Effects of Resistant Bacteria and Activators on Bioavailability of Cd in Contaminated Soil

LIANG Xiaodi; SHI Dingding; XU Shaohui; HUANG Chengtao; JIANG Daihua

doi:10.15933/j.cnki.1004-3268.2018.01.009

Abstract：In order to investigate the effect of resistant bacteria and activators on bioavailability of Cd in contaminated soil,the effects of resistant bacteria and several activators (such as organic fertilizer,EDTA,FA,citric acid) on the uptake of Cd by heavy metal-resistant plant ryegrass were studied in this experiment.The results indicated that the total biomasses of ryegrass of 50 mL/pot resistant bacteria (J1),200mL/pot resistant bacteria (J2),40 g/pot organic fertilizer (Y1),80 g/pot organic fertilizer (Y2),50mL/pot resistant bacteria + 40 g/pot organic fertilizer (JY1),100 mL/pot resistant bacteria + 80 g/pot organic fertilizer (JY2),5 g/pot FA (H1),50 g/pot FA (H2) treatments were increased by 22.89％-65.93％ compared with that of CK(water) in lateritic red earth and brown calcareous soil.But the total biomasses of ryegrass of EDTA and citric acid treatments were decreased.In lateritic red earth,compared with CK,the content of Cd in the upper and lower parts of ryegrass treated with microbial agents and activators increased by 8.28％-66.45％ and 10.92％-74.17,respectively.In brown calcareous soil,the Cd contents in the upper and lower parts of ryegrass treated with microbial agents and activators were 10.88％-70.97％ and 10.10％-51.82％ higher than that of CK,respectively.In lateritic red earth and brown calcareous soil,the uptake of Cd by the upper parts of ryegrass in J1,J2,Y1,Y2,JY1,JY2,E1(EDTA 5 mmol/pot),E2 (EDTA 15 mmol/pot) treatments increased by 6.93％-126.45％ compared with that of the control group.The greater the uptake of Cd by ryegrass,the less the amounts of weak acid dissolvable Cd and residual Cd in soil,but the more the amounts of reducible Cd and oxidizable Cd in soil.This study showed that cadmium-resistant bacteria and activators could improve the bioavailability of cadmium and the bioremediation effect on cadmium polluted soil by ryegrass,and had a good prospect of application and promotion.