Application of Activated Carbon from Jojoba Seed Residue in Refinery Wastewater Treatment

Abstract

The effluent flowing from oil refineries, which frequently goes into rivers, typically carries a variety of pollutants. In the present study, a quest has been undertaken to investigate the feasibility of using activated carbon prepared from both sub-fermented and unfermented jojoba seed residues for treatment of petroleum refinery wastewater. The biomass were carbonised and thermally activated at 700, 800 and 900°C respectively, then characterized for the adsorption of phenol, chemical oxygen demand (COD), biological oxygen demand (BOD), turbidity, chloride, phosphate, total dissolved solids (TDS), total suspended solid (TSS), pH, electrical conductivity and sulfate ions. The activated carbon obtained from the fermented jojoba residue at 800°C (i.e., SRB2) had, of all samples studied, the highest surface area (959 m²/g) and total pore volume (0.43 cm³/g). The sample showed a good adsorption capacity for not only lowering the COD (chemical oxygen demand reduction 76.29%) and BOD5 (bio-chemical oxygen demand 75%), but also to reduce turbidity, phenol and inorganic ion.

Although complete phenol removal was not achieved to meet environmental discharge standards, SRB2 showed the best performance among all samples and showed the best fit for Freundlich model isotherm, suggesting multilayer adsorption on a heterogeneous surface. FTIR analysis confirmed the involvement of both physisorption and chemisorption mechanisms, including π–π interactions, hydrogen bonding, and carbonyl-related bonding. SEM and pore size distribution analyses confirmed the micro- and mesoporous structure of SRB2, making it well-suited for phenol adsorption.

These findings highlight the effectiveness of fermented jojoba-derived activated carbon, particularly SRB2, as a sustainable, low-cost bio-adsorbent for reducing organic and inorganic pollutants in petroleum refinery wastewater.