生物法处理酸性矿山排水和垃圾渗滤液混合液

发布时间：2018-09-13 21:34

【摘要】：酸性矿山排水和垃圾渗滤液均是对环境污染严重,对人类危害大的两种废水。垃圾渗滤液的突出特点是有机污染物种类多且浓度高、生物降解性差、溶解盐高、氨氮浓度高。矿山酸性排水水量较大、pH值较低(一般为2-3),含高浓度的硫酸盐和可溶性的重金属离子。本文提出将垃圾渗滤液和酸性矿山排水混合调节后进行生物处理,混合后的调节废水中既含有高浓度的硫酸盐、又含有大量的有机质和重金属离子,且垃圾渗滤液本身具有良好的pH缓冲能力。这些为硫酸盐还原菌等厌氧微生物的生长和繁殖提供了适宜的条件。在厌氧条件下,有机质被包括硫酸盐还原菌在内的厌氧微生物分解代谢,并同时产生了一定的碱度,硫酸盐被还原成硫离子,而二价硫离子可以和重金属离子反应形成重金属硫化物,可以同步实现硫和重金属离子的去除。厌氧处理后的出水继而进一步通过缺氧和好氧的生物处理技术脱氮和进一步降低有机物的浓度。在上述废水的生物处理过程中还可以获得甲烷并回收重金属,较好地实现以废治废和废水的资源化转化。本文首先考察了酸性矿山排水和垃圾渗滤液在m(COD)/m(SO42-)为0.5.1和3等不同配比下,厌氧生物处理该混合废水的效果,并确定较优的配比值；其次,以酸性矿山排水和垃圾渗滤液混合后形成调节废水为进水,不额外接种厌氧污泥,先后启动和稳定运行了厌氧反应器；再次,先后通过人工合成废水和厌氧反应器的出水作为进水,启动和稳定运行了好氧和缺氧反应器；最后,初步实现厌氧和好氧-缺氧生物反应器的连续运行处理混合废水,以实现同步处理两种废水中的有机物、硫酸盐和氨氮的脱除。实验结果表明：1、在35℃厌氧条件下,相较于1m(COD)/m(SO42-)值为0.5和1,m(COD)/m(SO42-)值为3的混合液COD和硫酸盐去除效果最好,去除率分别达到66.04%和60.31%。2、按m(COD)/m(SO42-)值为3混合酸性矿山排水和垃圾渗滤液,得到混合废水的COD、硫酸盐和氨氮浓度分别为7500 mg/L.2500 mg/L和2000 mg/L。控制厌氧反应器的水力停留时间为20 d,调节废水中78%的COD和约80%的硫酸根被去除。3、厌氧反应器的出水直接进入30℃下水力停留时间为10d的好氧反应器,出水中氨氮和COD去除率分别在99%和85%以上。4、好氧反应器的出水直接进入30℃下水力停留时间为4d的缺氧反应器,出水中硝态氮和COD去除率分别在98%和96%以上。混合废水中总的COD、硫酸盐和氨氮的去除率分别为98%、80%和99%。
[Abstract]:Acid mine drainage and landfill leachate are two kinds of wastewater which pollute the environment seriously and do great harm to human beings. The landfill leachate is characterized by many kinds of organic pollutants and high concentration of organic pollutants, poor biodegradability, high dissolved salt and high concentration of ammonia nitrogen. The pH value of mine acid drainage is relatively low (generally 2-3), which contains high concentration of sulfate and soluble heavy metal ions. In this paper, after mixed regulation of landfill leachate and acid mine drainage, biological treatment is carried out. The mixed wastewater contains not only high concentration of sulfate, but also a large amount of organic matter and heavy metal ions. And the landfill leachate itself has a good pH buffer capacity. These provide suitable conditions for the growth and reproduction of anaerobic microorganisms such as sulfate reducing bacteria. Under anaerobic conditions, organic matter was catabolized by anaerobic microorganisms, including sulfate reducing bacteria, and a certain alkalinity was produced at the same time, and sulfate was reduced to sulfur ions. Divalent sulfur ions can react with heavy metal ions to form heavy metal sulfides, which can simultaneously realize the removal of sulfur and heavy metal ions. After anaerobic treatment, the effluent was further denitrified by anoxic and aerobic biological treatment and the concentration of organic matter was further reduced. Methane can also be obtained and heavy metals recovered in the process of biological treatment of the wastewater mentioned above. In this paper, the effects of anaerobic biological treatment of the mixed wastewater with different ratios of m (COD) / m (SO42-) 0.5.1 and 3 were investigated firstly, and the optimum ratio was determined. After mixing acid mine drainage and landfill leachate as the influent and without additional inoculation of anaerobic sludge, the anaerobic reactor was started and stably operated successively. Aerobic and anoxic reactors were started and stably operated successively through artificial synthetic wastewater and effluent of anaerobic reactor as influent. Finally, the continuous operation of anaerobic and aerobic anoxic bioreactor was preliminarily realized to treat mixed wastewater. In order to realize the simultaneous treatment of organic matter, sulfate and ammonia nitrogen in the two kinds of wastewater. The experimental results show that under the anaerobic condition of 35 鈩，

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