污泥龄及pH值对反硝化除磷工艺效能的影响
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摘要
以SBR成功富集后的反硝化聚磷菌(DPBs)为研究对象,分别考察了污泥龄(SRT,35、25、15 d)及pH值(7. 5、8. 0、8. 5)对反硝化除磷过程的影响.结果表明,SRT从35d缩短至25d,使活性污泥浓度(MLVSS)从2 821 mg·L~(-1)降低为2 301mg·L~(-1),而污泥负荷(F/M,以COD/MLVSS计)从0. 256 kg·(kg·d)~(-1)增加至0. 312 kg·(kg·d)~(-1),虽然净释磷量及净吸磷量有所下降,但是由于污泥活性的增加,此阶段厌氧释磷、缺氧吸磷及比反硝化速率均达到最高,分别为25. 07、15. 92及9. 45mg·(g·h)~(-1),污泥含磷率从4. 78%升为5. 33%,出水PO_4~(3-)-P浓度保持在0. 5 mg·L~(-1)以下,即PO_4~(3-)-P去除率稳定在95%以上;当SRT进一步缩短为15d时,MLVSS低至1448 mg·L~(-1),污泥中DPBs占聚磷菌(PAOs)的比例从82. 4%骤降为65. 7%,表明过短的SRT使得DPBs逐渐从系统中流失,此阶段污泥含磷率降至3. 43%,释磷、吸磷及比反硝化速率亦出现不同程度的降低.随着pH值的升高(7. 5～8. 0),厌氧释磷及缺氧吸磷速率也升高,pH值为8. 0时分别达到25. 86 mg·(g·h)~(-1)和16. 62 mg·(g·h)~(-1);当pH超过8. 0后,除磷效率快速下降,推测为磷化学沉淀导致.
In this work,the effects of the sludge retention time( SRT,35,25,or 15 d) and pH( 7. 5,8. 0,8. 5) on denitrifying phosphorus removal were investigated using denitrifying phosphorus bacteria( DPBs) enriched in a sequencing batch reactor( SBR).The results indicated that shortening the SRT from 35 d to 25 d resulted in a decrease in the mixed liquor volatile suspended solids( MLVSS) from 2 821 to 2 301 mg·L~(-1),while the sludge loading rate( F/M) increased from 0. 256 kg·( kg·d)~(-1) to 0. 312 kg·( kg·d)~(-1). Although the quantity of net phosphorus release and net phosphorus uptake decreased at this stage,the rates of anaerobic phosphorus release,anoxic phosphorus absorption,and denitrification reached their highest levels with values of 25. 07,15. 92,and 9. 45 mg·( g·h)~(-1),respectively,due to the increased sludge activity. Consequently,the phosphorus content of the sludge increased from 4. 78% to 5. 33%,and the removal rate of PO_4~(3-)-P was stable at above 95% with an average effluent PO_4~(3-)-P concentration below 0. 5 mg·L~(-1). When the SRT was further shortened to 15 d,the MLVSS decreased to values as low as 1 448 mg·L~(-1),and the proportion of DPBs in the phosphorus accumulating organisms( PAOs) decreased from 82. 4% to 65. 7%,indicating that the DPBs were gradually washed out from the system due to the excessively short SRT. At this stage,the phosphorus content of sludge decreased to 3. 43%,while the rates of phosphorus release,phosphorus absorption,and denitrification also decreased to some extent. When the pH was increased( 7. 5-8. 0),the anaerobic phosphorus release rate and the anoxic phosphorus absorption rate also increased,and reached 25. 86 mg·( g·h)~(-1) and 16. 62 mg·( g·h)~(-1),respectively,at a pH of 8. 0. When the pH exceeded 8. 0,the phosphorus removal efficiency dropped rapidly,supposedly due to phosphorus chemical precipitation.
