Application of Different Coagulants and Cost Evaluation for the Treatment of Oil and Gas Produced Water

Abstract

A coagulation treatment is a separation technology widely used in industries as a pre-treatment step to remove the dissolved organic matter in wastewater. However, the type of coagulant, the optimized dose, and the treatment cost associated with various commercially employed coagulants must be investigated for the treatment of oil and gas produced water. In this study, five widely employed coagulants—ferric chloride, aluminum potassium sulphate, chitosan, sodium sulfide, and magnesium oxide—were tested for the treatment of actual complex oilfield-generated produced water. Water quality parameters such as the total suspended solids (TSS), total dissolved solids (TDS), turbidity, salinity, and pH were assessed for a better understanding of different coagulant activities against the produced water treatment. All the coagulants were efficient for the treatment of produced water. The findings of this study showed that ferric chloride led to the best removal of total solids (74.25%) of all water quality parameters, with treatment costs of USD 4 per m−3 of produced water. The results from this study contribute to the environmentally friendly, broader, and cost-effective application of a coagulation treatment to produced water.