Study Of Energy Consumption Distribution In Electrokinetic Remediation Chrome Contaminated Soil

Background:In the process of industrialization and urbanization in China, the soil heavy metal pollution is more and more serious. Electrokinetic remediation technology is one of the effective ways to solve the soil heavy metal pollutionproblem. The electrokinetic remediation researches focus on influencing factors, improving the process of remediation, and field in-situ repair. However, the energy issues in process of remediation are important reasons that restricted its wider application.Objective:The distribution of total energy consumption in the process of electrokinetic remediation was explored, and made further analysis of distribution of energy consumption for the most energy-hungry parts. The main mechanism of electric process was used to assist to illustrate the distribution of energy consumption. In addition, this study explored the relationship between the energy consumption and removal efficiency, EC, and moisture content and so on.Methods:Under the condition of different electrolytes, and kaolin polluted with chromium and real chromium soil at chromium pollution site as the research object, conducted the electrokinetic remediation experiments. The current, voltage, conductivity, temperature, soil moisture content, the change of accumulated electric seepage volume and the distribution and removal of Cr in soil were monitored and recorded. On the basis of experimental data, combined with related knowledge such as series circuit and electric repair mechanism, the study explored the distribution of energy consumption in experiment and the relationship between energy consumption and the related indicators.Results:The total energy consumption of each device during the repair are respectively 250.8wh,323.2wh,293.3wh and 244.1wh.Soil chamber is the largest part of energy consumption, and accounts for the proportion of the total energy consumption in the range of 79.65%and 83.16%; Followed by electrode chamber, accounts for the proportion of the total energy consumption in the range of 7.87% and 12.36%; Diaphragm is the minimum part of energy consumption, accounted for in the range of 6.56%and 10.16%.In all parts of soil chamber, the part 4 is the most energy consumption, and accounts for the proportion of the energy consumption of soil chamber in the range of 28.65%and 36.14%. The greater the removal rate of Cr or its changes, the greater the energy consumption; The increase of soil conductivity would lead to reduce its energy consumption. Contrarily, the decrease of soil conductivity would lead to increase its energy consumption. The environment has a great effect on temperature of soil chamber in the process of electric repair. From the perspective of reducing the energy consumption, in the application of future should choose appropriate electrolyte to improve the electrical conductivity of soil chamber, and ensure that the soil moisture content satisfied a certain requirement.