In this work,the effects of the sludge retention time( SRT,35,25,or 15 d) and pH( 7. 5,8. 0,8. 5) on denitrifying phosphorus removal were investigated using denitrifying phosphorus bacteria( DPBs) enriched in a sequencing batch reactor( SBR).The results indicated that shortening the SRT from 35 d to 25 d resulted in a decrease in the mixed liquor volatile suspended solids( MLVSS) from 2 821 to 2 301 mg·L~(-1),while the sludge loading rate( F/M) increased from 0. 256 kg·( kg·d)~(-1) to 0. 312 kg·( kg·d)~(-1). Although the quantity of net phosphorus release and net phosphorus uptake decreased at this stage,the rates of anaerobic phosphorus release,anoxic phosphorus absorption,and denitrification reached their highest levels with values of 25. 07,15. 92,and 9. 45 mg·( g·h)~(-1),respectively,due to the increased sludge activity. Consequently,the phosphorus content of the sludge increased from 4. 78% to 5. 33%,and the removal rate of PO_4~(3-)-P was stable at above 95% with an average effluent PO_4~(3-)-P concentration below 0. 5 mg·L~(-1). When the SRT was further shortened to 15 d,the MLVSS decreased to values as low as 1 448 mg·L~(-1),and the proportion of DPBs in the phosphorus accumulating organisms( PAOs) decreased from 82. 4% to 65. 7%,indicating that the DPBs were gradually washed out from the system due to the excessively short SRT. At this stage,the phosphorus content of sludge decreased to 3. 43%,while the rates of phosphorus release,phosphorus absorption,and denitrification also decreased to some extent. When the pH was increased( 7. 5-8. 0),the anaerobic phosphorus release rate and the anoxic phosphorus absorption rate also increased,and reached 25. 86 mg·( g·h)~(-1) and 16. 62 mg·( g·h)~(-1),respectively,at a pH of 8. 0. When the pH exceeded 8. 0,the phosphorus removal efficiency dropped rapidly,supposedly due to phosphorus chemical precipitation.
引文
[1] Baeza J A, Gabriel D,Lafuente J. Improving the nitrogen removal efficiency of an A2/O based WWTP by using an on-line knowledge based expert system[J]. Water Research,2002,36(8):2109-2123.
[2] Oehmen A, Lemos P C, Carvalho G, et al. Advances in enhanced biological phosphorus removal:from micro to macro scale[J]. Water Research,2007,41(11):2271-2300.
[3] Xu X Y,Liu G,Zhu L. Enhanced denitrifying phosphorous removal in a novel anaerobic/aerobic/anoxic(AOA)process with the diversion of internal carbon source[J]. Bioresource Technology,2011,102(22):10340-10345.
[4] Zhou Y,Pijuan M,Yuan Z G. Development of a 2-sludge,3-stage system for nitrogen and phosphorous removal from nutrientrich wastewater using granular sludge and biofilms[J]. Water Research,2008,42(12):3207-3217.
[5] Carvalho G, Lemos P C, Oehmen A, et al. Denitrifying phosphorus removal:Linking the process performance with the microbial community structure[J]. Water Research,2007,41(19):4383-4396.
[6] Wang Y Y,Peng Y Z,Stephenson T. Effect of influent nutrient ratios and hydraulic retention time(HRT)on simultaneous phosphorus and nitrogen removal in a two-sludge sequencing batch reactor process[J]. Bioresource Technology,2009,100(14):3506-3512.
[7] Wang Y Y,Geng J J,Ren Z J,et al. Effect of COD/N and COD/P ratios on the PHA transformation and dynamics of microbial community structure in a denitrifying phosphorus removal process[J]. Journal of Chemical Technology and Biotechnology,2013,88(7):1228-1236.
[8] Zhang S H,Huang Y,Hua Y M. Denitrifying dephosphatation over nitrite:Effects of nitrite concentration,organic carbon,and pH[J]. Bioresource Technology,2010,101(11):3870-3875.
