含砷、铬废水处理条件对沉渣稳定性的影响

发布时间：2018-06-07 19:18

  本文选题：环境工程学 + 处理条件　； 参考：《安全与环境学报》2016年06期

【摘要】：通过TCLP毒性程序浸出试验,以砷、铬浸出质量浓度为控制指标,对含砷、铬废水处理产生的沉渣稳定性进行了研究,并结合废水中砷、铬去除率,确定该废水的最佳处理条件。在常温下,通过调节pH值、Fe~(2+)/Cr~(6+)物质的量比、Ca/As物质的量比、曝气时间等条件对处理工艺进行优化,考察不同处理条件对废水砷、铬去除率及沉渣砷、铬浸出质量浓度的影响。结果表明,pH值为6、Fe~(2+)/Cr~(6+)物质的量比为8、Ca/As物质的量比为5、曝气时间为50 min时,不仅Cr(Ⅵ)、总铬、总砷的排放质量浓度达到了GB 8978—1996《污水综合排放标准》的要求,总砷、总铬的浸出质量浓度也分别降低到0.78 mg/L、0.59 mg/L,远低于GB/T 5085.3—2007《危险废物鉴别标准:浸出毒性鉴别》规定的质量浓度,达到了安全堆放要求。对曝气产生的絮体进行XRD测试,结果表明,余留的Fe~(2+)经曝气氧化后产生的絮体是一种无定型态的氢氧化铁或水合氧化铁,其富含阳离子空位和OH-基团,能增加砷、铬的去除率。对优化前后的沉渣进行SEM扫描,结果表明,对各因素进行优化能增大沉渣的粒径,提高沉渣的稳定性。
[Abstract]:The stability of the sediment produced by the treatment of arsenic and chromium wastewater was studied by using the TCLP toxic procedure leaching test and the mass concentration of arsenic and chromium leached as the control index. The optimum treatment conditions of the wastewater were determined by combining with the removal rate of arsenic and chromium in the wastewater. At room temperature, the treatment process was optimized by adjusting the quantity ratio of the pH value of Fe ~ (2 +) / Cr ~ (1 +) ~ (6) and the mass ratio of Ca / as, aeration time, and so on. The effects of different treatment conditions on the removal rate of arsenic and chromium and the concentration of arsenic and chromium in the sediment were investigated. The results show that the mass concentration of Cr (鈪，

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