Removal Mechanism and Efficiency of Remediation for Lead Heavy Metal Contaminated Soil by Particle Size Screening and Electrokinetics Desorption Technology

Autor: HUANG, SHIH-HAN, 黃詩涵
Rok vydání: 2019
Druh dokumentu: 學位論文 ; thesis
Popis: 107
In this study uses physical and chemical methods to understand the removal efficiency of heavy metal lead in soil. The physical method is to analyze the ratio of different particle size and heavy metal concentration of heavy metal lead contaminated soil by dry or moist particle size screening, and then remove the high concentration of heavy metal lead contaminated soil and mixing with construction sand. Finally, the mixed soil is combined with planting corn for a pot experiment. Through the analysis of particle size screening and corn planting, after the particle size screening of lead heavy metal contaminated soil, the contaminated soil with a particle size of 2.83 mm or more for 53% of the total soil, and the concentration is 6540 mg kg-1 to 6436 mg kg-1. Therefore, the mixed construction sand is removed after this part. The concentration is not only reduced by 66%, the feasibility of subsequent corn planting growth, the contaminated soil after screening and mixing sand planted corn crop for eight weeks its similar to the original contaminated soil which shows the feasibility and practicability of this method for lead-contaminated soil treatment. The chemical method utilizes EDTA and combined with electrokinetics treatment technology to desorb heavy metal lead contaminated soil, and discusses its desorption parameters and optimal efficiency. When there is no significant decrease in the concentration of heavy metal lead in the soil due to the moisture content and the length of the static desorption time. But increasing the EDTA concentration to 0.1M and after 7 days of standing desorption, the operating fluid was removed according to the ratio of soil to water 1:5 improve the removal efficiency of lead heavy metals in actual soil by 79%. When using 0.1M EDTA and water content 40% lead heavy metal contaminated soil and place after 7 days recombination electrokinetics technology using tap water as electrolyte removal of EDTA operating fluid by electrodynamic desorption for 6 days. Test result display, the removal of heavy metal lead pollutants in soil can reach 60% and can meet the requirements of the Environmental Protection Agency of the Environmental Protection Administration, and the scope of control standards and monitoring standards stipulated in the Soil and Groundwater Pollution Remediation Act.
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