抗坏血酸/过硫酸盐氧化去除土壤中阿特拉津的效率及机理
REMOVAL EFFICIENCY AND MECHANISM OF ATRAZINE FROM CONTAMINATED SOIL BY PERSULFATE AND ASCORBIC ACID
杜宇 1孙淑晴 1戴雯 1曹梦华 1涂书新 1熊双莲1
作者信息
摘要
研究了抗坏血酸/过硫酸盐去除土壤中阿特拉津的效率、影响因素及机理.当抗坏血酸和过硫酸盐浓度分别为10,30 mmol/L,初始pH为3.0时,土壤中阿特拉津降解率达到92.4％.共存的无机阴离子(Cl-和HCO3-)会抑制阿特拉津的降解.低浓度溶解态有机质(0～2.5 mg/L)能促进阿特拉津的氧化降解,高浓度溶解态有机质(＞5 mg/L)会抑制阿特拉津的氧化降解.抗坏血酸一方面直接诱导过硫酸盐活化产生硫酸根自由基(SO4-·)和羟基自由基(·OH),另一方面促进土壤释放铁离子和Fe2+/Fe3+的循环,从而间接增强过硫酸盐的活化性能.此外,抗坏血酸增强了土壤中阿特拉津的解吸,降低了阿特拉津与氧化性自由基的传质阻力,有利于提升阿特拉津的氧化降解效率.抗坏血酸/过硫酸盐体系降解阿特拉津主要包括脱烷基氧化、脱氯和羟基化3种途径.
Abstract
The efficiency,influencing factors,and mechanism of removing atrazine from soil by ascorbic acid/persulfate were studied.When the concentrations of ascorbic acid and persulfate were 10 and 30 mmol/L,respectively,the degradation ratio of atrazine in soil achieved 92.4％at a pH of 3.0.The co-existing inorganic anions(Cl-and HCO3-)could inhibit the degradation of atrazine.Low concentrations of dissolved organic matter(0 to 2.5 mg/L)could promote the degradation of atrazine,while high concentrations of dissolved organic matter(＞5 mg/L)could inhibit the oxidation of atrazine.On the one hand,ascorbic acid could directly activate persulfate to generate sulfate radicals and hydroxyl radicals.On the other hand,ascorbic acid could promote the release of iron ions from the soil and the cycle of Fe2+/Fe3+,which indirectly enhances the activation of persulfate.In addition,ascorbic acid could enhance the desorption of atrazine from the soil and reduce the mass transfer resistance between atrazine and oxidative radicals,which was beneficial for promoting atrazine oxidation.The degradation pathways of atrazine in the ascorbic acid/persulfate system mainly involved dealkylation oxidation,dechlorination,and hydroxylation.
关键词
抗坏血酸/过硫酸盐/阿特拉津/土壤修复/氧化降解Key words
ascorbic acid/persulfate/atrazine/soil remediation/oxidation引用本文复制引用
基金项目
国家自然科学基金(21976065)
湖北省自然科学基金(2022CFD003)
出版年
2024
NETL
NSTL
万方数据