Electrochemical properties of treated marcasite sludge from jewelry production process

Abstract

The current trend is towards recycling and reuse of industrial solid waste to mitigate reliance on landfills. This research investigates the recycling of marcasite sludge (MS) from the jewelry industry for its potential application in electrochemical devices, particularly sensors. It is composes of pyrite (FeS2), cubic zirconia, and szomolnokite (FeSO4⋅H2O). Hydrothermal treatment at 180 °C for 4 h with varying amounts of sodium thiosulfate pentahydrate (Na2S2O3⋅5H2O) was employed to convert sulfate compounds in the sludge to FeS2, followed by calcination to remove excess sulfur. X-ray diffraction (XRD) analysis confirmed the complete conversion of FeSO4⋅H2O to FeS2. The electrochemical capacitance of a treated MS (TMS) modified screen-printed carbon electrode (SPCE) was investigated. The results show an enhancement of the electrochemical capacitance of SPCE after modification with TMS. This study explores the potential for recycling waste in high-value electrochemical applications.