Experimental Study On Adsorption Of Fluorine-containing Groundwater By Serpentine-clay Composite Particles

In many areas of our country exist fluoride groundwater pollution,the endanger of water pollution on the human body and the environment has caused human’s concern around the world,so the study of an economic and efficient fluoride removal method and adsorbent is particularly important.In this paper,the adsorption experiments were carried out by using the combination of experimental and theoretical analysis,static test and dynamic test.The results of adsorption experiment were carried out by using serpentine clay composite particles as follows:(1)The optimum experimental conditions for the determination of 200 mL and 5 mg / L of fluorine water by serpentine were determined by static single factor test.The particle size was 200 mesh,the dosage was 400 mg,the reaction time was 120 min,the oscillation speed was 150 r / min,the pH value was 6.0,the temperature was 30℃,serpentine on fluoride ion adsorption isotherm equation in line with Freundlich curve equation,adsorption process to meet the quasi-second-order kinetics model.(2)The optimum test conditions for the preparation of serpentine clay composite particles were determined by single factor and orthogonal test.The ratio of serpentine clay was 4:1,the temperature was 500℃,and the time of calcination was 2 h.(3)The optimum experimental conditions for the determination of 200 mL and 5 mg / L of fluorine water by serpentine clay composite particles were determined by static single factor test.The dosage was 500 mg,the reaction time was 120 min,the oscillation speed was 120 r / min,the optimum pH was 6.5,the reaction temperature 30℃.The adsorption isotherm equation of the composite particles is in accordance with the Freundlich curve equation.The adsorption process of F-satisfies quasi-second order kinetic model.(4)The results showed that the factors such as the quality of the adsorbent layer,the influent flow rate and the initial fluorine-containing water concentration had a great influence on the penetration point and the depletion point of the fluorine.The greater of the adsorption layer’s quality,The longer of the penetration point and the depletion point arrive,The inlet flow rate is inversely proportional to the point at which the penetration point and the depletion point arrive,The higher of the fluoride ion concentration,the shorter of the time to reach the point of penetration and the point of depletion...