Enhanced elemental mercury removal by facile sulfurization of agrowaste chars

Abstract

Facile sulfurization of char from agrowaste of coconut pith (CP) and elemental sulfur was developed towards producing cheaper adsorbents for elemental mercury (Hgº) adsorption. It was found that physicochemical properties of the sulfurized chars changed with the initial CP to elemental sulfur ratio (CPS) and sulfurization temperatures, that generally affected the Hgº adsorption. The CPS ratio of 1:1 and sulfurization temperature of 300 ºC (i.e. CPS300(1:1)) resulted in outstanding Hg° adsorption performance. Characterization of the char indicates the presence of the organic compounds, organic sulfur and elemental sulfur species onto the adsorbents were likely favoring the Hgº adsorption. The adsorption capacity of CPS300(1:1) was higher than 26077.7 μg/g, since the adsorbents still did not reach breakthrough time even after 80 d of adsorption process. The study on the effect of bed temperature found that the adsorbent was still effective in removing Hgº at any temperature (50 ºC to 200 ºC). The sulfurized-char however was non-regenerable.