Environmental impact of a domestic wastewater treatment plant using LCA approach under various treatment scenarios: a case study in Bangladesh

This study aims to determine the environmental footprint of the Dasherkandi WWTP in Dhaka, Bangladesh, using the life cycle assessment (LCA) approach. Five treatment scenarios have been developed considering various technological and resource recovery options, using a 'gate-to-gate' approach. The CML baseline 2000 method was used to determine the environmental impact. The net environmental benefits for scenario having tertiary treatment for water reclamation and anaerobic digestion for biogas generation were several orders of magnitude higher compared to those in the baseline scenario, particularly for impact categories such as abiotic depletion (2.7 times), acidification potential (3.0 times), ozone layer depletion (5.7 times), terrestrial ecotoxicity (1.9 times), and photochemical oxidation (3.3 times). Tertiary treatment (with water reclamation) has been found to reduce the corresponding environmental impacts by 1.4 to 8.6 times over all impact categories. An economic analysis showed that 4.49 BDT (1 BDT ≈ 0.0082USD) net financial gain could be realized with revenues from reclaimed water, biogas electricity, and fertilizer per m³ of wastewater treated. These findings can guide the design of environmentally and economically sustainable treatment technologies in developing countries like Bangladesh.