LIU Lulu1, GAO Yanzheng1, LIU Fang2, ZHU Jian2
(1. College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing 210095, China; 2. Institute of Environment and Resources, Guizhou University, Guiyang 550025, China)
Abstract: Paddy soil and overlying water around a coal gangue field in a mountain area of central Guizhou Province, China were sampled and analyzed to explore the bioavailability of heavy metals (chromium, copper, zinc, arsenic, cadmium, mercury and lead) and their release potentialfrom the soils. Results show that concentrations of cadmium, arsenic, mercury and some samples of copper in the polluted paddy soil exceed the Second Level of National Soil Environment Quality Standard.Content of labile cadmium increases obviously with increasing pollution degree of paddy soil. Labile Cd contents in paddy soils with intermediate and severe level of pollution increase 1.30 and 2.60 times of those with light level of pollution, respectively. During the period of rice growth (from June to August), the average concentrations (triple sampling) of cadmium in water samples overlying intermediately and severely polluted paddy soil are 11.3% and 27.3% higher than those of lightly polluted paddy soil, respectively. In polluted paddy soil flooding experiment for one to thirty days, the concentration of cadmium in the overlying water increased continually. After first 20 days of the experiment time, cadmium concentrations in water samples overlying intermediately and severely polluted paddy soil exceed the standard. It can be concluded that paddy soil affected by coal gangue effluent may cause cadmium pollution obviously.
Key words: coal yard; gangue; paddy soil; heavy metals pollution; release characteristics
EARTH AND ENVIRONMENT Vol. 43, No.2, Tot No.304, 2015, Page 152-158
