化学沉淀法处理电镀废液中重金属的实验研究

Experimental Study on the Treatment of Heavy Metal in Electroplating Wastewater by Chemical Precipitation Method

汽车工业的快速发展产生了大量的重金属含量较高的电镀废液,采用氟化钠和氢氧化钙为沉淀剂,去除汽车电镀废液中的重金属。考察了氟化钠投加量、氢氧化钙投加量,p H、反应温度及反应时间对重金属去除效果的影响。研究表明,溶液p H为8.0、温度为20℃时,向50m L废磷化液中投加0.42g的氟化钠和1.85g氢氧化钙反应1h后,锌、锰、镍三种重金属的去除率分别达到99.8%、99.5%、99.7%。处理后的废水满足《污水综合排放标准》(GB8978-2012)的二级标准要求。

The rapid development of automobile industry produced large amounts of high heavy metal wastewater. Use sodium fluoride and calcium hydroxide as precipitant to removal the heavy metal of the electroplating wastewater. Effects of sodium fluoride dosage,calcium hydroxide dosage,the p H,reaction temperature and reaction time were investigated by removal effect of heavy metal. The study showed that the appropriate condition was p H 8. 0,the temperature 20℃,to 50 m L waste electroplating wastewater dosing 0. 42 g sodium fluoride and 1. 85 g calcium hydroxide reaction 1h,Zinc,manganese and nickel removal rates were 99. 8%,99. 5% and 99. 7%. The treated wastewater meet the ＂ integrated wastewater discharge standard＂（ GB8978-2012） secondary standard requirements.