Laserfiche WebLink
ODOR CONTROL STUDY <br /> treat the air from this source . The advantages and disadvantages of modular and <br /> custom biofilters were previously discussed . <br /> Because emissions from the Sludge and Septage Storage Tanks are likely to contain <br /> high concentrations of organic sulfides and biofilters have had problems removing <br /> organic sulfides , it is recommended that an independent biofilter not be used to treat <br /> emissions from this source . Instead , the emissions from this source should be directed <br /> to the existing RSF scrubbers and treated on a 24 hours per day, 7 days per week <br /> basis . The dampers on the existing duct system should be opened to improve <br /> ventilation and the hatches and covers should remain closed . <br /> For the scrubber option , modifications would still be required for the existing RSF <br /> scrubber to increase odor removal efficiency when operating during belt filter press <br /> operation . Total construction costs and engineering costs for these improvements are <br /> estimated to be approximately $600 , 000 . Operating costs for this mode of operation are <br /> estimated at $ 75 , 000 per year, which is about $25 , 000 more than current operating <br /> costs . <br /> 3 . 2 . 3 Consideration of Alternative Technologies <br /> Odors from sludge processing facilities contain a complex mixture of hydrogen sulfide , <br /> organic sulfides , and other organic compounds . Many technologies that may work well <br /> for removal of hydrogen sulfide , such as carbon filters , are -not appropriate for the <br /> removal of organic sulfides . Other technologies , such as ozonation , are also ineffective <br /> for removal of organic sulfides and are generally cost prohibitive to implement. <br /> Packed tower odor control scrubbers operating with a chemical oxidant, such as sodium <br /> hypochlorite , are generally recognized in the industry as best available control <br /> technology for the removal of organic sulfides . Based on the results of the odor study <br /> described herein , PBSU would recommend installation of a two-stage packed tower <br /> scrubber for the RSF even if there were currently no odor control on -site . <br /> 3 . 2 .4 Recommended Improvements <br /> Total construction and operating costs for the various RSF options are shown in Table <br /> 6 . Based on the advantages and disadvantages discussed above and the costs shown <br /> in Table 6 , the following improvements to the RSF are recommended : <br /> • Add a permanent drain for the mechanical thickener so the all hatches and <br /> covers can remain closed . <br /> • Open the dampers in the ducts on the Sludge and Septage Storage Tanks so <br /> that the headspace in the tanks can be ventilated more effectively. <br /> • Add chlorine solution and controls to the existing RSF scrubbers as described <br /> above and operate both scrubbers in series . <br /> •9 22 Indian River County, Central Wastewater Treatment Facility <br /> 11 PBS&J #071230, February 2003 <br />