1、 摘摘 要:要:电镀是世界三大污染行业之一,随着我国乡镇电镀企业的迅速发展,我国的电 镀污染问题日趋严重。本文首先阐述了我国电镀废水的污染现状以及对人类产生的危 害,在对化学处理、离子交换、电解法、生物处理等电镀废水处理方法的分析和比较后, 结合乡镇电镀企业要求工艺简单、成本低等特点,决定采用 NaHSO4化学还原沉淀法处理 该企业的含铬、锌废水。本工艺是在 pH=2.5 时用 NaHSO4溶液将 Cr 6+还原为 Cr3+,在用 NaOH 溶液调节 pH=8 后生成 Cr(OH)3和 Zn(OH)2沉淀,在添加絮凝剂 PAC 和 PAM 后生成的 絮体在斜板沉淀池中沉淀,出水经砂滤器过滤后可
2、回用于砂滤器反冲洗水及各种溶液的 配制,或者达标排放,而污泥则统一交于专业的环保公司处理。在设计中采用了较为先 进的 ORP 测定仪、在线 pH 计和液位计实现反应过程的自动控制。通过设计计算确定了 各构筑物的尺寸以及设备的选型,并对设计和操作管理中的要求进行了说明,最后对电 镀废水治理的前景进行了展望。 关键字:关键字:电镀废水;Cr;Zn;化学还原沉淀法 AbstractAbstract:With the speedy development of the electroplating enterprise in towns in our country, electroplating i
3、ndustry,as one of the biggest pollutions in the world ,causes the pollution more and more severely . In this paper, describes the present situation of the electroplating effluent water pollution and the great harm it makes to the human kind has been described. After the analyses and the comparison o
4、f different ways for treatment of electroplating effluent such as chemical treatment process、ion exchange process、electrolytic method and biological process, I decide to adopt the NaHSO4 reduction-precipitation to treat the waste water containing Cr and Zn for the corporations , considering the features of the town electroplating corporations demands of simple techniques, low costs, etc. This technology is to deoxidize Cr 6+ into Cr3+ by NaHSO 4 solution at the PH=2.5, then adjust the PH to