Resilient Wastewater Management for Small Municipalities
Country: South Africa
South Africa's wastewater treatment plants (WWTPs) and collection systems are in a critical state, with 39% classified as such in the 2021 Green Drop report, posing significant environmental and public health risks. Despite substantial funding over the past 25 years, the condition of WWTPs has worsened, especially in small and medium-sized municipalities. This decline is due to a lack of technical, operational, managerial, and financial skills, hindering effective assessment, strategy development, and compliance.
The Department of Water and Sanitation (DWS) has identified the absence of internal municipal capability as a major barrier to sustainable wastewater management. Past technical and private-sector interventions have largely failed to address these challenges. The 2023 Green Watch report highlighted that half of the municipalities with critically failing WWTPs do not meet basic regulatory requirements.
Recognizing the need for innovative solutions, the DWS aims to develop practical frameworks and guidelines based on sound engineering principles to improve technical competency, optimize plant operations, and promote sustainable WWTP management. This project supports the DWS initiatives by creating a best practice framework that incorporates case studies and mathematical modelling to address technical gaps in small and medium-sized municipalities. The project proposes comprehensive plant audits and optimization using design and modelling tools to unlock hidden plant capacity, reduce capital and operating costs, improve regulatory compliance, and enhance long-term capacity assessments.
A medium-sized municipality (B3) was selected as a case study to demonstrate the approach’s efficacy. Outputs from the project will inform a training program for municipal staff, improving compliance and Green Drop scores in future audits. The initiative aligns with the DWS 2022 National Water and Sanitation Master Plan (NWSIP), which outlines strategies to rehabilitate wastewater infrastructure. It aims to build municipal capacity and provide scalable tools, frameworks, and guidelines for broader application, ensuring long-term sustainability in wastewater management.
Start/End Date: 2024/2026
Project Title: Guiding Small and Medium Sized Municipalities to Sustainable and Resilient Wastewater Management Solutions and Green Drop Certification
Process and Energy Use Optimization for a BNR ASP
Country: Canada
Process-Energy optimization study for a (BNR) activated sludge plant to optimize operational & control parameters to improve final effluent compliance as well as reduce aeration energy consumption. BIOWIN/BIOWIN Controller simulation was applied to optimize the process as well evaluate aeration control strategies. The project also involved training of Operators in the use of the calibrated BIOWIN model as well as development of simplified O&M manuals that include chemical dosing for supplementary carbon, standby chemical P removal and pH adjustment.
Dates Started/Ended: 2013/2016
Project Title: Process - Energy Optimization for a Biological Nutrient Removal Activated Sludge Plant
Operational and Control Methods for Energy Savings at ASPs
Country: South Africa
A change in the energy tariff from constant charge to time of use resulted in high energy costs at the client's large, activated sludge plants. TruSense was awarded the contract to undertake the investigation of optimum operational methods to save energy under this new tariff while ensuring final effluent compliance. A 158 Ml/d wastewater treatment plant was used the first case study plant.
Comprehensive process audit and mathematical modelling were applied to evaluate various options of reducing energy use in the activated sludge process. covering
Modelling results predicted savings in aeration costs of 26% through implementing optimized aeration control and up to 52% through implementing both influent flow balancing and optimized aeration control. Site implementation of optimization of current control strategies through introduction of variable DO setpoints achieved immediate savings on aeration costs of 25% (~£120 000 per year) aeration costs without incurring substantial capital expenditure but only changes in control protocols. More complex measures such as implementing flow balancing within the collection system are under review for site trials.
Start/End Date: 2011/2016
Project Title: Investigation of Operational and Control Methods to Save Energy at Activated Sludge Plants