[9]张建华,王淑莹,张淼,等.不同反应时间内碳源转化对反硝化除磷的影响[J].中国环境科学,2017,37(3):989-997.Zhang J H,Wang S Y,Zhang M,et al. Effect of conversion of internal carbon source on denitrifying phosphorus removal under different reaction time[J]. China Environmental Science,2017,37(3):989-997.
[10] Zhang M,Peng Y Z,Wang C,et al. Optimization denitrifying phosphorus removal at different hydraulic retention times in a novel anaerobic anoxic oxic-biological contact oxidation process[J]. Biochemical Engineering Journal,2016,106:26-36.
[11]鲍林林,李相昆,李冬,等.温度和污泥质量浓度对反硝化除磷的影响[J].哈尔滨商业大学学报(自然科学版),2008,24(4):400-403,408.Bao L L,Li X K,Li D,et al. Study on influence of temperature and MLSS on denitrifying phosphorus removal system[J]. Journal of Harbin University of Commerce(Natural Sciences Edition),2008,24(4):400-403,408.
[12] Belli T J,Bernardelli J K B,Da Costa R E,et al. Effect of solids retention time on nitrogen and phosphorus removal from municipal wastewater in a sequencing batch membrane bioreactor[J]. Environmental Technology,2016,38(7):806-815.
[13] Ersu C B,Ong S K,Arslankaya E,et al. Impact of solids residence time on biological nutrient removal performance of membrane bioreactor[J]. Water Research,2010,44(10):3192-3202.
[14]胡筱敏,李微,刘金亮,等. pH对以亚硝酸盐为电子受体反硝化除磷的影响[J].中南大学学报(自然科学版),2013,44(5):2144-2149.Hu X M,Li W,Liu J L,et al. Influence of pH on denitrifying phosphorus removal using nitrite as electron acceptor[J]. Journal of Central South University(Science and Technology),2013,44(5):2144-2149.
[15]吕亮,尤雯,韦佳敏,等.容积负荷对ABR-MBR工艺反硝化除磷性能的影响[J].环境科学,2018,39(1):239-246.LüL,You W,Wei J M,et al. Effect of volume loading rate(VLR)on denitrifying phosphorus removal by the ABR-MBR process[J]. Environmental Science,2018,39(1):239-246.
[16]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.
[17]由阳,彭永臻,王淑莹,等.强化生物除磷系统胞内聚合物测定方法优化[J].哈尔滨工业大学学报,2010,42(2):207-211.You Y,Peng Y Z,Wang S Y,et al. Optimization of intracellular polymer analysis for enhanced biological phosphorous removal system[J]. Journal of Harbin Institute of Technology,2010,42(2):207-211.
[18] Liu Y,Chen Y G,Zhou Q. Effect of initial pH control on enhanced biological phosphorus removal from wastewater containing acetic and propionic acids[J]. Chemosphere,2007,66(1):123-129.
[19] Wachtmeister A,Kuba T,Van Loosdrecht M C M,et al. A sludge characterization assay for aerobic and denitrifying phosphorus removing sludge[J]. Water Research,1997,31(3):471-478.
[20] Lee D,Kim M,Chung J. Relationship between solid retention time and phosphorus removal in anaerobic-intermittent aeration process[J]. Journal of Bioscience and Bioengineering,2007,103(4):338-344.
[21]王朝朝,闫立娜,李思敏,等. SRT对UCT-MBR反硝化除磷性能与膜污染行为的影响[J].中国环境科学,2016,36(6):1715-1723.Wang Z Z,Yan L N,Li S M,et al. Influence of sludge retention time on denitrifying dephosphatation propensity and membrane fouling behavior in a UCT-MBR process[J]. China Environmental Science,2016,36(6):1715-1723.
