The petroleum industry is one of the major contributors to water pollution globally. The industry can discharge different types of pollutants that can be carcinogenic, phytotoxic, and genotoxic. The nature of these pollutants can possess an immensely harmful effect on human health and aquatic life. Petroleum wastewater is considered to be a major hazard in the industry. In the last few decades, academic research efforts have been concentrated on finding sustainable, effective, and long-term treatment techniques for petroleum industry wastewater. The complex composition of the wastewater implies that it is often not feasible to use a single treatment technique but rather a combination of several techniques.