TruSense were the project leader for this project which forms part of the Water Research Commission’s energy efficiency in the water sector initiative. The objective of the project was to determine feasible practical aeration energy conservation measures that can be implemented at typical South African BNR activated sludge plants that not only result in aeration energy use reduction but also ensure final effluent compliance with permit requirements.Two BNR activated sludge plants Zeekoegat was (85 Ml/d) and JP Marais (15 Ml/d) were used as case studies.
The main tasks involved collection and analysis of data, energy audits and benchmarking, evaluation of aeration energy use reduction strategies through advanced modelling and simulation as well as financial analysis.
The Key findings from the project were:
Identified aeration ECMs can potentially save 9-40% of aeration energy consumption and cost.
Implementing the identified ECMs which include optimal process and aeration control results in improved biological nutrient removal and compliance with final effluent nitrogen and phosphorus limits.
In order to realise these savings local authorities, need to develop a clear energy management strategy and put in place robust systems and structures towards achieving this strategy.
Knowledge dissemination workshops were carried out to communicate the project findings to key stakeholders.
The project was undertaken in collaboration with the City of Tshwane and ERWAT who provided the case study plants as well as collection of wastewater data and analysis services