Set organic pollution as an impact category to achieve more comprehensive evaluation of life cycle assessment in wastewater-related issues

Abstract

For wastewater-related issues (WRI), life cycle assessment (LCA) is often used to evaluate environmental impacts and derive optimization strategies. To promote the application of LCA for WRI, it is critical to incorporate local impact of water pollutants. Organic pollution, a main type of water pollution, has not been given much consideration in current LCA systems. This paper investigates the necessity of setting a regionalized impact category to reflect the local impact of organic pollution. A case study is conducted concerning an upgraded wastewater treatment plant (WWTP) in China, which is assumed to meet different sewage control strategies. Chemical oxygen demand (COD) is selected to represent the organic pollution and treated as an individual impact category. CML 2002 is used to quantify the environmental impacts of different strategies. Results show that abnormal LCA results are generated with the traditional eutrophication impact category, and after the introduction of COD, more reasonable LCA results are obtained, making the entire comparison of different control strategies more meaningful and compelling. Moreover, BEES, Ecovalue 08, and Chinese factors are adopted here as different weighting methods. Different weighting results exhibited various trade-offs for the increasingly strict control strategies; the results of BEES and Ecovalue08 underlined the potential environmental burden, but the results of Chinese factors only emphasized the local environmental improvement. It is concluded that setting regionalized impact category for organic pollution can make LCA results more reasonable in wastewater treatment, especially in evaluating Chinese cases because of the serious water pollution caused by large quantities of COD emission.

Life cycle assessment of wastewater treatment in developing countries: A review

“…The most important advances in this topic have been made in China with several WWTP studies using Chinese normalization and weighting factors (Vera et al, 2015;Li et al, 2013;Zhao et al, 2018). Bai et al (2017) calculated specific Chinese normalization and weighting factors and obtained different environmental hierarchy for four discharge scenarios of a WWTP with activated sludge treatment when compared them with the results obtained with other non-Chinese normalization (CML (Guinée et al, 2001)) and weighting factors (BEES (Suh and Lippiatt, 2012)),…”

“…EPA (Lippiatt, 2007) and EDIP 2003 (Hauschild and Potting, 2005)). Further development of general weighting factors and specific freshwater and terrestrial toxicity-based normalization indicators for China have been highlighted as main priorities for future WWT-related LCAs (Bai et al, 2017;Zhao et al, 2018;Li et al, 2013;Wang et al, 2015). To develop widely accepted weighting factors, the involvement of wide range of stakeholders is crucial.…”

Life Cycle Assessment for Tertiary Wastewater Treatment and Reuse versus Seawater Desalination

“…-LCA has also been used to address the environmental impacts as well as the benefits of supplementing, upgrading, and improving treatment processes [32,[36][37][38]. The obtained results indicated that LCA was powerful for optimizing the interaction among the operational parameters, thus facilitating access to the optimum decision [39][40][41][42]. A categorized literature review for LCA and wastewater treatment in accordance to LCA requirements by ISO 14040 [43] is provided in the next sections.…”

“…Cradle-to-gate: From the stage of untreated wastewater input to sludge treatment. Zhao, et al [39] 10,000 m 3 WWTP Pradel and Aissani [40] 1 kg WWTP…”

“…The vast majority of wastewater LCA studies have used Ecoinvent [27-30, 36, 38, 40]. The USEtox and Ecoinvent databases were used in Li,et al [35] and Zhao, et al [39], respectively. Ma, et al [31] created new LCI processes based on a coal-based power generation plant located in China.…”