化学沉淀—微滤法处理含铬电镀废水实验研究

Experimental study on the treatment of electroplating wastewater containing chromium by chemical precipitation-micro-filtration process

采用化学沉淀—微滤膜组合工艺处理含铬电镀废水,通过调pH形成Cr(OH)3沉淀,为进一步提高处理效果,用微滤膜对上清液进行处理,去除被FeSO4絮凝的铬。考察了还原剂投加量、Cr6+还原pH、微滤膜处理时曝气量等因素对处理效果的影响。结果表明:微滤膜能够有效处理化学还原沉淀后的电镀废水中的铬,出水中的铬达到《电镀污染物排放标准》(GB 21900—2008)中特殊领域和地区一级标准。

Chemical precipitation-micro-filtration membrane process has been applied to the treatment of electro- plating wastewater containing chromium. Based on pH adjustment, Cr （OH）3 precipitation is formed. To get higher treatment effectiveness, micro-filtration membranes are used for treating the supernatant and remove the chromium flocculated by FeSO,. The effects of the factors, i.e. the dosage of reducing agent, Cr^6＋recovered pH and aeration rate while micro-filtration membrane treatment is carrying on, on the treatment effectiveness are investigated. The results indicate that micro-filtration membrane can remove the chromium from the electroplating wastewater treated by chemical precipitation. The effluent water quality reaches the special area and regional first class of Emission Standard of Pollutants for Electroplating （GB 21900-2008）.