Removal of sulfide from aqueous media by natural and copper modified eggshell biowaste

This paper studied modification of the eggshell (ES) biowaste by drying, calcination, and changing the surface structure by copper ion for the removal of sulfide from water and wastewater. Characterization of the surface morphology was conducted by SEM and XRD techniques. Batch and column experiments were applied and several factors were studied to investigate the optimum conditions for improving the sulfide removal efficiency by the calcined (at 900 °C) copper modified eggshell biosorbent (CES-Cu-900). The results showed that the highest efficiency of sulfide removal by CES-Cu-900 biosorbent was at particle sizes in the range 76–630 μm, the temperature of biosorbent/adsorbate mixture was at 50 °C and the contact time was 48 h. The results also showed that the removal of sulfide increased with increasing biosorbent dose and sulfide initial concentration. At the optimum conditions, the maximum amount of sulfide removed was 6.75 mg/g of biosorbent. It was found that CES-Cu-900 biosorbent could be recovered and reused for the removal of the sulfide with 80% efficiency after washing the material. Results using CES-Cu-900 biosorbent column method showed a sulfide removal efficiency of 77% at a flow rate ≤ 1 mL/min of the eluent. The biosorbent material was applied to remove sulfide in real samples from different locations in the Gaza Strip, and the efficiency of sulfide removal at low concentration was in the range (45–50%).