Evaluation of life cycle, exergy, and carbon footprint of wastewater treatment system by activated sludge method in petrochemical industries

Abstract

Wastewater management in petrochemical industries plays an effective role in reducing their environmental consequences. This study utilized life cycle assessment and carbon footprint methodologies to assess these environmental impacts. The objectives of the investigation were pursued using the ReciPe 2016, Cumulative Energy Demand, Cumulative Exergy Demand approaches, and sensitivity analysis. The outcomes of the endpoint analysis revealed that damage to resources, human health, and ecosystems received more than 98% of the total impact due to electricity consumption. Furthermore, electricity consumption and COD were responsible for the most significant midpoint-level consequences. The sensitivity analysis showed that a change of approximately 20% in electricity and chemical oxygen demand had the most significant impact on the ozone depletion category. The primary gas emitted as a result of the wastewater treatment process was carbon dioxide, which accounted for 99.78% of the carbon footprint associated with the process. Based on these findings, it can be inferred that replacing the current energy source with renewable alternatives would reduce over 90% of the environmental impacts of the wastewater treatment process in these industrial units.

Keywords

• life cycle assessment
• system exergy
• carbon footprint
• activated sludge treatment system