Analysis and Optimization of Mn Removal from Contaminated Solid Matrixes by Electrokinetic Remediation

Area of Science:

• Environmental Engineering
• Geotechnical Engineering
• Electrochemistry

Background:

• Electrokinetic remediation is a viable method for removing ionic contaminants from soils, sediments, and sludges.
• The effectiveness and energy efficiency of electrokinetic soil treatment are significantly influenced by electrical parameters and physicochemical conditions.

Purpose of the Study:

• To analyze the electrokinetic treatment of manganese-contaminated kaolinite clay.
• To investigate the impact of voltage, current intensity, moisture content, pH, and facilitating agents on manganese removal and energy consumption.

Main Methods:

• Electrokinetic treatment of kaolinite clay and water treatment plant sludge contaminated with manganese.
• Varied parameters including constant voltage vs. constant current, moisture content, pH control, and addition of organic acids (citric acid).
• Monitored metal removal efficiency and energy consumption.

Main Results:

• Constant voltage and constant current operations yielded similar results when low electric field intensity was maintained to prevent water electrolysis.
• High moisture content (above 50%) significantly enhanced manganese removal.
• pH control and organic acids improved manganese removal but increased energy costs; optimal conditions included 10-30 V, citric acid, and slightly acidic cathode pH.

Conclusions:

• Electrokinetic remediation is effective for manganese removal from contaminated soils and sludges, particularly with optimized parameters.
• Controlling electrical conditions, moisture, and pH is crucial for efficient metal removal and energy management.
• The study demonstrated successful removal of manganese and other metals from water treatment sludge using pH control.