Coal Mining And Evaluation Of Environmental Quality Of Surface Water In Karst Areas

This text focused on a coal mine in Guihua villas,Zhuzang town,Zhijin county, Guizhou province as a researching object,analyzing the pollution contents and estimating the polluted degree of the river water quality in coal mine area and river deposit releasing,sprinkling soaking water of natural coal and gangues in coal mine area by the way of investigating bodily and collecting typical samples,and researched if the coal mine exploiting had an effect on the kaste surface water quality.The results showed the following main conclusions:1.The main pollutions were SO₄^2-,Fe,Mn in the river of coal mine area,of which the highest contents respectively reached 3861.3,111.5,17.60 mg/L.There were some differences among up river,middle fiver and lower fiver,and the highest was the up river,then was middle river,lower river and unpolluted water.For the dry and damp water,the pH and contents of Mn,Cu,Zn were lower in.damp water because of diluting and oxidizing,while the contents of SO₄^2-,Fe were higher in damp water.2.Taking the surface water environment quality standard as estimated standard. To pH,all the acid water didn't reach the standard;to SO₄^2-,all water exceeded the standard except the unpolluted water,and the up water exceeded fifteen times;to Fe and Mn,most exceeded the standard and the up water respectively exceeded 370 times and 175 times;to Cu and Zn,all the water basically reached the standard.3.The releasing ion content order of upper water in fiver deposit of coal mine area was SO₄^2-＞Fe＞Mn＞Zn＞Cu＞Pb＞Cd.The smaller the pH was,the bigger the contents of SO₄^2-,Fe,Mn,Zn,Cu were.The pH and contents of SO₄^2-,Fe,Mn exceeded the standard;the contents of Zn,Cu,Pb and Cd basically reached the v standard.This all indicated that the SO₄^2-,Fe,Mn of deposit releasing had an effect on surface water.4.The ion contents were higher in static condition compared with the dynamic condition,so the static water had a larger effect on the surface water.The kinds of deposit had an effect on the ion contents in static and dynamic condition.The contents of Fe,Mn,Zn by pollution releasing were the highest in blue deposit,then were yellow deposit,and the river bottom sludge were the lowest;the pH by pollution releasing were the highest in yellow deposit,then were river bottom sludge,and the blue deposit were the lowest;the contents of SO₄^2-,Cu by pollution releasing were the highest in blue deposit,then were river bottom sludge,and the yellow deposit were the lowest.5.The main pollutions were SO₄^2-,Fe,Mn,Cu and Zn in the soaking water of simulation sprinkling and the pH varied from 2.6 to 7.5 in soaking water.At the beginning of sprinkling,the contents of SO₄^2-,Fe,Mn,Cu,Zn in the soaking water were higher,then going down.The sprinkling pH and time had an effect on the contents of soaking water.When the pH was above six,most of the heavy metal contents reached the standard,and had no effect on surface water,while the pH was below four,which accelerated the spilling of Fe,Mn,Zn and exceeded the v standard.