REDUCED SULFUR (TRS) MONITORING IN WASTEWATER/BIOSOLIDS PROCESS EMISSIONS – EVALUATION AND SELECTION OF METHODS

Reliable monitoring of total reduced sulfur (TRS), hydrogen sulfide (H2S), and other individual reduced sulfur compounds under field conditions can present a formidable challenge to the field engineer. Perhaps the most critical aspect of any monitoring program is the selection of the appropriate methodology for a particular application. It is critical that the sample collection and analyses procedure provide data consistent with the end use of the data, as well as satisfy the program purpose and objectives. Emissions data are required for a variety of applications at wastewater treatment plants and biosolids composting facilities including: 1) regulatory compliance 2) air pollution control device performance, and 3) odor diagnostics and characterization.This presentation will provide a critical review of sample collection and analyses procedures available for monitoring of TRS, H2S and individual reduced sulfur species commonly found in wastewater/biosolids process emissions. A variety of continuous emissions monitoring methods, grab sampling techniques and integrated measurement techniques will be examined. These will include H2S monitors (Jerome, Interscan), EPA Reference Methods (15, 15A, 16, 16A, and 16B), gas chromatography/flame photometric detection (GC/FPD), continuous emissions monitors (CEMs), as well as colorimetric tubes (eg Draeger). The critical features of each method will be summarized including advantages and disadvantages. A process to assist users in the selection of appropriate methods for a particular application will be presented to include program design considerations.Case study data will be provided from several representative applications including performance testing of wet scrubbers, compliance emissions monitoring and characterization of process emissions from a biosolids composting facility. Method performance data collected during actual field applications will be presented including precision and accuracy measurements and method intercomparison data.