


纯膜MBBR工艺处理微污染水工程启动研究
韩文杰,周家中,王忠祥,时丹,刘凯,周宸宇,吴迪
(1.青岛思普润水处理股份有限公司 山东 青岛 266510)
摘要:为研究纯膜MBBR工艺用于微污染水处理的工程启动过程,采用两级纯膜MBBR工艺处理低基质河道水,研究了启动过程生物膜硝化性能,并同步分析了生物膜厚度、生物量变化以及微生物种群变化情况。结果显示,采用MBBR工艺处理微污染水,在冬季最不利水温条件下不接种污泥原水启动,经历10天系统调试成功,出水氨氮开始稳定达标,一二级MBBR区出水氨氮分别为1.35±0.38mg/L、0.43±0.15mg/L,系统氨氮去除率达到88.98±3.03%,一二级容积负荷分别为0.182±0.026kgN/m3/d和0.066±0.020kgN/m3/d;同时,系统具有一定的COD去除效果,相比进水,出水中DOM组分增加了富里酸类物质;启动过程中,负荷增长至14天达到稳定,生物膜生物量增长滞后于负荷增长,并于28d达到稳定,一二级生物量分别为2.66±0.36g/m2和2.14±0.19g/m2,对应生物膜厚度分别达到174±33um、136±30um;生物膜负荷具有一定余量,能够抵抗进水负荷冲击;启动阶段,生物膜物种丰富度于21d基本达到稳定,一级生物膜的物种丰富度、物种分布的均匀程度高于二级生物膜,具有更高的物种多样性;生物膜中优势微生物主要有Nitrospira、Hyphomicrobium、Nitrosomonas、Kouleothrix、Pedomicrobium、Pedobacter等,其中硝化菌群Nitrospira在一二级生物膜中相对丰度达到8.48-13.60%、6.48-9.27%,Nitrosomonas在一二级生物膜中相对丰度达到2.89-5.64%,0.00-3.48%,而Hyphomicrobium和Pedomicrobium等菌属的存在可能与进水中芳香烃类DOM的转化有关。采用MBBR工艺处理微污染水,通过在已有絮凝沉淀池内镶嵌悬浮载体系统,强化氨氮处理效果,工程验证技术路线可行,且启动周期短,处理效果稳定,可为微污染水旁位处理提供技术思路。
关键词:纯膜MBBR;悬浮载体;微污染水;硝化;生物量;生物膜厚度;高通量测序
Research on Start-up of Pure MBBR Process for Micro-polluted Water Treatment
HAN Wen-jie, ZHOU Jia-zhong, WANG Zhong-xiang, SHI Dan, LIU Kai, ZHOU Chen-yu, WU Di
(Qingdao Spring Water Treatment Co.Ltd., Qingdao 266555,China)
Abstract:In order to research the start-up process of pure-MBBR Process for micro-polluted water treatment, two-stage pure MBBR was used to treat low substrate river water. The nitrification performance of biofilm during the start-up process was studied, and the changes of biofilm thickness, biomass and microbial population were analyzed simultaneously. The results showed that under the most unfavorable temperature in winter, the effluent ammonia began to reach the standard after 10 days without inoculation of sludge, and the effluent ammonia nitrogen of the first and second level MBBR area was 1.35±0.38mg/L、0.43±15 mg/L, the corresponding loads of the first and second MBBR aera was 0.182±0.026kgN/m3/d and 0.066±0.020kgN/m3/d respectively. At the same time, the system has a certain COD removal effect, compared with the influent, the DOM component in the effluent increases the fulvic acid substances. During the start-up process, the nitrification load growth was stable in 14 days, the growth of biofilm biomass lagged behind the nitrification load growth, and reached stability in 28 days, the biomass of the first and second MBBR aera was 2.66±0.36 g/m2 and 2.14±0.19 g/m2 respectively, the corresponding biofilm thickness reached 174±33um、136±30um,respectivly.Teh biofilm has light impact resistance. The species richness of biofilm reached a stable level in 21 days. The species richness and species distribution uniformity of biofilm in the first MBBR aera was higher than those of second MBBR aera, with higher species diversity. The dominant microorganisms in biofilm were Nitrospira, Hypomicrobium, Nitrosomonas, Kouleothrix, Pedomicrobium, Pedobacter, etc. the relative abundance of Nitrospira in the first and second MBBR biofilm was 8.48-13.60% and 6.48-9.27%, respectivly. The relative abundance of Nitrosomonas in the first and second MBBR biofilm was 2.89-5.64%, 0.00-3.48%, respectivly. However, the presence of bacteria such as Hyphomicrobium and Pedomicrobium may be related to the transformation of DOM in influent. MBBR process is used to treat micro polluted water. By embedding suspended carrier system in the existing flocculation sedimentation tank, the ammonia nitrogen treatment effect is strengthened. The engineering verification shows that the technical route is feasible, the start-up period is short, and the treatment effect is stable. It can provide technical ideas for micro-polluted water treatment.
