Environmental Geochemistry Of Different Dynamic Water Bodies In Luling Mining Area

In addition to rivers and shallow groundwater,there are collapse ponds formed by coal mining,which are important water sources for industrial and agricultural production,fishery farming and nearby residents’ living in coal mining areas.From the hydrological dynamic point of view,the collapse pond water is relatively static,and the river and shallow groundwater are in a flowing state(but the velocity of the former is fast,and the velocity of the latter is very slow).Because they are all developed in the shallow surface of the same area,there will be different degrees of hydrogeochemical relations between them.Therefore,it is of great theoretical and practical significance to study the hydrogeochemical differences and relations of different dynamic shallow water bodies in the same area.Based on the three different dynamic shallow surface water bodies(collapse ponds,shallow groundwater and weihe River)in Luling mining area,the characteristics of the conventional water chemistry content of the three water bodies are clarified by sampling,testing and result analysis,the hydrogeochemical effects and their influencing factors of the water bodies are studied by the analysis of piper three-line maps and Gibbs maps,and the fluorine formation effect and mechanism of the high fluorine content in the water are discussed On the basis of the study of the metal content and pollution characteristics of three water weights,the health risk evaluation was carried out,and the water environmental quality evaluation of the three water bodies was carried out by using fuzzy metamodels,and the main results were as follows:(1)Shallow groundwater and collapse pond water are mainly Na+-HCO3-,and Tuohe river is Na+-SO42--Cl-.According to Gibbs diagram,rock weathering plays a leading role in the hydrochemical characteristics of the three water bodies.The ion combination scale map reflects that the weathering and dissolution of silicate rock will affect the hydrochemical characteristics of the three water bodies.The results of correlation analysis show that there may be ion exchange between shallow groundwater and collapse pond,and the collapse pond and shallow groundwater have the same source.(2)The high fluorine area of shallow groundwater is mainly concentrated on the northeast side of the study area and G1 points.The fluorine content of the River Luhe along the upstream to downstream river decreases before increasing and then decreasing(consistent with the characteristics of the change of the collapsed pond).The Gibbs diagram of fluorine shows that the formation of fluorine in the three water bodies is controlled by the dissolution of fluorine-containing minerals[fluorspar(CaF2),apatite(Ca5(PO4)3F,etc.).Through the analysis of ion exchange,it is found that the ion exchange intensity of shallow groundwater is the largest,which is an important hydrogeochemical action for the formation of high fluorine water.Competitive adsorption and human factors have little impact on the fluorine exceeding standard in the three water bodies.(3)The spatial distribution of Cr in shallow groundwater is as follows:high value areas are distributed in blocks,with point source pollution,in which the content of Mn is higher in the areas centered on point G2 and point G8;the content of Mn is higher in the southeast,southwest and northeast of the study area,and lower in other areas;the spatial distribution of Fe is relatively uniform,with higher concentration in the central area centered on point G33 and point G2 and lower concentration in the surrounding areas Low;the spatial distribution of as is characterized by low concentration in the southwest and high concentration in the northwest.The concentration of as in the northern area of Tuohe river is higher than that in the southern area;the concentration of CD and Pb is higher in the western area and lower in the central area.The Fe content of Tuohe River first decreases and then increases along the flow direction(basically consistent with the collapse pond),and the as content first increases and then decreases along the flow direction(roughly consistent with the collapse pond),the distribution of other heavy metals changed little.(4)The health risk assessment results of heavy metal elements show that among the three water bodies,Tuohe river has the largest non carcinogenic risk,and shallow groundwater has the smallest non carcinogenic risk.Cr element has a certain carcinogenic risk for children,and the risk is higher than that for adults.As element in Tuohe River and collapse pond can cause carcinogenic risk for children.The total carcinogenic health risk of shallow groundwater is less than that of Tuohe River and collapse pond.(5)The fuzzy matter-element model is used to evaluate the water quality of shallow groundwater,Tuohe River and collapse pond in the study area.The results show that classⅡ water and class Ⅲ water of shallow groundwater account for 2.78%and 77.78%respectively,and 19.4%of the water samples are class Ⅳ water;class Ⅲ water of Tuohe River accounts for 70%and class Ⅳ water accounts for 30%;4#collapse pond has the best water quality and 2#collapse pond has the worst water quality.The water quality of three different dynamic water bodies is ranked It is:shallow groundwater>river water>collapse pond water.Figure[35]Table[22]References[89]...