Aeration Tank As a Bioscrubber for Odor and VOC Control

An odor and air emissions control and wastewater treatment system upgrade was developed at the Spectraserv facility in South Kearny, New Jersey. The Spectraserv South Kearny facility is used for the dewatering of liquid residuals, which consist primarily of municipal wastewater treatment plant sludges, water treatment sludges, septage, and industrial wastewater sludges. The treatment system upgrade uses existing tankage as a biological reactor for odor and air emissions control from the site's dewatering building and for reduction of biochemical oxygen demand (BOD) that is currently discharged to the sewer. The upgrade provides a positive means of odor control using a proven technology while also reducing the organic load to the local Publicly Owned Treatment Works (POTW). The aeration tank operates as a bioscrubber and removes contaminants from the building air through a combination of chemical and biological processes. Treatability testing on the site wastewater was conducted to determine biodegradation rates and other data relevant to determining effectiveness for air emissions and odor control. Modeling of expected emission rates and odor levels at the property boundary was also conducted to evaluate the viability of this approach. Modeling results indicate diffusion of foul air into a biological treatment tank provides excellent removal of hydrogen sulfide (>95%), ammonia (>98%) and VOCs (>89%) should be anticipated. Odor modeling was also conducted to evaluate the effectiveness of the bioscrubber at controlling odors at the fence line. Results indicate the dilution to threshold odor intensity (D/T) from the aeration tank for ammonia and hydrogen sulfide will be less than 5, thus obviating the need for additional controls. The bioscrubber is currently in the start-up phase. An intensive data collection program is underway and will include analysis of inlet and outlet air quality, as well as inlet and outlet liquid quality and various operational parameters, including dissolved oxygen and temperature in the aeration tank. The broader applicability of this approach, as an odor control and air contaminant control technology, includes other industrial categories facing air emission control requirements from wastewater treatment and process units (e. g., chemicals and petroleum). Additionally, a similar approach was used at a textile mill for opacity control.