Key words:Pure-MBBR;Suspended carrier;Micro-polluted water;Nitrification;Biomass;Biofilm thickness;High throughput sequencing
微污染水,即受到轻度污染的自然水体,其物理、化学和微生物指标已不能达到《地面水环境质量标准》中的水质要求,多数情况涉及氨氮和CODMn的微量污染。由于其污染浓度不高,水质一般低于GB18918-2002中一级B或A标准,若采用传统方法处理难以有效富集活性污泥,因此多采用生物膜法处理。早先,固定床类生物膜法得以应用,如曝气生物滤池、生物接触氧化等,但存在水头损失高、滤料结团堵塞、反冲洗后影响处理效果稳定性等问题[1][2],应用受到限制。移动床生物膜反应器(MBBR)在污水处理领域广泛应用,其在微污染水领域的应用亦受到关注。与市政污水应用的MBBR形式不同,微污染水基于生物膜,称之为纯膜MBBR工艺(Pure MBBR)。目前,在效果验证方面,徐斌等[3]在以MBBR工艺处理黄浦江微污染水的中试试验中,验证了低进水基质下MBBR能够展现出良好的硝化性能,在进水氨氮和CODMn分别为0.65-3.05mg/L、5.9-6.3mg/L的基础上,氨氮和CODMn去除率均值分别为61.0%、5.05%;施东文等[4]应用MBBR中试处理黄河中下游微污染水,在进水氨氮和CODMn分别为为0.15-0.76mg/L、3.32-4.81mg/L的基础上,氨氮和CODMn去除率均值分别可达54.8%、10.4%;左倬等[5]在研究以MBBR中试去除盐龙湖原水中氮磷时发现,在进水氨氮平均浓度为0.41mg/L的基础上,出水降至0.12mg/L,核算平均氨氮去除率为64.4%。工程应用方面,熊水应等[6]在处理京杭古运河原水过程中应用纯膜MBBR工艺,处理规模15万t/d,在原水氨氮浓度0.86-2.91mg/L的基础上,MBBR池出水氨氮浓度可降至0.15-0.90mg/L之间,平均氨氮去除率在77%左右,出水全年稳定达标;周正兴等[7]在江苏某自来水厂提标改造项目中利用MBBR工艺处理微污染河道水,处理规模30万t/d,在进水氨氮和CODMn均值分别为1.01mg/L、7.4mg/L的基础上,氨氮及CODMn去除率分别可达57.43%、20.30%,出水稳定达标。综上,当前针对MBBR工艺处理微污染水的报道多局限于中试试验,实际工程应用报道较少,而仅有的工程应用也主要关注运行效果,针对MBBR启动过程中悬浮载体挂膜及影响因素研究少有报道。
本文主要针对MBBR工艺应用于河道水脱氨的工程效果,研究了启动和运行阶段悬浮载体硝化性能及其生物膜生物量和微生物组成变化,弥补MBBR工艺处理微污染水启动过程研究的缺失,为MBBR应用于微污染水处理提供理论和调试依据。
1 项目简介
广东某水质净化厂,设计水量为260万m3/d,处理水体为微污染河道水,共分为两期,水量均为130万m3/d。水厂原处理工艺为单级混凝工艺,对进水中的TP、SS、COD去除效果较好,但对氨氮几乎没有处理能力;为响应政府河道水治理号召,强化水厂对氨氮的处理能力,采用纯膜MBBR对水厂进行改造,切割39%混凝沉淀区并镶嵌MBBR工艺包形成MBBR区,MBBR区设置两级工艺,池体中间设置拦截筛网,将悬浮载体固定于各池体内。MBBR区悬浮载体填充率为40%,所投加悬浮载体类型为SPR-III型,材质为高密度聚乙烯(HDPE),载体直径25±0.5mm,高10±1mm,有效比表面积大于800m2/m3,附着生物膜后比重与水接近,符合《水处理用高密度聚乙烯悬浮载体填料(CJ/T461-2014》行业标准[8]。MBBR区设置穿孔曝气保证悬浮载体的流化与供氧,设计气水比1.5。
改造前后水厂主要工艺流程和设计进出水水质分别如图1和表1所示。其中,对于氨氮处理要求与进水水质相关,当进水氨氮≥6mg/L,需满足系统氨氮去除量>5mg/L;进水氨氮为3-6mg/L时,系统氨氮去除率需≥84%;进水氨氮<3mg/L时,要求出水氨氮≤0.5mg/L。