Enhanced pressurized electro-osmotic dewatering technology for slurry

Abstract

Efficient slurry dewatering is critical in numerous engineering and environmental applications. Traditional electro-osmosis methods often struggle with uneven electrical field distribution and electrode corrosion, limiting their performance. To address these challenges, this study presents an enhanced pressurized electro-osmotic dewatering (EPEOD) technology featuring a three-electrode array configuration and a fabric electrode (FE) material. This configuration offers bi-directional water migration, superior corrosion resistance, and uniform electric current distribution, enhancing dewatering efficiency significantly. Experiments were conducted using slurry samples of bentonite and kaolin in varying proportions to assess the variation in dewatering performance and soil properties. The findings demonstrated that the proposed technique significantly improved water removal, reducing the initial moisture content from 325 % to a final moisture content of 94.3 % for a 100 % bentonite sample. This performance was notably better than that of other methods, such as mechanical dewatering (MD), electro-osmotic dewatering (EOD), and pressurized electro-osmotic dewatering (PEOD) with electrode reversal (ER) technique with a final water content of 130.4 %. The electrode array configuration and the fabric electrode minimize corrosion and reduce electrical potential loss at the electrode-soil interface. Ion concentration profiles indicated that Ca²⁺ ions are primarily responsible for the transportation of pore water toward the cathode. The EPEOD process was shown to alter soil properties, including reductions in liquid limits (LL) and plasticity indices (PI). Overall, this study highlights the effectiveness of the proposed novel EPEOD technique in enhancing slurry dewatering performance by implementing a three-electrode array configuration and a fabric electrode material.