Removal of Dimethyl Sulfide from Aqueous Solution Using Cost-Effective Modified Chicken Manure Biochar Produced from Slow Pyrolysis

This study investigated the characteristics of using a cost-effective, amine-modified biochar (BC) derived from chicken manure for removing dimethyl sulfide (DMS) from an aqueous solution. The amine-modified BC showed much higher adsorption of DMS compared to commercial activated carbons under varying conditions of contact time, initial concentration, and adsorbent dosage. The DMS removal efficiency increased as the adsorbent dosage was increased from 0.01 to 0.25 g and reached 92.4% even at the relatively low adsorbent dose of 0.015 g. The DMS adsorption capacity of the amine-modified BC (mg/g) increased with increasing DMS concentration, while the incremental rate of the removal efficiency decreased. The adsorption process was well explained by a pseudo-second-order kinetics model. The adsorption of DMS is more appropriately described by the Freundlich isotherm (R2 = 0.989) than by the Langmuir isotherm (R2 = 0.942). The DMS removal efficiency was only reduced by 23.4% even after 10 recovery cycles. The surface area of the amine-modified BC was much higher (9.4 ± 1.2 times) than that of the unmodified BC. The amine-modified BC with a high surface area of 334.6 m2/g can be utilized as a cheap and effective alternative adsorbent to commercial activated carbon for DMS removal.