Combining Process Modelling and LCA to Assess the Environmental Impacts of Wastewater Treatment Innovations

Abstract

Alternative wastewater treatment (WWT) technologies with lower environmental impacts seem to be the way forward in the pursuit of sustainable wastewater treatment plants (WWTPs). Process modelling of material and energy flows together with life-cycle assessment (LCA) can help to better understand these impacts and show the right direction for their development. Here, we apply this combined approach to three scenarios: conventional WWT; conventional WWT + chemically enhanced primary treatment (CEPT); conventional WWT + CEPT + side stream partial nitritation/anammox (PN/A). For each scenario, equations were developed to calculate chemical oxygen demand and nitrogen flow (solid and dissolved form) through the WWTP and to estimate the energy demands of its unit operations. LCA showed that the main environmental impact categories for all scenarios were global warming potential (GWP), eutrophication potential (EP) and marine aquatic eco-toxicity potential (MAETP). Compared with conventional WWT, CEPT and CEPT combined with PN/A resulted in a higher sum of normalized and weighed environmental indicators, by 19.5% and 16.4%, respectively (20.0% and 18.3% including biogenic carbon). Interestingly, the environmentally positive features of the alternative scenarios were often traded-off against other increased negative impacts. This suggests that further development is needed to consider these technologies a sustainable alternative.

Financial and Economic Investment Evaluation of Wastewater Treatment Plant

“…Conventional wastewater treatment plants (WWTPs) reduce water pollution but contribute to air pollution because their inputs (energy and materials) are linked to emissions [23,24]. Therefore, LCA (life cycle assessments) are increasingly used to assess the impact of these plants on pollution, all with the aim of applying such WWTPs that have zero impact on the environment [25,26]. Furthermore, recent research offers solutions for key energy savings of WWTPs to provide energy and financial savings during wastewater treatment.…”

Review of Latest Advances in Nature-Inspired Algorithms for Optimization of Activated Sludge Processes

“…The design and operation of wastewater treatment plants must consider quite a few uncertain factors, such as the physical and chemical composition of wastewater and the biological composition of organisms used to treat the wastewater. There are increasing concerns about the environmental impacts of wastewater, in terms of safe treatment, safe disposal, and safe reuse [1][2][3]. Over the years, this has led to Artificial Intelligence techniques, predominantly nature-inspired Artificial Intelligence techniques, being used for process control within treatment plants to maximize the efficiency of treatment and decrease energy consumption [4].…”

Distributed Generation Power Systems in Wastewater Management

“…Therefore, nowadays they are being replaced by renewable energy sources such as biogas and/or photovoltaics with or without battery storage [10]. Biogas is the most frequently used renewable source in WWTPs [10,11]. The combined generation of heat and power from biogas is a very profitable technology for WWTPs [12].…”