Media: Cary intends to purchase media for the replacement of the existing media with new, random, inorganic media with hydrophilic pores. The first section of the existing biofilters includes humidification stages followed by the existing biofilter cells, to house the new media. The existing biofilter systems were manufactured by Enduro/Bay. However, we will consider an approved alternative that meets ALL the following requirements. a) Designed to continuously treat and effectively remove: o hydrogen sulfide o ammonia o reduced sulfur compounds o eliminate odors in the foul air exhausted from the solids handling facilities as specified b) Hydrogen sulfide, mercaptans and associated odorants will be removed by microbial action within media furnished for the existing biofilter c) Promote thorough mixing and contact between the odorous air d) Pre-formulated with buffering agents, activated carbon or nutrients e) Suitable to handle the sulfide loads as specified f) Shall not shrink or swell with varying moisture content g) Performance and Design Criteria: o Density shipping: 35-40 lbs/cubic feet o Density operating: 55-60 lbs/cubic feet o Pressure Drop at 10 ft/min: 0.4”/ft o Pressure Drop at 5 ft/min: 0.2”/ft o Vessel 1 Width: 14 feet o Vessel 1 Length: 50 feet o Vessel 1 Height: 5.4 feet o Vessel 2 Width: 8.5 feet o Vessel 2 Length: 11 feet o Vessel 2 Height: 6 feet o Vessel 3 Width: 8.5 feet o Vessel 3 Length: 11 feet o Vessel 3 Height: 6 feet o Vessel 1 Media Volume: 3,750 cubic feet o Vessel 2 Media Volume: 561 cubic feet o Vessel 3 Media Volume: 561 cubic feet o Maximum initial Pressure Drop (inlet flange to outlet flange), inches of water column…………………………2 o Maximum final Pressure Drop (inlet flange to outlet flange), inches of water column…………………………8 o Minimum EBRT, 35 seconds o Average Foul Air Inlet Concentrations (ppm) ▪ Hydrogen Sulfide ….4 ▪ Methyl Mercaptan----1.5 ▪ Dimethyl Disulfide….0.5 ▪ Carbon Disulfide……0.5 ▪ Carbonyl Sulfide……0.5 ▪ Dimethyl Sulfide……0.5 o Outlet: Average hydrogen sulfide removal efficiency to be equal to or greater than 99.0 percent over a test period that includes both average and peak conditions or average outlet H2S concentration to be less than 0.5 ppmv. Whichever is more stringent. Peak Total Reduced Sulfur Compounds shall not exceed 5 ppm. o Odor Concentration: ▪ Outlet: Average outlet odor removal efficiency to be equal to or greater than 90.0 percent over the test period that includes both average and peak conditions or an average concentration not to exceed 300 dilutions-to- threshold (D/T). Whichever is more stringent. ▪ Performance testing shall be based on the performance of the biofilter only; the use and performance of the carbon scrubber system shall not be used in the determination of removal efficiencies by the biofilter. o Existing Fan Design - Air Flow up to 7800 scfm o Components of System to be compatible with conditions and constituents to which they will be subjected to during normal operation. Compounds with which the MATERIALS of construction must be compatible with include, but are not limited to: ▪ Hydrogen Sulfide ▪ Sulfuric Acid ▪ Ammonia ▪ Dimethyl Sulfide ▪ Methyl Mercaptan and other Mercaptans ▪ Other Reduced Sulfur Compounds (RSCs) o Biofilter system must be able to re-acclimate after upset conditions within a period of three weeks o Air temperature, degrees F 50 to 105 o Relative Humidity: >90 percent
