新型序批式生物膜法(SBBR)脱氮除磷试验.pdf

新型序批式生物膜法 SBBR 脱氮除磷试验 ＊ 蒋山泉 肖海文 翟 俊 郑泽根 重庆大学城市建设与环境工程学院三峡库区生态环境教育部重点实验室, 重庆大学 400030 摘要 采用新型序批式生物膜法 SBBR 处理生活污水, 研究在厌氧 缺氧模式下生物聚磷以及同时硝化反硝化的特 性。试验表明 , 正常工况下出水 TP 去除率为 84, TN 去除率为 80。DO 是 SBBR 同时硝化反硝化的控制因素, 且适 当缩短泥龄有利于除磷。 关键词 序批式生物膜法 同时硝化反硝化 SND 除磷 ＊国家十五科技攻关重大专项 2004BA604A01 0 引言 序批式生物膜反应器 SBBR 是在序批式活性污 泥反应器 SBR 中引入生物膜而开发出来的一种新 型复合式生物膜反应器, 是目前国内外正在研究、应 用的一种污水生物处理新工艺 。SBBR 除保留了 SBR 基建费用少,操作简单、 灵活、能有效脱氮除磷等优点 之外 ,还具有污泥产量较少,生物量多, 处理能力强等 特点 。 本文拟采用一种壁挂式的软性填料的 SBBR, 兼 具固定填料式和微孔膜式特点 [ 1 -2] 。在好氧的情况 下,生物反应器中发生同时硝化和反硝化过程 。 SBBR 以A O 模式运行可以很好的聚磷 [ 3] , 若能 实现同步硝化和反硝化具有一定的现实意义。但二 者对控制反应的各类参数 溶解氧 、 有机碳、 微环境和 污龄 要求不尽相同 。本试验以 SBBR处理生活污水 为主要目的 ,探讨实现除磷和 SND 的可行性 同步除 磷脱氮 , 以及主要影响因素。 1 试验设备及过程 1. 1 试验装置 试验装置如图 1 所示。反应器主体为塑料制成, 总有效容积为15 L, 底部为沉淀区并有排泥装置。另 有搅拌器和粘砂块鼓风曝气装置, 可控制进水 、 厌氧、 好氧 、 静止 、 排泥等操作过程。 SBBR 反应器填料区为立体网格状 、填充比为 20 填料与生物膜所占体积比 ,填料均匀分布于反 应器壁周围,既有利于混合液向生物膜传质又有利于 避免气流的直接冲刷 。 1. 2 软性填料 填料的最小单位为一半球形纤维束, 直径约 5 cm。填充方式为壁挂式即靠壁向心排列在支架上 图 1 SBBR 装置 呈网状,这种排列规范整齐,并可调节各单位距离 ,整 个系统有 243单位。该反应器为单层填料 ,若放大试 验可方便组合多层填料。 图 2 软性填料示意 1. 3 生物膜培养与驯化 培养驯化生物膜分为 2 个阶段。第一阶段 系统 加入活性污泥, 使用原污水闷曝 ,该阶段运行40 d ,使 系统挂膜成功, 厚度为 3～ 5 mm 。取 1单位生物膜载 体洗脱称量 ,换算出整个系统生物量为8 000 mg L ,表 明 SBBR 生物量较大 。第二阶段 培育系统聚磷能 力,聚磷菌是兼性菌 ,需要在厌氧 好氧条件下进行培 养和驯化 , 每一周期为12 h, 其中6 h厌氧, 6 h好氧曝 气,该阶段运行20 d共 40个周期 。 1. 4 试验用水 1 次进水10 L, 处理污水采自某高校生活区。水 质富含氨氮 ,C N 为 5～ 7。 24 环 境 工 程 2008年 2 月第26 卷第1 期 表 1 原水水质mg L pH 除外 项目CODNH3TPTNpH 范围202. 8～ 487 35. 0～ 75. 0 4. 00～ 8. 00 43. 0～ 80 . 0 7. 02～ 7 . 66 均值310. 055. 06. 0063 . 07 . 28 水温控制在20℃ 左右。运行方式为A O, 一般情 况下为厌氧3 h, 好氧7 h。瞬时进水 ,鼓风曝气 ,曝气 量为0. 06 m 3 h DO 为4. 1 mg L 。沉淀0. 5 h后出水。 若不作说明所用数据为平均值 。 2 结果与讨论 2. 1 COD对 N、 P 去除的影响 由图 3 可知进水 COD 浓度与厌氧释磷量成正相 关,厌氧释磷越多好氧聚磷越彻底 。根据生物聚磷理 论聚磷菌只有在厌氧时充分释磷后才能在好氧条件 下过量吸磷,所以碳源是生物除磷的一个制约因素, 但磷的释放受碳源种类和聚磷菌吸收能力的限制 ,聚 磷菌往往只能吸收易于降解的有机碳并在体内合成 为聚羟基丁酸酯 PHB ,污水中的碳源只有一小部分 被聚磷菌吸收同化。 图3 COD 对聚磷的影响 由图 4 可知出水脱氮率在试验所用 COD COD 215～ 460 mg L 范围之内伴随 COD 增高而增加,最低 为67, 最高达 87, 远超过微生物正常生理需要, 同时硝化反硝化 SND 同时进行, 这是由于生物膜致 密深厚 ,它增大了氧向污泥内部渗透阻力 ,形成缺氧 区和厌氧区 [ 4- 5] 。在内层生物膜中存在反硝化细菌, 这些反硝化细菌利用原水或生物膜中储存有机物以 及死亡的细菌作为有机碳源, 将好氧生物膜层中产生 的硝态氮转化为氮气 。硝化与反硝化这一矛盾过程 同步发生尤其是伴随生物聚磷的进行, 节约了碳源简 化了处理工艺。 2. 2 曝气时间对除磷脱氮的影响 图5 表明好氧段曝气时间对除磷的影响。可以 发现曝气过长、过短均不利于 TP 的去除。曝气4 h以 下聚磷菌新陈代谢功能未完全展开 ,体内储存的 PHB 未有充分氧化掉 ,从而抑制过量聚磷, 长期以此模式 图4 COD 对脱氮的影响 运行影响聚磷菌的培养 。长时间曝气也会造成聚磷 能力的下降, 因为长时间的曝气使聚磷菌体内 PHB 过度消耗不利于聚磷能力的保持。但曝气时间长对 同时硝化反硝化有益 。综上考虑,曝气时间7 h为宜 。 图 5 曝气时间对脱氮除磷的影响 2. 3 DO 对脱氮除磷的影响 图6 显示除磷率随好氧段 DO 增加而增高 , 当 DO 3. 5 mg L 时 ,TP 去除率 84; DO 1. 5 mg L, TP 去除率约为 57。这可从生物膜的结构及A O 运 行模式得到解释。由于存在溶解氧对生物膜的穿透 率问题 ,生物膜在曝气时始终有一个厌氧区域, 并且 生物膜吸附有大量的碳源 ,当 DO 过低厌氧区扩大, 整个 SBBR系统会出现“同时除磷释磷”现象 。 图 6 DO 对除磷的影响 DO 对 TN 去除率影响也很大, 由图 7 可知 DO 在 3～ 4. 5 mg L时 TN 去除最彻底 , TN 去除率 80。 DO 太高太低均不利于 TN 的去除 。DO 太高 ,加快了 氧气向生物膜的传递速率, 扩大了好氧层 ,压缩缺氧 层并使有机质降解速度加快, 从而用于反硝化的空间 和碳源减少 ,同步的硝化反硝化受到削弱 。DO 过低, 有机质降解缓慢。硝化菌是完全的好氧型自养菌不 需要碳源, 系统内碳源对硝化菌有抑制作用。若硝化 作用不完全 ,反硝化难以为继, 硝化反硝化的平衡被 打破 ,从而造成反应时间延长 、 出水水质变差 。因此, 25 环 境 工 程 2008年 2 月第26 卷第1 期 DO 约为3. 