University of Massachusetts Amherst
Water and Energy Technology Center
Case Studies
On-Site Generated PAA: A Green Alternative
for Wastewater Disinfection
A comparative evaluation of four commercially available peracetic acid (PAA) formulations and a proprietary, on-site generated PAA formulation (PAA-OSG) was conducted to assess their efficacy in inactivating Escherichia coli (E. coli) strain (ATCC® 25922™) in both laboratory cultures and municipal wastewater.
PAA-OSG demonstrated comparable disinfectant performance to commercial PAA formulations and equivalent chlorine doses. These findings suggest that PAA-OSG is a viable alternative to conventional PAA disinfectants for wastewater treatment, with the potential to significantly reduce the carbon footprint associated with chemical transportation.
Enhancing Grit
Washing Efficiency
A pilot-scale grit washing system was evaluated for its effectiveness in removing contaminants from wastewater. The system was installed at the Amherst wastewater treatment plant and subjected to rigorous testing using various sand-slurry mixtures.
Results indicated that the system was highly efficient in removing solids from the wastewater, particularly for larger particle sizes. To optimize the system’s performance, a level sensor was integrated to automate the dewatering process. This enhancement significantly improved the system’s efficiency and reduced energy consumption by up to 80%.
Power Reduction and Performance Enhancement
in Wastewater Aeration
Water resource recovery facilities (WRRFs) are energy-intensive, with aeration processes consuming up to 70% of total power. This study focuses on optimizing aeration motor performance at the Amherst WRRF to reduce energy consumption and extend equipment life.
By installing high-resolution energy monitoring equipment, we identified significant power inefficiencies during motor ramp-up and operational fluctuations. A model was developed to assess the impact of reducing ramp-up speed on dissolved oxygen levels, demonstrating minimal effect on treatment performance. Implementing a slower ramp-up time resulted in a 2 kWh per motor, per cycle reduction in energy consumption, translating to over $4,000 in annual savings.
Additionally, reduced power fluctuations mitigated motor stress. These findings highlight the potential for substantial energy savings and extended equipment life through optimized aeration motor control in WRRFs.
