A Global Systematic Review of Factors Affecting the Biological Treatment of Wastewater Containing Petroleum Substances

Introduction: A variety of treatment methods, including biological remediation, have been employed to address oil-contaminated wastewater. Bioremediation, which involves using microorganisms to mitigate or eliminate pollutants, is recognized as an environmentally friendly, cost-effective, and evolving technique for removing and breaking down various environmental contaminants, including those from oil industry. Materials and Methods: This systematic review not only introduces biological treatment but also explores factors contributing to its success. In this study, a search was performed with keywords including petroleum substances, bioremediation, and biological treatment on Scopus, ScienceDirect, Web of Science, and PubMed, and 1349 studies were obtained, and 61 articles were finally chosen according to exclusion and inclusion criteria. Results: A significant increase was observed in research articles over the past five years, likely reflecting the growing awareness of the need to remediate petroleum pollution in recent years. The nature of petroleum wastewater varies depending on the specific crude oil refining process, and factors that have the greatest effect on biological treatment include temperature, pH, inhibitors, time, oxygen, nutrients, nature, concentration of pollutants, and microorganism type. No single species of microorganism can break down all petroleum compounds. Conclusion: This study allows decision-makers to evaluate these factors before implementing and investing in this method, ensuring its effectiveness in reducing petroleum pollution concentrations.