[22]王亚宜,王淑莹,彭永臻. MLSS、pH及NO2--N对反硝化除磷的影响[J].中国给水排水,2005,21(7):47-51.Wang Y Y,Wang S Y,Peng Y Z. Influence of MLSS,pH and NO2--N concentration on denitrifying phosphorus removal[J].China Water&Wastewater,2005,21(7):47-51.
[23]郭琇,孟昭辉,董晶颢.厌氧池中pH值对生物除磷的影响[J].哈尔滨商业大学学报(自然科学版),2005,21(3):292-293,297.Guo X,Meng Z H,Dang J H. Study on pH value effect on removal of biological phosphorus in anaerobic pool[J]. Journal of Harbin University of Commerce(Natural Sciences Edition),2005,21(3):292-293,297.
[24] Sun L,Cao W P,Zhang H F,et al. Optimal growth conditions and nutrient removal characteristic of a denitrifying phosphorusaccumulating organism[J]. Desalination and Water Treatment,2016,57(52):25028-25035.
[25] Ng W J,Ong S L,Hu J Y. Denitrifying phosphorus removal by anaerobic/anoxic sequencing batch reactor[J]. Water Science and Technology,2001,43(3):139-146.
[2] Oehmen A, Lemos P C, Carvalho G, et al. Advances in enhanced biological phosphorus removal:from micro to macro scale[J]. Water Research,2007,41(11):2271-2300.
[3] Xu X Y,Liu G,Zhu L. Enhanced denitrifying phosphorous removal in a novel anaerobic/aerobic/anoxic(AOA)process with the diversion of internal carbon source[J]. Bioresource Technology,2011,102(22):10340-10345.
[4] Zhou Y,Pijuan M,Yuan Z G. Development of a 2-sludge,3-stage system for nitrogen and phosphorous removal from nutrientrich wastewater using granular sludge and biofilms[J]. Water Research,2008,42(12):3207-3217.
[5] Carvalho G, Lemos P C, Oehmen A, et al. Denitrifying phosphorus removal:Linking the process performance with the microbial community structure[J]. Water Research,2007,41(19):4383-4396.
[6] Wang Y Y,Peng Y Z,Stephenson T. Effect of influent nutrient ratios and hydraulic retention time(HRT)on simultaneous phosphorus and nitrogen removal in a two-sludge sequencing batch reactor process[J]. Bioresource Technology,2009,100(14):3506-3512.
[7] Wang Y Y,Geng J J,Ren Z J,et al. Effect of COD/N and COD/P ratios on the PHA transformation and dynamics of microbial community structure in a denitrifying phosphorus removal process[J]. Journal of Chemical Technology and Biotechnology,2013,88(7):1228-1236.
[8] Zhang S H,Huang Y,Hua Y M. Denitrifying dephosphatation over nitrite:Effects of nitrite concentration,organic carbon,and pH[J]. Bioresource Technology,2010,101(11):3870-3875.
[9]张建华,王淑莹,张淼,等.不同反应时间内碳源转化对反硝化除磷的影响[J].中国环境科学,2017,37(3):989-997.Zhang J H,Wang S Y,Zhang M,et al. Effect of conversion of internal carbon source on denitrifying phosphorus removal under different reaction time[J]. China Environmental Science,2017,37(3):989-997.
[10] Zhang M,Peng Y Z,Wang C,et al. Optimization denitrifying phosphorus removal at different hydraulic retention times in a novel anaerobic anoxic oxic-biological contact oxidation process[J]. Biochemical Engineering Journal,2016,106:26-36.
[11]鲍林林,李相昆,李冬,等.温度和污泥质量浓度对反硝化除磷的影响[J].哈尔滨商业大学学报(自然科学版),2008,24(4):400-403,408.Bao L L,Li X K,Li D,et al. Study on influence of temperature and MLSS on denitrifying phosphorus removal system[J]. Journal of Harbin University of Commerce(Natural Sciences Edition),2008,24(4):400-403,408.
