电镀废水中氨氮及COD的去除

Elimination of NH3-N and COD in Electroplating Wastewater

电镀废水水质复杂,含有多种污染物,其中Ni+、Cu2+等重金属已得到良好的回收利用,但对有机污染物和氨氮的去除研究鲜见报道。本文采用铁碳微电解法对电镀废水进行预处理,可确保出水中残留重金属不影响后续生物反应,预氧化表面活性剂、光亮剂及其它助剂,提高了废水的可生化性;进而通过水解酸化和好氧膜生物反应器(MBR)的生物处理降低废水的COD和氨氮,由于电镀废水中硝酸盐含量较高,会抑制好氧池内氨氮的硝化作用,MBR出水回流至水解池,并在水解池进水中添加适当的碳源,可确保出水氨氮低于15 mg/L。铁碳微电解+水解酸化+MBR工艺可有效的降低电镀废水中的氨氮和COD。

Electroplating wastewater contain heavy metals, acid, organic waste and many other contaminations. Heavy metal recycling is well developed due to the profitability of metal recycle industries such as Ni^＋ and Cu^2＋. While the study of organic pollutants in electroplating wastewater is still in the starting stage. The removal of NH3-N and COD in electroplating wastewater by hydrolytic acidification ＋ aerobic membraine bio reactor （MBR） was investigated using iron-carbon micro-electrolysis as the pretreatment to insure the lowest heavy metal concentration and increase biodegradability of wastewater. The effluent NH3-N concentration is less than 15 mg/L after the treatment of hydrolytic acidification ＋ MBR recycling process. Carbon resource is added according to the NH3-N concention. The iron-carbon micor-electroplating and hydrolytic acidification ＋ MBR process remove NH3-N and COD in electro- plating wastewater effectively.