Sewage sludge-derived materials as efficient adsorbents for removal of hydrogen sulfide

Sewage sludge-derived materials were used as adsorbents of hydrogen sulfide from moist air. The adsorbent obtained by carbonization at 950 degreesC ha s a capacity twice of that of coconut shell-based activated carbon. The cap acity of the sludge-derived materials increases with increasing carbonizati on temperature. It is likely that during carbonization at 950 degreesC a mi neral-like phase is formed that consists of such catalytically active metal s as iron, zinc, and copper. The results obtained demonstrate that the pres ence of iron oxide significantly increases the capacity of commercial carbo n and activated alumina. The sludge-derived adsorbents are efficient for hy drogen sulfide removal until the pore entrances are blocked with sulfur as the product of oxidation reaction. For materials in which the catalytic eff ect is predominant, hydrogen sulfide is adsorbed until all pores are filled with sulfur. There is also indication that chemisorption plays a significa nt role in the removal of hydrogen sulfide from moist air.