5 mg L时较为理想。 图 7 DO 对脱氮的影响 2. 4 污泥龄 SRT 对除磷脱氮的影响 图8 表明保持 SRT 为25 d较为合适 。此时 TP 去 除率达到最高点为 84,同时 TN 去除率 80。 除磷最终通过排除污泥的方式实现, 适当减小 SRT 、增加膜的脱落量可提高系统除磷率, 所以反冲 洗是强化除磷的必要措施 。SBBR一个重要特点是剩 余污泥 脱落的生物膜 量少 [ 5] 。因为 SBBR 中的生 物膜上存在比活性污泥中较高级的微生物, 因此, 食 物链比 SBR 的要长得多 , 污泥的产生量也比 SBR 要 少得多。并且膜的脱落受各种因素影响 生物膜自身 生理结构特性、系统曝气量 、 进水水质以及反冲洗强 度等 ,只有部分脱落的生物膜是自然“蜕落” ,当排除 的污泥量大于系统新生的污泥量时生物膜会变薄 、 变 小,生物量的过多流失反过来又影响除磷能力 ,因而 SRT 不宜太低。 由于生物膜附着填料表面生长 ,生物固体停留时 间较长 ,因此在生物膜上能够大量生长世代时间较 长、 增殖速率慢的微生物 , 如硝化菌。保持较长的 SRT 有益硝化作用。另外 ,SRT 长, 系统生物量往往 丰富 、 生物膜宽厚,有益于生物膜的吸附 、 储存碳源功 能的发挥, 这是同时硝化反硝化必备的条件 。所以 SBBR 脱氮率随 SRT 增加而增高。 图8 SRT 对除磷脱氮的影响 2. 5 反冲洗 缩短 SRT , 排除脱落生物膜需要反冲洗, 控制反 冲洗的方法和强度很重要。本试验装置反冲洗与沉 淀排水系统统一 , 不需要专业的设备和工序 见 图2 。 具体的方法是反应结束时开动搅拌机高速搅 拌,必要时转动搅拌器,使之上下左右运动,驱使老化 陈旧的生物膜脱落, 同时最大可能避免新生生物膜过 早剥落 。脱落的生物量与搅拌的时间和强度相关。 这种反冲洗的优点是工艺简单 、 易于操作 。一般情况 下4～ 6周反冲洗操作一次。 3 结论 1 序批式生物膜生物构成丰富、吸附截留能力 强,具备生物聚磷和 SND 的客观条件。SBBR 以厌氧 缺氧方式运行可以同步脱氮除磷。在试验所采用的 合适工况下 DO 3. 5 mg L , SRT 25 d , TN 去除 率 80,TP 去除率为 84。 2 聚磷在好氧段需要较高 DO 浓度 , 而较低的 DO 下生物膜中才能形成适当缺氧好氧的微环境, 同 时硝化反硝化才能稳定发生 。DO 浓度在 3. 5 mg L 是聚磷和 SND 的结合点 。 3 SBBR除磷需要较短的SRT ,而 SND 要求相对 较长的SRT , 及时清除脱落生物膜加强反冲洗并把 SRT 控制在25 d,可以兼顾系统除磷和脱氮。 参考文献 [ 1] 王亚宜. 序批式生物膜技术 SBBR 的应用及其发展. 浙江工业 大学学报, 2006, 34 2 213 -218 [ 2] 李军, 王宝贞, 聂梅生. 淹没序批式生物膜法除磷工艺特性研 究. 中国给水排水, 2001, 17 7 1 -15 [ 3] 荣宏伟, 吕炳南, 张子辉. 序批式生物膜法生物除磷的试验研 究. 湘潭矿业学院学报, 2004, 19 1 88 -91 [ 4] Pochana K, Keller J, Lant P . Model development for simultaneous nitrification and denitrification. Wat. Sci. Tech. , 1999, 39 1 235 -243 [ 5] Daniel M, Timothy A P , Craig W. Biologicaltreatment of cyanide containing wastewater. Water Research,2000, 34 7 2105 -2109 作者通信处 蒋山泉 400044 重庆市沙坪坝区重庆大学城市建设 与环境工程学院 E -mail jiangshange 163. com 2007- 04-17 收稿 排污新标准 在江苏太湖 江苏省环保厅日前出台江苏太湖地区城镇污水处理厂及重点工业行业主要污染物排放限值 , 并于 2008 年1 月 1日正式实 施。 新标准中, 6 大行业的COD、氨氮、总磷排放限值, 比原执行标准均提高了28. 3、66. 7和50, 这是太湖蓝藻事件后江苏首 次大幅度修改排污标准。 新标准实施后, 江苏太湖地区 1 3的企业将“ 关、停、并、转” 。 摘自“中国环境报” 26 环 境 工 程 2008年 2 月第26 卷第1 期 ENHANCEMENT OF NUTRIENT REMOVAL FROM DOMESTIC WASTEWATER WITH HRAP IN RURAL AREASHuang Xiangfeng He Shaolin Chen Guang et al7 Abstract In this paper, enhancement of nutrient removal from domestic wastewater was studied in a high-rate algal pond system HRAP in rural area of Taihu. At HRT of 8d and 4d for algal pond and hydrophyte pond respectively , dissolved CODCrin the treated effluent was below 100 mg L. The annual average removal efficiency was 46. 6 for total nitrogen and 90. 4 for ammonia.The major removal mechanism for ammonia removal in two -stage HRAP was biological assimilation, nitrification and ammonia evaporation, among which nitrification dominated. In hydrophyte pond, total nitrogenwas mainly removed through precipitation of particular organic nitrogen and denitrification of inorganic nitrogen. The annual average of effluent phosphoruswas 3. 