溶解氧对HLB-MR反应器回收城市污水中有机物的影响
|
摘要
为优化高负荷生物絮凝-膜反应器(HLB-MR)的工艺参数,提高其资源化城市污水的效能,文章采用平行对比实验,考察了不同溶解氧(DO)条件下反应器的有机物去除效率、生物絮凝效果、有机物回收效果和膜污染状况。结果表明:在DO分别为1～2 mg/L和6～8 mg/L时,HLB-MR反应器有机物去除效率均在90%以上,其出水总COD均保持在30 mg/L左右;DO为1～2 mg/L时,反应器内胶体COD的絮凝效率为83%,其值低于DO为6～8 mg/L时的89%;总COD的回收率在DO为1～2 mg/L条件时为70.2%,也低于DO为6～8mg/L时的77.5%,但两反应器内悬浮态COD占浓缩液总COD的比例相差不大且均超过了94%,均利于有机物的回收利用;跨膜压差变化表明DO为6～8 mg/L时反应器膜污染程度较DO为1～2 mg/L时严重。从有机物回收与膜污染控制两方面综合比较,浓度为1～2mg/L是HLB-MR反应器较优的DO控制参数。
In order to optimize the process parameter of high loaded bioflocculation membrane reactor and improve its efficiency for recovering organics in municipal wastewater, the organics removal, bioflocculation, organics recovery and membrane fouling of the reactor were investigated under different dissolved oxygen(DO) in parallel. When the HLB-MR operated at DO of 1～2 mg/L and 6～8 mg/L, the organics removal efficiencies could all reach above 90% and the COD of permeate were all stable at around 30 mg/L. The flocculation efficiency of colloid COD was 83% at the DO of 1～2 mg/L, lower than 89% at the DO of 6～8 mg/L. The recovery rate of total COD was 70.2% at the DO of 1～2 mg/L, also lower than 77.5% at the DO of 6～8 mg/L. However, the ratios of suspended COD to the total COD of the concentrate in the two HLB-MRs were not much different and all exceeds 94%, which was beneficial to organics recovery. Development of the transmembrane pressure at different DO concentrations indicated that the membrane fouling at the DO of 6～8 mg/L was more serious than that of 1～2 mg/L. After the comparison of organics recovery and membrane fouling, 1～2 mg/L is the preferred DO concentration control parameter for HLB-MR.
In order to optimize the process parameter of high loaded bioflocculation membrane reactor and improve its efficiency for recovering organics in municipal wastewater, the organics removal, bioflocculation, organics recovery and membrane fouling of the reactor were investigated under different dissolved oxygen(DO) in parallel. When the HLB-MR operated at DO of 1～2 mg/L and 6～8 mg/L, the organics removal efficiencies could all reach above 90% and the COD of permeate were all stable at around 30 mg/L. The flocculation efficiency of colloid COD was 83% at the DO of 1～2 mg/L, lower than 89% at the DO of 6～8 mg/L. The recovery rate of total COD was 70.2% at the DO of 1～2 mg/L, also lower than 77.5% at the DO of 6～8 mg/L. However, the ratios of suspended COD to the total COD of the concentrate in the two HLB-MRs were not much different and all exceeds 94%, which was beneficial to organics recovery. Development of the transmembrane pressure at different DO concentrations indicated that the membrane fouling at the DO of 6～8 mg/L was more serious than that of 1～2 mg/L. After the comparison of organics recovery and membrane fouling, 1～2 mg/L is the preferred DO concentration control parameter for HLB-MR.
引文
[1]Gao H,Scherson Y D,Wells G F,et al.Towards energy neutral wastewater treatment:methodology and state of the art[J].Environmental Science:Processes and Impacts,2014,16(6):1223-1246.
[2]Verstraete W,Vlaeminck S E.Zerowastewater:short-cycling of wastewater resources for sustainable cities of the future[J].International Journal of Sustainable Development&World Ecology,2011,18(3):253-264.
[3]Yamamura H,Okimoto K,Kimura K,et al.Hydrophilic fraction of natural organic matter causing irreversible fouling of microfiltration and ultrafiltration membranes[J].Water Research,2014,54(5):123-136.
