Migration Characteristics Of Cd In Municipal Sludge Amendcd Soil

This article applied municipal sludge into loess,which was referred to as municipal sludge amended soil.On the one hand,with the test of growing plant in pot to study migration characteristic of Cd in municipal sludge amended soil-plant ecosystem.On the other hand,A field pot experiment was conducted out for loess and to study the effects of the speciation of Cadmium forms and their bioavailability,in the loess soils.The main research result are as follow:(1)After the application of municipal sludge,the activity were increased of Sucrase、urease、alkaline phosphatase. The Activity of Sucrase、urease、alkaline phosphatase of the Soil first increase and then decrease with increase of stress levels of cadmium. p H of the loess soil with municipal sludge was less than that of loess,after the application of municipal sludge,the content were increased of organic matter content、EC、nitrogen content of the loess soil.Contents Of heavy metals in the amended soil with municipal sludge increased,but they were less than the threshold of soil contamination.(2)The biomass of potato first increase and then decrease with increase of stress levels of cadmium.increased with the increase of stress levels and this phenomenon was a significant positive correlation(P <0.05), and the maximum content of cadmium of various parts of potato in stress levels of 45.32 mg·kg-1. After the application of municipal sludge, the growthing and biomass significantly were improved of potato.(3)After the application of municipal sludge,the activity were reduce t of cadmium. The content of cadmium of various parts of potato increased with the increase of stress levels. With increasing concentrations of exogenous Cadmium,exchangeable and carbonate bound continued to increase,while the organic state and residual decreased.The main chemical speciation in soil converted to exchangeable and carbonate bound.(4)The content of cadmium of various parts of potato increased with the increaseof stress levels and this phenomenon was a significant positive correlation(P <0.05), and the maximum content of cadmium ofvarious parts of potato t were the shoots, followed by the roots and peel, the minimum is tubers.The application of sludge can promote the absorption of cadmium in potato.