摘要
为开发含Cr(Ⅵ)废水处理工艺提供必要资料,对不同条件下Fe(Ⅲ)催化有机酸光化学还原Cr(Ⅵ)进行了比较研究。研究结果表明,Cr(Ⅵ)的还原不仅受pH、Fe(Ⅲ)或有机酸的起始浓度以及共存阳离子的影响,而且还与有机酸种类有关。低pH的酸性条件有利于Cr(Ⅵ)的光化学还原,在pH 3.0条件下经3 h后的还原率达89.9%,在pH 5.0经3 h后其还原率为37.3%。Fe(Ⅲ)或有机酸起始浓度增高会促进Cr(Ⅵ)的还原,在pH 3.0和Fe(Ⅲ)浓度高于Cr(Ⅵ)浓度条件下导致在3 h后Cr(Ⅵ)的光化学还原率达100%。共存Al(Ⅲ)或Cu(Ⅱ)会抑制Cr(Ⅵ)的光化学还原。由Fe(Ⅲ)催化3种有机酸对Cr(Ⅵ)的光化学还原作用大小次序为:酒石酸>柠檬酸>苹果酸。还对不同条件影响Cr(Ⅵ)的光化学还原可能机制作了讨论。
In order to provide necessary data for developing Cr （Ⅵ）-contained wastewater treatment process, Fe（ Ⅲ ） catalyzed photochemical reduction of Cr （ Ⅵ ） by organic acids in water was comparatively in- vestigated under various conditions. The results showed that the reduction of Cr（Ⅵ） not only was affected by pH, initial concentrations of Fe（Ⅲ ） and organic acids, and coexisted cations, but also related to the kind of organic acids. Acidic pH conditions favored the photochemical reduction. Cr（Ⅵ） reduction rate reached 89.9% through 3 h under pH 3.0 and it achieved 37.3% at pH 5.0. An increase in initial concentration of Fe（Ⅲ） or organic acid promoted Cr（Ⅵ ） reduction, and a higher concentration of Fe （ Ⅲ ） at pH 3.0 could lead up to 100% Cr（Ⅵ） reduction after 3 h test. The coexisted Al（Ⅲ ） or Cu（ Ⅱ ） would have inhibition on Cr（Ⅵ） re- duction. The degree order of Fe （ Ⅲ） catalyzed photochemical reduction of Cr （ Ⅵ ） by three kinds of organic acids were as follows： tartaric acid 〉 citric acid 〉 malic acid. The possible mechanisms of those conditions affecting the photochemical reduction of Cr（Ⅵ） were discussed.
出处
《环境工程学报》
CAS
CSCD
北大核心
2013年第1期191-195,共5页
Chinese Journal of Environmental Engineering
基金
南京师范大学高层次人才引进资助项目(2010611XGQ0058)
