, led to the variation of hydroxyalkanoate (HA) composition and yield. The kinetic model presented here for PHA production by activated sludge could forecast the PHA yield, PHA productivity, the carbon source transform rate and the biomass yield for accurately, which was improved by lab-scale experiments.
     The industrial-scale production of PHA from sludge fermentation liquid by excess sludge establishs the sustainably economical and social value, due to the realization of the reduction and reuse of real waste and excess sludge, as well as the wide application potential of PHA product as common package material. Comparing with the PHA production by pure culture and by activated sludge from synthesized wastewater, the PHA production cost by excess sludge as inoculation and sludge fermentation liquid as carbon source was low enough. The saving cost of the PHA production by excess sludge from sludge fermentation liquid includes, the carbon substrate cost, the PHA production process configuration and operation cost, the excess sludge disposal cost, the bacterial selection and enrich cost. The strive is the byproduct during operation.
引文
1郝晓地,朱景义,曹秀芹.利用混合菌群活性污泥法实现生物可降解塑料PHA的合成.生态环境. 2005, 14(6): 967-971.
    2 A.J. Anderson and E.A. Dawes. Occurrence, Metabolism, Metabolic Role, and Industrial Uses of Bacterial Polyhydroxyalkanoates. Microbiological Reviews. 1990, 54(4): 450-472.
    3 H. Salehizadeh and M.C.M. Van Loosdrecht. Production of polyhydroxyalkanoates by mixed culture: recent trends and biotechnological importance. Biotechnology Advances. 2004, 22(3): 261-279.
    4 G. Braunegg, G. Lefebvre, and K.F. Genser. Polyhydroxyalkanoates, biopolyesters from renewable resources: Physiological and engineering aspects. Journal of Biotechnology. 1998, 65(2-3): 127-161.
    5 J.M.L. Dias, P.C. Lemos, L.S. Serafim, et al. Recent advances in polyhydroxyalkanoate production by mixed aerobic cultures: From the substrate to the final product. Macromolecular Bioscience 2006, 6(11): 885-906
    6 H. Satoh, Y. Iwamoto, T. Mino, et al. Activated sludge as a possible source of biodegradable plastic. Water Science and Technology. 1998, 38(2): 103-109.
    7 L.S. Serafim, P.C. Lemos, R. Oliveira, et al. Optimization of polyhydroxybutyrate production by mixed cultures submitted to aerobic dynamic feeding conditions. Biotechnology and Bioengineering. 2004, 87(2): 145-160.
    8 S.A. Mino T,生物高分子.聚酯I (生物系统和生物工程法生产),陈国强主译. Vol. 3a. 2004.7,北京:化学工业出版社. 183-261, 359-379.
    9 L.L. Madison and G.W. Huisman. Metabolic engineering of poly(3-hydroxyalkanoates): From DNA to plastic. Microbiology and Molecular BiologyReviews. 1999, 63(1): 21-53.
    10 L.S. Serafim, P.C. Lemos, C. Levantesi, et al. Methods for detection and visualization of intracellular polymers stored by polyphosphate-accumulating microorganisms. Journal of Microbiological Methods. 2002, 51(1): 1-18.
    11 S.Y. Lee. Bacterial polyhydroxyalkanoates. Biotechnology and Bioengineering. 1996, 49(1): 1-14.
    12 L.S. Serafim, P.C. Lemos, C. Torres, et al. The Influence of Process Parameters on the Characteristics of Polyhydroxyalkanoates Produced by Mixed Cultures. Macromolecular Bioscience. 2007, DOI: 10.1002/mabi.200700200.
    13 A. Steinbu¨chel. Biodegradable plastics. Current Opintion of Biotechnology. 1992, 3: 291-297.
    14 S.Y. Lee. Plastic bacteria? Progress and prospects for polyhydroxyalkanoate production in bacteria. Trends in Biotechnology. 1996, 14(11): 431-438.
    15王建龙,文湘华.现代环境生物技术. 2001,北京:清华大学出版社. 372-388.
    16 L.L. Wallen and W.K. Rohwedder. POLY-β-HYDROXYALKANOATE FROM ACTIVATED SLUDGE. Environmental Science & Technology. 1974, 8(6): 576-579.
    17 M.C.M. vanLoosdrecht, M.A. Pot and J.J. Heijnen. Importance of bacterial storage polymers in bioprocesses. Water Science and Technology. 1997, 35(1): 41-47.
    18 J.E. Kadouri D, Okon Y, S. Castro-Sowinski. Ecological and Agricultural Significance of Bacterial Polyhydroxyalkanoates. Crtical Reviews In Microbiology. 2005, 31(2): 55-67.
    19陈国强,张广,赵锴,等.聚羟基脂肪酸酯的微生物合成、性质和应用.无锡轻工大学学报. 2002, 21(2): 197-208.
    20 L.M. Whang and J.K. Park. Competition between polyphosphate- and glycogen-accumulating organisms in enhanced-biological-phosphorus-removal systems:Effect of temperature and sludge age. Water Environment Research. 2006, 78(1): 4-11.
    21 Mino T, Liu WT, Satoh H, et al. Possible metabolism of polyphosphate accumulating organisms (PAOs) and glycogen non accumulating organisms (GAOs) in enhanced biological phosphate removal process. in Proceedings 10th Forum Appl Biotechnol Brugge. 1996. Belgium.
    22 L.S. Serafim, P.C. Lemos, S. Rossetti, et al. Microbial community analysis with a high PHA storage capacity. Water Science and Technology. 2006, 54(1): 183-188
    23 S. Ciesielski, A. Cydzik-Kwiatkowska, T. Pokoj, et al. Molecular detection and diversity of medium-chain-length polyhydroxyalkanoates-producing bacteria enriched from activated sludge. Journal of Applied Microbiology. 2006, 101(1): 190-199.
    24 M. Beccari, M. Majone, P. Massanisso, et al. Bulking sludge with high storage response selected under intermittent feeding. Water Research. 1998, 32(11): 3403-3413.
