Dewatering Treatment and Catalytic Application of Sludge by Glow Discharge Plasma

In this paper, glow discharge plasma (GDP) was used to remove organic contaminants of sludge and improve sludge dewaterability. Fe-rich sludge as a catalyst combined GDP to form heterogeneous Fenton reaction, which was used to remove 2,4-dichlorophenoxyacetic acid (2,4-D) in aqueous solution. The surface micrographs and chemical composition of Fe-rich sludge was analysed by the Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS). The effect of initial pH0 on hydrogen peroxide (H2O2) yield in GDP was discussed. The removal of 2,4-D was associated with the synergetic effect of adsorption and oxidative, and hydroxyl radicals (•OH) play a dominant role. This study provides an environmentally-friendly technology to improve sludge dewaterability and a potentially low-cost catalyst for 2,4-D removal in water, which is significant for the reuse of Fe-rich sludge.