【作者】 冯华军；

【导师】 沈东升；

【作者基本信息】 浙江大学 ， 环境工程， 2008， 博士

【摘要】 在对浙江省三个地级市五个取样点为期一年的生活污水水质调研的基础上,结合流体力学及化学反应工程学原理,对分散式生活污水厌氧生物处理反应器进行比选,确定了最优的填料式厌氧折流板反应器（CABR）。之后,以浙江大学华家池校区家属区生活污水作为CABR反应器进水,进行了为期4个月的运行试验,就其去污性能及三大类群厌氧微生物的演替规律进行了系统的研究。同时,详细研究了CABR反应器在不同温度下抗负荷冲击的性能及机理。此外,为解决厌氧工艺脱氮性能差的缺陷,开发了一种适合于分散式生活污水处理的无回流脱氮反应器,并对其性能及机理进行初步探讨和研究。本论文主要研究结论简述如下:（1）浙江省生活污水有机物和磷浓度较低,氮浓度较高,可生化性较好,但C/N相对较低,平均值仅为6.10,不利于常规生物脱氮;调查的生活污水水质季节变化明显,但地区差异不显著;污染物浓度1月份最高,7月份最低;据此对已有的模拟生活污水配置方法进行了优化,使优化配置的模拟污水4个特征比值（B/C,C/N,碱度/TN以及NH₄⁺-N/TKN）接近实际生活污水。（2）CABR反应器总体呈现平推流流态,结构性能优良,总死区率仅为10%左右。但随着格数的增多,反应器内部流速增加,从而导致水力死区有上升趋势。以理想多釜全混合反应器为参照,综合考虑反应器效能和容积利用率,确定6格的CABR反应器为最优。（3）6格CABR反应器在温度为28±1℃、HRT为48h的条件下,以实际生活污水为进水,需要3周左右才能完成启动。CABR反应器稳定运行后,出水TCOD、SS等指标均能达到《污水综合排放标准中》（GB8978-1996）的一级排放标准,但对营养元素（N、P）的去除效能较差:单纯采用CABR反应器无法完全消除腐植酸在水体中形成“三致”物质的风险;尽管CABR反应器对于对粪大肠杆菌和蛔虫卵的去除率分别高达99.82%和98.87%,但仍需后续的消毒措施保证其出水的安全性。（4）对6格CABR反应器启动及运行过程的微生物机理研究表明,CABR反应器内微生物的优势种群随着运行阶段的变化而有所变化;CABR反应器不同格室的微生物相似性较高,没有出现明显的微生物相分离现象。在启动初期首先是发酵细菌和产氢产乙酸细菌的大量增殖,而当运行至4个月左右时产甲烷细菌数量才有较为明显的增加;达到稳定运行阶段时,三大类群厌氧微生物之间的数量差异几乎接近1/10。CABR反应器在启动阶段中约有63%的基质被用于细胞合成;而当进入稳定运行期后,大约只有1/5的基质被用于细胞合成。（5）系统研究了不同温度下水力、水质负荷冲击对CABR反应器处理低浓度生活污水性能的影响,结果表明,CABR反应器对负荷冲击有很好缓冲能力,但是这种缓冲能力随着温度的下降而下降:在温度较高时（28℃）无论是水力冲击还是水质冲击对反应器的运行性能均没有显著影响;但在10℃下运行时,负荷冲击会对CABR反应器的运行性能产生显著影响。综合微生物活性、中间产物、可溶性微生物产物、TCOD容积去除率等指标变化以及采用灵敏度比和均方差比的定量判别依据表明,CABR反应器在10-28℃下处理低浓度生活污水时,抗水质冲击的稳定性均要好于抗水力冲击的稳定性。（6）首次开发的一种无回流脱氮反应器通过约90天的运行,平均出水TCOD为42.3±12.8mg/L,低于《城镇污水处理厂污染物排放标准》（GB18918-2002）中的一级A排放标准。在本试验的五种水质运行工况下,TN和NH4₊⁺-N去除性能良好,最高可达76%和89%。TN去除率受污水水质C/N决定,NH₄⁺-N去除率主要与最后一级的污水投配比有关。对于浙江省生活污水而言,以NH₄⁺-N达标的前提下尽量去除TN为原则,最后一级的配水比以不超过30%为宜。经济性分析表明,与传统的A²/O工艺相比,无回流脱氮反应器至少能节省51.1%的动力消耗,是一种有效、经济和方便的分散式生活污水处理工艺。更多还原