[12] Belli T J,Bernardelli J K B,Da Costa R E,et al. Effect of solids retention time on nitrogen and phosphorus removal from municipal wastewater in a sequencing batch membrane bioreactor[J]. Environmental Technology,2016,38(7):806-815.
[13] Ersu C B,Ong S K,Arslankaya E,et al. Impact of solids residence time on biological nutrient removal performance of membrane bioreactor[J]. Water Research,2010,44(10):3192-3202.
[14]胡筱敏,李微,刘金亮,等. pH对以亚硝酸盐为电子受体反硝化除磷的影响[J].中南大学学报(自然科学版),2013,44(5):2144-2149.Hu X M,Li W,Liu J L,et al. Influence of pH on denitrifying phosphorus removal using nitrite as electron acceptor[J]. Journal of Central South University(Science and Technology),2013,44(5):2144-2149.
[15]吕亮,尤雯,韦佳敏,等.容积负荷对ABR-MBR工艺反硝化除磷性能的影响[J].环境科学,2018,39(1):239-246.LüL,You W,Wei J M,et al. Effect of volume loading rate(VLR)on denitrifying phosphorus removal by the ABR-MBR process[J]. Environmental Science,2018,39(1):239-246.
[16]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.
[17]由阳,彭永臻,王淑莹,等.强化生物除磷系统胞内聚合物测定方法优化[J].哈尔滨工业大学学报,2010,42(2):207-211.You Y,Peng Y Z,Wang S Y,et al. Optimization of intracellular polymer analysis for enhanced biological phosphorous removal system[J]. Journal of Harbin Institute of Technology,2010,42(2):207-211.
[18] Liu Y,Chen Y G,Zhou Q. Effect of initial pH control on enhanced biological phosphorus removal from wastewater containing acetic and propionic acids[J]. Chemosphere,2007,66(1):123-129.
[19] Wachtmeister A,Kuba T,Van Loosdrecht M C M,et al. A sludge characterization assay for aerobic and denitrifying phosphorus removing sludge[J]. Water Research,1997,31(3):471-478.
[20] Lee D,Kim M,Chung J. Relationship between solid retention time and phosphorus removal in anaerobic-intermittent aeration process[J]. Journal of Bioscience and Bioengineering,2007,103(4):338-344.
[21]王朝朝,闫立娜,李思敏,等. SRT对UCT-MBR反硝化除磷性能与膜污染行为的影响[J].中国环境科学,2016,36(6):1715-1723.Wang Z Z,Yan L N,Li S M,et al. Influence of sludge retention time on denitrifying dephosphatation propensity and membrane fouling behavior in a UCT-MBR process[J]. China Environmental Science,2016,36(6):1715-1723.
[22]王亚宜,王淑莹,彭永臻. MLSS、pH及NO2--N对反硝化除磷的影响[J].中国给水排水,2005,21(7):47-51.Wang Y Y,Wang S Y,Peng Y Z. Influence of MLSS,pH and NO2--N concentration on denitrifying phosphorus removal[J].China Water&Wastewater,2005,21(7):47-51.
[23]郭琇,孟昭辉,董晶颢.厌氧池中pH值对生物除磷的影响[J].哈尔滨商业大学学报(自然科学版),2005,21(3):292-293,297.Guo X,Meng Z H,Dang J H. Study on pH value effect on removal of biological phosphorus in anaerobic pool[J]. Journal of Harbin University of Commerce(Natural Sciences Edition),2005,21(3):292-293,297.
[24] Sun L,Cao W P,Zhang H F,et al. Optimal growth conditions and nutrient removal characteristic of a denitrifying phosphorusaccumulating organism[J]. Desalination and Water Treatment,2016,57(52):25028-25035.
[25] Ng W J,Ong S L,Hu J Y. Denitrifying phosphorus removal by anaerobic/anoxic sequencing batch reactor[J]. Water Science and Technology,2001,43(3):139-146.