Novel synthetic method for magnetic sulphonated tubular trap for efficient mercury removal from wastewater

Highly efficient Hg(II) adsorption from wastewater remains a crucial task for human health and environment protection. In present work, a simple method was used to develop a carbon-based mercury magnetic "trap" (magnetic sulphonated tubular trap, MSTT) as proved by increasing surface area and wide diameter porous magnetic trap with a high density of strong Hg(II) chelating groups. Various parameters including the initial concentration of Hg(II), pH, contact time and adsorbent dosage are analyzed. The adsorption results of MSTT and sulphonated tubular trap (STT) are closely fitted with the Langmuir adsorption isotherm with maximum adsorption capacities were 970.87 (mg/g) and 952.38 (mg/g). It reveals 99.9 ± 0.5% Hg(II) adsorption occurs at pH 6.8, which is close to neutral pH. These traps can efficiently reduce Hg(II) from 10 (mg/L) to 0.3 (μg/L) in a short time of 10 min. This level is lower than the permissible limit for the drinking water. The calculated thermodynamic parameters ΔH°, ΔG°, and ΔS° indicate that the adsorption of Hg(II) onto MSTT and STT are endothermic, spontaneous and random adsorption process. The regeneration of adsorbents and high Hg(II) adsorption efficiencies in the presence of other metal ions will endow the prepared MSTT and STT with a promise for efficient Hg(II) adsorption for environmental remediation.