    25 S. Rossetti, M.C. Tomel, C. Levantesi, et al. "Microthrix parvicella": a new approach for kinetic and physiological characterization. Water Science and Technology. 2002, 46(1-2): 65-72.
    26 D. Dionisi, C. Levantesi, V. Renzi, et al. PHA storage from several substrates by different morphological types in an anoxic/aerobic SBR. Water Science and Technology. 2002, 46(1-2): 337-344.
    27 A.M.P. Martins, J.J. Heijnen, and M.C.M. van Loosdrecht. Effect of feeding pattern and storage on the sludge settleability under aerobic conditions. Water Research. 2003, 37(11): 2555-2570.
    28 M.A.M. Reis, L.S. Serafim, P.C. Lemos, et al. Production of polyhydroxyalkanoates by mixed microbial cultures. Bioprocess and BiosystemsEngineering. 2003, 25(6): 377-385.
    29 M. Majone, K. Dircks, and J.J. Beun. Aerobic storage under dynamic conditions in activated sludge processes. The state of the art. Water Science and Technology. 1999, 39(1): 61-73.
    30 M.C.M. van Loosdrecht and J.J. Heijnen. Modelling of activated sludge processes with structured biomass. Water Science and Technology. 2002, 45(6): 13-23.
    31 R. Perez-Feito and D.R. Noguera. Recovery of polyhydroxyalkanoate from activated sludge in an enhanced biological phosphorus removal bench-scale reactor. Water Environment Research. 2006, 78(7): 770-775.
    32 J. Yu and L.X.L. Chen. Cost-effective recovery and purification of polyhydroxyalkanoates by selective dissolution of cell mass. Biotechnology Progress. 2006, 22(2): 547-553.
    33 P.C. Lemos, L.S. Serafim, M.M. Santos, et al. Metabolic pathway for propionate utilization by phosphorus-accumulating organisms in activated sludge: C-13 labeling and in vivo nuclear magnetic resonance. Applied and Environmental Microbiology. 2003, 69(1): 241-251.
    34戈进杰.生物降解高分子材料及其应用. 2002-09,北京:化学工业出版社. 217-244.
    35 J. Xu, B.H. Guo, Z.M. Zhang, et al. A mathematical model for regulating monomer composition of the microbially synthesized polyhydroxyalkanoate copolymers. Biotechnology and Bioengineering. 2005, 90(7): 821-829.
    36 N.V. Mantzaris. Model predicts PHA copolymer biosynthesis. Industrial Bioprocessing. 2005, 27(11): 3-4.
    37 M. Majone, M. Beccari, D. Dionisi, et al. Role of storage phenomena on removal of different substrates during pre-denitrification. Water Science and Technology. 2001, 43(3): 151-158.
    38 M. Beccari, D. Dionisi, A. Giuliani, et al. Effect of different carbon sources on aerobic storage by activated sludge. Water Science and Technology. 2002, 45(6): 157-168.
    39 H. Satoh, T. Mino, and T. Matsuo. Uptake of organic substrates and accumulation of polyhydroxyalkanoates linked with glycolysis of intracellular carbohydrates under anaerobic conditions in the biological excess phosphate removal processes. Water Science and Technology. 1992, 26(5-6): 933-942.
    40 J. Yu. Production of PHA from starchy wastewater via organic acids. Journal of Biotechnology. 2001, 86(2): 105-112.
    41 J. Hollender, D. van der Krol, L. Kornberger, et al. Effect of different carbon sources on the enhanced biological phosphorus removal in a sequencing batch reactor. World Journal of Microbiology & Biotechnology. 2002, 18(4): 359-364.
    42陈国强.可再生资源为原料的新材料产业:“生态塑料”. 2005: 12-18.
    43陈国强,吴琼.生物可降解塑料——聚羟基脂肪酸酯(PHA)的生产技术研究.精细与专用化学品. 2001, 9(18): 21-27.
    44 P.H. Yu, H. Chua, and P.A.L. Huang. Conversion of food industrial wastes into bioplastics with municipal activated sludge. Macromolecular Symposia. 1999, 148: 415-424.
    45 M.H. Choi, J.K. Rho, H.J. Lee, et al. First-order kinetics analysis of monomer composition dependent polyhydroxyalkanoic acid degradation in Pseudomonas spp. Biomacromolecules. 2003, 4(2): 424-428.
    46 L.Z. Zheng, Z. Li, H.L. Tian, et al. Molecular cloning and functional analysis of (R)-3-hydroxyacyl-acyl carrier protein : coenzyme A transacylase from Pseudomonas mendocina LZ. Fems Microbiology Letters. 2005, 252(2): 299-307.
    47 R.G. Kranz, K.K. Gabbert, and M.T. Madigan. Positive selection systems for discovery of novel polyester biosynthesis genes based on fatty aciddetoxification. Applied and Environmental Microbiology. 1997, 63(8): 3010-3013.
    48 G.Q. CHEN, Q. WU, J. XI, et al. Microbial production of biopolyesters2polyhydroxyalkanoates. Natural Science. 2000, 10: 843.
    49 G.Q. CHEN, W. Q , Z. K, et al. Functional polyhydroxyalkanoates synthesized by microorganisms J Polymer Science. 2000, 18: 389.
    50 P.R. Patnaik. Perspectives in the modeling and optimization of PHB production by pure and mixed cultures. Critical Reviews in Biotechnology. 2005, 25(3): 153-171.
    51 W.N. He, W.D. Tian, G. Zhang, et al. Production of novel polyhydroxyalkanoates by Pseudomonas stutzeri 1317 from glucose and soybean oil. Fems Microbiology Letters. 1998, 169(1): 45-49.
    52陈国强,卢晓云.一种生产聚羟基脂肪酸酯的重组菌株及其构建方法与应用. 2003,发明专利申请号: CN03120769.3.
