| The Dahuofang reservoir, which has rich mineral resources in valley region, isthe most strategically important water source in Liaoning province, moreover, themine enterprise in the upper reaches and its slag created during the productiveprocess cause great threat to the water safety of Dahuofang reservoir.Through the investigation of natural conditions of reservoir basin and theenterprise of basin risk source, preliminarily established recognition system ofdahuofang reservoir upstream mineral enterprise key risk source, identify risk sourceenterprise30home and do the risk classification, the results show there are8severerisk source enterprise of risk level Ⅲ, and17moderate risk source enterprise of risklevelⅡ, and5mild risk source enterprise of risk levelⅠ.Field survey found, the most of mining enterprise wastewater have been reused,and main pollution risk comes from tailing pond. Gold, copper, iron were chosen as3kinds of mineral enterprise to have a sampling survey analysis to the tail slag andleachate of the enterprise through the analysis of environment pollution elements ofmineral type characteristics and regional distribution from8identified severe risksource enterprise of risk level Ⅲ. The results show that: the mineral enterprises(tailing pond) of gold and copper are the largest water quality potential threats ofDahuofang reservoir, iron ore take second place, and the main pollutants are cyanide,heavy metal Cu, Zn, Cd, As.For further analysis of potential risk source of seabed sediment reservoir, itmake a collecting and detection in storm season of the stations in three warehousingrivers (She river, Sunzi river, Hun river), which study the pollution characteristics ofthe heavy rain runoff from upstream water of Dahuofang reservoir, and describe thedegree of runoff in the heavy rain pollution through the applications of pollutantsaverage concentration (EMC). The results show that: heavy rains caused no seriouswater pollution, but have a density current phenomenon to appear. Through thechange of turbidity conclude the density current carry a large sediment to inventory, which can affect the granularity composition of reservoir surface sediments, and alsoaffects the heavy metal content in sediments.After the heavy rain, collect the reservoir bottom sediment, make a monitoringcomparison with the results before a thunderstorm, analyzes its heavy metalchanging trends and distribution, and the potential ecological risk index method wasused to analyze the content and distribution for heavy metals in Cu, Zn, Cr, Cd, Pb,Hg of Dahuofang reservoir surface sediments after heavy rain. Assessing thepollution degree and the potential ecological risk index, finally verified theevaluation results using i.e. geoaccumulation index. The results show that:(1) Thechanging trends and regularity of distribution in the heavy metal element ofsediments is conforms with the monitoring results before heavy rain;(2) The resultsof two evaluation method are basically the same. The order of potential ecologicalharm degree in heavy metals of dahuofang reservoir surface sediments after theheavy rain is Cd＞Hg＞Cu＞Pb＞As＞Cr＞Zn, the section Hun68(influenced byHunHe heavily) is the most seriously polluted and the largest harmful in potentialecological risk of all the section.It should has a preliminary filter to the priority control risk characteristicspollutants for Dahuofang reservoir through the basic data of the investigation andanalysis of risk pollution source, in order to offer some basis to the relevantdecision-making departments for formulating priority control list of pollutants ofDahuofang reservoir. The features pollutants which need to be priority control inupstream catchments areas of Dahuofang reservoir are cyanide, Hg, Cd, As, Cu, Ni,Pb, Cr, Zn. |
PDF Full Text Request