Petrochemical Wastewater Remediation by Microalgae

Petrochemical industry wastewater (WW) is complicated and refractory, reported to have high chemical oxygen demand (COD), and biological oxygen demand (BOD) with benzene, toluene, ethyl benzene, and xylene as well as organic contaminants like alkanes and aromatic compounds. The organic and inorganic elements in petrochemical effluent are frequently added during processes. The direct disposal of the contaminated/processed water discharged from petrochemical industries poses significant environmental risks. The petrochemical industry continuously experiences challenges in reducing the environmental impact of generated WW from oil and gas production processes. For reuse, discharge, or final disposal, adequate management, or treatment is required. Though numerous treatment options are available like membrane processes, advanced oxidation, adsorption, and coagulation, when it comes to green technology, microalgae have performed extremely well. Microalgae have the ability to grow in diverse wastewater. Microalgae are very effective at removing pathogens, heavy metals (HMs), pesticides, phosphorus, nitrogen, and other contaminants from wastewater. Microalgae species have been used to treat petrochemical WW because they thrive in WW environments. Furthermore, biomass from microalgae is a great way to produce a variety of valuable metabolites. Unlike bacteria, the biomass of microalgae is used as a feedstock for a variety of industries, i.e. fertilizer, stabilizing agents, supplemental medications, and bioenergy. Reusing nutrients in the petrochemical WW for growing microalgae results in reduced additional nutrient costs. This chapter gives an overview of recent research conducted for petrochemical WW remediation by microalgae, recent developments, and future trends.