This study investigated the removal of H2S from the effluent of the crude oil desalting plant using batch mode adsorption. Three adsorbents, including Cu2O, reboiler limescale, and activated carbon were used for H2S removal. Initial concentration, adsorbent dosage, and pH were also examined using Box–Behnken design and the H2S removal rate was considered as the response. The highest H2S removal rate for Cu2O under optimum conditions was 95%, obtained at pH = 5.6, an adsorbent dosage of 1830 mg/l, and an initial concentration of 435.9 mg/l. To achieve the highest removal of H2S, the optimum conditions were determined as pH = 9, an adsorbent dosage of 1670 mg/l, and an initial concentration of 445.7 mg/l for reboiler limescale, and pH = 5.4, an adsorbent dosage of 1750 mg/l, and an initial concentration of 282.82 mg/l for activated carbon. At these conditions, the removal percentage of H2S were 45.6 and 51.45 for reboiler limescale and activated carbon, respectively. Also for a more detailed study, the physicochemical properties of adsorbents were also investigated using FT-IR, SEM, and BET techniques.
