Development of Nickel-Impregnated Nitrogen-Doped Activated Carbon for Micro-solid-phase Extraction of Chlorinated Hydrocarbons from Wastewater

This work presents the synthesis and modification of cost-effective groundnut shell-based carbon sorbent and its utilization to extract chlorinated hydrocarbons from wastewater. The synthesized carbon sorbent was doped with nitrogen by treatment with melamine and further decorated with different weight percent of nickel by solid-state impregnation to achieve nickel-decorated nitrogen-doped carbon sorbents. The physicochemical properties of the sorbents were studied using Brunauer–Emmett–Teller, Fourier transform infrared spectroscopy, and field-emission scanning electron microscope. Each sorbent was then sealed into a polypropylene membrane like a tea bag and utilized to extract the chlorinated hydrocarbons from an aqueous sample and quantified using GC–MS. All the extraction-related parameters were optimized. The overall process presented a wide linear range (10–800 ng mL⁻¹) with a coefficient of correlation between 0.9875 and 0.9943. The limit of detection (1.85–3.45 ng mL⁻¹) and reproducibility (1.2–11%) were observed with relative recovery from the wastewater sample in the range of 85.4 to 114%.