Optimization of oilfield produced water treatment parameters using Agro-based adsorbents: A comprehensive review

Abstract

Produced water from oil and gas extraction constitutes a major, complex waste stream demanding efficient, sustainable treatment solutions. Agro-based adsorbents derived from agricultural residues offer cost-effective, environmentally compatible alternatives due to their high porosity and functional surface chemistry. This review systematically synthesizes recent peer-reviewed studies to critically evaluate key optimization parameters affecting adsorption efficacy, including adsorbent dosage, contact time, pH, temperature, particle size, carbonization, chemical activation, and the use of single versus blended biomass systems. Findings reveal that chemically activated agro-based adsorbents achieve hydrocarbon removal efficiencies of up to 96%, markedly outperforming raw biomass, which typically attains 61–70%. Carbonization enhances adsorption capacity to approximately 90–93% by improving pore architecture and hydrophobicity. Optimal adsorption consistently occurs at near-neutral pH (6–8), with equilibrium reached within 60–120 minutes. Particle size reduction yields a 20–25% increase in removal efficiency, while elevated temperatures negatively impact adsorption due to exothermic behaviour. Blended biomass adsorbents demonstrate synergistic performance gains of 10–25% over single-source materials, though variability persists due to the absence of standardized optimization protocols. The review identifies a critical gap in integrated multi-parameter optimization frameworks, limiting the translation of laboratory-scale successes to industrial applications. It advocates for future research emphasizing coupled parameter modelling, continuous-flow system validation, and comprehensive techno-economic analyses to enable scalable, robust agro-based produced water treatment technologies. This work advances the field by providing a holistic, optimization-driven perspective essential for developing sustainable, high-performance adsorption systems in petroleum wastewater management.