MBBR-纳滤法联合强化污水厂二级出水脱氮研究

发布时间：2018-07-31 17:36

【摘要】：众所周知,我国是一个典型的农业大国,氨氮是我国地表水污染的首要污染物。随着我国“十二五”期间对污水处理厂出水水质的提标改造,城镇污水处理厂的水质排放标准已经逐步提升,对于城镇污水处理厂的处理工艺提出了越来越高的要求,因此亟待寻找一种经济有效的处理工艺,使出水水质达到国家的规定排放标准。本文采用了MBBR(Moving Bed Biofilm Reactor,移动床生物膜反应器)—纳滤联合生物反应器技术,以某生物技术有限公司污水车间二级出水水质情况为依据,针对城镇污水处理厂的二沉池出水的脱氮处理性能进行了研究。通过对MBBR所需填料的基本性质进行分析,考察了影响氧传递效率的相关因素,并最终确定其最佳填料投加率为40%。此外,确定了纳滤膜的最佳运行参数,同时考察了操作压力对纳滤膜通量和截留率的影响,发现纳滤膜对COD和NH4+-N具有一定的截留效果,其截留率与膜孔径和污染物的浓度有关;一定程度地升高COD和氨氮浓度有利于使污染物在MBBR反应器内得到去除。在此基础上,结合前期实验结果,采用MBBR反应器进行启动实验,调整优化反应器参数,通过实时监测反应器的COD浓度及反应器的三氮和总磷浓度,并通过改变溶解氧浓度(DO)和水力停留时间(HRT),探究了对反应器脱氮效果的影响,结果表明:当DO浓度达到3 mg·L-1、HRT为8 h时MBBR生物膜反应器运行效果最好,此时填料内部通过显微镜可以明显看到生物膜的厚度增加,对污水中COD的去除率超过80%,氨氮去除率达到65%;最后,自行设计运行了MBBR-纳滤联合生物脱氮反应器,持续监测了反应器内COD浓度及三氮的变化,并考察了反应器内单一周期的脱氮运行情况,发现联合反应器与传统的MBBR生物反应器相比去除效果更好,对污水中COD的去除率超过90%,氨氮去除率达到80%,长时间监测出水,水质指标均达到国家一级A排放标准。
[Abstract]:As we all know, China is a typical agricultural country, ammonia nitrogen is the primary pollutant of surface water pollution in China. With the upgrading of the effluent quality of the sewage treatment plant during the 12th Five-Year Plan period, the water quality standard of the urban wastewater treatment plant has been gradually improved, and the treatment process of the urban sewage treatment plant has been put forward more and more high requirements. Therefore, it is urgent to find an economical and effective treatment process to make the effluent quality meet the national discharge standard. In this paper, the MBBR (Moving Bed Biofilm Reactor, moving bed biofilm reactor (MBR) and the combined nanofiltration bioreactor (NBR) technology are adopted, based on the secondary effluent quality of a wastewater plant of a certain biotechnology limited company. The denitrification performance of secondary sedimentation tank effluent from urban sewage treatment plant was studied. Based on the analysis of the basic properties of the fillers required by MBBR, the related factors affecting the oxygen transfer efficiency were investigated, and the optimum filler addition rate was determined to be 40%. In addition, the optimal operating parameters of nanofiltration membrane were determined, and the effects of operating pressure on flux and rejection rate of nanofiltration membrane were investigated. It was found that nanofiltration membrane had a certain interception effect on COD and NH4 N. The retention rate is related to the membrane pore size and the concentration of pollutants, and increasing the concentration of COD and ammonia nitrogen to a certain extent is conducive to the removal of pollutants in the MBBR reactor. On this basis, combined with the previous experimental results, the start-up experiment was carried out by using MBBR reactor, the parameters of the reactor were adjusted and optimized, and the concentration of COD and the concentration of trinitrogen and total phosphorus of the reactor were monitored in real time. The effects of (DO) and HRT on denitrification were investigated. The results showed that when do concentration was 3 mg / L ~ (-1) and HRT was 8 h, MBBR biofilm reactor had the best operation effect. At this time, the thickness of biofilm was obviously increased by microscope inside the packing, the removal rate of COD in sewage exceeded 80 and the removal rate of ammonia-nitrogen reached 65. Finally, the MBBR-nanofiltration combined biological denitrification reactor was designed and operated by ourselves. The changes of COD concentration and trinitrogen in the reactor were continuously monitored, and the denitrification operation of the single period in the reactor was investigated. It was found that the combined reactor had better removal efficiency than the traditional MBBR bioreactor. The removal rate of COD in sewage is over 90 and the removal rate of ammonia nitrogen is 80. The effluent is monitored for a long time and the water quality index is up to the first class A discharge standard of the country.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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