Removal of sulfide ions from aqueous solutions using carbon- and silicon-containing sorbents

Abstract

ABSTRACTSulfide ions are among the most common pollutants in natural waters. Sulfide sorption methods are widely used in the waste water treatment practice. The most promising sorbents for removing sulfide ions are porous carbon materials. In the present study we researched sorption capacity of the carbon- and silicon-containing samples of rice and buckwheat processing wastes, as well as the activated carbon, carbon fiber, chitosan and natural silicates toward the sulfide ions in aqueous solutions. It was found that the most effective sorbent from the studied ones is the carbon fiber Aktilen B (99%) and from plant wastes – carbonaceous sorbents obtained from rice straw (77–98%) and buckwheat (94%). We studied the physico-chemical and structural properties of the carbonaceous sorbent based on rice straw and it was found that this sample is amorphous and has a predominant microporous structure. At the concentration of sulfide ions ranging from 140 to 800 µg l−1, the studied sorbent reduces the amount of sulfide ions to 0.4–1.4 of the maximum permissible concentration and can be used for treating natural and post-treating waste waters.