污泥回流比对双污泥BCR反硝化除磷效果的影响
2017-09-11钟悦升荣宏伟张朝升
钟悦升,荣宏伟,张朝升
(广州大学土木工程学院,广州 510006)
污泥回流比对双污泥BCR反硝化除磷效果的影响
钟悦升, 荣宏伟*, 张朝升
(广州大学土木工程学院,广州 510006)
双污泥工艺; 反硝化除磷菌; 脱氮除磷; 污泥回流比
1 试验材料与方法
1.1 试验装置
试验装置主要包括了厌氧释磷池、生物膜好氧硝化池、缺氧反硝化池以及后曝气池,其体积分别为5.4、4.7、6.3 L,同时还设有中沉池(与生物膜好氧硝化池合建)和终沉池(与后曝气池合建),其体积分别为91.6、78.5 L (图1). 厌氧释磷池、缺氧反硝化池以及后曝气池都分别设置了机械搅拌器,从而保证泥水能够混合均匀. 生物膜好氧硝化池的挂膜采用的是组合填料膜片,同时采用粘砂块微孔曝气头来进行曝气,使得好氧硝化生物膜附着在上面来进行硝化作用. 工艺进水流量及曝气量由转子流量计调节,超越污泥流量和回流污泥流量则分别用2台隔膜计量泵控制.
1.2 试验用水
1:进水;2:厌氧释磷反应池;3:生物膜好氧硝化池;4:中沉池;5:释磷污泥;6:硝化液;7:缺氧反硝化池;8:后曝气池;9:终沉池;10:回流污泥;11:出水;12:剩余污泥;13:曝气头;14:提升搅拌器;15:污泥循环泵;16:空气压缩机
图1 双污泥BCR反硝化除磷试验装置
1.3 试验污泥
本次实验的接种污泥为广州市某污水处理厂二沉池的污泥,并在实验室中利用SBBR反应器培养驯化好氧硝化生物膜,以及通过SBR反应器对污泥进行反硝化除磷驯化,使活性污泥具有稳定而高效的脱氮除磷效果.
1.4 检测项目及方法
1.5 工艺运行条件
水力停留时间约为8 h,流量约为2.05 L/h. 生物膜硝化池溶解氧约为4.0 mg/L,后曝气池溶解氧约为2.0 mg/L. 当分别把回流污泥和超越污泥的回流比控制在R为0.6、0.4、0.2时,厌氧释磷池、缺氧反硝化池和后曝气池内污泥质量浓度基本相等,分别约为4 000~5 000、2 500~3 500、1 000~2 000 mg/L.
2 结果与讨论
2.1 污泥回流比对BCR工艺CODCr去除效果的影响
CODCr的去除率随污泥回流比降低而下降(图2). 当污泥回流比R分别控制为0.6、0.4和0.2时,BCR系统的CODCr去除率均值分别为89.98%、89.48%和82.38%,相对应的出水的CODCr质量浓度均值分别为21.50、23.11、37.67 mg/L. 在污泥回流比为0.2时,由于厌氧释磷池和缺氧反硝化池中的污泥质量浓度偏低,降低了污泥对碳源的利用效率,使工艺的CODCr的去除效果有所下降. 由于厌氧释磷池与好氧生物膜硝化池的合建,厌氧释磷池出水的CODCr被好氧生物膜硝化池稀释并去除,改善了双污泥工艺中由于CODCr进入缺氧区而带来的不利影响.
图2 不同回流比下BCR系统对ρ(COD)Cr的去除效果
Figure 2 COD removal by BCR system under different recycle ratios
图3 不同回流比下BCR系统对的去除效果
Figure 3 Ammonia nitrogen removal by BCR system under different recycle ratios
图4 BCR系统在不同回流比下对的去除效果
Figure 4 Nitrate nitrogen removal BCR system under different recycle ratios
图5 BCR系统在不同回流比下对ρ(TN)的去除效果
Figure 5 TN removal by BCR system under different recycle ratios
2.3 污泥回流比对总磷去除的影响
图6 BCR系统在不同回流比下对ρ(TP)的去除效果
Figure 6 TP removal by BCR system under different recycle ratios
3 结论
(1)把污泥回流分别控制为0.6、0.4时,BCR工艺出水中的CODCr、氮和磷都达到国家《城镇污水处理厂染物排放标准》(GBl8918-2002)一级A排放标准. 在污泥回流比为0.2的条件下,处理效果明显下降.
