Electrokinetic Remediation Of Fluorine-contaminated Soils

The fluoride is inorganic pollutant that it is one of the environmental pollutants. Fluoride and human health are closely related, too much or too little intaking of fluorine will be detrimental to human health. With the development of industry and the generation of industry"three wastes", the soil in many areas are contaminated by fluorine, resulting in fluorosis. So the electrokinetic remediation of fluorine-contaminated soil technology is of great importance and practical significance.This paper firstly described the status of remediation of contaminated soils, discussed kaolin's mechanism of adsorption and desorption. By using electrodynamics method to study the various conditions influencing electrokinetic remediation of fluorine-contaminated soils, the author strived to find the best electric repair conditions.The fluoride pollution soil of electrodynamics repair mainly includes different soil column lengths, different electrolytic time, different electrolytic voltage and different electrolyte four parts experiment to discuss its influencing factors, and collect data, calculate the removal rate of pollutants, according to fluoride various indexes and comprehensive evaluation results.The main research conclusions include:1.Kaolin's adsorption and desorption have rules to follow. Extending adsorption time, reducing the fluorine solution concentration, adjusting pH value to neutral can increase kaolin's adsorption rate of fluoride. Longer desorption time can increase kaolin's fluoride desorption rate, pH value, alkali concentration has little effect on desorption.2.Through the experiment of repairing fluoride contaminated soil by electrokinetic remediation, we studied the influence of various conditions on the experiment, and found electrodynamics technology is a convenient, safe, good and time-saving way to repair fluorine-contaminated soil. Using this method to remove pollutants in fluorine, the removal efficiency reached 79%, which shows that the method is feasible.3.In electrokinetic remediation experiments, selecting 10cm long soil column the experimental effect is good and the length is right; the selection of repair time shall be determined according to experiment. When the experimental current through the soil is very low and has no change in a long time, the experiment should be stopped,because if the current is too weak to reach the effects of removal, continuing the experiment is just consuming energy. The increase of electrolytic voltage is conducive to the removal of pollutants in soil. According to the electrokinetic remediation test, the higher removal efficiency of fluorine-contaminated soil can be obtained in 2.0V/cm the voltage. The selection of the electrolyte is also the key to electrodynamics experiments, which is of great influence. The experimental results show that the anode electrolyte using 0.05 mol/L NaOH solution is the best, it can not only remove the soil fluoride efficiently but also save resources.