Physicochemical investigation of mercury sorption on mesoporous thioacetamide/chitosan from wastewater

Mercury is a toxic environmental element, so it was necessary to prepare a new, highly efficient, cheap sorbent to remove it. A mesoporous thioacetamide/chitosan (MTA/CS) was manufactured via a simplistic strategy; the chitin deacetylation to gain chitosan (CS) and the addition of thioacetamide. The as-prepared MTA/CS was characterized using X-ray diffraction, EDX, SEM, FTIR, and BET surface analysis. According to the findings, the MTA/CS was effectively synthesized. The removal behaviors of Hg²⁺ onto MTA/CS composite were inspected, which suggested that the MTA/CS composite exhibited great sorption properties for Hg²⁺ in liquid solutions. The maximal Hg²⁺ sorption capacity was 195 mg/g. The effects of temperature, Hg²⁺ concentration, contacting time, and MTA/CS concentration on sorption were analyzed. The 2nd-order model and Langmuir isotherm were suitable for the physicochemical adsorption processes. Thermodynamic analysis showed that the Hg²⁺ adsorption process onto the MTA/CS composite is exothermic and occurred spontaneously. The desorption condition of Hg²⁺ from its loaded MTA/CS was also gained. Likewise, the MTA/CS sorbent was undoubtedly regenerated by 0.8 M NaNO₃ 80 min contacting and 1:50 S:L ratio. The versatility and durability of MTA/CS sorbent were investigated via nine sorption-extraction cycles. The optimum parameters were applied to wastewater. Based on the result, the as-prepared MTA/CS might be a potential sorbent for removing Hg²⁺ from liquid solutions.