33mg L. Aimedat unsatisfactory nutrient removalinHR AP system, enhancement strategies were proposed, such as lowering thewater depth in hydrophyte pond and using waste gypsum as planting medium to construct complex hydrophyte pond. After the modification, the HRT of hydrophyte pondwas reducedto 1. 6dwhile total nitrogen andphosphorus in the treated effluentwasmaintained below 5 mg L and 1 mg L respectively , which met the first class of national wastewater discharge limit GB18918-2002 . Keywords high-rate algal pond, hydrophyte pond, domestic wastewater in rural areas, nutrient removal and enhancement EXPERIMENT ON DENITRIFYING PHOSPHORUS REMOVAL FROM LOW CARBON SOURCE URBAN WASTEWATERRong Hongwei Peng Yongzhen Zhang Chaosheng 11 Abstract An innovative anaerobic -aerobic -anoxic -aerobic sequencing batch biofilm reactor AO 2-SBBR was developed by introducing an anoxic phase in the anaerobic - aerobic sequencing batch biofilm reactor AO -SBBR based on the theory of denitrifying phosphorus removal in the experiment.The proportion of denitrifying phosphorus removal bacteria DPBincreased from 14. 82 to 63. 04 of total PAOs by four stages of selection and domestication.When the concentration of CODCr, TP, TN and NH 4-N of influent was 156. 41, 4. 64, 33. 08 and 30. 64mg L respectively, the concentration of TP, TN and NH 4-N of effluent was 1. 06, 17. 55 and 4. 32mg L.The efficiency of TP, TN and NH 4-N removal was alternatively 77. 15, 46. 94 and 85. 9.The AO2-SBBR process was effective to solve the affect of low CODCr concentration on simultaneous biological phosphorus and nitrogen removal from urban wastewater. Keywords low carbon source urban wastewater, simultaneous biological phosphorus and nitrogen removal, denitrifying phosphorus removal and AO2-SBBR process RAPIDSTARTOFAEROBICGRANULARSLUDGEREACTORWITH INTERMITTENT PHOSPHORUS REMOVALGao Jingfeng GuoJianqiu Bi Huanyu et al 15 Abstract The real domestic wastewater was treated in SBR under alternate anaerobic aerobic conditions.The effect of decreasing settling time on the ation of aerobic granular sludge AGSfor phosphorus removal was investigated. Small AGS appearedwhen the settling time was 6 min; the settling time was changed to 4 min after 6d, at the same time, the AGS was mature.It spent 28d to cultivate AGS for phosphorus removal after the settling time was gradually decreased.The average effluent phosphorus concentration was 0 . 92 mg L, maximum value was 3. 34mg L and minimum value was 0mg L. There were lots of epistylis rotans around the AGS. The diameter percentage of the granules between 0. 0～ 0 . 3 mm, 0. 3～ 0 . 6 mm and 0. 6 mm was 44. 88, 51. 61and 3. 