(2)只要厌氧释磷区和缺氧吸磷区污泥质量浓度不低于2 000 mg/L,则污泥回流比对去除CODCr、氮和磷的影响都不大. 当超越污泥回流比和回流污泥回流比都为0.4时,双污泥BCR反硝化除磷工艺的处理效果最好,对CODCr、磷和总氮处理效果都最好.
[1] 华光辉,张波. 城市污水生物除磷脱氮工艺中的矛盾关系及对策[J]. 给水排水,2002,26(12):1-4.
HUA G H,ZHANG B. Contradiction and measures in biological N and P removal of municipal wastewater treatment[J]. Water & Wastewater Engineering,2002,26 (12):1-4.
[2] 张洁,胡卫新,张雁秋. 改进型双泥反硝化除磷脱氮工艺——一种可望从根本上解决脱氮除磷矛盾的新工艺[J]. 环境污染与防治,2005,27(3):232-235.
ZHANG J,HU W X,ZHANG Y Q. Modified two-sludge system on denitrifying dephosphatation and nitrogen removal: the system solved contradiction about nitrogen and phosphorus removal drastically[J]. Environmental Pollution and Control,2005,27(3):232-235.
[3] ZUTHI M F R,GUO W S,NGO H H,et al. Enhanced biological phosphorus removal and its modeling for the activated sludge and membrane bioreactor processes[J]. Bioresource Technology,2013,139(13):363-374.
[4] MARCELINO M ,WALLAERT D ,GUISASOLA A ,et al. A two-sludge system for simultaneous biological C,N and P removal via the nitrite pathway[J]. Water Science & Technology A Journal of the International Association on Water Pollution Research,2011,64(5):1142-1147.
[5] KAPAGIANNIDIS A G,ZAFIRIADIS I,AIVASIDIS A. Effect of basic operating parameters on biological phosphorus removal in a continuous-flow anaerobic-anoxic activated sludge system[J]. Bioprocess & Biosystems Engineering,2012,35(35):371-382.
[6] 刘莹,彭永臻,王淑莹. A2N工艺的固有弊端分析及其对策研究[J]. 工业用水与废水,2010,41(6):1-5.
LIU Y,PENG Y Z,WANG S Y. A study on inherent shortcomings of A2N process and countermeasures thereof[J]. Industrial Water & Wastewater, 2010,41(6):1-5.
[7] 李相昆,姜安玺,于健,等. 连续流双污泥反硝化同时除磷系统影响因素[J].沈阳建筑大学学报,2005,21(5):560-563.
LI X K,JIANG A X,YU J,et al. Study on the affecting factors of continuous-flow two-sludge system [J]. Journal of Shenyang Jianzhu University (Natural Science),2005,21(5):560-563.
[8] 杨庆娟,王淑莹,刘莹,等. 污泥回流比对A2N反硝化除磷工艺脱氮除磷的影响[J]. 中国给水排水,2008,24(13):37-41.
YANG Q J,WANG S Y,LIU Y,et al. Study on influence of sludge recycle ratio on removal of nitrogen and phosphorous in A2N denitrifying phosphorus removal process [J]. China Water & Wastewater,2008,24(13):37-41.
[9] 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.
[10] 朱文韬,吕锡武,史静. 电子受体和MLSS对反硝化除磷的影响[J]. 净水技术,2014,33(5):31-37.