[4]Huang H,Lee N,Young T,et al.Natural organic matter fouling of low-pressure,hollow-fiber membranes:effects of NOM source and hydrodynamic conditions[J].Water Research,2007,41(17):3823-3832.
[5]Liao B Q,Lin H J,Langevin S P,et al.Effects of temperature and dissolved oxygen on sludge properties and their role in bioflocculation and settling[J].Water Research,2011,45(2):509-520.
[6]洪俊明,尹娟.溶解氧对动态膜生物反应器的处理效果及膜污染特性[J].化工进展,2011,30(5):1130-1134.Hong Junming,Yin Juan.Effect of dissolved oxygen on DMBR treatment efficiency and characteristics of membrane fouling[J].Chemical Industry and Engineering Progress,2011,30(5):1130-1134.
[7]Tan T W,Ng H Y.Influence of mixed liquor recycle ratio and dissolved oxygen on performance of pre-denitrification submerged membrane bioreactors[J].Water Research,2008,42(4):1122-1132.
[8]国家环境保护总局.水和废水监测分析方法[M].第四版.北京:中国环境科学出版社,2002.State Environmental Protection Administration of China.Monitoring and Analytic Methods of Water and Wastewater[M].4th ed.Beijing:Environmental Science Press of China,2002.
[9]Faust L,Temmink H,Zwijnenburg A,et al.Effect of dissolved oxygen concentration on the bioflocculation process in high loaded MBRs[J].Water Research,2014,66(3):199-207.
[10]Rasmussen H,Bruus J H,Keiding K,et al.Observations on dewaterability and physical,chemical and microbiological changes in anaerobically stored activated sludge from a nutrient removal plant[J].Water Research,1994,28(2):417-425.
[11]Starkey J E,Karr P R.Effect of low dissolved oxygen concentration on effluent turbidity[J].Journal-Water Pollution Control Federation,1984,56(7):837-843.
[12]Wilén B M,Nielsen J L,Keiding K,et al.Influence of microbial activity on the stability of activated sludge flocs[J].Colloids and Surfaces B:Biointerfaces,2000,18(2):145-156.
[13]Caccavo F,Frolund B,Van Ommen K F,et al.Deflocculation of activated sludge by the dissimilatory Fe(Ⅲ)-reducing bacterium Shewanella alga BrY[J].Applied and Environmental Microbiology,1996,62(4):1487-1490.
[14]Rasmussen H,Nielsen P H.Iron reduction in activated sludge measured with different extraction techniques[J].Water Research,1996,30(3):551-558.
[15]Wilén B M,Balmér P.The effect of dissolved oxygen concentration on the structure,size and size distribution of activated sludge flocs[J].Water Research,1999,33(2):391-400.
[16]Reid E,Liu X,Judd S J.Sludge characteristics and membrane fouling in full-scale submerged membrane bioreactors[J].Desalination,2008,219(1):240-249.
[17]杨文静,樊耀波,徐国良,等.膜生物反应器操作条件对EPS含量及膜污染的影响[J].膜科学与技术,2010,30(6):41-48.Yang Wenjing,Fan Yaobo,Xu Guoliang,et al.The effect of operation conditions on EPS concentration and membrane fouling in MBR[J].Membrane Science and Technology,2010,30(6):41-48.
[18]Wang Z,Wu Z,Tang S.Extracellular polymeric substances(EPS)properties and their effects on membrane fouling in a submerged membrane bioreactor[J].Water Research,2009,43(9):2504-2512.
[19]Stoller M.On the effect of flocculation as pretreatment process and particle size distribution for membrane fouling reduction[J].Desalination,2009,240(1):209-217.
[20]欧阳科,谢珊,刘辉.曝气量对膜生物反应器污泥特性和膜污染的影响[J].中国给水排水,2011,27(13):19-22.Ouyang Ke,Xie Shan,Liu Hui.Influence of aeration rate on activated sludge characteristics and membrane fouling in membrane bioreactor[J].China Water and Wastewater,2011,27(13):19-22.
[2]Verstraete W,Vlaeminck S E.Zerowastewater:short-cycling of wastewater resources for sustainable cities of the future[J].International Journal of Sustainable Development&World Ecology,2011,18(3):253-264.
