Role of various parameters in synthesis of insoluble agrobased xanthates for removal of copper from wastewater

The research identifies and studies the parameters involved in the synthesis of two types of insoluble agrobased xanthates, named insoluble baggase xanthate (IBX) and insoluble wood xanthate (IWX) and their ability to remove heavy metals from wastewater. Copper was selected as the model metal and the metal removal capacity of IBX and IWX were expressed by copper loading (mg of copper removed/g of IBX or IWX). It was observed that contact times of 3 h and alkali strengths of 4 mol/L were necessary during alkalization. The maximum base material to alkali ratio (w/w) was 1.125 without sacrificing proper mixing of the base material alkali mixture. Optimum contact time during xanthation was 4 h with a carbon-disulfide to base material ratio (w/w) of 1.25. Only strong bases like NaOH, KOH contributed high copper loadings and the starting liquor was reused twice without sacrificing the copper removal capacity of IBX and IWX. Maximum copper loadings achieved with IBX and IWX were 26.9 ± 0.15 and 27.8 ± 0.39 mg/g, respectively.