Submitted to: Water Environment Federation
Publication Type: Abstract Only
Publication Acceptance Date: February 19, 2003
Publication Date: February 19, 2003
Citation: McConnell, L.L., Hyunook, K., Arispe, S. 2003. Characterization of odors and evaluation of odor control techniques utilizing solid-phase microextraction [abstract]. WEF/AWWA/CWEA Joint Residuals and Biosolids Managment Conference, Pre-Conference Workshop, Workshop A, "Managing Odors from Biosolids - New Science and New Solutions", February 19, 2003, Baltimore, MD. p. 20-22.
Odor Research is, in part, an analytical chemistry problem. Compounds that cause odors are generally, extremely volatile, reactive and more polar that typical volatile organic compounds. This instability increases the likelihood of degradation or transformation during sample collection, processing and analysis. Some Common Odorants are: hydrogen sulfide, sulfides, mercaptans, amines, volatile fatty acids, indole, skatole, and p-cresol. A variety of methods are needed to assess the effectiveness of odor control technologies. In many cases, new approaches are needed that are easy, reliable, quick and inexpensive. These methods should provide quantitative information at a compound specific-level and should work with existing gas chromatography (GC) and GC-mass spectrometry (MS) equipment. Solid Phase Microextraction is a commercially available device. A thin, coated fused silica fiber equilibrates with organic compounds in gas or aqueous phases in proportion to their concentration in the sample. After exposure to the sample, the coated fiber is desorbed in the injection port of the GC for separation and analysis of a number of common odorants. Different coatings are available for different compound classes. This technique has been used to quantitate key odorous gases in the headspace over biosolids and compost samples. Calibration of the SPME fiber is carried out using standard gases generated from certified permeation devices. In a study of unit processes of a large wastewater treatment plant, the magnitude of reduced sulfur gases increased as the solids were concentrated in the system. The increase in reduced sulfur gases correlated with the drop in oxidation-reduction potential of the sludge. Trimethylamine was present in the headspace only after liming of the final biosolids product.