WATER ENVIRONMENT RESEARCH FOUNDATION (WERF) PHASE 3 BIOSOLIDS ODOR RESEARCH RESULTS, FINDINGS, AND RECOMMENDATIONS FOR CAKE ODOR REDUCTION

The WERF Phase 3 Project 03-CTS-9T entitled “Biosolids Processing Modifications for Cake Odor Reduction” encompasses nine research agenda items developed from the results of Phase 2, which was completed under WERF Project No. 00-HHE-5T (Adams et al, 2003). Phase 3 has been a 3-year project dedicated to testing hypotheses in the laboratory as well as on pilot-scale and full-scale bases, to determine the causes and biosolids odors and find ways to remediate them. The Phase 3 project has concluded and the Final Report has been drafted, which is due for publication in late 2007.Laboratory and full-scale investigations conducted in Phase 3 have included:The role of cations in odor production from anaerobically-digested biosolidsThe effect of anaerobic digestion parameters such as mixing, detention time, temperature, and phasing on cake odor production.Effects of dewatering processes and their control parameters on cake odorsEffects of chemical addition on cake odorsDemonstration of promising research findings at full-scale biosolids digestion and dewatering facilities has constituted the last portion of this project to date. Email and fax surveys were used to contact wastewater treatment facilities and professionals with an interest or need to reduce their biosolids cake odors. The project team developed and distributed additional surveys and requests for interest to chemical vendors and equipment suppliers.The main goal of this last phase of the project was to match wastewater or biosolids facilities that need to reduce biosolids odors with specific technologies, chemicals, or biological agents, in order to demonstrate the efficacy of promising laboratory findings at full-scale WWTPs when opportunities for such demonstrations presented themselves.