Chemical Immobilization Of Heavy Metals In Contaminated Soils Around Nonferrous Mine

Development of mineral resources is a major aspect of the heavy metal pollution. Treatment of heavy metal contaminated soil is imminent.Chmical remediation technology is widely applied because of simple and small investment.but the fixed effect of the traditional chemical stabilizer for a variety of heavy metal contaminated soil is not prominent.In this paper, A new type of TMT-sulfate compound stabilizer was developed based on the chemical stabilizer screening in solution. Traditional chemical stabilizer and TMT-sulfate compound stabilizer, and the effect of different factors on the fixed heavy metal was investigated. The results are as follows:(1) Calcium phosphate, sodium phosphate, sodium sulfide and TMT reduced the heavy metal ions concentration in solution significantly, the fixed ability of heavy metal ions by TMT was decreased when the solution containing DTPA. But after adding iron salts the fixed ability would be increased.(2) The fixed effect of Calcium phosphate, sodium phosphate, which complexed with ferric sulfate were not well on heavy contaminated soil, the available contents of Pb、Cd reduced less than60%。the available contents of Pb、Cd reduced76.8%、63.1%after adding Sodium sulfide complexed with ferric sulfate.(3) The available contents of Pb、Cd reduced91.4%,88.9%with95g·kg-1ferric hydroxide of TMT-iron compound system. But application rates of Fe greater than5%by weight can lead to problems with soil structure. The available contents of Pb、Cd reduced more than90%with TMT-ferric chloride,but the soil conductivity increased,and strong absorption capacity of ferric chloride inhibited the growth of plants.(4) Controlled the soil moisture to70%of field capacity, fixed for60days, the available contents of Pb, Cd reduced more than80%and the available contents of As reduced60%with35.7g/kg ferric sulfate and0.04L/kg TMT.