有机阴离子和溶解氧对稳定纳米铁去除水中铬(Ⅵ)的影响  

Effects of Organic Anion and Dissolved Oxygen on Removal Cr(Ⅵ) by Stabilized Nanoscale Zero-valent Iron in Water

作　　者：张娜[1] 夏宏彩[1] 李宁[1] 赵倩倩[1] 李铁龙[1,2] 金朝晖[1,2] 

机构地区：[1]南开大学环境科学与工程学院,天津300071 [2]南开大学环境污染过程与基准教育部重点实验室,天津300071

出　　处：《高校化学工程学报》2011年第5期882-887,共6页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金(批准号:40971254);青年科学基金项目(20907023)

摘　　要：以硼氢化钾为还原剂,壳聚糖为稳定剂制备纳米零价铁,研究有机阴离子(柠檬酸根、草酸根和乙二胺四乙酸根)和溶解氧对壳聚糖稳定纳米铁去除Cr(Ⅵ)的影响,并探讨其影响机理。结果表明,5.357 mmol?L?1的铁与0.769 mmol·L-1的Cr(Ⅵ)反应80 min后,在有机阴离子浓度为4 mmol·L-1时,柠檬酸根和草酸根使得壳聚糖稳定纳米铁对Cr(VI)去除率分别降低16.9%和9.6%,且草酸根的zeta电位绝对值(32.06)小于柠檬酸根的(38.27),柠檬酸根对Cr(Ⅵ)去除效果影响较大;而乙二胺四乙酸根使得壳聚糖稳定纳米铁对Cr(Ⅵ)去除率提高24.3%,乙二胺四乙酸根的zeta电位绝对值为2.51,可与Fe(Ⅲ)或Cr(Ⅲ)形成稳定配合物,间接提高Cr(Ⅵ)的去除率;在溶解氧含量为2.31 mg·L-1时,壳聚糖稳定纳米铁溶液对Cr(Ⅵ)的去除率提高约9.0%。Using potassium borohydride as reducer and chitosan as stabilizer, the nanoscale zero-valent iron was prepared and was used to remove the Cr （Ⅵ） containing in wastewater. The effects of organic anions （citrate, oxalate and ethylene diamine tetraacetic acid） and dissolved oxygen （DO） in the wastewater on the Cr（Ⅵ） removal were investigated. The results show that, in contrast to the control reactor, the removal capability of Cr（Ⅵ） decreases by 16.9% and 9.6% in the reactors containing citric and oxalate, respectively. Further results show that the absolute value of potential Zeta of oxalate （32.06 mV） is lower than that of citric （38.27 mV）, which indicates that the inhibition of citric on the Cr（Ⅵ） removal is stronger. However, the existence of EDTA increases the Cr （Ⅵ） removal capability by 24.3% which is caused by the formation of a stable complex with Fe （Ⅲ） and Cr （Ⅲ）. In addition, it was found that the Cr （Ⅵ） removal capability increases by 9.0% when the DO in the wastewater decreases from 6.01 mg-L-1 to 2.31 mg-L-1.

关 键 词：稳定纳米铁 有机阴离子 溶解氧 铬Cr(Ⅵ) 

分 类 号：TB302.2[一般工业技术—材料科学与工程] X522[环境科学与工程—环境工程]