摘要
以二硫代羧基化壳聚糖(DTCTS)为高分子重金属絮凝剂,研究DTCTS在不同的影响因素(水力条件、体系pH值、Cr(Ⅵ)初始浓度、共存浊度、共存有机配位剂等)下对Cr(Ⅵ)的去除效果。结果表明:当水力条件为快搅速度140 r/min、快搅速度1.5 min、慢搅速度40 r/min、慢搅时间10 min时,DTCTS对Cr(Ⅵ)的去除效果最好,Cr(Ⅵ)去除率最高可达到97.8%。体系pH值对Cr(Ⅵ)的去除有一定影响,pH值为2.5时,Cr(Ⅵ)和总铬去除率均在96%以上。当水样中存在有机配位剂(三氯乙酸、氨基乙酸、乙酸钠)及浊度时,对DTCTS除Cr(Ⅵ)均有一定的抑制作用,但随着DTCTS投加量增大,抑制作用减弱或消除。红外分析表明Cr(Ⅵ)被DTCTS还原为Cr(Ⅲ),还原产物与DTCTS分子链中的二硫代羧基会发生螯合反应生成沉淀,且DTCTS分子链中的羟基和胺基也参与反应。
Dithiocarboxyl chitosan(DTCTS)was used as macromolecule heavy metal flocculant,and the removal efficiency of Cr(Ⅵ)by DTCTS at different influencing factors,such as hydraulic conditions,initial pH,initial concentration of Cr(Ⅵ),coexisting turbidity,and coexisting organic coordination agents,was investigated.The experimental results showed that the highest removal rate of Cr(Ⅵ)could reach 97.8%by DTCTS at the optimal hydraulic conditions,which were as follows:the fast stirring speed was 140 r/min,the fast stirring speed was 1.5 min,the slow stirring speed was 40 r/min,and the slow stirring time was 10 min.The pH value of the system had a certain influence on the removal of Cr(Ⅵ),and the removal rate of Cr(Ⅵ)and total chromium were above 96%at pH 2.5.The coexisting organic coordination agents(trichloroacetic acid,aminoacetic acid,sodium acetate)and turbidity in the water samples had a certain inhibitory effect on the removal of Cr(Ⅵ)by DTCTS,but the inhibitory effect was weakened or eliminated with the increase of DTCTS dosage.Infrared analysis showed that Cr(Ⅵ)was reduced to Cr(Ⅲ)by DTCTS,and the reduction product Cr(Ⅲ)could chelate with the dithiocarboxyl groups on the molecular chain of DTCTS,and the hydroxyl groups and amine groups on the molecular chain of DTCTS were also involved in the reaction.
作者
马玉
王刚
杨凯
周雅琦
张航
Ma Yu;Wang Gang;Yang Kai;Zhou Yaqi;Zhang Hang(School of Environmental and Municipal Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)
出处
《环境工程》
CAS
CSCD
北大核心
2023年第S01期75-79,共5页
Environmental Engineering
基金
国家自然科学基金项目“含硫高分子螯合-絮凝剂的制备及其捕集重金属性能差异性研究”(51368030)
兰州交通大学天佑创新团队项目(TY202005)
关键词
高分子絮凝剂
氧化还原
螯合
重金属
含Cr(Ⅵ)废水
macromolecule flocculant
oxidation and reduction
chelation
heavy metal
chromium(Ⅵ)-containing wastewater
