三种有机肥水溶性分解产物对铜、镉吸附的影响

ADSORPTION OF COPPER AND CADMIUM ON TWO SOILS AS AFFECTED BY WATER-SOLUBLE PRODUCTS OF THREE ORGANIC MATERIALS

研究了稻草、紫云英和猪粪的水溶性分解产物对铜和镉的沉淀作用及其在红壤和潮土上的吸附影响。结果表明三种水溶性分解产物对钢镉的沉淀及吸附有双重效应：络合效应和pH提高效应。在相同的pH值条件下，有机分解产物通过络合作用而不同程度地抑制了铜和镉的沉淀作用及其在两种土壤上的吸附。由于铜具有较强的形成络合物的能力，所以有机分解产物对铜的抑制效果强于对镉的抑制效果。吸附等温线表明，在不调节pH时，三种有机分解产物均通过提高体系的pH值而促进了钢镉的吸附。

Effects of water-soluble products of rice straw, Chinese milk vetch and pig manure on precipitation and adsorption of Cu and Cd on a red soil and a fluvo-aquic soil were studied. Two opposite effects, pH-raising effect and complexing effect were observed. At same pH values, the water-soluble organic products depressed Cu and Cd precipitation and adsorption by forming soluble organic-metal complexes. Cu adsoprtion was more strongly inhibited than Cd adsorption because of the stronger complexation ability of copper. The adsorption isotherms showed that the water-soluble products enhanced Cu and Cd adsorption by raising pH values when the pH values were not adjusted.