Analysis of Heavy Metal Pollution in the Environment of Laoheba Phosphate Mine in Mabian Region，Sichuan Province

Laoheba phosphate mineral resources are rich in Mabian region, and mining activities are frequent. The impact on the soil and water environment is unclear in the mining area. In order to find out the pollution degree of heavy metals in the mine environment, water body and soil in the Laoheba phosphate ore area, the content and distribution characteristics of heavy metals (Cd, As, Cu, Cr, Pb, Zn) in the surface water and surface soil were evaluated by taking the soil and water environment in the Laoheba phosphate ore area as the research object. The results indicate that the water quality in the study area is good, and the pollution degree of heavy metals and phosphorus is low, which conforms to the relevant indexes of the Environmental Quality Standard for Surface Water (GB3838-2002)Ⅲ. Compared with the background value of soil elements in Sichuan Province, the mean value of metal elements in the soil is 8.75 times, 3.36 times, 1.94 times, 1.48 times, 1.36 times, and 7.47 times of Cd, Pb, Zn, Cu and P. Compared with the background values of soil elements in China, Cd exceeds the standard by 10 times, Pb 4.40 times, Zn 2.48 times, As 1.88 times, Cu 2.12 times and Cr 1.42 times. The potential ecological hazard index method showed that the pollution degree of heavy metals in the surface soil of Laoheba phosphate mine was Cd> As > Pb > Cu> Zn>Cr, followed by Cd element, followed by As, Pb and Zn, which was a moderate ecological pollution risk. The accumulation index method showed that the pollution degree of heavy metals in the surface soil of Mabian Laoheba phosphate mine was Cd>Pb>As>Zn>Cu>Cr, and the pollution degree of Cd and Pb was moderate. In conclusion, the heavy metal pollution of phosphate ore has little influence on water body, while the heavy metal pollution of soil cannot be ignored in Laoheba, Mabian.