高分子絮凝剂DTMPAM复配FeCl3协同去除水中Cr(Ⅵ)和Cr(Ⅲ)的性能及机理  

Performance and mechanism of macromolecule flocculant DTMPAM compounded with FeCl3 for the synergetic removal of Cr(Ⅵ)and Cr(Ⅲ)from aqueous solution

作　　者：周雅琦 王刚[1] 杨晓敏 马玉 张航 ZHOU Yaqi;WANG Gang;YANG Xiaomin;MA Yu;ZHANG Hang(School of Environmental and Municipal Engineering,Lanzhou Jiaotong University,Lanzhou 730070)

机构地区：[1]兰州交通大学环境与市政工程学院,兰州730070

出　　处：《环境科学学报》2023年第5期271-280,共10页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.51368030)。

摘　　要：为了有效提高水中Cr(Ⅵ)和Cr(Ⅲ)去除效果,将高分子絮凝剂二硫代羧基化羟甲基聚丙烯酰胺(DTMPAM)和三氯化铁(FeCl3)进行复配应用到含铬废水的处理中,通过絮凝实验法分别考查了DTMPAM复配FeCl3前后对含Cr(Ⅵ)水样和含Cr(Ⅲ)水样的去除性能.结果表明,DTMPAM在pH值分别为3.0、4.0、5.0时,单独投加DTMPAM对含Cr(Ⅲ)水样中Cr(Ⅲ)的去除效果均不太理想,Cr(Ⅲ)的最高去除率分别为23.80%、41.11%、42.38%;FeCl3的投药顺序和浓度对DTMPAM复配FeCl3去除水样中Cr(Ⅲ)具有较大影响,按照先投加FeCl3后调节pH值再投加DTMPAM进行絮凝的投药顺序,且FeCl3浓度为60 mg·L^(-1)时,含Cr(Ⅲ)水样中Cr(Ⅲ)的最高去除率可达到99.55%.单独投加DTMPAM对含Cr(Ⅵ)水样中Cr(Ⅵ)具有良好的去除效果,而对总Cr的去除效果较差,当pH值为3.0、DTMPAM投加量为330 mg·L^(-1)时,Cr(Ⅵ)的最高去除率可以达到96.21%,总Cr的最高去除率为63.27%;而DTMPAM复配FeCl3后,当DTMPAM投加量为420 mg·L^(-1)、FeCl3的浓度为60 mg·L^(-1)时,Cr(Ⅵ)的最高去除率为98.64%,总Cr的最高去除率达可到90.60%.DTMPAM复配FeCl3去除水中Cr(Ⅵ)、Cr(Ⅲ)的主要机理有氧化还原作用、螯合沉淀作用和絮凝沉降作用等,FeCl3起到了重要的协同作用使Cr(Ⅲ)、总Cr的去除效果显著提升.To improve effectively the removal efficiency of Cr(Ⅵ)and Cr(Ⅲ)in aqueous solution,the macromolecule flocculants dithiocarboxyl hydroxymethy-polyacrylamide(DTMPAM)and ferric chloride(FeCl3)were compounded in the treatment of chromium-containing wastewater.The performance of DTMPAM before and after the compound of FeCl3 was investigated for the removal of Cr(Ⅵ)and Cr(Ⅲ)in water samples by employing flocculation experiment.The results show that the removal of Cr(Ⅲ)in water samples containing Cr(Ⅲ)by only using DTMPAM was poor at pH 3.0,4.0 and 5.0,and the maximum removal rate of Cr(Ⅲ)was 23.80%,41.11%and 42.38%,respectively.The adding order and concentration of FeCl3 had a great influence on the removal of Cr(Ⅲ)by compounding DTMPAM with FeCl3.The highest removal rate of Cr(Ⅲ)in the water sample containing Cr(Ⅲ)could reach 99.55%when the concentration of FeCl3 was 60 mg·L^(-1),and the adding order of FeCl3 was followed by pH adjustment before flocculation.For water samples containing Cr(Ⅵ),the highest removal rate of Cr(Ⅵ)and total Cr was 96.21%and 63.27%respectively at pH 3.0 and 330 mg·L^(-1) of DTMPAM dosage when DTMPAM was only added;while the maximum removal rate of Cr(Ⅵ)and total Cr could reach 98.64%and 90.60%respectively at 420 mg·L^(-1) of DTMPAM and 60 mg·L^(-1) of FeCl3 dosage when DTMPAM and FeCl3 were compounded.The main mechanism of compounding DTMPAM with FeCl3 for the removal of Cr(Ⅵ)and Cr(Ⅲ)includes oxidation and reduction,chelation precipitation,and flocculation settlement,and FeCl3 plays an important role in improving significantly the removal efficiency of Cr(Ⅲ)and total Cr by synergetic action.

关 键 词：重金属 三氯化铁 含铬废水 螯合沉淀 氧化还原 

分 类 号：X703[环境科学与工程—环境工程]