一分快三_一分快三平台_首页
Immobilization of Lead by Alishewanella sp. WH16-1 in Pot Experiments of Pb-Contaminated Paddy Soil

Gaoting Zhou & Xian Xia & Hui Wang & Liqiong Li & Gejiao Wang & Shixue Zheng & Shuijiao Liao

Abstract This study investigates the effectiveness and mechanism of decreasing the bioavailability of Pb in
bacterial culture and in pot experiments of Pbcontaminated paddy soil by Alishewanella sp. WH16-1. The WH16-1 strain was isolated from mine soil and exhibited high resistances to many heavy metals, especially
to Pb2+ (2070 mg/L) and Cr (VI) (2340 mg/L). During cultivation of the WH16-1 strain with the addition
of 100 mg/L Pb2+, Pb2+ was precipitated, and 84.13 % of Pb2+ was removed in 72 h. The precipitant
was observed by transmission electron microscopy (TEM) and further confirmed to be PbS by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). TheWH16-1 strain was incubated in Pb2+-added paddy soil pot experiments for 60 days and compared with the uninoculated Pb2+-added paddy soil. Comparison showed that the exchangeable and carbonate-bound Pb in the paddy soil decreased by 14.04 and 10.69 % (P < 0.05), respectively. The Fe-Mn oxide-bound Pb, organic matter-bound Pb and the residual Pb increased by 4.47, 19.40, and 22.78 % (P < 0.05), respectively. Compared with the uninoculated Pb2+-added paddy soil, the dry weight of rice significantly increased by 28.59 %, and the Pb concentrations in rice, husk, leaves, and culms in Pb2+-added paddy soil pot experiment incubated with the WH16-1 strain significantly decreased by 26.18, 26.94, 26.61, and 25.56 % (P < 0.05), respectively. These results suggest that Alishewanella sp. WH16-1 can reduce the bioavailability of Pb in soil. This bacterium may be applicable for the biological stabilization of Pb in Pb-contaminated paddy soil.



Designed By Alex