某污水处理厂A~2/O工艺冬季生物反硝化过程的影响因素研究
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摘要
针对污水处理厂冬季反硝化脱氮效率不佳的问题,以常州市某污水处理厂A~2/O工艺为研究对象,模拟探讨了不同外加碳源、碳源投加量、溶解氧(DO)和硝态氮浓度对生物处理系统反硝化脱氮能力的影响。结果表明,外加有机碳源对系统的反硝化效能有明显的强化效果。3种外加有机碳源(乙酸、乙醇和乙酸钠)中,乙酸为最佳碳源。当乙酸投加量为40mg/L时,系统反硝化脱氮效率最高,比反硝化速率可达1.964mg/(g·h),反硝化碳耗最少,为7.14 mg/mg。DO与比反硝化速率成反比,DO≤0.20mg/L时,反硝化能力最强。硝态氮初始质量浓度为20mg/L左右时,反硝化能力最强。在实际工程应用中,可以通过提高硝化效果或直接调整回流比实现反硝化脱氮最优条件,将有助于提高系统的冬季脱氮效果。
Aimed at the poor denitrification performance of wastewater treatment plant in winter,the A~2/O process of a wastewater treatment plant in Changzhou was taken as the research object,the effects of different external carbon sources,carbon source dosage,dissolved oxygen(DO)and nitrate concentration on denitrification capacity of biological treatment system were simulated and discussed.The results showed that the external organic carbon source had a significant strengthening effect on the denitrification efficiency of the system.Comparing three kinds of external organic carbon sources(acetic acid,ethanol and sodium acetate),acetic acid was the best carbon source.When the dosage of acetic acid was 40 mg/L,the denitrification efficiency of the system was the highest,the special denitrification rate could reach 1.964 mg/(g·h),and denitrification carbon consumption was the lowest,only 7.16 mg/mg.The reflux DO was inversely proportional to the special denitrification rate.When DO was≤0.20 mg/L,the special denitrification ability was the strongest,and the highest denitrification capacity was achieved when the initial nitrate concentration was about 20 mg/L.In practical engineering applications,the optimum conditions for denitrification should be realized by increasing the nitrification effect or directly adjusting the reflux ratio,which would help to improve the nitrogen removal efficiency of the system in winter.
Aimed at the poor denitrification performance of wastewater treatment plant in winter,the A~2/O process of a wastewater treatment plant in Changzhou was taken as the research object,the effects of different external carbon sources,carbon source dosage,dissolved oxygen(DO)and nitrate concentration on denitrification capacity of biological treatment system were simulated and discussed.The results showed that the external organic carbon source had a significant strengthening effect on the denitrification efficiency of the system.Comparing three kinds of external organic carbon sources(acetic acid,ethanol and sodium acetate),acetic acid was the best carbon source.When the dosage of acetic acid was 40 mg/L,the denitrification efficiency of the system was the highest,the special denitrification rate could reach 1.964 mg/(g·h),and denitrification carbon consumption was the lowest,only 7.16 mg/mg.The reflux DO was inversely proportional to the special denitrification rate.When DO was≤0.20 mg/L,the special denitrification ability was the strongest,and the highest denitrification capacity was achieved when the initial nitrate concentration was about 20 mg/L.In practical engineering applications,the optimum conditions for denitrification should be realized by increasing the nitrification effect or directly adjusting the reflux ratio,which would help to improve the nitrogen removal efficiency of the system in winter.
引文
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[10] YANG X P,ZHONG L,ZHOU L X.Effect of carbon source and dissolved oxygen on denitrification by aerobic denitrifier Pseudomonas mendocina AD6[J].Environmental Science,2010,31(6):1633-1639.
[11] PATUREAU D,BERNET N,DELGENS J P,et al.Effect of dissolved oxygen and carbon-nitrogen loads on denitrification by an aerobic consortium[J].Applied Microbiology&Biotechnology,2000,54(4):535-542.
[12]李培,潘杨.A2/O工艺内回流中溶解氧对反硝化的影响[J].环境科学与技术,2012,35(1):103-106.
[13]温沁雪,唐致文,陈志强,等.A2 O工艺好氧末段溶解氧变化对脱氮除磷影响[J].环境工程学报,2011,5(5):1041-1046.
[14]尚会来,彭永臻,张静蓉,等.不同电子受体反硝化过程中C/N对N2O产量的影响[J].环境科学,2009,30(7):2007-2012.
[15] FAN H,LIU X,HAO W,et al.Oxygen transfer dynamics and activated sludge floc structure under different sludge retention times at low dissolved oxygen concentrations[J].Chemosphere,2017,169:586-595.
[16]杨敏,孙永利,郑兴灿,等.不同外加碳源的反硝化效能与技术经济性分析[J].给水排水,2010,36(11):125-128.
[2]吉芳英,陈思,刘娜.污水处理中微生物反硝化脱氮过程及代谢规律[J].四川理工学院学报(自然科学版),2013,26(4):10-14.
[3] SIRIVEDHIN T,GRAY K A.Factors affecting denitrification rates in experimental wetlands:field and laboratory studies[J].Ecological Engineering,2006,26(2):167-181.
[4]曹岳.城市污水特征及碳源组分结构对反硝化影响研究[D].太原:太原理工大学,2016.
[5] HIEN T T,PARK H D,JO H Y,et al.Influence of different substrates in wetland soils on denitrification[J].Water Air&Soil Pollution,2011,215(1/2/3/4):549-560.
[6]王洪贞,李毅.不同外碳源对生物反硝化影响的研究[J].科学技术与工程,2013,13(19):5728-5731.
[7]孙永利,许光明,游佳,等.城镇污水处理厂外加商业碳源的选择[J].中国给水排水,2010,26(19):84-86.
[8] LEE N M,WELANDER T.The effect of different carbon sources on respiratory denitrification in biological wastewater treatment[J].Journal of Fermentation&Bioengineering,1996,82(3):277-285.
[9]谭佑铭,罗启芳.不同碳源对固定化反硝化菌脱氮的影响[J].卫生研究,2003,32(2):95-97.
[10] YANG X P,ZHONG L,ZHOU L X.Effect of carbon source and dissolved oxygen on denitrification by aerobic denitrifier Pseudomonas mendocina AD6[J].Environmental Science,2010,31(6):1633-1639.
[11] PATUREAU D,BERNET N,DELGENS J P,et al.Effect of dissolved oxygen and carbon-nitrogen loads on denitrification by an aerobic consortium[J].Applied Microbiology&Biotechnology,2000,54(4):535-542.
[12]李培,潘杨.A2/O工艺内回流中溶解氧对反硝化的影响[J].环境科学与技术,2012,35(1):103-106.
[13]温沁雪,唐致文,陈志强,等.A2 O工艺好氧末段溶解氧变化对脱氮除磷影响[J].环境工程学报,2011,5(5):1041-1046.
[14]尚会来,彭永臻,张静蓉,等.不同电子受体反硝化过程中C/N对N2O产量的影响[J].环境科学,2009,30(7):2007-2012.
[15] FAN H,LIU X,HAO W,et al.Oxygen transfer dynamics and activated sludge floc structure under different sludge retention times at low dissolved oxygen concentrations[J].Chemosphere,2017,169:586-595.
[16]杨敏,孙永利,郑兴灿,等.不同外加碳源的反硝化效能与技术经济性分析[J].给水排水,2010,36(11):125-128.