ZHU W T,LV X W,SHI J. Effect of electron acceptors and MLSS on denitrifying phosphorus removal [J]. Water Purification Technology,2014,33(5):31-37.
[11] 吕娟. NO2-N、MLSS对反硝化脱氮除磷的影响[J]. 水资源与水工程学报,2014,25(5):207-210.
LV J. Effect of NO2-N and MLSS on denitrifying phosphorus removal [J]. Journal of Water Resources and Water Engineering,2014,25(5):207-210.
[12]KAPAGIANNIDIS A G,ZAFIRIADIS I,AIVASIDIS A. Upgrading the efficiency of an external nitrification BNR system -the modified dephanox process[J]. Chemical Engineering Journal,2011,175(22):124-135.
[13]刘婧. 改良型双污泥系统反硝化除磷工艺的试验研究[D]. 哈尔滨:哈尔滨工业大学,2008.
[14] 徐玉洁,张雁秋,杨德军,等. 改良型双污泥工艺处理低C/N城市污水[J]. 安徽农业科学,2011,39(10):5992-5993.
XV Y J,ZHANG Y Q,YANG D J,et al. Treatment of low C/N urban sewage by new type two-sludge process [J]. Journal of Anhui Agricultural Sciences,2011,39(10):5992-5993.
[15] 杨鹏,张朝升,荣宏伟,等. 双污泥BCR反硝化同步脱氮除磷的试验研究[J]. 环境科学与技术,2014,37(3):74-77.
YANG P,ZHANG C S,RONG H W,et al. Denitrifying denitrification and phosphorus removal process in two-sludge BCR [J]. Environmental Science & Technology,2014,37(3):74-77.
[16]国家环保总局. 水和废水检测分析方法[M]. 北京:中国环境科学出版社,2002.
【中文责编:成文 编辑助理:冷佳奕 英文审校:李海航】
Influence of Sludge Recycle Ratio on Removal of Nitrogen and Phosphorous in Two-Sludge BCR Denitrifying Phosphorus Removal Process
ZHONG Yuesheng, RONG Hongwei*, ZHANG Chaosheng
(School of Civil Engineering, Guangzhou University, Guangzhou 510006, China)
The influence of different sludge ratios from middle sedimentation tank to anoxic reactor (exceeding sludge ratio) and from final sedimentation tank to anaerobic reactor (recycled sludge ratio) on denitrifying phosphorus removal in two-sludge BCR denitrifying phosphorus removal process was investigated using simulated domestic wastewater. Results showed that when the ratios of two kinds of sludge are 0.6, 0.4 and 0.2, the resulting average CODCrremoval rates are 89.98%, 89.48% and 82.38%, total nitrogen removal rates are 79.94%, 80.58% and 65.47%, and phosphorus removal rates are 88.81%, 91.64% and 77.06%, respectively. The effluent COD concentrations are 20.94, 21.67 and 37.66 mg/L, total nitrogen concentrations are 5.72, 5.75 and 10.85 mg/L, and phosphorus concentrations are 0.76, 0.59 and 1.62 mg/L, respectively. Compared to two-sludge A2N process, the problem of high ammonia nitrogen has been improved. When the ratios of two kinds of sludge are 0.4, two-sludge BCR denitrifying phosphorus removal process has the best pollutant removal efficiency. Since the aeration tank and sedimentation tank are integrated, denitrifying dephosphatation with nitrate as electron acceptor occurred under anoxic condition due to contribution of denitrifying phosphorus removal bacteria.
two-sludge denitrifying phosphorus removal process; denitrifying phosphorus removing bacteria; phosphorus and nitrogen removal; sludge recycle ratio
2016-02-04 《华南师范大学学报(自然科学版)》网址:http://journal.scnu.edu.cn/n
国家自然科学基金项目(51278133,21477027);广东省科技计划项目(2014a020216049);广州市教育系统创新团队项目(13C01)
X703.1
A
1000-5463(2017)04-0057-05
*通讯作者:荣宏伟,教授,Email:rhwcn@139.com.