Life cycle assessment of industry wastewater treatment plant: a case study in Vietnam

Abstract

This study employs Life Cycle Assessment (LCA) to evaluate the environmental impacts of wastewater treatment systems in industrial zones of Vietnam. Focusing on two treatment technologies—Anoxic–Oxic (OA) and Sequencing Batch Reactor (SBR)—as well as different electricity production methods and sludge management strategies, the research aims to identify opportunities for enhancing sustainability and reducing environmental footprints. Utilizing the ReCiPe v1.13 method and SimaPro 9.6.0.1 software, the study assesses key impact categories: climate change, freshwater eutrophication, human toxicity and freshwater ecotoxicity. The results showed that the OA system resulted in 30% lower climate change impacts than the SBR system (0.61 vs. 0.87 kg_{CO2 eq}) but 24% higher freshwater eutrophication (6.17 × 10⁻⁴vs. 4.69 × 10⁻⁴ kg_{P eq}). Utilizing electricity produced from natural gas resulted in an 8.4% reduction in climate change impacts compared to using electricity from the local grid (0.6 vs. 0.66 kg_{CO2 eq}) and an 81% reduction in freshwater ecotoxicity (1.29 × 10⁻³vs. 2.18 × 10⁻⁵ kg_{1,4-DB eq}). Additionally, endpoint analysis of Scenario 0 highlights that the AAO biological and coagulation tanks are the main contributors to Human Health and Resource impacts, with respective scores of 13.8 mPt and 11.5 mPt, demonstrating areas for targeted improvement. The utilization of sewage sludge as fertilizer reduces the impact on climate change by 80% (0.036 vs. 0.3 kg_{CO2 eq}) and nearly eliminates freshwater eutrophication (5.01 × 10⁻⁶vs. 1.77 × 10⁻⁴ kg_{P eq}) compared to landfill. These findings provide detailed insights into different treatment processes and resource utilization strategies, offering a robust framework for enhancing sustainability in developing countries.