    53 H. Chua, P.H.F. Yu, and L.Y. Ho. Coupling of waste water treatment with storage polymer production. Applied Biochemistry and Biotechnology. 1997, 63-5: 627-635.
    54 C.H. Yu PH, Huang AL, Ho KP. Conversion of industrial food wastes by Alcaligenes latus into polyhydroxyalkanoates. Appllied Biochemistry and Biotechnology. 1999, 77-79: 445-454.
    55 W.F. Hu, H. Chua, and P.H.F. Yu. Synthesis of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) from activated sludge. Biotechnology Letters. 1997, 19(7): 695-698.
    56 P.H. Hu, H. Chua, A.L. Huang, et al. Conversion of industrial food wastes by Alcaligenes latus into polyhydroxyalkanoates. Appllied Biochemistry and Biotechnology. 1999, 77-9: 445-454.
    57 H. Satoh, T. Mino, and T. Matsuo. PHA production by activated sludge.International Journal of Biological Macromolecular. 1999, 25(1-3): 105-109.
    58 C.K. Ma, H. Chua, P.H.F. Yu, et al. Optimal production of polyhydroxyalkanoates in activated sludge biomass. Applied Biochemistry and Biotechnology. 2000, 84-86: 981-989.
    59 H. Takabatake, H. Satoh, T. Mino, et al. PHA (polyhydroxyalkanoate) production potential of activated sludge treating wastewater. Water Science and Technology. 2002, 45(12): 119-26.
    60 H. Takabatake, H. Satoh, T. Mino, et al. Recovery of biodegradable plastics from activated sludge process. Water Science and Technology. 2000, 42(3-4): 351-356.
    61 L.S. Serafim, P.C. Lemos, and M.A.M. Reis. Change in metabolism of PHA accumulation by activated sludge modifying operating conditions. Water Science and Technology. 2002, 46(1-2): 353-356.
    62 S.Y. Lee, H.H. Wong, J.I. Choi, et al. Production of medium-chain-length polyhydroxyalkanoates by high-cell-density cultivation of Pseudomonas putida under phosphorus limitation. Biotechnology and Bioengineering. 2000, 68(4): 466-470.
    63 K.H. Law, Y.C. Leung, H. Lawford, et al. Production of polyhydroxybutyrate by Bacillus species isolated from municipal activated sludge. Appllied Biochemistry and Biotechnology. 2001, 91-93: 515-24.
    64 M. Zielinska and I. Wojnowska-Baryla. Removal of organic compounds from municipal wastewater by immobilized biomass. Polish Journal of Environmental Studies. 2004, 13(5): 573-577.
    65 D. Dionisi, G. Carucci, M.P. Papini, et al. Olive oil mill effluents as a feedstock for production of biodegradable polymers. Water Research. 2005, 39(10): 2076-2084.
    66 Y.D. Zheng, B.H. Zhong, W.S. Ma, et al. Structure characterization of polyhydroxyalkanoates produced from activated sludge in waste water treatmentprocess. Chemical Journal of Chinese Universities-Chinese. 2000, 21(6): 991-993.
    67 K. Liu, H. Chua, W.H. Lo, et al. Sphaerotilus natans isolated from activated sludge and its production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate). Applied Biochemistry and Biotechnology. 2002, 98: 1061-1073.
    68 C.K. Ma, H. Chua, P.H.F. Yu, et al. Optimal production of polyhydroxyalkanoates in activated sludge biomass. Applied Biochemistry and Biotechnology. 2000, 84-6: 981-989.
    69 P.H.F. Yu, H. Chua, A.L. Huang, et al. Transformation of industrial food wastes into polyhydroxyalkanoates. Water Science and Technology. 1999, 40(1): 365-370.
    70 D. Dionisi, M. Majone, G. Vallini, et al. Effect of the applied organic load rate on biodegradable polymer production by mixed microbial cultures in a sequencing batch reactor. Biotechnology and Bioengineering. 2006, 93(1): 76-88.
    71 J.M.L. Dias, L.S. Serafim, P.C. Lemos, et al. Mathematical modelling of a mixed culture cultivation process for the production of polyhydroxybutyrate. Biotechnology and Bioengineering. 2005, 92(2): 209-222.
    72 D. Dionisi, M. Beccari, S. Di Gregorio, et al. Storage of biodegradable polymers by an enriched microbial community in a sequencing batch reactor operated at high organic load rate. Journal of Chemical Technology and Biotechnology. 2005, 80(11): 1306-1318.
    73 D. Dionisi, M. Majone, V. Papa, et al. Biodegradable polymers from organic acids by using activated sludge enriched by aerobic periodic feeding. Biotechnology and Bioengineering. 2004, 85(6): 569-579.
    74 D. Dionisi, M. Majone, A. Miccheli, et al. Glutamic acid removal and PHB storage in the activated sludge process under dynamic conditions. Biotechnology and Bioengineering. 2004, 86(7): 842-851.
    75 C. Kasemsap and C. Wantawin. Improvement of waste value as biodegradable plastic. 2004. Rhodes, Greece: WIT Press, Southampton, SO40 7AA, United Kingdom.
    76 P.C. Lemos, L.S. Serafim, and M.A.M. Reis. Polyhydroxyalkanoates production by activated sludge in a SBR using acetate and propionate as carbon sources. Water Science and Technology. 2004, 50(10): 189-194.
    77 M.A. Drnevich and D.R. Noguera. Production of polyhydroxyalkanoate during treatment of low-phosphorus-content wastewater. Water Environmental Research. 2004, 76(4): 380-383.
    78 S.K. Hahn, Y.K. Chang, B.S. Kim, et al. Optimization of Microbial Poly(3-Hydroxybutyrate) Recovery Using Dispersions of Sodium-Hypochlorite Solution and Chloroform. Biotechnology and Bioengineering. 1994, 44(2): 256-261.
    79 W.F. Hu, Synthesis of Polyhydroxyalkanoates (PHAs) from Excess Activated Sludge, in Depart. Civil & Structural Engineering. 2004, H.K. POLYTECHNIC UNIVERSITY: Hong Kong.
