摘要
采用NaOH和Na2CO3饱和溶液调节电镀含铬废水pH,分离废水中Cr(VI)与Cr(III)及杂质,在氧化分离后的含铬滤渣和含铬污泥回收其中的铬。含铬废渣氧化回收铬的最佳工艺条件为反应时间90min,温度70℃,pH8.5～9.0,含铬废渣中铬的回收率达到95%;预处理和废渣氧化回收两部分的含Cr(VI)溶液合并,加入Pb(NO3)2溶液作为沉淀剂生成中铬黄颜料,铬的回收率在99.9%以上,产品符合国标GB/T3184-93的质量标准;处理后的排放水中Cr(VI)的浓度小于0.3mg/L,总Cr含量小于0.8mg/L,达到《污水综合排放标准》(GB8978-1996)的要求;处理后的废渣中的铬低于0.5%(干样),主要为难氧化难浸出的Cr(Ⅲ)铬盐,可以安全填埋。处理工艺达到了对含铬废水和含铬污泥无害化处理和资源化利用的目的,环境效益和经济效益显著。
The removal of Cr（Ⅲ） and impurity from highly concentrated chromium electroplating wastewater was investigated, the pH was 8.5-9.0 which adjusted with NaOH and Na2CO3. The recovery of chromium in residue and sludge was investigated too, the optimum conditions were as follow; temperature was 70℃, pH was 8,5-9.0, contact time was 90 min. The effluents contained Cr（Ⅳ） was used to product lead chromate that Pb（NO3）2 was precipitator. The recovery rate of Cr（Ⅳ） was 99.9 % in precipitation process. Lead chromate content was more than 91.0 %. The recovery rate of Cr in sludge was 95.0 %. Total Cr and Cr（Ⅳ） was less than 0.8 mg/L and 0.3 mg/L respectively in letting wastewater.
出处
《广东化工》
CAS
2009年第7期179-181,188,共4页
Guangdong Chemical Industry
关键词
含铬废水
含铬污泥
中铬黄
回收
chromiumwastewater
chromium sludge
lead chromate
recovery
