污泥中的DOM对中国土壤中Cd吸附的影响Ⅰ.纬度地带性差异

研究了中国不同纬度地带土壤中水溶性有机质（DOM）对Cd的等温吸附行为影响的差异，并进一步探讨其作用机理。研究结果表明：在南方酸性土壤中，DOM对Cd吸附的影响以促进作用为主；而在北方的中性和碱性土壤中，主要表现为抑制作用。同一土壤中，DOM对A层土壤中Cd吸附的抑制作用大于B层，这与A层土壤TOC含量较高有关。DOM的酸碱缓冲作用和土壤对DOM的吸附作用是影响DOM对Cd吸附抑制作用的两个主要因素。

Effect of DOM derived from sewage sludge on Cd adsorption in different soils in China (Ⅰ).difference in latitudinal zonal soils

A series of batch experiments of isotherms adsorption were conducted to compare the impact of DOM on Cd adsorption in several kinds of latitudinal zonal soils in China. It is shown that DOM can enhance the adsorption of Cd in acidic soils and reduce it in alkaline and neutral soils. In same kind of soil, DOM reduce Cd adsorption in A horizon greater than in B horizon, it mainly due to the higher TOC content in A horizon. The pH buffer function of DOM and the adsorption of DOM in soils may be the two dominative factors that could affect the efficacy of DOM on Cd adsorption in soils.