    80 S. Khanna and A.K. Srivastava. Recent advances in microbial polyhydroxyalkanoates. Process Biochemistry. 2005, 40(2): 607-619.
    81 J.I. Choi and S.Y. Lee. Process analysis and economic evaluation for poly(3-hydroxybutyrate) production by fermentation. Bioprocess Engineering. 1997, 17(6): 335-342.
    82 T. Yamane. Yield of Poly-D(-)-3-Hydroxybutyrate from Various Carbon-Sources - a Theoretical-Study. Biotechnology and Bioengineering. 1993, 41(1): 165-170.
    83 K. B and S. F, Production of poly-(3- hydroxyalkanoates) from waste streams. Environmental economic comparison of biotechnology with traditional alternatives, ed. I.M. KHP. 1998: Delft: Tudelft Press. 4.
    84 C. J and L. SY. Process analysis and economic evaluation for poly (3-hydroxybutyrate) production by fermentation. Bioprocess Eng 1997, 17: 335-342.
    85 A.A. Randall, Y. Chen, Y.H. Liu, et al. Polyhydroxyalkanoate form and polyphosphate regulation: keys to biological phosphorus and glycogen transformations? Water Science and Technology. 2003, 47(11): 227-33.
    86 W.F. Hu, S.N. Sin, H. Chua, et al. Synthesis of polyhydroxyalkanoate (PHA) from excess activated sludge under various oxidation-reduction potentials (ORP) by using acetate and propionate as carbon sources. Appllied and Biochemical Biotechnology. 2005, 121-124: 289-301.
    87 F.J. Loge, E.R. Coats, M.P. Wolcott, et al. Poop to plastic: Commercial production of polyhydroxyalkanoates in municipal and industrial wastewater treatment. in AIChE Annual Meeting, Conference Proceedings. 2005.
    88 S. Yan, R.D. Tyagi, and R.Y. Surampalli. Polyhydroxyalkanoates (PHA) production using wastewater as carbon source and activated sludge as microorganisms. Water Science and Technology. 2006, 53(6): 175-180.
    89 G.C. Du, L.X.L. Chen, and J. Yu. High-efficiency production of bioplastics from biodegradable organic solids. Journal of Polymers and the Environment. 2004, 12(2): 89-94.
    90 S. Yan, S. Subramanian, R. Tyagi, et al. Polymer production by bacterial strains isolated from activated sludge treating municipal wastewater. Water Science and Technology. 2008, 57(4): 533-539.
    91 L. HY, H. PV, D. JL, et al. Production of polyhydroxyalkanoate during treatment of tomato cannery wastewater. Water Environment Research. 2008, 80(4): 367-372.
    92 S. Bengtsson, A. Werker, and T. Welander. Production of poly-hydroxyalkanoates by glycogen accumulating organisms treating a paper mill wastewater. Water Science and Technology. 2008, 58(2): 323-330.
    93 E.R. Coats, F.J. Loge, W.A. Smith, et al. Functional stability of a mixed microbial consortium producing PHA from waste carbon sources. Applied Biochemistry and Biotechnology. 2007, 137: 909-925.
    94 D.K.Y. Solaiman, R.D. Ashby, T.A. Foglia, et al. Conversion of agricultural feedstock and coproducts into poly(hydroxyalkanoates). Applied Microbiology and Biotechnology. 2006, 71(6): 783-789.
    95 A.A. Koutinas, Y. Xu, R. Wang, et al. Polyhydroxybutyrate production from a novel feedstock derived from a wheat-based biorefinery. Enzyme and Microbial Technology. 2007, 40(5): 1035-1044.
    96 M.G.E. Albuquerque, M. Eiroa, C. Torres, et al. Strategies for the development of a side stream process for polyhydroxyalkanoate (PHA) production from sugar cane molasses. Journal of Biotechnology. 2007, 130(4): 411-421.
    97 E. Coats, F. Loge, M. Wolcott, et al. Synthesis of polyhydroxyalkanoates in municipal wastewater treatment. Water Environment Research. 2007, 79(12): 2396-2403.
    98 N. Gurieff and P. Lant. Comparative life cycle assessment and financial analysis of mixed culture polyhydroxyalkanoate production. Bioresource Technology. 2007, 98(17): 3393-3403.
    99 P.G. Ward, M. Goff, M. Donner, et al. A two step chemo-biotechnological conversion of polystyrene to a biodegradable thermoplastic. Environmental Science & Technology. 2006, 40(7): 2433-2437.
    100 T.M. Keenan, S.W. Tanenbaum, and J.P. Nakas, Microbial formation of polyhydroxyalkanoates from forestry-based substrates, in Feedstocks for the Future: Renewables for the Production of Chemicals and Materials. 2006, Amer Chemical Soc: Washington. 193-209.
    101 K.M. Lee and D.F. Gilmore. Modeling and optimization of biopolymer (polyhydroxyalkanoates) production from ice cream residue by novel statisticalexperimental design. Applied Biochemistry and Biotechnology. 2006, 133(2): 113-148.
    102 G. Sin, A. Guisasola, D.J.W. De Pauw, et al. A new approach for modelling simultaneous storage and growth processes for activated sludge systems under aerobic conditions. Biotechnology and Bioengineering. 2005, 92(5): 600-613.
    103 G. Braunegg, G. Lefebvre, G. Renner, et al. Kinetics as a Tool for Polyhydroxyalkanoate Production Optimization. Canadian Journal of Microbiology. 1995, 41: 239-248.
    104 J.J. Beun, K. Dircks, M.C.M. Van Loosdrecht, et al. Poly-beta-hydroxybutyrate metabolism in dynamically fed mixed microbial cultures. Water Research. 2002, 36(5): 1167-1180.
    105 J. Yu and Y.T. Si. A dynamic study and modeling of the formation of polyhydroxyalkanoates combined with treatment of high strength wastewater. Environmental Science & Technology. 2001, 35(17): 3584-3588.
