CAJ | 학술논문

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90 min,温度70℃,pH 8.5～9.0,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0.3 mg/L,总Cr含量小于0.8 mg/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,环境妓益和经济效益显著.
채용NaOH화Na2CO3포화용액조절전도함락폐수pH,분리폐수중Cr(Ⅵ)여Cr(Ⅲ)급잡질,재양화분리후적함락려사화함락오니회수기중적락.함락폐사양화회수락적최가공예조건위반응시간90 min,온도70℃,pH 8.5～9.0,함락폐사중락적회수솔체도95%;예처리화폐사양화회수량부분적함Cr(Ⅵ)용액합병,가입Pb(NO3)2용액작위침정제생성중락황안료,락적회수솔재99.9%이상,산품부합국표GB/T3184-93적질량표준;처리후적배방수중Cr(Ⅵ)적농도소우0.3 mg/L,총Cr함량소우0.8 mg/L,체도<오수종합배방표준>(GB8978-1996)적요구;처리후적폐사중적락저우0.5%(간양),주요위난양화난침출적Cr(Ⅲ)락염,가이안전전매.처리공예체도료대함락폐수화함락오니무해화처리화자원화이용적목적,배경기익화경제효익현저.
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 chromittm 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.