【作者】 王琦；

【导师】 杨云龙；

【作者基本信息】 太原理工大学 ， 环境工程， 2010， 硕士

【摘要】 焦化废水是一种有机物浓度和氨氮浓度都较高的难生化降解的有机废水。由于含有大量的难生物降解及有毒物质,因而成为公认难处理工业废水之一。于传统的处理方法活性污泥法对比,对难生物降解的有机物和氨氮处理效果较差。本课题是根据焦化废水的水质特点,以太原煤气公司第二焦化厂的焦化废水为研究对象,采用A2/O2工艺,并在O1段投加固定化优势菌进行试验研究。研究结果表明: A2/O2工艺投加固定化优势菌在进水氨氮为203.53~674.93mg/L,COD为817.4~1874.2mg/L,pH值为7.0~8.2的水质条件下,以3.27倍的平均回流比的情况下,系统总的氨氮处理效率平均为98.21%,总的COD处理效率平均为93.65%。通对各种固定化方法的比较分析,决定采用的固定化方法为聚乙烯醇(PVA)-硼酸包埋固定法。这种固定化方法的优点是,PVA价格低廉,且该固定化方法易于操作处理;引入海藻酸钠的效果好,它对微生物起到了保护的作用,降低了硼酸对微生物的毒性,并能提高微生物的相对活性;易于固液分离,有利于开展下一步应用于工业化生产的试验研究。该工艺总体效果控制的关键工艺段为好氧反应器O1段,因为在此投加固定化优势菌,主要控制系统最终出水氨氮。实验结果表明:该段在其进水温度为25.1~27.8℃,pH值为5.9~7.3,碱度为366.67~598.12 mg/L(以CaCO3计)的条件下,处理氨氮为39.38~165.36mg/L(平均91.40mg/L) ,以16.76~21.55h(平均为18.21h)的HRT,处理后出水氨氮为4.47~19.83mg/L(平均11.31mg/L),氨氮平均去除率为87.04%。投加固定化优势菌前该段的氨氮平均去除率为82.94%。可见,固定化优势菌的投加,使得该段氨氮去除率增长了4.1个百分点。经过试验研究得出该整套工艺的最佳运行参数(该参数由最佳运行阶段时的各项数值平均得出)。由于本试验中将固定化优势菌投加在好氧反应器O1段中,所以其它各段的反应运行参数没有变化,只将O1段的反应运行参数进行了统计。结果为:当该段反应器温度为26.5℃,pH为6.8,HRT为18h时的氨氮去除效率达到最高。采用投加固定化优势菌的A2/O2工艺处理焦化废水,在进水氨氮浓度不断升高(在一定范围内)的情况下,能够使出水浓度达到《污水综合排放标准》(GB8978-1996)中的一级排放标准(氨氮<15mg/L)。工艺合理,技术可行,效果稳定。更多还原

【Abstract】 Coke plant wastewater is a typical, containing high concentration ammoniacal nitrogen, and difficult biodegradational industry wastewater.?Because it contains lots of hard—biodegraded and toxicant substances,it is considered to be one of the most difficult industrial waste water to purify.The traditional method to deal with the coke plant wastewater is a means using by the active dreggy mud, which has less effect on the hard-degraded substance and ammoniacal nitrogen. According to characteristic of the coke plant wastewater, the paper studied the nitrogen removal mechanism and effect in detail by A2/O2 process, during which also added the immobilized preponderant bacilli at the process of O1 and made the study to treat the coke wastewater of the second coke plant which belongs to one of coal gas company in Taiyuan.Experimental results demonstrate: the effluent NH3-N and COD removal rate concentration could achieve 98.21% and 93.65%. While t NH3-N concentration was 203.53~674.93mg/L , COD concentration was 817.4~1874.2mg/L , pH value was 7.0~8.2 , and the average rate of circumfluence was 3.27.By comparation between a variety of methods of immobilized, the decision of this examination used for immobilization of polyvinyl alcohol (PVA) - borate-embedded. The advantage of this method is, PVA have low prices, and the method is easy to operate; the effect of introduction of dium alginate is good, and its protection microorganisms play a role in the and reduce the toxicity of boric acid, and this can improve the relative activity of microorganisms; it is easy to do solid-liquid separation, and be propitious to the next step that help to carry out the tests applied to industrial production of research.The key stage of the process controlling was aerobic reactor (O1), in which put the immobilized predominance bacterium could control the last effluent Ammoniacal—nitrogen. The experimental result showed: the temperature of the effluent wastewater was 25.1~27.8℃, the pH value was 5.9~7.3, alkalinity was 366.67~598.12 mg/L(measured by CaCO3), the NH3-N was 39.38~165.36mg/L(the average was 91.40mg/L), the HRT was 16.76~21.55h(the average was 18.21h),the average removal ratio of NH3-N was 87.04%. Before adding the immobilized predominance bacterium, the average removal ratio of NH3-N was 82.94%. So, adding the immobilized predominance bacterium made the average removal ratio of NH3-N increase 4.1 percent.After the experimentation the whole operating parameters had been got (This parameters was got by the best value when the average reached). Due to the result of this experimentation was adding immobilized predominance bacterium in the aerobic reactor O1 only, others had no changed, only got the statistical parameters of O1. Results as follows: When the reactor temperature is above 26.5℃, pH is 6.8, HRT is 18h, at the time of the highest NH3-N removal efficiency.It will make the chroma of effluent NH3-N reach the primary national standard (NH3-N <15mg/L) about“The standard of sewage comprehensive discharge”(GB8978-1996) to adopt the anaerobic-anoxic-aerobic-aerobic biological reactor(A2/O2), in which put immobilized predominance bacterium to deal with coke plant wastewater when the chroma of effluent of NH3-N increases constantly. This technology is technique feasible and has stable effect.更多还原