[3]Yamamura H,Okimoto K,Kimura K,et al.Hydrophilic fraction of natural organic matter causing irreversible fouling of microfiltration and ultrafiltration membranes[J].Water Research,2014,54(5):123-136.
[4]Huang H,Lee N,Young T,et al.Natural organic matter fouling of low-pressure,hollow-fiber membranes:effects of NOM source and hydrodynamic conditions[J].Water Research,2007,41(17):3823-3832.
[5]Liao B Q,Lin H J,Langevin S P,et al.Effects of temperature and dissolved oxygen on sludge properties and their role in bioflocculation and settling[J].Water Research,2011,45(2):509-520.
[6]洪俊明,尹娟.溶解氧对动态膜生物反应器的处理效果及膜污染特性[J].化工进展,2011,30(5):1130-1134.Hong Junming,Yin Juan.Effect of dissolved oxygen on DMBR treatment efficiency and characteristics of membrane fouling[J].Chemical Industry and Engineering Progress,2011,30(5):1130-1134.
[7]Tan T W,Ng H Y.Influence of mixed liquor recycle ratio and dissolved oxygen on performance of pre-denitrification submerged membrane bioreactors[J].Water Research,2008,42(4):1122-1132.
[8]国家环境保护总局.水和废水监测分析方法[M].第四版.北京:中国环境科学出版社,2002.State Environmental Protection Administration of China.Monitoring and Analytic Methods of Water and Wastewater[M].4th ed.Beijing:Environmental Science Press of China,2002.
[9]Faust L,Temmink H,Zwijnenburg A,et al.Effect of dissolved oxygen concentration on the bioflocculation process in high loaded MBRs[J].Water Research,2014,66(3):199-207.
[10]Rasmussen H,Bruus J H,Keiding K,et al.Observations on dewaterability and physical,chemical and microbiological changes in anaerobically stored activated sludge from a nutrient removal plant[J].Water Research,1994,28(2):417-425.
[11]Starkey J E,Karr P R.Effect of low dissolved oxygen concentration on effluent turbidity[J].Journal-Water Pollution Control Federation,1984,56(7):837-843.
[12]Wilén B M,Nielsen J L,Keiding K,et al.Influence of microbial activity on the stability of activated sludge flocs[J].Colloids and Surfaces B:Biointerfaces,2000,18(2):145-156.
[13]Caccavo F,Frolund B,Van Ommen K F,et al.Deflocculation of activated sludge by the dissimilatory Fe(Ⅲ)-reducing bacterium Shewanella alga BrY[J].Applied and Environmental Microbiology,1996,62(4):1487-1490.
[14]Rasmussen H,Nielsen P H.Iron reduction in activated sludge measured with different extraction techniques[J].Water Research,1996,30(3):551-558.
[15]Wilén B M,Balmér P.The effect of dissolved oxygen concentration on the structure,size and size distribution of activated sludge flocs[J].Water Research,1999,33(2):391-400.
[16]Reid E,Liu X,Judd S J.Sludge characteristics and membrane fouling in full-scale submerged membrane bioreactors[J].Desalination,2008,219(1):240-249.
[17]杨文静,樊耀波,徐国良,等.膜生物反应器操作条件对EPS含量及膜污染的影响[J].膜科学与技术,2010,30(6):41-48.Yang Wenjing,Fan Yaobo,Xu Guoliang,et al.The effect of operation conditions on EPS concentration and membrane fouling in MBR[J].Membrane Science and Technology,2010,30(6):41-48.
[18]Wang Z,Wu Z,Tang S.Extracellular polymeric substances(EPS)properties and their effects on membrane fouling in a submerged membrane bioreactor[J].Water Research,2009,43(9):2504-2512.
[19]Stoller M.On the effect of flocculation as pretreatment process and particle size distribution for membrane fouling reduction[J].Desalination,2009,240(1):209-217.
[20]欧阳科,谢珊,刘辉.曝气量对膜生物反应器污泥特性和膜污染的影响[J].中国给水排水,2011,27(13):19-22.Ouyang Ke,Xie Shan,Liu Hui.Influence of aeration rate on activated sludge characteristics and membrane fouling in membrane bioreactor[J].China Water and Wastewater,2011,27(13):19-22.