【作者】 王建辉；

【导师】 尹军；

【作者基本信息】 哈尔滨工业大学 ， 环境科学与工程， 2014， 博士

【摘要】 随着工农业的迅速发展，人们合成并应用了越来越多的有机物，其中难降解有机物占了很大比例。难降解有机废水污染物毒性大、成份复杂、化学耗氧量高，一般生物处理工艺对其几乎没有降解效果，如果这些物质不加治理即向环境排放，势必严重污染环境和威胁人类的身体健康，是目前水污染防治研究的热点与难点。五氯酚（Pentachlorophenol，PCP）废水是一种具有代表性的难降解有机废水。尽管当前国内外对含PCP废水处理方法的研究取得了一定进展，但是这些方法普遍存在能耗高、难以控制以及易造成二次污染等方面的问题。本研究针对PCP废水处理技术的研究现状，基于微生物共代谢作用优选适于处理含难降解有机废水的低能耗、低运行费用、低污泥产率的处理工艺，即采用微曝气的SBR工艺（序批式活性污泥法，Sequencing Batch Reactor, SBR）。通过试验，系统地研究了基于共代谢作用微曝气SBR工艺处理水中PCP的处理效能、污泥活性及影响因素，优化了稳定运行的最佳工况，对驯化前后微好氧颗粒污泥的宏基因组进行测定，构建了微曝气SBR共代谢处理PCP废水的基因文库，考察了驯化前后系统内微生物种群丰度、多样性变化、群落分布及系统发育，结合试验结果和动力学模型拟合结果，对PCP去除过程进行了系统分析。为PCP及其它有毒难降解有机物的生物降解提供理论基础和技术储备，为指导实际工程设计提供技术支持。采用异步接种法对微曝气SBR共代谢系统微好氧颗粒污泥培养与驯化。取自城市污水处理厂二沉池的絮状污泥经模拟废水培养30d可实现完全颗粒化，所形成的微好氧颗粒污泥结构性明显。投加共代谢基质、在进水PCP浓度为1mg/L驯化时，未投加共基质碳源的反应器细菌大量溶解死亡；投加海藻糖、葡萄糖、乙酸和酵母膏的反应器内微好氧颗粒污泥具有一定耐受能力。驯化期间逐步提高PCP浓度，经80d左右可完成PCP进水浓度50mg/L的驯化，出水效果由好到差依次为海藻糖、葡萄糖、酵母膏、乙酸。海藻糖作为共代谢基质，可以获得较高活性的生物量，同时可以刺激脱氯反应，每个PCP驯化浓度下，海藻糖可将驯化降解时间缩短近一倍，且PCP去除率、CODCr去除率及AOX去除率均可达98%以上。微曝气SBR共代谢系统长期运行结果表明，环境因素及运行控制参数都会影响系统PCP去除效果。当DO浓度控制在0.3mg/L、ORP维持在-100mV、pH值在6.7-7.5范围、PCP负荷为20×10-3kg/(m3·d)、海藻糖投加量为10mg/L、系统温度为30℃、NaHCO3投加量为800mg/L、反应时间控制为6h时，PCP及其他污染物的去除效果同时达到最佳状态，其中DO浓度须严格控制，过高的DO浓度易导致微好氧颗粒污泥解体，由此可推测DO为微好氧颗粒污泥系统运行控制的关键参数。借助高通量测序技术对驯化前后微好氧颗粒污泥的宏基因组进行测定，构建了PCP驯化前后微曝气SBR系统内细菌的16S rDNA克隆文库。结果表明驯化前后反应器细菌文库容量均能够满足预测需要。OTU聚类分析微生物菌落结构表明，驯化后反应器优势OTU主要属于变形菌门的β-变形菌纲脱氯菌属（Dechloromonas），其OTU所代表的微生物种类在数量上占有相当优势，属于降解PCP的优势菌群，且与PCP降解菌Phanerochate chrysosporium和Desulfitobaterium dehalogenus菌的序列具有最高的同源性，可能是PCP生物降解过程中的作用主体。与驯化前反应器相比，PCP驯化后的微好氧颗粒污泥中微生物多样性和菌落丰度降低，分析其原因可能与底物的改变和PCP毒性影响有关。基于莫诺方程式，建立了微曝气SBR共代谢降解PCP的动力学模型和微好氧颗粒污泥的通用动力学模型，并应用两模型对本研究中微曝气SBR微好氧反应过程进行拟合，理论拟合结果与试验结果吻合度均大于97%；微好氧颗粒污泥降解PCP的通用模型对微曝气SBR系统的进行预测表明，粒径增加有利于提高厌氧区与好氧区体积比，有助于PCP及中间降解产物的矿化降解；DO浓度增加不利于PCP、TeCP、TCP等高氯酚的矿化降解，有利于低氯酚DCP的矿化；过量的海藻糖与氯酚类物质竞争关键酶上的活性位置，将抑制PCP及其中间产物的矿化降解；PCP负荷过高对共代谢关键酶活性的抑制作用越明显，这将导致PCP降解不完全，中间产物大量积累，废水脱毒化作用不彻底。更多还原

