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

Thi Kieu Loan Nguyen; Huu Hao Ngo; Wenshan Guo; Thuy Le Hong Nguyen; Soon Woong Chang; Dinh Duc Nguyen; Sunita Varjani; Zhongfang Lei; Lijuan Deng

doi:10.1016/j.scitotenv.2021.147135

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

Sci Total Environ. 2021 Aug 25:784:147135. doi: 10.1016/j.scitotenv.2021.147135. Epub 2021 Apr 16.

Authors

Thi Kieu Loan Nguyen¹, Huu Hao Ngo², Wenshan Guo¹, Thuy Le Hong Nguyen¹, Soon Woong Chang³, Dinh Duc Nguyen⁴, Sunita Varjani⁵, Zhongfang Lei⁶, Lijuan Deng¹

Affiliations

¹ School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NWS 2007, Australia.
² School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NWS 2007, Australia; NTT Institute of Hi-Technology, Nguyen Tat Thanh University, Ho Chi Minh City, Viet Nam. Electronic address: ngohuuhao121@gmail.com.
³ Department of Environmental Energy Engineering, Kyonggi University, 442-760, Republic of Korea.
⁴ Department of Environmental Energy Engineering, Kyonggi University, 442-760, Republic of Korea; Institution of Research and Development, Duy Tan University, Da Nang, Viet Nam.
⁵ Gujarat Pollution Control Board, Gandhinagar, Gujarat, 382 010, India.
⁶ Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoidai, Tsukuba, Ibaraki 305-8572, Japan.

PMID: 33894605
DOI: 10.1016/j.scitotenv.2021.147135

Abstract

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.

Keywords: Energy recovery; Environmental impacts; Life cycle assessment; Materials; Recycle; Wastewater treatment plant.