不同氧化物硼负载体吸附锰离子的特性研究  

Mn^(2+) ADSORPTION CHARACTERISTICS OF DIFFERENT B-LOADED OXIDES

作　　者：王娟[1] 廖水姣[1] 朱端卫[1] 任丽英[1] 周文兵[1] 丁家旺[1] 

机构地区：[1]华中农业大学微量元素研究中心,武汉430070

出　　处：《土壤学报》2006年第5期749-755,共7页Acta Pedologica Sinica

基　　金：国家自然科学基金项目(40371064)资助

摘　　要：以人工合成针铁矿(Goethite,简写为G),水锰矿(Manganite,简写为M),经硼砂处理的吸附态针铁矿(简写为Ad-B-G),吸附态水锰矿(简写为Ad-B-M),经硼酸处理的包被态针铁矿(简写为Oc-B-G),包被态水锰矿(简写为Oc-B-M)等6种氧化物为研究对象,在等温条件下,用吸附平衡法研究了6种硼负载体对Mn2+的吸附解吸行为。结果表明,吸附Mn2+能力:Oc-B-G>Ad-B-G>G;Ad-B-M和Oc-B-M吸附Mn2+量最大,M吸附能力最弱。6种硼负载体Mn2+吸附量随pH升高而增加,但铁氧化物和锰氧化物之间有差别。不同形态锰氧化物吸附Mn2+前后溶液pH变化不同,吸附等量Mn2+离子时,Ad-B-M向溶液中释放H+量最多,Oc-B-M最少。上述结果说明,硼的参与不仅可改变氧化物吸附Mn2+离子的行为,而且对反应体系的影响也不尽相同。Six types of oxides, i. e, Goethite （G）, Manganite （M） Ad-B-G （goethite treated with borax）, Ad-B-M （manganite treated with borax）, Oc-B-G （goethite treated with boric acid） and Oc-B-M （manganite treated with boric acid） were used as objects in the study on Mn^2＋ adsorption characteristics of B-loaded oxides in an isothermal condition with the adsorption equilibrium method. The results show that in terms of Mn^2 ＋ adsorption capacity, the 3 minerals of the goethite series followed the order of Oc-B-G 〉 Ad-B-G 〉 G, and the other 3 minerals were in the same order, Oc-B-M 〉 Ad-B-M 〉 M. Their capacity rose with the pH of the solution, which, however, differed between the two series of oxides. It was believed that oxides treated with boron increased adsorption of Mn^2 ＋ , and Mn^2＋ was more readily adsorbed by the manganite series of oxides than the goethite series. Electronic property PZC （Point of Zero Charge） of the minerals might be the main factor caused these differences. Mn^2＋ sorption increased with the concentration of Mn^2＋ in the solution. The ratio of proton-to-manganese stoichiometry on these minerals was in the order of Oc-B-M 〈 M 〈 Ad-B-M and Oc-B-G 〉 Ad-B-G 〉 G. The decrease in release of H^＋ into solution was due to changes in surface charge and number of active sites on the surface or the micro-particle size of oxide. These results provided strong support for the phenomenon that application of boron to acidic soil could relax acidification of the soil.

关 键 词：针铁矿 水锰矿 硼 吸附 PZC 化学剂量比 

分 类 号：S153[农业科学—土壤学]