Study On Effect Of Manganese Removal In Groundwater From Uranium Tailings Pond Leakage By PRB Technology

This paper use the hydroxyapatite coated quartz sands as the materals of PRB for manganese removal experiments by sol gel method to solve the manganese pollution in regional groundwater of uranium tailings leakage in JiangXi.Conduct effect research on manganese removal in groundwater of uranium tailings leakage using PRB technology.Then the effect of particle size,dosage,pH value,contact time,initial manganese concentration and uranium concentration on manganese removal were investigated,and best test condition have been confirm.Finally,adsorption mechanism of manganese removal by materals have been discussed according to the adsorption isotherm research and adsorption kinetics research.However,to confirm the effect of manganese removal in water,factors such as the particle size,hydraulic load,initial concentration of manganese and concentration of uranium(Ⅵ)have been considered,and the Thomas model and Yoon-Nelson model were used to fit the experimental datum.Major research results as follow:(1)As the results of static test,when composite with different sizes of 0.15-0.30 mm,0.30-0.60 mm,0.60-1.18 mm,under the condition of pH value of solution is 5.0,the contact time is 240 min,the initial Mn concentration is 5mg/L,the saturated sorption capacity of 0.5g(10g/L),0.6 g(12g/L),1.5g(30g/L)were 0.482mg/g,0.382 mg/g,0.159 mg/g and the removal rate were 96.33%,93.90%,97.45%.The process of adsorption fit three wellestablish models namely,Langmuir,Freundlich and pseudo-second-kinetic model.There is also an interference in the process of manganese removal by composites has some relation with the size of quatz sands when uranium exist in solution.(2)As the results of dynamic continuous PRB column studies,the capacity of manganese removal can be improved when the particle diameter decreass under the certain condition.Moreover,when the size of composite is 0.15-0.30 mm,the initial concentration of manganese is 5 mg/L,hydraulic loading is 13.75m3/m2 d,pH value is 5.0,saturated manganese sorption capacity of composites is 1.51mg/g and manganese removal efficiency can reach 79.74%.Hydroxyapatite coated quartz sands have a good efficiency in manganese removal in water.However,even though the existence of uranium make a big interference in the pocess of manganede removal in PRB column,uranium removal rate can maintain at 100% when manganese sorption capacity lose.Thomas model and Yoon-Nelson model can well describe the behavior of adsorption of manganese removal in PRB dynamic column using hydroxyapatite coated quartz sands,and provide reliable design parameter information for the practical application of hydroxyapatite coated quartz sands.(3)Hydroxyapatite coated quartz sands as the materals of PRB column is able to handle high manganese contamination groundwater containining aniumn.Howver,it’s a promising way for remediation of the region of groundwater with contaminant of manganese in uranium tailings.