    106 D. Dionisi, M. Majone, R. Ramadori, et al. The storage of acetate under anoxic conditions. Water Research. 2001, 35(11): 2661-2668.
    107 D. Dionisi, V. Renzi, M. Majone, et al. Storage of substrate mixtures by activated sludges under dynamic conditions in anoxic or aerobic environments. Water Research. 2004, 38(8): 2196-2206.
    108 M. Majone, M. Beccari, D. Dionisi, et al. Role of storage phenomena on removal of different substrates during pre-denitrification. Water Science and Technology. 2001, 43(3): 151-158.
    109 T. Mino, M.C.M. Van Loosdrecht, and J.J. Heijnen. Microbiology and biochemistry of the enhanced biological phosphate removal process. Water Research. 1998, 32(11): 3193-3207.
    110 W.T. Liu, T. Mino, K. Nakamura, et al. Glycogen accumulating population and its anaerobic substrate uptake in anaerobic-aerobic activated sludge withoutbiological phosphorus removal. Water Research. 1996, 30(1): 75-82.
    111 A.A. Randall and Y.H. Liu. Polyhydroxyalkanoates form potentially a key aspect of aerobic phosphorus uptake in enhanced biological phosphorus removal. Water Research. 2002, 36(14): 3473-3478.
    112 A. Hiraishi and S.T. Khan. Application of polyhydroxyalkanoates for denitrification in water and wastewater treatment. Applied Microbiology and Biotechnology. 2003, 61(2): 103-109.
    113 B.M. Gibbs, L.R. Shephard, K.A. Third, et al. The presence of ammonium facilitates nitrite reduction under PHB driven simultaneous nitrification and denitrification. Water Science and Technology. 2004, 50(10): 181-188.
    114 R.J. Zeng, R. Lemaire, Z. Yuan, et al. Simultaneous nitrification, denitrification, and phosphorus removal in a lab-scale sequencing batch reactor. Biotechnology and Bioengineering. 2003, 84(2): 170-178.
    115 H.-P. Shi and C.-M. Lee. Combining anoxic denitrifying ability with aerobic-anoxic phosphorus-removal examinations to screen denitrifying phosphorus-removing bacteria. International Biodeterioration and Biodegradation. 2006, 57(2): 121-128.
    116 L. Qin, Y. Liu, and J.H. Tay. Denitrification on poly-beta-hydroxybutyrate in microbial granular sludge sequencing batch reactor. Water Research. 2005, 39(8): 1503-1510.
    117 H. Satoh, T. Mino, and T. Matsuo. PHA production by activated sludge. International Journal of Biological Macromolecules. 1999, 25(1-3): 105-109.
    118 C.S.K. Reddy, R. Ghai, Rashmi, et al. Polyhydroxyalkanoates: an overview. Bioresource Technology. 2003, 87(2): 137-146.
    119 A.K.S. Shilpi Khanna. Recent advances in microbial polyhydroxyalkanoates. Process Biochemistry. 2005, 40: 607-619.
    120 K.A. Third, M. Newland, and R. Cord-Ruwisch. The effect of dissolved oxygenon PHB accumulation in activated sludge cultures. Biotechnology and Bioengineering. 2003, 82(2): 238-250.
    121 Y.K. Hiroshi Shimizu, Hironobu Kodama, Shioya, Suteaki Maximum Production Strategy for Biodegradable Copolymer P(HB- co-HV) in Fed-Batch Culture of Alcaligenes eutrophus. Biotechnology and Bioengineering. 1999,
    62(5): 518-525. 122 S.H. Chuang, C.F. Ouyang, H.C. Yuang, et al. Phosphorus and polyhydroxyalkanoates variation in a combined process with activated sludge and biofilm. Water Science and Technology. 1998, 37(4-5): 593-597.
    123 M. Pijuan, J.A. Baeza, C. Casas, et al. Response of an EBPR population developed in an SBR with propionate to different carbon sources. Water Science and Technology. 2004, 50(10): 131-8.
    124 G. Lefebvre, M. Rocher, and G. Braunegg. Effects of low dissolved-oxygen concentrations on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) production by Alcaligenes eutrophus. Applied and Environmental Microbiology. 1997, 63(3): 827-833.
    125 M.C. Keung, Recovery of Bioplastics from Activated Sludge Wastewater Treatment Process, in Depart. Civil and Structural Engineering. 2000, H.K. POLYTECH. UNIVERSITY,: Hong Kong.
    126 C. Krishna and M.C.M. Van Loosdrecht. Effect of temperature on storage polymers and settleability of activated sludge. Water Research. 1999, 33(10): 2374-2382.
    127 U.G. Erdal, The Effects of Temperature on System Performance and Bacterial Commuity Structure in a Biological Phosphorus Removal System 2002, Virginia Polytechnic Institute and State University: Virginia.
    128 C.D.M. Filipe, G.T. Daigger, and C.P.L. Grady. A metabolic model for acetate uptake under anaerobic conditions by glycogen accumulating organisms:Stoichiometry, kinetics, and the effect of pH. Biotechnology and Bioengineering. 2001, 76(1): 17-31.
    129 A.S.M. Chua, H. Takabatake, H. Satoh, et al. Production of polyhydroxyalkanoates (PHA) by activated sludge treating municipal wastewater: effect of pH, sludge retention time (SRT), and acetate concentration in influent. Water Research. 2003, 37(15): 3602-3611.
    130 G.J.F. Smolders, J. Vandermeij, M.C.M. Vanloosdrecht, et al. Model of the Anaerobic Metabolism of the Biological Phosphorus Removal Process - Stoichiometry and pH Influence. Biotechnology and Bioengineering. 1994, 43(6): 461-470.
    131 F. Carrasco, D. Dionisi, A. Martinelli, et al. Thermal stability of polyhydroxyalkanoates. Journal of Applied Polymer Science. 2006, 100(3): 2111-2121.
