Environmental impacts and greenhouse gas emissions assessment for energy recovery and material recycle of the wastewater treatment plant.

This study investigated the environmental burdens concerning the recycling/recovery process of a wastewater treatment plant's construction material waste and biogas. Detailed data inventories of case studies were employed in several scenarios to explore the role of end-of-life treatment methods. The ReCiPe 2016 and the Greenhouse gas Protocol life cycle impact methods were conducted to measure the impact categories. The construction and demolition phases were considered for recycling potential assessment, while the operational phase was examined for assessing the advantages of energy recovery. Metal and concrete recycling show environmental benefits. Increasing the reprocessing rate requires more water consumption but results in: firstly, a decrease of 18.8% in total damage; secondly, reduces problematic mineral scarcity by 3.9%; and thirdly, a shortfall in fossil fuels amounting to 11.6%. Recycling concrete helps to reduce the amount of GHG emissions 1.4-fold. Different biogas treatment methods contribute to various outcomes. Biogas utilization for on-site energy purposes has more advantages than flaring and offsite consumption. Electricity and heat generation originating from biogas can provide 70% of the energy requirement and replace 100% natural gas usage. Biomethane production from biogas requires extreme power and more resources. Meanwhile, producing heat and electricity can offset 102.9 g of fossil CO2, and manufacturing biomethane contributes the equivalent of 101.2 g of fossil fuel-derived CO2. Reducing 10% of recovered electricity creation could rise 19.19% global warming indicator of the wastewater treatment plant.