有机酸作用下黄壤无机纳米微粒对Cd~(2+)吸附动力学特性

为探究有机酸对镉在纳米粒级土壤上的有效性及其形态的影响,基于超声—离心—冻融法,应用到四川省名山河流域老冲积黄壤中,获得纳米微粒(≤100 nm),分别研究不同分子量有机酸(柠檬酸、富里酸、EDTA)及其组合(柠檬酸+EDTA、柠檬酸+富里酸、富里酸+EDTA)对土壤纳米微粒吸附Cd~(2+)动力学特性的影响。结果表明,土壤纳米微粒对Cd~(2+)的动力学吸附量大小关系表现为:柠檬酸+EDTA富里酸柠檬酸+富里酸柠檬酸富里酸+EDTAEDTA。总的来看,EDTA的抑制作用最强,最能降低土壤纳米微粒对Cd~(2+)的吸附。

Kinetics Characteristics of Cadmium Adsorption by Inorganic Nanoparticles under Organic Acid Application to Yellow Soil

In order to explore the effect of organic acids on the efficiency and the form of cadmium in nanoparticles soil,the ultrasound-centrifugal-thaw method was used to extract nanoparticles in the old alluvial yellow soil of Mingshan River basin (≤ 100 nm),Sichuan Province.The cadmium adsorption kinetics by soil nanoparticles was analyzed under the applications of different molecular weight organic acids (citric acid,fulvic acid,EDTA) and their combinations (citric acid + EDTA,citric acid and fulvic acid,fulvic acid + EDTA).The results showed that adsorption amount of cadmium by soil nanoparticle decreased as follows:citric acid + EDTA＞ fulvic acid＞ citric acid and fulvic acid ＞ citric acid ＞ fulvic acid + EDTA ＞ EDTA.Overall,EDTA had the strongest inhibition and reduced cadmium adsorption by soil nanoparticles.