    132 A. Steinbuchel and H.E. Valentin. Diversity of Bacterial Polyhydroxyalkanoic Acids. Fems Microbiology Letters. 1995, 128(3): 219-228.
    133 K. Sudesh, H. Abe, and Y. Doi. Synthesis, structure and properties of polyhydroxyalkanoates: biological polyesters. Progress in Polymer Science. 2000, 25(10): 1503-1555.
    134 D. Dionisi, M. Majone, V. Tandoi, et al. Sequencing batch reactor: Influence of periodic operation on performance of activated sludges in biological wastewater treatment. Industrial & Engineering Chemistry Research. 2001, 40(23): 5110-5119.
    135 M.D. Peddie CC, Jenkins CJ. Use of ORP for monitoring and control of aerobic sludge digestion. Journal of Environmental Engineering. ASCE 1990, 116(3): 461-471.
    136 S. Jiang, Y. Chen, Q. Zhou, et al. Biological short-chain fatty acids (SCFAs) production from wasted-activated sludge affected by surfactant. WaterResearch. 2007, 41(14): 3112-3120.
    137 Y. Jaffer, T.A. Clark, P. Pearce, et al. Potential phosphorus recovery by struvite formation. Water Research. 2002, 36(7): 1834-1842.
    138 APHA, Stand methods for the examination of water and wastewater, 19th edition, Washington D.C., USA. 1995: Washington, DC: American Public Health Association.
    139 H. Yuan, Y. Chen, H. Zhang, et al. Improved bioproduction of short-chain fatty acids (SCFAs) from excess sludge under alkaline conditions. Environmental Science & Technology. 2006, 40(6): 2025-2029.
    140 W. Punrattanasin, A.A. Randall, and C.W. Randall. Aerobic production of activated sludge polyhydroxyalkanoates from nutrient deficient wastewaters Water Science and Technology. 2006, 54(8): 1-8.
    141 C.D.M. Filipe, G.T. Daigger, and C.P.L. Grady. Stoichiometry and kinetics of acetate uptake under anaerobic conditions by an enriched culture of phosphorus-accumulating organisms at different pHs. Biotechnology and Bioengineering. 2001, 76(1): 32-43.
    142 Y. Liu, Y. Chen, and Q. Zhou. Effect of initial pH control on enhanced biological phosphorus removal from wastewater containing acetic and propionic acids. Chemosphere. 2007, 66(1): 123-129.
    143 T.M. Louie, T.J. Mah, W. Oldham, et al. Use of metabolic inhibitors and gas chromatography/mass spectrometry to study poly-beta-hydroxyalkanoates metabolism involving cryptic nutrients in enhanced biological phosphorus removal systems. Water Research. 2000, 34(5): 1507-1514.
    144 H. Pereira, P.C. Lemos, M.A.M. Reis, et al. Model for carbon metabolism in biological phosphorus removal processes based on in vivo C-13-NMR labelling experiments. Water Research. 1996, 30(9): 2128-2138.
    145 W.F. Hu, S.N. Sin, H. Chua, et al. Synthesis of polyhydroxyalkanoate (PHA)from excess activated sludge under various oxidation-reduction potentials (ORP) by using acetate and propionate as carbon sources. Applied Biochemistry and Biotechnology. 2005, 121: 289-301.
    146 C.R. Hood and A.A. Randall. A biochemical hypothesis explaining the response of enhanced biological phosphorus removal biomass to organic substrates. Water Research. 2001, 35(11): 2758-2766.
    147 C. Levantesi, L.S. Serafim, G.R. Crocetti, et al. Analysis of the microbial community structure and function of a laboratory scale enhanced biological phosphorus removal reactor. Environmental Microbiology. 2002, 4(10): 559-569.
    148 J.I. Choi and S.Y. Lee. Efficient and economical recovery of poly(3-hydroxybutyrate) from recombinant Escherichia coli by simple digestion with chemicals. Biotechnology and Bioengineering. 1999, 62(5): 546-553.
    149 A.L. Wong, H. Chua, W.H. Lo, et al. Synthesis of bioplastics from food industry wastes with activated sludge biomass. Water Science and Technology. 2000, 41(12): 55-59.
    150 P.A.L. Wong, M.K. Cheung, W.H. Lo, et al. Investigation of the effects of the types of food waste utilized as carbon source on the molecular weight distributions and thermal properties of polyhydroxybutyrate produced by two strains of microorganisms. E-Polymers. 2004.
    151 L.M. Tobella, M. Bunster, A. Pooley, et al. Biosynthesis of poly-beta-hydroxyalkanoates by Sphingopyxis chilensis S37 and Wautersia sp PZK cultured in cellulose pulp mill effluents containing 2,4,6-trichlorophenol. Journal of Industrial Microbiology & Biotechnology. 2005, 32(9): 397-401.
    152 A.L. Wong, H. Chua, and P.H.F. Yu. Microbial production of polyhydroxyalkanoates by bacteria isolated from oil wastes. Applied Biochemistry and Biotechnology. 2000, 84-6: 843-857.
    153 T.M. Keenan, S.W. Tanenbaum, A.J. Stipanovic, et al. Production and characterization of poly-beta-hydroxyalkanoate copolymers from Burkholderia cepacia utilizing xylose and levulinic acid. Biotechnology Progress. 2004, 20(6): 1697-1704.
    154 P.G. Ward, G. de Roo, and K.E. O'Connor. Accumulation of polyhydroxyalkanoate from styrene and phenylacetic acid by Pseudomonas putida CA-3. Applied and Environmental Microbiology. 2005, 71(4): 2046-2052.
    155 S.N. Tang, A. Fakhru'l-Razi, M.A. Hassan, et al. Feasibility study on the utilization of rubber latex effluent for producing bacterial biopolymers. Artificial Cells Blood Substitutes and Immobilization Biotechnology. 1999, 27(5-6): 411-416.