【Abstract】 The composition of refractory organic wastewater are complex, toxicity and their chemical oxygen consumption are very high. The general microbialal most no degradation effect on this kind of wastewater, if these substances without governance discharge to the environment, it will seriously pollutes the environment and threaten human health. With the rapid development of industry and agriculture, increasing amounts of organic matter have been synthesized, there fractory organic matter accounted for a large proportion, is a important question of research on the prevention and control of water pollution. Pentachlorophenol (PCP) wastewater is one kind of representative high toxicity, stable structure, and refractory organic industrial wastewater. Despite the current domestic and international research on the methods of treatment of wastewater containing PCP has made some progress, most of these methods have high energy consumption, it is difficult to control and easily loading to secondary pollution problems. The aim of this study is to propose SBR(Sequencing Batch Reactor) overcome the current method’s drawback, which is preferably suitable for processing of refractory organic wastewater with low energy consumption, low operation cost, low sludge yield biological co-metabolism technology, micro aeration SBR cometabolism. Through the experiment, the factors which influence micro aeration SBR process co-metabolism process PCP treatment efficiency and sludge activity were studied; the optimum operating conditions for stable operation was optimized; the acclimation of micro aerobic granular sludge metagenome library was constructed; micro aeration SBR cometabolism of PCP wastewater treatment, the acclimation in microbial population abundance, diversity, community distribution and phylogeny were studied. With the help of simulation test results and the system dynamic model, the amplification was successfully applied in practical engineering. This study would provide theoretical basis and technical reserves for biodegradation of PCP and other toxic and refractory organics, and provide technical support for the practical engineering design.The asynchronous inoculation method was employed to culture and domesticate granular sludge in the micro aeration SBR cometabolism system. Having been cultured for30d, floc sludge from city sewage treatment secondary sediment tank with synthetic wastewater can reach the full particles, the formation of which has obvious structural characters. With cometabolism substrate, the influent PCP concentration was1mg/L acclimation, not adding cosubstrate carbon source reactor bacteria dissolve dead; reactor adding trehalose, glucose, acetate and yeast extract in the micro aerobic granular sludge has a certain tolerance. The concentration of PCP was gradually increased during acclimatization, the effluent effect from good to poor were trehalose, glucose, yeast extract, acetic acid, when acclimation was completed by the influent PCP concentration of50mg/L in80d. Trehalose as cometabolism substrate, which can obtain higher biomass activity, can produce the dechlorination rate higher stimulation dechlorination reaction resulting in the system. In each PCP acclimation concentration, trehalose could be acclimated degradation time which shortens nearly half time, and the removal rates of PCP, CODCr removal rate and AOX removal rate can reach98%or more.Micro aeration SBR co-metabolism system in long-term operation results showed that restrictive ecological factors, environmental factors and operation parameters would influence the removal rate of PCP. When the concentration of DO in0.3mg/L, ORP maintained at-100mV, adjusting the pH value within the range of6.7-7.5, PCP load is20×10-3kg/(M3·d), trehalose dosage is10mg/L, temperature is30℃, NaHCO3dosage is800mg/L, reaction time is6h, the removal effect of PCP and other pollutants reach the best state. Especially, the DO concentration must be controlled strictly, since the high concentration of DO can cause the micro aerobic granular sludge disintegration. It suggests that the DO is a key factor for operation and control of aerobic granular sludge system.Through the measuring of metagenomem in high-throughput sequencing technology on domestication and micro aerobic granular sludge before and after the acclimation, the PCP micro aeration bacteria in SBR system16S rDNA clone library was consructed. The results showed that bacterial library capacity after acclimation reactor can meet the requirements of prediction. The OTU clustering analysis indicated that microbial community structure, the domestication of reactor advantages of OTU mainly belong to Proteobacteria beta Proteobacteria dechlorinating bacteria (Dechloromonas), microbial species represented by OTU has many advantages in quantity, which belongs to PCP degradation dominant bacteria, and the sequence and PCP degrading bacteria Phanerochate Chrysosporium and Desulfitobaterium dehalogenus bacteria has the highest homology, may be the main role in the process of biodegradation of PCP. Compared to the domestication of reactor, microbial diversity and colony abundance decreased PCP acclimated micro aerobic granular sludge may be related with the changes and PCP toxicity effects of substrate.Based on the Monod equation, a dynamic model of the SBR micro aeration cometabolic degradation of PCP and micro good general dynamic model of aerobic granular sludge were built. The simulation and application of the models in two micro aeration SBR micro was good at the oxygen evolution reaction, the theoretical simulation results and the experimental results are in good agreement, which is above97%; the model of aerobic granular sludge degrading PCP micro aeration SBR system to predict that the increase of particle size is conducive to the improvement of the anaerobic zone and the aerobic zone volume ratio, contributes to PCP degradation and intermediate degradation products; the increase of the concentration of DO is not conducive to the degradation of PCP, TeCP, TCP hig-hchlorophenol, conducive to low-chlorophenol DCP mineralization; active position in excess of trehalose and chlorophenols competition key enzyme, will inhibit the degradation of PCP and its intermediate product; PCP load on key enzymes of co-metabolism and inhibited is more obvious, which will lead to the degradation of PCP incompletely, to accumulate a large number of intermediate products, wastewater and toxic effect degradation incompletely.更多还原