微生物法处理湿法炼锌行业污酸废水工艺的研究

发布时间：2018-04-16 04:35

本文选题：酸性重金属废水 + 硫酸盐还原菌　；参考：《北京有色金属研究总院》2017年硕士论文

【摘要】：有色金属冶炼行业一直以来都是重金属污染的主要来源之一。在当前环保要求日益提高的大背景下,如何卓有成效地处理有色金属冶炼行业重金属废水成为摆在企业面前一个亟待解决的问题。本课题研究的是微生物法处理湿法炼锌行业的污酸废水。湿法炼锌行业污酸废水具有以下三个特点:第一是水中的SO42-浓度较高,第二是水水体中溶有大量重金属离子,第三是水的pH值很低。目前国内的锌冶炼厂对于这种废水所采用的比较常用的处理方法是石灰三段中和法。这种方法尽管可以达到去除水中重金属的目的,但是处理过程中会产生大量的中和渣。在当前的环保政策下,这种危险废渣无疑将增加企业的税收成本。本研究采用微生物法处理一段中和出水,不仅能大大减少中和渣的产量,而且也可以达到去除重金属的目的。根据小试规模设计加工了上流式厌氧污泥床反应器(UASB),在实验室完成搭建。按照实际废水中和到pH值为5.5的水质配制了模拟废水,接种了硫酸盐还原菌(SRB),完成了 UASB反应器的启动,出水Zn2+的去除率达到92%～96%。比较了碳源浓度为500 mg/L、1000 mg/L、1500 mg/L的条件下UASB对实际废水的处理效果,并用分子生物学的方法对各碳源浓度下UASB反应器内的微生物群落结构进行了研究。结果表明比较3种不同的碳源浓度对SRB丰度的影响,碳源浓度为1000 mg/L时SRB的丰度最大;而在1000 mg/L的水样中的微生物是一种杂菌体系,SRB占其中的13.86%;通过物种分类学鉴定,确定了实际起硫酸盐还原作用的微生物为脱硫弧菌属Desulfovibrio;通过生物信息学构建了系统发生进化树,得到了 Desulfovibrio的系统分类学地位。在小试研究的基础上,到我国某锌冶炼厂的污水处理车间进行了中试扩大试验。按照1 m3/d污酸一段中和出水的处理量完成了中试系统的设计、加工与搭建,在现场完成了 SRB反应塔的静态启动、小流量连续启动、A/O生物反应池的启动,分梯度进污酸废水启动了整个中试系统。中试系统运行稳定后,出水中的各重金属离子浓度均可以达到铅锌工业污染排放标准,其中Zn2+浓度低于1.5 mg/L,Cd2+浓度低于0.05 mg/L,Pb2+浓度低于 0.5 mg/L。
[Abstract]:Non-ferrous metal smelting industry has been one of the main sources of heavy metal pollution.Under the background of increasing environmental protection requirements, how to deal effectively with heavy metal wastewater in non-ferrous metal smelting industry has become a problem to be solved urgently in front of enterprises.In this paper, microbial treatment of wastewater from zinc hydrometallurgy industry is studied.The wastewater from zinc hydrometallurgy industry has the following three characteristics: the first is the high concentration of so _ 42- in water, the second is that there are a large number of heavy metal ions dissolved in water, and the third is that the pH value of water is very low.At present, three stage neutralization of lime is commonly used in domestic zinc smelters to treat this kind of wastewater.Although this method can remove heavy metals in water, a large amount of neutralized slag will be produced in the treatment process.Under the current environmental policy, this hazardous waste will undoubtedly increase the tax cost of enterprises.In this study, the production of neutralized residue and the removal of heavy metals could be greatly reduced by microbiological treatment of one-stage neutralization effluent.UASBN reactor was designed and manufactured according to the scale of the experiment, and the UASBX reactor was built in the laboratory.According to the actual wastewater and the water quality with pH 5.5, the simulated wastewater was prepared, and the sulfate-reducing bacteria was inoculated. The start-up of the UASB reactor was completed, and the removal rate of Zn2 in the effluent reached 92 ~ 96%.The effects of UASB on the treatment of actual wastewater under the condition of 500mg / L ~ 1000mg / L ~ (-1) mg/L carbon source concentration were compared. The microbial community structure in UASB reactor was studied by molecular biological method.The results showed that the effects of three different carbon source concentrations on the abundance of SRB were compared. The maximum abundance of SRB was observed when the concentration of carbon source was 1000 mg/L, while the microorganism in the water sample of 1000 mg/L accounted for 13.86% of the total abundance of SRB.It was confirmed that the actual microorganisms of sulfate reduction were Desulfovibrio, and phylogenetic phylogenetic tree was constructed by bioinformatics, and the phylogenetic status of Desulfovibrio was obtained.On the basis of the experimental study, a pilot scale test was carried out in a sewage treatment plant of a zinc smelter in China.The design, processing and construction of the pilot system were completed according to the treatment capacity of the neutralization and effluent of 1 m3 / d sewage acid. The static start-up of the SRB reactor was completed at the site, and the start-up of the A / O biological reactor was continuously started with small flow rate.The whole pilot-scale system was started.After stable operation of the pilot system, the concentration of heavy metal ions in the effluent can reach the emission standard of lead-zinc industrial pollution. The concentration of Zn2 is less than 1.5 mg / L ~ (-1) CD _ (2) < 0.05 mg / L ~ (-1) Pb _ (2) < 0.5 mg / L ~ (-1) 路L ~ (-1) 路L ~ (-1) 路L ~ (-1).
【学位授予单位】：北京有色金属研究总院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X758

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