Use of carbon materials for produced water treatment: a review on adsorption process and performance

The oil and gas production is identified by consuming a large amount of water and generating massive produced water. The produced water is either reinjected into the underground layers or released into the rivers and oceans that can cause severe damage to the environment due to toxic elements such as salts, oil and grease, and polyaromatic hydrocarbons. So produced water treatment and management can reduce the significant threats to the soil and water resources and solve the lack of water in different water-consuming sectors. During the last decades, adsorption methods, such as using expanded graphite and activated carbon materials, have attracted scientists’ attention because these adsorbents are cost-effective and practical. This study aimed to review expanded graphite’s synthesis, adsorption process, and efficient factors in removing heavy oil, heavy metals, benzene, toluene, ethylbenzene, and xylenes, and organic acids from produced water and compare with other adsorbents, including activated carbon and residual biomass. Based on the results of extensive research works, expanded graphite’s high adsorption feature suggested that graphite can be a promising adsorbent in actual produced water treatment.