【作者】 马华敏；

【导师】 孙德智；

【作者基本信息】 北京林业大学 ， 环境科学， 2011， 硕士

【摘要】 由于高纬度寒冷地区冬季漫长,废水水温过低,致使废水生物处理单元中微生物的代谢能力下降,导致设置于户外的污水生化处理设施的处理效率大幅度降低,经处理后出水水质难于达标。我国目前尚缺乏针对冬季冰封期低温废水处理的成热集成技术。为此,需要寻求合适有效的低温稳定运行强化技术,保证寒冷地区冬季污水处理达标。围绕这一目的,本文以城市污水作为处理对象,研究了采用缺氧-好氧移动床生物膜反应器(MBBR)处理低温城市污水的效能。实验室小试在常温(T=20℃)和低温(T=8℃)条件下,分别研究了模拟城市污水水质在不同参数组合下,经好氧MBBR处理的效能,得到在低温8℃下好氧MBBR运行的最优参数组合为：填料填充比为40%,HRT=4h,DO=7～8mg/L。在最优参数组合下,将填料填充量为50%的的缺氧MBBR与好氧MBBR连接,调整硝化液回流比为200%,得到在低温8℃的条件下,缺氧-好氧MBBR对COD和NH4+-N的去除率可分别可达90.70%和71.65%,当进水中COD和NH4+-N浓度分别在400mg/L和30mg/L左右时,出水中COD和NH4+-N含量均可达到《城镇污水处理厂污染物排放标准(GB18918-2002)》中的一级A标准,此时TN的去除率可达65.65%。根据小试实验结果,在大庆市东城区污水处理厂设计了中试缺氧-好氧MBBR系统,用以处理大庆市东城区实际生活污水。实验结果表明,该系统在温度为15～20℃的条件下启动时间短,即使在进水COD、氨氮浓度较低的情况，好氧MBBR依然可在较短的时间内完成生物挂膜。常温(T=20～25℃)条件下,当进水COD、NH4+-N、TN的平均浓度分别为450mg/L、45mg/L和50mg/L时,经缺氧-好氧MBBR处理后的出水中COD、NH4+-N和TN浓度可分别稳定于48.1 mg/L、3.41 mg/L和13.32mg/L以下,达到《城镇污水处理厂污染物排放标准(GB18918-2002)》中的一级A标准。中试实验中,从秋季进入冬季后,水温从20℃骤降至13℃,对反应器的运行带来了明显的冲击。反应器硝化、反硝化能力均明显下降,出水中COD、NH4+-N、TN含量不断升高。此时,通过搭建保暖措施控制水温在8～13℃左右,同时降进水负荷降低至0.4m3/h,稳定一段时间后,随着微生物对低温的不断适应,反应器的除污能力开始缓慢回升,此时逐渐调整进水负荷至0.5m3/h,8～13℃的低温环境运行2个月的结果表明,调整稳定后的反应器对COD、NH4+-N、TN的去除率分别可以达到90%、88%和60%以上,此时出水中COD、NH4+-N、TN含量分别在50mg/L、5mg/L和15mg/L以下,仍达到《城镇污水处理厂污染物排放标准(GB18918-2002)》中的一级A标准。更多还原

【Abstract】 In the high-latitude cold region, metabolic capability of micro-organisms of the treatment units was decreased by the low temperature, which leads to the removal efficiency reduction of the outdoor biological sewage treatment facilities. So, steady operation of the sewage treatment plant was greatly affected and the quality of the treated water can hardly reach the related standard. China is lack of maturely integrated technology with the low temperature sewage treatment in the winter. For this reason, effective strengthening technique in low temperature is seeked to make sure the quality of the treated water reaching the standard in the cold region. Therefore, the dissertation mainly studies the treatment efficiency of low temperature wastewater by A/O process MBBR(Moving Biological Bed Reactor).The lab experiment was carried out in the conditions of room temperature (T=20℃) and low temperature (T=8℃) respectively. The treatment efficiency of stimulant municipal wastewater by Oxic MBBR was studied in different conditions, and the optimal parameters of Oxic MBBR were obtained in the 8℃low temperature. The optimal parameters of Oxic MBBR were the filling radio of suspended carriers 40%. HRT 4h and DO concentration 7-8mg/L.Under the optimal conditions, when the Anoxic MBBR, whose filling radio of suspended carriers is 50%. was connected with Oxic MBBR and the internal recycle ratio was adjusted at 200%, the removal efficiencies of COD and NH4--N in the 8℃of sewage temperature can reach 90.70% and 71.65% respectively, when the influent concentration of COD and NH4+-N was about 400mg/L and 30mg/L respectively, the content of COD and NH4--N in the effluent can both reach the first level A criteria specified in the national discharge standard while the removal efficiencies of TN can reach 65.65%.To investigate the practical treatment efficiency of the domestic sewage pilot-scale models were designed and set in the east district wastewater treatment plant of Daqing city based on the lab experiment results. The Pilot-scale Research was started from summer, the experimental results showed that the starting time of this system is short in the temperature between 15℃and 20. Even in low average influent concentrations that COD, NH4(?)-N and TN was 450mg/L.45mg/L and 50mg/L. the effluent concentration of COD. NH4(?)-N and TN was below 48.1 mg/L,3.41 mg/L and 13.32mg/L respectively after treatment, which meet the first level A criteria specified in the national discharge standard.In the Pilot-scale reach, when the season went into winter from autumn to. the water temperature decreased from 20℃to 13℃suddenly, taking an obvious impact on the reactor operation. The ability of nitrification and denitrification was both decreased, the effluent concentration of COD, NH4(?)-N and TN was increased continuously. In this time, the water temperature was controlled at 13 C by building warmth retention measures, and meanwhile, the influent load was decreased to 0.4m3/h. After a period of tranquilization. with the continuous adaptation of microorganism, the removing ability of the reactors rose slowly, then the influent load was adjusted to 0.5m3/h. The results of two month operation in low temperature(8-13℃) showed that the removal efficiency of COD. NH4(?)-N and TN can reach 90%,88% and 60% respectively after the reactors was adjusted stably, and the effluent concentration of COD. NH4(?)-N and TN is below 50mg/L,5mg/L and 15mg/L, which meets the first level A criteria specified in the national discharge standard.更多还原