    156 M.A. Hassan, Y. Shirai, N. Kusubayashi, et al. Effect of organic acid profiles during anaerobic treatment of palm oil mill effluent on the production of polyhydroxyalkanoates by Rhodobacter sphaeroides. Journal of Fermentation and Bioengineering. 1996, 82(2): 151-156.
    157 M.A. Hassan, Y. Shirai, H. Umeki, et al. Acetic acid separation from anaerobically treated palm oil mill effluent by ion exchange resins for the production of polyhydroxyalkanoate by Alcaligenes eutrophus. Bioscience Biotechnology and Biochemistry. 1997, 61(9): 1465-1468.
    158 M.A. Hassan, Y. Shirai, N. Kusubayashi, et al. The production of polyhydroxyalkanoate from anaerobically treated palm oil mill effluent by Rhodobacter sphaeroides. Journal of Fermentation and Bioengineering. 1997, 83(5): 485-488.
    159 A.R. NorAini, M.A. Hassan, Y. Shirai, et al. Production of organic acids from palm oil mill effluent during continuous anaerobic treatment. Asia-Pacific Journal of Molecular Biology and Biotechnology. 1999, 7(2): 179-184.
    160 G.T. Daigger and C.J. Grady. The dynamics of microbial growth on soluble substrates. An unifying theory. Water Research. 1982, 16(4): 365-382.
    161 M.C.M. van Loosdrecht, M.A. Pot, and J.J. Heijnen. Importance of bacterial storage polymers in bioprocesses. Water Science and Technology. 1997, 35(1): 41-47.
    162 Y. Liu. Chemically reduced excess sludge production in the activated sludge process. Chemosphere. 2003, 50: 1-7.
    163 S. Lee and J. Yu. Production of biodegradable thermoplastics from municipal sludge by a two-stage bioprocess. Resources, Conservation and Recycling. 1997, 19(3): 151-164.
    164 J. Tong and Y. Chen. Enhanced biological phosphorus removal driven by short-chain fatty acids produced from waste activated sludge alkaline fermentation. Environmental Science & Technology. 2007, 41(20): 7126-7130.
    165 E. Lie and T. Welander. Method for determination of the readily fermentable organic fraction in municipal wastewater. Water Research. 1997, 31(6): 1269-1274.
    166 Y. Chen, S. Jiang, H. Yuan, et al. Hydrolysis and acidification of waste activated sludge at different pHs. Water Research. 2007, 41(3): 683-689.
    167 M.F.M. Din, Z. Ujang, M.C.M. van Loosdrecht, et al. Optimization of nitrogen and phosphorus limitation for better biodegradable plastic production and organic removal using single fed-batch mixed cultures and renewable resources. Water Science and Technology. 2006, 53(6): 15-20.
    168 Y.J. Wang, F.L. Hua, Y.F. Tsang, et al. Synthesis of PHAs from waster under various C : N ratios. Bioresource Technology. 2007, 98(8): 1690-1693.
    169 M. Cai, J. Liu, and Y. Wei. Enhanced biohydrogen production from sewage sludge with alkaline pretreatment. Environmental Science & Technology. 2004, 38(11): 3195-3202.
    170 T.M. Keenan, J.P. Nakas, and S.W. Tanenbaum. Polyhydroxyalkanoate copolymers from forest biomass. Journal of Industrial Microbiology & Biotechnology. 2006, 33(7): 616-626.
    171 S. Bengtsson, A. Werker, M. Christensson, et al. Production of polyhydroxyalkanoates by activated sludge treating a paper mill wastewater. Bioresource Technology. 2008, 99: 509-516.
    172 J.J. Beun, F. Paletta, M.C.M. Van Loosdrecht, et al. Stoichiometry and kinetics of poly-beta-hydroxybutyrate metabolism in aerobic, slow growing, activated sludge cultures. Biotechnology and Bioengineering. 2000, 67(4): 379-389.
    173 M. Majone, i.M. Beccar, D. Dionisi, et al. Effect of periodic feeding on substrate uptake and storage rates by a pure culture of Thiothrix (CT3 strain). Water Research. 2007, 41(1): 177-187.
    174 B.S. Kim, S.C. Lee, S.Y. Lee, et al. Production of Poly(3-Hydroxybutyric Acid) by Fed-Batch Culture of Alcaligenes-Eutrophus with Glucose-Concentration Control. Biotechnology and Bioengineering. 1994, 43(9): 892-898.
    175 T. Yamane, M. Fukunaga, and Y.W. Lee. Increased PHB productivity by high-cell-density fed-batch culture of Alcaligenes latus, a growth-associated PHB producer. Biotechnology and Bioengineering. 1996, 50(2): 197-202.
    176 S.Y. Lee, K.M. Lee, H.N. Chang, et al. Comparison of Recombinant Escherichia-Coli Strains for Synthesis and Accumulation of Poly-(3-Hydroxybutyric Acid) and Morphological-Changes. Biotechnology and Bioengineering. 1994, 44(11): 1337-1347.
    177 http://sc.info.gov.hk/gb/www.epd.gov.hk/epd/cindex.html.
    178 G.C. Du and J. Yu. Green technology for conversion of food scraps to biodegradable thermoplastic polyhydroxyalkanoates. Environmental Science and Technology. 2002, 36(24): 5511-5516.
    179 K.S. Cho, H.W. Ryu, C.H. Park, et al. Poly(hydroxybutyrate-co-hydroxy-valerate) from swine waste liquor by Azotobacter vinelandii UWD. Biotechnology Letters. 1997, 19(1): 7-10.
    180 B.S. Kim and H.N. Chang. Production of poly(3-hydroxybutyrate) from starch by Azotobacter chroococcum. Biotechnology Letters. 1998, 20(2): 109-112.
    181 D.H. Rhu, W.H. Lee, J.Y. Kim, et al. Polyhydroxyalkanoate (PHA) production from waste. Water Science and Technology. 2003, 48(8): 221-228.
    182 V. Oeding and H.G. Schlegel. Beta-ketothiolase from Hydrogenomonas eutropha H16 and its significance in the regulation of poly-beta-hydroxybutyrate metabolism. Journal of Biochemistry. 1973, 134: 239-248.
