| Long-term mining of coal mine has caused many problems of water ecological environment,one of which is the heavy metal pollution caused by mine water discharge.Colloidal organic matter in water is an important adsorptive carrier of heavy metals,which determines the migration and transformation of heavy metals.This study analyzed the composition characteristics of colloidal organic matter and heavy metal in mine water through field investigation of mine drainage in different coalfields,and selected typical mines to clarify the influence of mine drainage on the composition of colloidal organic matter in rivers.Laboratory simulation tests were carried out to reveal the influence mechanism of colloidal organic matter in rivers on Cu migration and transformation under the influence of mine drainage.To explore the environmental behavior of heavy metals under the influence of natural organic colloid on mine drainage,in order to provide theoretical support for the restoration and treatment of water environment in coal mine area.The research results of this thesis are as follows:（1）Through the investigation of coal mine drainage,it was found that the key coalfields in Shanxi and Henan were all highly mineralized mine drainage,with high contents of heavy metals Mn,Zn,Fe and Cu.The colloidal organic matter（COM）in mine drainage had obvious endogenous characteristics,little contribution from terraced input,and low overall humification degree.COM components in mine water included humic fluorescent components and protein-like fluorescent components（tyrosine and tryptophan）,and protein-like fluorescent components were divided into main fluorescent components.The colloid organic carbon（COC）concentration and oxidation reduction potential（ORP）in mine water positively correlated with the average molecular weight of COM,and the concentration of COM and the relative fluorescence intensity had a close positive correlation with the concentrations of total dissolved solids and Ca2+,Mg2+,SO42-.（2）In the study of the influence of typical coal mine drainage on COM and heavy metal composition in rivers,it was found that the heavy metal elements in rivers were mainly Mn,As,Fe,Zn and Cu,the upstream and downstream comparative analysis results showed that the mine drainage has no significant effect on the content of heavy metals in rivers.COM in the river under the influence of mine drainage was mainly composed of humic fluorescent components,and the endogenous characteristics of COM were significant.The mine drainage reduced the fluorescence intensity of COM at the outlet and reduced the concentration of COM in the downstream by 5%.Mine drainage had no significant effect on COM composition of river,but there wrere differences in the sources of COM fluorescence components between river water and sediment.（3）The experiment of COM binding with heavy metal Cu in river showed that Cu tended to bind with COM of lower molecular weight,and the binding ability of COM in water with the same molecular weight was greater than that in sediment.The binding order of COM and Cu was humus>tyrosine>tryptophan.COM mainly quenching with humus-like substances,and the fluorescence quenching phenomenon was more obvious in sediment group.The fluorescence intensity of humus decreased after the combination of COM and Cu,and the binding capacity of COM and Cu in sediments（log Ka=4.11 and 3.98）was stronger than that in surface water of the river（log Ka=3.84and 3.74,n=0.53 and 0.54）.However,due to the few binding sites of COM in sediments（n=0.50 and 0.44）,the stability after binding was poor.In the river that were not affected by mine drainage,COM could effectively remove Cu from water and reduced the bioavailability and toxicity of Cu,while mine drainage could inhibit the adsorption and removal of Cu from rivers by COM. |
