摘要
砷被列为环境中最重要的毒物,有机质对砷环境地球化学行为的影响日益受到关注。本研究针对有机质不同活性官能团对砷吸附的影响,用批实验方法探究砷与不同有机质共存时砷在针铁矿上的吸附等温线及吸附动力学,并通过Zeta电位及红外光谱探究不同有机质对砷吸附的影响。结果表明:加入羧甲基纤维素、单宁酸、对苯醌和十二烷基苯磺酸均抑制了针铁矿上砷的吸附,且砷的吸附符合Freundlich吸附等温模型;当加入4种有机质时,砷在针铁矿表面吸附符合准二级吸附动力学模型;随着pH的变化,含有不同官能团的有机质对砷吸附速率的影响不同;单宁酸、十二烷基苯磺酸、羧甲基纤维素和对苯醌体系砷吸附速率常数分别为0.37、0.03、0.02和0.01 mg·g^(-1)·h^(-1);因此,单宁酸能够显著提高砷的吸附速率,对苯醌可以有效降低砷的吸附速率,这可能是由于它们的官能团与砷之间的作用方式不同所导致的;Zeta电位结果表明,砷、单宁酸和针铁矿之间能够形成三元络合物,红外光谱测定结果也证明了三元络合物的形成。
Arsenic is listed as one of the most important poisons in the environment.The influence of organic matter on the environmental geochemical behavior of arsenic has attracted more and more attention.Aiming to understand the influence of different active functional groups of organic matter on arsenic adsorption,a batch experimental method was used to explore the adsorption isotherm and adsorption kinetics of arsenic on goethite with the coexistence of different organic matters.The influence of different organic matters on arsenic adsorption was explored by Zeta potential and infrared spectrum.The results showed that the addition of carboxymethyl cellulose,tannic acid,p-benzoquinone and dodecylbenzene sulfonic acid inhibited the adsorption of arsenic on goethite,and the adsorption of which was fit well with the Freundlich adsorption isotherm model.When the four kinds of organic matter were added respectively,the adsorption of arsenic on the surface of goethite was well described by pseudo-second-order kinetic model.Moreover,with the changes of pH,organic matter with different functional groups had different effects on the adsorption rate of arsenic.The arsenic adsorption rate constants of tannic acid,dodecyl benzenesulfonic acid,carboxymethyl cellulose and p-benzoquinone were 0.37,0.03,0.02,and 0.01 mg·g^(-1)·h^(-1),respectively.Tannic acid can significantly increase the adsorption rate of arsenic,while p-benzoquinone can effectively reduce the adsorption rate of arsenic,probably due to the different modes of interaction between their functional groups and arsenic.The results of Zeta potential measurement showed that the ternary complexes were formed among arsenic,tannic acid,and goethite.The results of infrared spectrum also evidenced the formation of ternary complexes.
作者
孙美玲
冶育芳
赵志西
马晓燕
谢青青
SUN Meiling;YE Yufang;ZHAO Zhixi;MA Xiaoyan;XIE Qingqing(College of Chemistry and Chemical Engineering,Xinjiang Normal University,Urumqi 830054,China)
出处
《生态学杂志》
CAS
CSCD
北大核心
2023年第5期1115-1122,共8页
Chinese Journal of Ecology
基金
国家自然科学基金项目(41867051)
天山青年计划项目(2018Q025)
新兴污染物与生物标志物检测创新团队(2021D14017)资助。
关键词
砷
有机质
针铁矿
arsenic
organic matter
goethite
