【作者】 蓝惠霞；

【导师】 陈中豪；

【作者基本信息】 华南理工大学 ， 环境工程， 2005， 博士

【摘要】 五氯酚（PCP）是具有致畸、致癌、致突变作用的难生物降解的异型生物质，作为杀菌剂、防腐剂大量使用，在皮革、纺织、造纸等废水中广泛存在，是美国环保局（EPA）以及我国环境优先控制的重点污染物之一。目前，顺序厌氧-好氧工艺已被证实是最可行的方法，但是使好氧和厌氧过程在时间和空间上分离，导致工艺流程长，占地面积大。针对目前工艺存在的缺点，本文提出采用同时好氧-厌氧的微好氧颗粒污泥工艺处理PCP废水，对微好氧颗粒污泥的培养、颗粒污泥形成机理以及对PCP的降解过程和降解机理进行深入研究。 首先对微好氧颗粒污泥的培养进行研究。分别以解体和完好的厌氧颗粒污泥作为种泥进行培养。解体的絮状污泥经过培养形成颗粒污泥后，用PCP进行驯化，形成的颗粒污泥由于结构疏松发生解体。采用厌氧颗粒污泥为种泥，边培养边不断提高PCP浓度进行驯化，污泥对废水的降解能力不断提高，最终得到性能优良的微好氧颗粒污泥。与厌氧颗粒污泥处理PCP的文献报道相比，微好氧颗粒污泥中同时存在厌氧、好氧微环境，PCP在厌氧区降解产生的低氯代酚，在好氧区能够及时降解，从而消除对厌氧区微生物的抑制，因此对PCP能够彻底矿化，不会发生低氯代酚中间产物的积累。 通过污泥培养过程照片观察以及对污泥微生物的扫描电镜观察，重点分析了上层絮状污泥颗粒化机理：在颗粒化初始和形成阶段，丝状菌形成三维框架、二价金属阳离子架桥以及胞外多聚物（ECPs）粘连的作用是非常重要的；而在颗粒污泥形成后的增长阶段，质子跨膜迁移引起的细胞脱水作用变得显著，二价阳离子架桥和ECPs的作用在这一阶段也同样很重要。下层厌氧颗粒污泥的转变为微好氧颗粒污泥的过程与上层颗粒污泥形成后的增长阶段相似。 在建立了同时好氧-厌氧的微好氧处理系统后，在动态条件下首先考察了限制性生态因子溶解氧浓度（DO）、pH、氧化还原电位（ORP）、PCP负荷和葡萄糖浓度的作用规律，实验结果表明在微氧范围，溶解氧浓度的增加有利于PCP的矿化，而超出微氧范围，对PCP及中间氯酚降解产生不利影响；pH低于6.7或高于7.5都会引起PCP和COD_Cr的降解率的下降，ORP的降低，有利于PCP及中间产物TeCP和TCP的降解，不利于DCP的矿化；PCP负荷小于1.5×10^-2kg.m^-3.d^-1范围内，对PCP以及COD_Cr的降解影响不大；葡萄糖浓度适当增加有利于PCP以及COD_Cr的降解，浓度过高则产生负面影响。接下来考察了水力学上升流速、NaHCO₃加入量和水力学停留时间对反应器工作性能的影响。在实验所确定的最佳条件范围，即DO浓度为0.6mg.L^-1左右，pH在6.7-7.5范围，水力更多还原

【Abstract】 Pentachlorophenol (PCP) is a toxic and hardly biodegradable xenobiotic and widely used as biocide and wood preserving-agent. Large quantities of PCP are also produced by some industry processes. It has been placed on the Priority List of Pollutants by the U.S. Environmental Protection Agency and our country. Sequence anaerobic-aerobic technology was approved to be the most efficient PCP removal technology , but aerobic and anaerobic processes were separated timely and spatially. In this paper, a promising technology - microaerobic granule was proposed to treat PCP containing waste water.Firstly, cultivation of microaerobic granules was studied. Disaggregated and whole anaerobic granules were taken as inoculum, respectively. Granules formed through flocculent sludge disaggregated after acclimation with PCP due to loosen structure. Culture and acclimation with PCP were simultaneously conducted when whole anaerobic granules was taken as inoculum. With time on, degradation of waste water was increasing. Good capability microaerobic granules was formed at last. Compared to anaerobic granules in literature, PCP could be mineralized completely with microaerobic granules, and no lower chlorophenols accumulated.Granulation mechanism of flocculent lied in upper layer was studied, emphasizedly. Before mature granules formation, three-frame structure formed by filamentous bacteria, bridge formed by two value metal cations and conglutination of extracellular polymers (ECPs) played important roles. After mature granules formation, effect of cellular dehydration caused by proton translocation became most important in granules growing up, but effects of two value metal cations and ECPs were also important. This period is similar with modification process of lower layer granules.After simultaneously aerobic-anaerobic system was established, effects of restrictive ecological factors such as dissolved oxygen (DO) concentration, pH, oxidation-reduction potential (ORP), PCP loading rate and concentration of glucose on the system were studied firstly under dynamic condition. Experimental results show, increasing of DO concentration in microaerobic range was in favor of PCP mineralization, but DO concentration beyond this range, disadvantage effects might occur. PCP and CODcr removal rates decreased when pH was lower than 6.7 or higher than 7.5. Decrease of ORP made for degradation of PCP, TeCP and TCP, while made更多还原