Effects Of Differents Of Stabilizers On The Remediation For Heavy Metal Contaminated Alkaline Soil

Soil pollution induced by heavy metal has become a worldwide problem. Management and remediation of contaminated farmland, to ensure the quality and safety of agricultural products has become a top priority. In order to investigate the effects of several kinds of stabilizers on remediation for heavy metal contaminated alkaline-soil, and to selection of stabilizers suitable for repair northern heavy metal contaminated alkaline soil, with simulated soil culture experiment and pot experiment, study on the repairing effect of 14 kinds of stabilizers, such as phosphates, natural modified synthetic minerals, organic etc. The results were shown as below:1. The contents of available Pb in soils decreased with using bentonite, KH2PO4, biochar, modified biochar, 3 g·kg-1 pleiotropic bacteria, sepiolite, illite(3000 mesh), illite(800 mesh), chicken manure, bacterial manure. The optimum was KH2PO4, next was modified biochar.2. The contents of available Cd in soils decreased with using 9 g·kg bentonite, KH2PO4, biochar, modified biochar, 9 g·kg-1 and 12 g·kg-1 molecular bond TM stabilizer, 3 g·kg-1 and 6 g·kg-1 pleiotropic bacteria, sepiolite, illite(3000 mesh), illite(800 mesh), 3 g·kg-1 polyphenols, 15 g·kg-1 and 20 g·kg-1 chicken manure, 15 mg·kg-1 and 20 g·kg-1 bacterial manure. The optimum was modified biochar, next was KH2PO4.3. The immobilizing effects of 9 g·kg-1 KH2PO4, biochar and 20 g·kg-1 modified biochar on available Pb were similar at different incubation times. 3 g·kg-1 and 6 g·kg-1 KH2PO4, 10 g·kg-1 modified biochar brought a slight increase. For 15 g·kg-1modified biochar, increase were significant. The acetic acid extractable, reducible Pb contents reduced, and the residual increased. The optimum is KH2PO4.4. The immobilizing effects of 6 g·kg-1 KH2PO4, 10 g·kg-1 and 15 g·kg-1 biochar on available Cd were similar at different incubation times. 9 g·kg-1 KH2PO4, 10 g·kg-1modified biochar were slight increase. 3 g·kg-1 KH2PO4, 20 g·kg-1 biochar, 15 g·kg-1and 20 g·kg-1 modified biochar could bring a significant increase. The acetic acid extractable, reducible Cd contents reduced, and the residual increased. The optimum is modified biochar.5. All treatments could increase wheat height, reduce Pb and Cd contents in wheat leaves and roots. The effects of order was: KH2PO4 > modified biochar > biochar.6. All treatments could increase the soil available Pb and Cd contents, and the best is KH2PO4. KH2PO4 could convert the acetic acid extractable and reducible Pb and Cd into residual. Biochar and modified biochar could convert the acetic acid extractable and reducible Pb and Cd into oxidizable and residual.7. KH2PO4 under the presentation of Pb could form Pb3(P3O9)2·3(H2O), which was undissolve in water. KH2PO4 reduced the bioavailability of lead. The surface features of modified biochar had been changed. The specific area of modified biochar is larger than biochar. It provided the possibility for absorption of more heavy metals.