不同类型原料生物炭对镉吸附机理探究

Study on the adsorption mechanism of cadmium by biochar from different types of raw materials

以鸡粪、竹粉、污泥为原料分别在550℃下热解制备生物炭(鸡粪炭、竹炭、污泥炭),对3种生物炭吸附水中Cd^(2+)的具体机理进行了定量研究。结果表明:4种吸附机理贡献率随生物炭原料不同而不同,其中沉淀作用为鸡粪炭>污泥炭>竹炭,离子交换为污泥炭>鸡粪炭>竹炭,官能团络合和Cd^(2+)-π螯合均为竹炭>污泥炭>鸡粪炭;4种吸附机理贡献率均呈现相同规律,即沉淀作用>离子交换>官能团络合>Cd^(2+)-π螯合。

Biochars were prepared by pyrolysis of chicken manure,bamboo and sludge as raw materials at 550℃.The specific adsorption mechanism of Cd^(2+)by three biochars was studied.The results showed that the contribution rates of the four adsorption mechanisms varied with biochar from different raw materials.The contribution rate of precipitation was chicken manure biochar>sludge biochar>bamboo biochar,and ion exchange was sludge biochar>chicken manure biochar>bamboo biochar.The contribution rates of functional group complexation and Cd^(2+)-πchelation were bamboo biochar>sludge biochar>chicken manure biochar.The contribution rates of the four adsorption mechanisms showed a phase pattern,namely precipitation>ion exchange>functional group complexation chelation>Cd^(2+)-πchelation.