Na2S与高聚复配絮凝剂处理酸性高As废水  

Study on Treatment of Acidic High-Arsenic Wastewater with Na_2S and Polymer Composite Flocculants

作　　者：成应向[1,2] 宋伟龙[1,3,2] 许友泽[1,2] 戴友芝[3] 邱亚群[1,2] 王强强[1,2] 

机构地区：[1]湖南省环境保护科学研究院,湖南长沙410004 [2]水污染控制技术湖南省重点实验室,湖南长沙410004 [3]湘潭大学化工学院,湖南湘潭411105

出　　处：《环境科学研究》2013年第9期1007-1013,共7页Research of Environmental Sciences

基　　金：国家水体污染控制与治理科技重大专项(2010ZX07212-008);湖南省科技计划项目(2012FJ4275)

摘　　要：以酸性高As废水为处理对象,利用硫化法去除并回收As,研究了Na2S·9H2O投加量、反应初始pH、反应时间、Na2S·9H2O投加方式对As去除效果的影响,并通过XRD(X射线衍射)、XRF(X射线荧光光谱分析)对回收的As渣进行分析;对处理后的含As废水,利用高聚复配絮凝剂深度脱As,研究了絮凝剂优化条件、絮凝剂投加量、反应pH对深度脱As的影响并与常见絮凝剂进行对比.结果表明,Na2S·9H2O投加量为55 g/L、两段投加、反应时间为5 min、初始pH为2.0的条件下可达最佳除As效果,处理后As回收率达98%以上,出水ρ(As)为0.61 g/L,As渣中w(As)、w(S)分别达49.15%、40.98%,其他重金属元素几乎未检出.在絮凝剂n(Fe)∶n(Si)=5∶1、投加量为7 mL/L、pH为8的条件下可得最优深度脱As效果,出水ρ(As)低于0.3 mg/L,同等条件下优于常规絮凝剂处理效果.多批次扩大试验结果表明,组合技术处理废水水质稳定,As回收率平均可达98%以上,出水ρ(As)低于0.3 mg/L.An efficient and low-cost technology was developed for high concentration arsenic wastewater recycling by combining the advantages of sulfuration and polymer composite flocculants. In the experiment, the high-arsenic wastewater from a smelter was chosen as the treatment object. The arsenic was recycled using Na2S·9H2O for sedimentation. The Na2S·9H2O dosage, dosing manner, initial pH, reaction time were optimized before the experiments. The arsenic dregs were characterized by X-ray diffraction （XRD） and X-Ray Fluorescence （XRF）. The results showed more than 98% of arsenic was recovered under the optimal condition with Na2S·9H2O dosage of 55gL, a charging style of twice dosing, an initial pH of 2.0and a reaction time of 5minutes. The arsenic content in the treated wastewater was 0.61gL, and contents of arsenic and sulfur in arsenic dregs reached as the percentages of 49.15% and 40.98% with other heavy metallic ions. The wastewater from sulfuration process was consequently treated with a polymer composite flocculants. The parameters such as optimal proportioning, dosage, pH and flocculants were investigated first. The results showed that：under the condition of Fe∶Si=5∶1, flocculant dosage of 7mLL and pH of 8, arsenic can be deeply removed,and the remaining arsenic concentration was lower than 0.3mgL. These results demonstrated that this method is superior to the common flocculants under the same conditions. Based on above findings, expanded multi-batch experiments using combination technique （sulfuration with a polymer composite flocculants） were conducted as well. And the results showed that：the average recovery rate of arsenic was higher than 98%, and average residual arsenic content was less than 0.3mgL. The experimental results proved that the combined technique can achieve the reclamation of high-arsenic wastewater, with promising application on the engineering and commercial uses.

关 键 词：Na2S 高聚复配絮凝剂 高As废水 

分 类 号：X783[环境科学与工程—环境工程]