当前位置: X-MOL 学术Chem. Eng. J. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Effect of solution chemistry on the reactivity and electron selectivity of zerovalent iron toward Se(VI) removal
Chemical Engineering Journal ( IF 15.1 ) Pub Date : 2018-07-17 , DOI: 10.1016/j.cej.2018.07.113
Junlian Qiao , Yadan Song , Yuankui Sun , Xiaohong Guan

Both the reactivity and electron selectivity (ES) of zerovalent iron (ZVI) are critical for successful application of ZVI. In this study, taking Se(VI) as a probe contaminant, the influences of pH (3.0–10.0) and coexisting ions (e.g., Ca2+, Mg2+, Cl, SiO32−, SO42−, and PO43−) on the reactivity and ES of ZVI were comprehensively investigated. It was demonstrated that, the ES of ZVI was low in general and merely 0.9–12.1% of electrons donated by ZVI were effectively used for Se(VI) reduction under different conditions. Both Se(VI) removal rate and ES were significantly influenced by pH and both of them achieved maximum at pH 5.0, while further increasing or decreasing pH values would deteriorate the ZVI performance. Depending on the types and concentrations, coexisting ions could exert different effects on ZVI reactivity and ES, negatively, negligibly or positively. For example, relative to Cl, Ca2+, Mg2+, and SiO32− did not show any significant influence on Se(VI) removal rate but could enhance ES by 3.0–50.3%. The presence of SO42− and PO43− hindered Se(VI) removal rate during their tested concentration range, while they could enhance ES at a low concentration level and depress ES at high concentration levels. X-ray absorption fine structure analysis revealed that, pH and coexisting ions could influence the transformation of ZVI corrosion products and thereby impact the electron transfer from ZVI to Se species at the water-particle interface.



中文翻译:

溶液化学性质对零价铁去除Se(VI)的反应性和电子选择性的影响

零价铁(ZVI)的反应性和电子选择性(ES)都是成功应用ZVI的关键。在这项研究中,考虑硒(VI)作为探针污染物,pH值的影响(3.0-10.0)和共存离子(例如Ca 2+,Mg的2+,氯- ,的SiO 3 2-,SO 4 2-,和PO 4 3−)对ZVI的反应性和ES进行了全面研究。结果表明,ZVI的ES通常较低,在不同条件下ZVI捐赠的电子中只有0.9–12.1%有效地用于Se(VI)还原。Se(VI)的去除率和ES都受pH值的显着影响,并且两者在pH 5.0时均达到最大值,而进一步提高或降低pH值则会降低ZVI性​​能。取决于类型和浓度,共存离子可能对ZVI反应性和ES产生负面,微不足道或正面的不同影响。例如,相对于氯- ,钙2+,镁2+,和SiO 3 2-对Se(VI)的去除率没有显着影响,但可以使ES提高3.0-50.3%。SO 4 2-和PO 4 3-的存在会在其测试浓度范围内阻碍Se(VI)的去除率,而它们可以在低浓度下增强ES并在高浓度下抑制ES。X射线吸收精细结构分析表明,pH和共存离子会影响ZVI腐蚀产物的转化,从而影响水粒子界面处ZVI向Se物种的电子转移。

更新日期:2018-07-17
down
wechat
bug