Sustainable treatment of oil produced water using novel methods – A review

Abstract

Oil Produced water (OPW) is a highly undesirable discharge from oil exploration and petroleum industries. The composition of produced water is highly heterogeneous, comprising distinct organic and inorganic compounds, including heavy metals and sulphate-reducing bacteria. The characteristics of the OPW depend on the age of the rigs, depth, and geochemistry. The contamination of ecosystems by produced water from oil fields poses a substantial risk to public health, highlighting the urgent need for innovative treatment strategies to clean this effluent before its discharge into aquatic systems. This review explores emerging approaches for the remediation of produced water, focusing on the associated environmental hazards, advanced oxidation processes, and membrane-based removal techniques that leverage graphene aerogel composites. The exceptional properties of graphene aerogels, including their expansive surface area, hydrophobic and oleophilic nature, and proficient electron transfer capabilities significantly enhance the efficacy of produced water treatment. For example, a Polybenzimidazole polymer membrane, modified with graphene oxide and reduced graphene oxide, successfully treated 99.9 % of the produced water. Likewise, a porous graphene aerogel, synthesized through a hydrothermal method, demonstrated an impressive adsorption capacity of 223 g/g for oil and organic solvents present in the produced water.