51 respectively , the floc -like activated sludge and AGS coexisted. The control of alternate anaerobic aerobic conditions made the phosphorus removal AGS more compact than short -cut nitrifying AGS and this is favorable for the stable maintenance of AGS.The results show that under the selective pressure of settling time, aerobic sludge granulation can be divided into three phases selection of good settling zoogloea, self-aggregation and maturation. Keywords phosphorus removal, aerobic granular sludge, real domestic wastewater, rapid start -up and settling time STUDY ON THE EFFECT AND MECHANISM OF pH AND AERATION ON IRON -CARBON REDUCTION PRETREATMENT OF NITROBENZENE WASTEWATERDai Peng 18 Abstract The mechanism was investigated, which indicated the effect of pH and aeration on iron -carbon reduction treatment for nitrobenzene wastewater.Result of this research proved that pH was an important parameter on iron -carbon reduction.Suitable aeration could enhance the result of iron-carbon reduction effectively. Under the conditions of pH 2～ 4 and aeration1. 50 m3 m2h, the CODCrremoval rate of nitrobenzene wastewater was 50～ 60, the removal rate of nitrobenzene concentrationwas ashigh as 90, and the B C ratio enhancedfrom lower than 0. 1 to 0 . 40. Keywords nitrobenzene wastewater, aeration and iron-carbon reduction COMPARATIVE TEST ON THE START-UP OF TWO KINDS PACKING MATERIALS IN BIOLOGICAL AERATED FILTERZeng Zhengzhong Wang Houcheng Li Bo et al 21 Abstract Fly-ash cellular granule and zeolite granule were tested on their start -up in the same conditions. The test results showed that the start-up speed of the fly -ash cellular granule was similar with the zeolite media, and the removal rate of CODCr 60 was slightly higher than the zeolite biofilm 55in the end, but the NH 4-N removal rate of the zeolite biofilm was higher than the fly -ash cellular granule, up to about 70. Keywords packing materials, biological aerated filter, zeolite and fly -ash cellular granule BIOLOGICAL NITROGEN AND PHOSPHORUS REMOVAL IN NEW SEQUENCING BATCH BIOFILM REACTOR SYSTEMJiang Shanquan Xiao Haiwen Zhai Jun et al 24 Abstract A new sequencing batch biofilm reactor SBBR was used to treat real domestic wastewater. The characteristics of simultaneous nitrification and denitrification and removal phosphorus of sequencing batch biofilm reactor SBBR in treating domestic sewage under the condition of anaerobic anoxic processwere studied. Results from the studies were presented that under the optimization situation of treating process, effluent 2 ENVIRONMENTAL ENGINEERING Vol. 26, No. 1,Feb. , 2008 TN removal rate was 80 and its TP removal rate was 84. DO was the key factor of simultaneous nitrification and denitrification of SBBR. Reducing SRT properly was availability to removal phosphorus. Keywords SBBR, simultaneous nitrification seawater salinity was 10 500 mg L and Cl-concentration was 5 700 mg L , the effect of seawater salinity on the removal efficiency of organics and ammonia was not serious. Keywords ing toilet with seawater, seawater salinity , organics, ammonia and SBR process THE INDUSTRIAL APPLICATION OF SH -A PROCESS TREATING COKING SEWAGE Shan Mingjun Hu Xiaomin Wang Xu et al 30 