Synthesis of carbon modified with polymer of diethylenetriamine and trimesoyl chloride for the dual removal of Hg (II) and methyl mercury ([CH₃Hg]⁺) from wastewater: Theoretical and experimental analyses

A novel adsorbent was synthesized by modification of waste rubber tiers derived activated carbon (AC) with diethylenetriamine (DETA)-trimesoyl chloride (TMC) copolymer. The synthesized AC/DETA-TMC nanocomposite was characterized by FT-IR and SEM/EDX techniques. Dependency of the adsorption yield on the batch parameters was studied via factorial design method. From the non-linear Langmuir isotherm model, the adsorption capacity of the AC/DETA-TMC nanocomposite was determined as 317.3 and 263.6 mg g⁻¹ for inorganic mercury (Hg²⁺) and organic mercury (methyl mercury; [CH₃Hg]⁺, respectively. The adsorption kinetic mechanism of both mercury species was recognized well by the PSO model. The thermodynamic calculations verified that the adsorption processes progressed spontaneously and exothermically. The cycling adsorption/desorption treatments exposed that the produced nanocomposite showed still reusable performance in moderate level until seven cycles. The nanocomposite demonstrated high removal performance in case of wastewater samples. To investigate the power of the interactions between studied chemical species, DFT calculations were performed and adsorption energies were calculated. It is important to note that theoretical results support the experiments made.