【作者】 余容；

【导师】 万金泉；

【作者基本信息】 华南理工大学 ， 环境工程， 2010， 硕士

【摘要】 废纸造纸废水中存在着一类难降解的苯类有机污染物,不利于造纸废水处理率的进一步提高,通过共代谢的微生物作用将难降解苯类污染物转化为无毒物质或彻底降解已成为近年来研究的热点,但是在生物法处理废水的工程应用中,丝状菌膨胀现象时有发生,对系统运行效果产生不利影响。本课题对造纸废水中典型难降解有机物邻苯二甲酸二丁酯(DBP)和二甲苯的共代谢降解以及其对微生物的影响和碳源共代谢条件下丝状菌膨胀现象进行深入研究。采用逐渐增加进水COD浓度,固定水力停留时间的方法对反应器进行启动,34天就能达到很好的启动效果。反应器运行稳定,出水水质稳定,COD总去除率平均达88%,DBP的降解率从49%逐渐上升到75%；二甲苯的降解率从55%逐渐上升到78%。葡萄糖和甲酸共同作为碳源共代谢基质时,COD的去除率平均为96.5%；DBP的去除率平均为87.6%；二甲苯的去除率平均为90.2%,处理效果均要优于仅有葡萄糖和甲酸单独作为共代谢基质。当碳源共代谢基质为葡萄糖和甲酸时,厌氧段的多糖为103mg/gMLVSS,一级兼氧段多糖为125 mg/gMLVSS;当仅有葡萄糖作为共代谢基质时,厌氧段的多糖为89mg/gMLVSS,一级兼氧段多糖为97mg/gMLVSS;且随着COD负荷的减少,多糖含量也减少；当碳源共代谢基质为葡萄糖和甲酸时,厌氧段的蛋白质为13mg/gMLVSS,一级兼氧段蛋白质为21 mg/gMLVSS;蛋白质随水流的变化没有多糖变化明显。当二甲苯的浓度低于40mg／L时,其对微生物脱氢酶活性的抑制率低于25%,为轻度抑制；而大于80mg／L时,其对脱氢酶活性的抑制由中度抑制逐渐转为轻度抑制。相对于二甲苯,DBP对微生物的抑制作用稍强。大分子有机物的水解酸化主要发生在24小时之内。在第1、2天,DBP和二甲苯对污泥耗氧速率抑制较大,但随着DBP和二甲苯的逐渐降解,其对微生物耗氧速率的影响逐渐减小。当HRT为8h时,一级兼氧段pH值下降到4.7左右,低pH值使生物膜中原有的生态体系失去平衡,生物相发生变化。能适应低pH值的丝状微生物迅速繁殖,而其它微生物因为不能适应低pH值环境数量减少,引起菌胶团解体,发生丝状菌膨胀。对造纸废水中引起丝状菌膨胀的微生物进行了鉴定,为Fungi.spp。研究表明,pH值是引起其过快增长的关键因素。DBP对Fungi.spp和菌胶团细菌的生长都有抑制作用,但其对Fungi.spp的抑制程度更大一些。在一定程度上,DBP对抑制Fungi.spp膨胀发生有一定作用。当葡萄糖和甲酸一起添加时,Fungi.spp和菌胶团细菌的比生长速率增加幅度大于单独添加葡萄糖和甲酸时Fungi.spp和菌胶团细菌的比生长速率。当单独添加葡萄糖时,菌胶团细菌比生长速率的增加大于单独添加甲酸时；但单独添加甲酸时,Fungi.spp比生长速率的增加大于单独添加葡萄糖时。更多还原

【Abstract】 A class of refractory organic pollutants exists in regenerated papermaking wastewater, which is not conducive to improve wastewater treatment rate.How to translate benzene into non-toxic pollutants or make it completely degrade by microbial co-metabolism has become a research hotspot in recent years, but filamentous bulking phenomena occurs in engineering applications, which has a negative impact on effluent quality. In this research co-metabolism degradation of refractory organic pollutants, the impact refractory organic pollutants on microorganism and filamentous bulking phenomena were studied so that they can provide a theoretical basis for engineering practice.By increasing the influent COD and fixing hydraulic retention time to start the reactor, it can bring good start effect after 34 days.Effluent quality was stabile;COD average removal rate was 88%; dibutyl phthalate degradation rate gradually increased from 49% to 75%; xylene degradation rate gradually increased from 55% to 78%.COD removal rate was 96.5%;DBP removal rate was 87.6%;xylene removal rate was 90.2% with glucose and formic acid as a carbon source.The removal rate was better than glucose and formic acid as a carbon source alone.With glucose and formic acid as a carbon source,there was 103mg/gMLVSS polysaccharide at anaerobic phase and 89mg/gMLVSS polysaccharide at first anoxic phase.With glucose and formic acid as a carbon source alone, there was 89mg/gMLVSS polysaccharide at anaerobic phase and 97mg/gMLVSS polysaccharide at first anoxic phase.Polysaccharide decreased as COD reduced.With glucose and formic acid as a carbon source, there was 13mg/gMLVSS protein at anaerobic phase and 21mg/gMLVSS protein at first anoxic phase.The change of protein was smaller than that of polysaccharide as current.When the xylene concentration was lower than 40mg/L,its inhibition rate of microbial dehydrogenated activity was less than 25%,a mild degree;while it was more than 80mg/L, its inhibition of dehydrogenated activity translated a moderate degree into a mild degree.And comparing to xylene, dibutyl phthalate had more serious inhibition on the microorganisms. Macromolecular organic acidification mainly occurred in 24 hours.In the first two days,the inhibition rate of oxygen consumption was higher, but as dibutyl phthalate and xylene degradation,its inhibition rate of oxygen consumption gradually decreased.While HRT was 8h, pH decreased to 4.7 in first anoxic phase and filamentous bulking occurred.Biofilm ecosystem was out of balance at low pH value and biological phase changed. Some filamentous micro-organisms which adapted to low pH value grew rapidly, while other microbes which did not adapt to a low pH value grew slowly. Zoogloea disintegrated and filamentous bulking occurred. The predominant bulking causing filamentous microorganism in the paper mill effluent treatment system was identified.Fungi spp.was found to be the predominant filamentous microorganisms.The kinetics study revealed that the pH was a critical factor affecting the excessive growth of Fungi spp.The limiting percentage of filamentous is higher than that of floc-forming bacteria. The increase rates of floc-forming bacteria and filamentous were highest when glucose and formic acid were provided together. The increase rate of floc-forming bacteria while glucose was provided was higher than that while formic acid was provided, but the increase rate of filamentous while formic acid was provided was higher than that while glucose was provided.更多还原