    183 J. Pramanik, P.L. Trelstad, A.J. Schuler, et al. Development and validation of a flux-based stoichiometric model for enhanced biological phosphorus removal metabolism. Water Research. 1999, 33(2): 462-476.
    184 K.Y. Doi Y., Nakamura Y. et al. . Nuclear magnetic resonance studies of poly-(3)-hydroxybutyrate and polyphosphate metabolism in Alcaligenes eutrophus. Applied Environmental Microbiology. 1989, 55: 2932-2938.
    185 M. Maurer, W. Gujer, R. Hany, et al. Intracellular carbon flow in phosphorus accumulating organisms from activated sludge systems. Water Research. 1997, 31(4): 907-917.
    186 P.C. Lemos, L.S. Serafim, and M.A.M. Reis. Synthesis of polyhydroxyalkanoates from different short-chain fatty acids by mixed cultures submitted to aerobic dynamic feeding. Journal of Biotechnology. 2006, 122(2): 226-238.
    187 C. Lopez, M.N. Pons, and E. Morgenroth. Endogenous processes during long-term starvation in activated sludge performing enhanced biological phosphorus removal. Water Research. 2006, 40(8): 1519-1530.
    188 N.D. Wang, Experimental study and mathematical modeling of enhanced biological phosphorus removal using glucose as the dominant substrate. 2001,Environmental Engineering in University of Saskatchewan: Saskatoon, Canada: 25-37.
    189 Y. Comeau, W. K. Oldham, K. J. Hall. . Dynamics of carbon reserves in biological dephosphatation of wastewaters. in Biological phosphate removal from wastewaters:proceedings of the International Conference of Advanced Water Pollution Control. 1987. Oxford, United Kingdom: Pergamon Press.
    190 M.C. Wentzel, L.H. Lo¨tter, R.E. Loewenthal, et al. Metabolic behavior of Acinetobacter spp. in enhanced biological phosphorusremoval—a biochemical model. Water S. A. (Pretoria). 1986, 12: 209–224.
    191 M. T., V. Arun, Y. Tsuzuki, et al. Effect of phosphorus accumulation on acetate metabolism in the biological phosphorus removal process. in Biological phosphate removal from wastewaters: proceedings of the International Conference of Advanced Water Pollution Control. 1987. United Kingdom: Pergamon Press, Oxford,.
    192 M.C. Wentzel, Lotter, R.H., Ekama, G.A., Loewenthal, R.E., Marais, G.V.R. Evaluation of biochamical models for biological excess phosphorus removal. Water Science and Technology. 1991, 23: 567-576.
    193 N.D. Wang, J. Peng, and G. Hill. Biochemical model of glucose induced enhanced biological phosphorus removal under anaerobic condition. Water Research. 2002, 36(1): 49-58.
    194 G.J.J. Kortstee, K.J. Appeldoorn, C.F.C. Bonting, et al. Recent developments in the biochemistry and ecology of enhanced biological phosphorus removal. Biochemistry-Moscow. 2000, 65(3): 332-340.
    195 T. Mino, M. Van Loosdrecht, and J. Heijnen. Microbiology and biochemistry of enhanced biological phosphate removal process. Water Research. 1998, 32: 3193- 3207.
    196 Z.K. Erdal, U.G. Erdal, and C.W. Randall. Biochemistry of enhanced biologicalphosphorus removal and anaerobic COD stabilization. Water Science and Technology. 2005, 52(10-11): 557-567.
    197 A. Oehmen, P.C. Lemos, G. Carvalho, et al. Advances in enhanced biological phosphorus removal: From micro to macro scale. Water Research. 2007, 41(11): 2271-2300.
    198 Y. Dai, Z.G. Yuan, K. Jack, et al. Production of targeted poly(3-hydroxyalkanoates) copolymers by glycogen accumulating organisms using acetate as sole carbon source. Journal of Biotechnology. 2007, 129(3): 489-497.
    199 L.M. Whang, C.D.M. Filipe, and J.K. Park. Model-based evaluation of competition between polyphosphate- and glycogen-accumulating organisms. Water Research. 2007, 41(6): 1312-1324.
    200 R.P.X. Hesselmann, R. Von Rummell, S.M. Resnick, et al. Anaerobic metabolism of bacteria performing enhanced biological phosphate removal. Water Research. 2000, 34(14): 3487-3494.
    201 A.S. Ciggin, O. Karahan, and D. Orhon. Effect of feeding pattern on biochemical storage by activated sludge under anoxic conditions. Water Research. 2007, 41(4): 924-934.
    202 K.A. Third, N. Burnett, and R. Cord-Ruwisch. Simultaneous nitrification and denitrification using stored substrate (PHB) as the electron donor in an SBR. Biotechnology and Bioengineering. 2003, 83(6): 706-720.
    203 M.A. van Aalast-van Leeuwen, M.A. Pot, M.C.M. vanLoosdrecht, et al. Kinetic modeling of poly(beta-hydroxybutyrate) production and consumption by Paracoccus pantotrophus under dynamic substrate supply. Biotechnology and Bioengineering. 1997, 55(5): 773-782.
    204 J.J. Beun, E.V. Verhoef, M.C.M. Van Loosdrecht, et al. Stoichiometry and kinetics of poly-beta-hydroxybutyrate metabolism under denitrifying conditions in activated sludge cultures. Biotechnology and Bioengineering.2000, 68(5): 496-507.
    205 S. Pratt, Z.G. Yuan, and J. Keller. Modeling aerobic carbon oxidation and storage by integrating respirometric, titrimetric, and off-gas CO2 measurements. Biotechnology and Bioengineering. 2004, 88(2): 135-147.
    206 R.A.J. Verlinden, D.J. Hill, M.A. Kenward, et al. Bacterial synthesis of biodegradable polyhydroxyalkanoates. Journal of Applied Microbiology. 2007, 102: 1437–1449.

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