利用氧化物对土壤中汞的吸附特性,研究了汞污染土壤中添加铁锰和铁铝复合氧化物对土壤汞有效性的影响.结果表明,在土壤中添加氧化物后,土壤中有效态汞的含量明显降低,在相同添加量下铁铝复合氧化物比铁锰复合氧化物的吸附效果好.14 d时间内,添加铁铝氧化物后,两种土壤中有效态汞的含量分别降低了94.60%和93.11%;添加铁锰氧化物后,两种土样中有效态汞的含量分别降低了88.69%和87.85%,可见两种氧化物是土壤中有效态汞的有效吸附剂.通过方程拟合研究了氧化物对土壤中有效态汞吸附的规律,其中,铁铝氧化物对土壤中有效态汞的吸附规律以Elovich方程和权函数方程拟合度较好,铁锰氧化对土壤中有效态汞的吸附规律以Elovich方程拟合效果最好,零级速率方程及指数方程的拟合效果则相对较差.
The objective of this study was to test the adsorption effect of Fe-Mn binary oxide and Fe-Al binary oxide on available Hg in soil. With the addition of oxides into soil available, Hg content decreased obviously, and the adsorption effect of Fe-Al binary oxide was better than that of Fe-Mn binary oxide. During the 14 days experiment time, available Hg content decreased by 94.60% and 93.11% in two types of soils after Fe-Al binary oxide was added. In comparison, available Hg content decrease by 88.69% and 87.85% after Fe-Mn binary oxide was added. This indicated that the two oxides are effective adsorbents for available Hg in soil. It was also demonstrated that adsorption effect of Fe-Al binary oxide on available Hg was fitted better with Elovich equation and power function equation, and adsorption effect of Fe-Mn binary oxide on available Hg can be described by Elovich equation. In contrast, zero-order kinetic equation and parabolic diffusion equation fit relatively poorly.