Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: February 22, 2004
Publication Date: February 22, 2004
Citation: Arispe, S., Kim, H., McConnell, L.L., Torrents, A., Ramirez, M., Peot, C. 2004. Measuring odorous gases in solids processes of a large WWTP [abstract]. WEF Residuals and Biosolids Management Conference and Exhibition 2004, Workshop C, Managing Odors and Biosolids. Paper No. 24.
Solids handling processes are important sources of odor in Waste Water Treatment Plants (WWTP's). The odor quality of upstream solids processes will also control the character of the final biosolids product for land application. Odor-causing chemicals may be present in influent waters, or they may be formed via degradation of organic matter during treatment processes. Key parameters such as pH, oxidation-reduction potential (ORP), metals concentration, polymer, and temperature can control production of such chemicals as methyl mercaptan, dimethylsulfide, dimethyldisulfide, and p-cresol. A control scheme that requires feedback from within the WWTP system is needed to respond to conditions that enhance the production of odor-causing chemicals. However detailed simultaneous measurements of plant conditions and odorous chemical concentrations from different solids processes are required to design this control scheme with the goal of minimizing the production of highly odorous biosolids. A large WWTP in Washington, DC was selected for this study. In the first stage, weekly grab samples are being collected from all major solids processes along with dewatered sludge. Eight months of a 12-month survey have been completed.
Along with numerous ancillary measurements to characterize the sludge, fifteen key odorous gases are being measured in the headspace over sludge using solid phase microextraction fibers followed by analysis by gas chromatography-mass spectrometry. Target analytes are from the sulfide, mercaptan, amine, cresol, and volatile fatty acid groups. Correlation analysis of odor chemical analysis and sludge characteristics will be used to determine factors controlling odor production and to assess sources.