Abstract The SH-A process is used for treating coking wastewater from a sewage treatment station of coking factory in Dandong, which can replace the er process for the treatment of wastewater. As compared with the flow chart, treating effect, energy loss and stable operation, it is showed that the new process with high nitrogen removal rate and low operation cost. The water quality of the final effluent meets the first grade of Intergrate Wastewater Discharge Standard GB8978 -1996 .The water can be reused to quench cokes in coking factories.This process is quite suitable for application to treat coking wastewater in coking industry. Keywords nitrosation, anaerobic ammonium oxidation, coking sewage and biological nitrogen removal SEASONAL REMOVAL EFFICIENCY STUDIES ON A SUBSURFACE FLOW CONSTRUCTED WETLAND FOR TREATING HEAVY OIL PRODUCED WATER Tong Kun Li Gang Ji Guodong 32 Abstract Seasonal operation perance in summer andwinterof a subsurface flow constructedwetland SFCWfor treating heavy oil producedwater was carried.The SFCW has two reedbeds No. 1 andNo. 2inthe series arrangement with the hydraulic loading rate of 0. 18and 0. 09 m3 m2dfor the reed bed No. 1 andNo. 2, respectively. Results obtained show that the SFCW has removal rates of oil, CODCr, BOD5, TN, and SS being 79. 22, 81. 20, 89. 67, 87. 61, and 89. 47 in summer, while those figures in winter are 77. 57, 78. 98, 79. 05, 71. 35, and 89. 88, respectively. Keywords heavy oil produced water, subsurface flow constructed wetland with two reed beds in the series arrangement and seasonal changes PERANCE COMPARISON BETWEEN PRESSURIZED AND NORMAL BIOLOGICAL CONTACT OXIDATION PROCESSESZhang Yong Zhang Linsheng Xia Mingfang et al 35 Abstract The running parameters and perance were compared between pressurized and normal biological contact oxidation process in this paper. The studies showed that the perance of pressurized biological contact oxidation process improved remarkably . When controlled the pressure as 0. 3MPa and the volume load under 15 kg CODCr m3d , the likely HRT was about 1. 0 h, the CODCrremoved rate could reach 80～ 95 percent, and the CODCrof effluentwas below 100mg L. In that condition, the dissolved oxygenwas about 4～ 5 mg L, and the air -water ratio was only 1～ 4 ∶ 1. In same condition the normal biological contact oxidation process air -water ratio was 10∶ 1, HRT was about 1. 5～ 2. 0 h, and the volume loadwhich could bear was only 5. 3 kg CODCr m3d. Keywords pressure, bio -contact oxidation process, air -water ratio, volume load and dissolved oxygen TRANSATION OF BAG -TYPE DEDUSTING SYSTEMS FOR THE DESULPHURIZATION STATIONS AND THE VANADIUM -EXTRACTING CONVERTERS IN PANZHIHUA IRON AND STEEL GROUPCOMPANYYao Xiaoyong 38 Abstract In view of the environmental pollution of the desulphurization stations and the extractive vanadium-extracting converters, Panzhihua Iron and Steel Grou