| The Shifosi Reservoir is a flood-stricken plain reservoir on the main stream of the Liaohe River.Due to the excessive content of heavy metals in the sediments of the Liaohe River upstream of the reservoir,the sediment in the reservoir contains some heavy metals.In the reservoir area,due to the establishment of groundwater source in Shenyang agricultural high-tech industrial zone,the exploitation of water source accelerates the infiltration and replenishment of surface water.The sediment is used as a channel for the connection of surface water and groundwater,and whether the migration and transformation of heavy metals will be the source of water.It has an impact and becomes a concern.Through the research on the distribution characteristics of heavy metal chromium and the migration and pollution prevention and control in the sediment in the reservoir area,this study can provide technical support for the water supply security of the agricultural high-tech industrial zone in Shenyang,and the water environment of Shifosi Reservoir.The scientific control of pollution prevention provides.This research has mainly completed the following aspects.1.Analysis of the environmental characteristics of Shifosi Reservoir.Through the natural profile data of the Shifosi Reservoir area,the hydrometeorological and hydrogeological conditions in the reservoir area are analyzed.Master the environmental characteristics of the Shifosi Reservoir area.2.Distribution characteristics and risk assessment of heavy metal chromium in the reservoir area of Shifosi Reservoir.The sampling points are set in the reservoir area,and the chromium content of the soil sample is detected.According to the results,the spatial distribution in the reservoir area is determined as the chromium content in the eastern part of the reservoir is higher than that in the west and the middle,and the chromium content in the soil near the water source is higher.The potential ecological risk assessment of Hakanson was used to evaluate the chromium pollution,that is,the ecological risk of chromium in the soil near the water source was higher.3.Static adsorption and desorption tests of chromium in the sediment of the reservoir area.Static adsorption and desorption experiments were carried out to study the static adsorption and desorption processes of chromium under different lithologies and temperatures.The results show that the adsorption and desorption capacities of chromium in three lithologic soils are different,and the adsorption capacity is:silty clay>powder The sandy soil>fine sand has the opposite desorption capacity;the adsorption and desorption rate constants increase with the increase of temperature,but the difference of the saturated adsorption amount of each soil at different temperatures is small.The maximum adsorption amount,the desorption amount,and the reaction rate constant were determined by mathematical model fitting.4.The migration of chromium into the bottom sediment of the reservoir area is an indoor test.Through the indoor soil column experiment,the migration and transformation of chromium in the soil column during the infiltration and recharge of groundwater with different water storage heights and different seasons are simulated.The test results show that with the increase of water storage height,the diffusion coefficient and dispersion of porous media in sediments also increase;the dynamic migration test shows that when the local surface water is infiltrated into the groundwater,the chromium in the porous medium is also As the water flows downward,the transport volume also increases with the increase of the water storage height,and the surface soil sample is most affected by the change of the water environment.At the same time,the chemical reaction in the soil column is also continuously carried out.The reduction reaction is more obvious,and the conversion of hexavalent chromium to trivalent chromium leads to an increase in the content of trivalent chromium.In winter,although the hydraulic connection between surface water and groundwater is weakened,the redox reaction in the sediment still occurs continuously,heavy metals Chromium also presents a downward trend.5.Environmental capacity analysis of heavy metal chromium in the sediment of the reservoir area.The critical value of chromium content in different lithologic sediments is determined by the current balance method and the environmental effect method,and the capacity of chromium is determined and the environmental capacity is determined.The current environmental capacity level in the study area is determined by the soil existing environmental capacity comprehensive index method.The results show that the sediment in the reservoir area has a certain capacity for heavy metal chromium,and the dynamic environment capacity is greater than the static environment capacity.6.Research on prevention and control technology of heavy metal chromium pollution in sediments of reservoir area.Under the stress of hexavalent chromium,reed and pupa have strong chromium enrichment ability and good growth.The two plants can be planted to reduce the damage caused by heavy metal chromium to the reservoir environment.This research has certain significance for expanding the research field of chromium migration and transformation.It also plays an important role in reservoir water environment quality and groundwater source safety protection.It also has important guiding significance for pollution prevention and control and protection work in the study area. |
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