【Abstract】 The water quality of sewage in Zhejiang province was established by evaluating samples collected from five sites in three typical cities.Based on fluid mechanics and chemical reaction engineering principles,the best Carrier Anaerobic Baffled Reactor （CABR）was then chosen for decentralized sewage treatment.Subsequently,the removal effects on pollutants and the mechanism of anaerobe succession in the CABR were investigated using sewage from the residential district of the Huajiachi Campus of Zhejiang University as influent for four months.The performance and mechanisms of shock resistance to short-term changes in temperatures in the CABR were also evaluated while treating the sewage.Furthermore,to overcome deficient denitrification that often occurs in anaerobic biological reactors,a novel denitrifying reactor without circumfluence was developed and evaluated.The primary results of this study are summarized as follows:（1）The sewage produced in Zhejiang province is characterized by a low organic and phosphorus concentration and a high nitrogen level.This results in the sewage having good biodegradability,but poor microbial denitrification due to the low C/N ratio（approximately 6.10）.In addition,the sewage water quality in Zhejiang province was found to vary significantly by season,but not by region.The pollutant concentration was found to be highest in January and lowest in July.Finally,the four typical ratios（B/C,C/N,Alkalinity/TN and NH₄⁺-N/TKN）of the optimized synthesis wastewater were similar to those of actual domestic sewage.（2）The CABR has good structure and effect,with a dead zone of no more than 10%.In addition,the CABR shows a state of plug flow during operation.However,the hydraulic dead zone tended to increase as the number of chambers in the CABR increased in response to the increase in upflow velocity.When the effectiveness and capacity of the reactor was considered,a CABR with six chambers was found to be optimal.（3）The CABR with six chambers started up successfully after approximately three weeks with the influent of actual domestic sewage at a 48 h HRT and 28±1℃. In addition,the TCOD and SS concentrations of the effluent water met the first integrated wastewater discharge standard（NEPA,GB8978-1996）.However,this system showed poor removal of nutrients such as N and P.In addition,the CABR was not able to completely eliminate the risk of xenobiotic matter as a result of the formation of humic acid.Although this system was able to remove 99.82%and 98.87%of the fecal coliforms and ascaris eggs,respectively,it must be used in conjunction with appropriate post-disinfection processes to guarantee the safety of the effluent.（4）Evaluation of the microbe development during start-up and running stage revealed that the predominant community in the CABR varied as the process of acclimation.There was high microbe comparability in six chambers without appearance of biofacies separation.In addition,fermentative bacteria and hydrogen-producing acetogenic bacteria reproduce significantly during the initial stage of start-up,while methanogens breed obviously until the fourth month of operation. Furthermore,the concentrations of these three anaerobes differed by approximately 1/10 of an order of magnitude during the stable running stage.Finally,63%and 20% of the substrate in the wastewater was metabolized by these organisms during start-up and stable operation,respectively.（5）The CABR has good performance shock resistance.However,the shock resistance declined as the temperature decreased.Although there was little effect on performance observed at high temperatures（28℃）,low temperatures（10℃） significantly reduced the performance of the CABR.In addition,the shock resistance of the CABR was greater when water quality was considered than when water quantity was considered at 10℃-28℃.These findings are based on sensitivity ratios and standard deviations,as well as the variation in indexes used to evaluate microbial activity,the formation of intermediate products,soluble microorganism products and the volume of TCOD removal.（6）The average TCOD of the effluent of the novel denitrifying reactor with no circumfluence was 42.3±12.8mg/L after 90 days of operation.This value is lower than the discharge standard for pollutants released from municipal wastewater treatment plants（GB18918-2002）.In addition,when the five different experimental influents were evaluated,this system removed 76%and 89%of the TN and NH₄⁺-N from the wastewater,respectively.The denitrifying reactor without circumfluence also showed a good effect on denitrification with the influent of high C/N ratio.The removal efficiency of TN in this system was dependant on the C/N ratio of the influent, whereas the NH₄⁺-N removal was dependant on the last influent flow distribution ratio. For sewage in Zhejiang Province,it is reasonable to assume that the ratio of the last influent flow distribution was less than 30%.This would indicate that this system removed the highest amount of TN from the wastewater and that the NH₄⁺-N concentration met the discharge standards for municipal wastewater.These findings indicate that the power consumption of the denitrifying reactor without circumfluence was lower than that of treatment facilities of conventional A²/O processes,which would result in at least a 51.1%reduction in energy consumption.Consequently,the denitrifying reactor without circumfluence was found to be the most effective, economical and convenient system for the treatment of decentralized sewage.更多还原