Articles
Publication Date: 2026
Water Resources and Industry (22123717)35
Wastewater from the baker's yeast industry contains high concentrations of organic and inorganic pollutants, necessitating effective treatment to minimize environmental impact. This study examines the falling film evaporator (FFE) and forced circulation evaporator (FCE) as single-effect units, as well as their combined performance in a multi-effect evaporator (MEE). To evaluate the performance of these systems, concentration reduction (C-RE), pollution load reduction (PL-RE), and grey water footprint reduction (GWF-RE) metrics are applied. Additionally, a new energy-based indicator is introduced to measure energy consumption per unit of pollutant reduction (ECI-PL) and grey water footprint reduction (ECI-GWF), providing a broader perspective on treatment sustainability. Based on C-RE, FFE removes 98.9 % of total phosphorus (TP), 94.4 % of biochemical oxygen demand (BOD5), and 93.5 % of chemical oxygen demand (COD), while FCE achieves the highest total nitrogen (TN) reduction at 32.8 %. GWF-RE for TP is observed at 99.4 % in FFE, 91.5 % in FCE, and 94.2 % in MEE. Energy consumption analysis reveals that the ECI-PL for TP removal ranges from 297 to 2560 kWh/kg. Despite its high energy demand, this process effectively reduces pressure on receiving water bodies, preserving between 617 (FFE) and 631 m3 (MEE) of freshwater for every kg of TP removed. These findings demonstrate that advanced evaporator systems effectively reduce the ecological footprint of baker's yeast wastewater, enhancing environmental sustainability. The results show that FFE is the most efficient in pollutant removal while maintaining lower energy consumption; however, TN reduction remains limited in this system. © 2025 The Authors.
Publication Date: 2025
Cleaner Environmental Systems (26667894)19
The stress exerted on aquatic environments by wastewater discharge outlets, including those from industrial parks, can be quantified through a refined assessment of the grey water footprint (GWF). The conventional total GWF (TGWF), widely used in practice, sums the GWFs of mixed outlets without identifying a critical pollutant (CP), which is essential for effective pollution control and management strategies. A novel methodology was developed to calculate the weighted total grey water footprint (W-TGWF), integrating all discharge outlets by considering dilution effects and identifying the final CP. This study, conducted over four months from October 2022 to January 2023, evaluated TGWF and W-TGWF simultaneously for mixed outlets of treatment processes, Activated Sludge (AS) and Membrane Bioreactor (MBR), operated in parallel to treat wastewater from an industrial park in Isfahan province, central Iran. The mixed influent wastewater at the equalization tank, representing the total inlet GWF, ranged from 1.55 to 2.06 million cubic meters per month (MCM/month). For mixed outlets, W-TGWF consistently yielded lower values than TGWF, showing reductions of 22 %, 13 %, 26 %, and 5 % from October to January. The periodic average W-TGWF was 15,304 m3/month based on NH4 as the CP. In contrast, TGWF reached 18,909 m3/month, 24 % higher, due to the simultaneous influence of NH4 and F parameters without definitive CP identification. These findings show that TGWF tends to overestimate environmental stress and obscure pollutant prioritization. The weighted approach offers a more accurate and ecologically meaningful framework for assessing mixed GWFs, with direct implications for water management and regulation. © 2025 The Authors
