Application data for dry-scrubbing media in collection systems

Dry-scrubbing systems have been used for many years to control odors in wastewater applications. The systems have ranged in size from larger multiple bed scrubbers for force mains and large pump station applications to smaller single bed systems and modular systems in small wet wells, motor control centers, and other areas. Two reasons for their continued use are simplicity of design, operation, and maintenance as well as the ability to remove a wide range of odorous gases Equipment used for dry-scrubbing is inherently simple in ideology, design, and maintenance. The main purpose is to allow the dry-scrubbing media to contact the contaminant laden air stream. Various dry-scrubber systems and configurations may be applied, all of which can include a number of multipurpose gas-phase air filtration medias. Methods of applying these systems will be included here. Collection systems vary in the amount of odorous gases emitted depending on geographical location, time of year, population, and other factors. Data showing some of these differences have been collected and will be presented here to show what concentrations of H2S may be encountered. Two very important factors to consider here are both average concentration of the system and maximum concentrations. Dry-scrubbing systems have been specified for many years. Some standard practices are to require Challenge Testing of the dry-scrubbing systems after installation. These are generally based on average concentrations in the collection system area and must show a certain removal efficiency of the contaminant. Such testing will be presented to show the efficiencies of these systems for the odorous gas.