Use of High Rate Biotrickling Filters Operating at 7 s EBRT for Odor Control at Municipal WWTP

摘要

ProblemrnThe Buckman Water Reclamation Facility (WRF) is the largest and oldest wastewater treatmentrnplant operated by JEA, a regional utility serving Northeast Florida. Due to the generally highrnconcentration of odorous compounds, in particular H_2S, in the wastewater, along with productionrnof odors during the wastewater treatment processes, the plant creates significant odor challengesrnfor JEA. This is compounded by the fact that the plant is located in a densely-populated arearnwithin the urban core of the city.rnSolutionrnIn order to reduce the odor impact on its neighbors, JEA purchased three biotrickling filters asrnpart of a larger plant expansion at the Buckman WRF. Two separate EcoFilter~? EF1242rnbiotrickling filter systems were designed to treat odor from the existing Biosolids DisposalrnBuilding and the Influent Pump Station, and a single EcoFilter EF82 biotrickling filter systemrnwas designed to treat odors from the existing Raw Sludge Holding Tank. The two EcoFilterrnEF1242 systems replaced existing chemical scrubbers.rnThe biotrickling filter treating air from the Biosolids Disposal Building has a design airflowrncapacity of 26,335 m~3/hr (15,500 cfm), with a corresponding empty-bed residence time (EBRT)rnof 6.7 s. The biotrickling filters at the Influent Pump Station and Sludge Holding Tank treatrn25,485 m~3/hr (15,000 cfm) and 6796 m~3/hr (4,000 cfm), respectively, at EBRT of less than 7 s.rnThe 26,335 m~3/hr (15,500 cfm) design airflow of the biotrickling filter installed at the BiosolidsrnDiposal Building is believed to be the highest airflow treated by any single biotrickling filterrnvessel in the world. The system is designed to achieve more than 90% reduction of overall odorsrnplus eliminate more than 99% of the H2S in the odorous air. After startup and acclimation, thernEcoFilter system removed > 99.99% of inlet H2S from the airstream, which had an average inletrnH2S concentration of 148 ppmv.rnImpactrnThe biotrickling filter system treating odorous air from the JEA Buckman WRF BiosolidsrnDisposal Building has demonstrated more than 99.99% H2S removal at an EBRT of 7.0 s and >rn99% H2S removal with an EBRT of 3.5 s. The significance of this installation is that normalrnindustry standards require biological systems to be designed for 10-20 s EBRT, which results inrnlarger reactor vessels and high capital cost. By demonstrating removal of both H2S and odors atrnless than half of the industry normal EBRT, the EcoFilter proved to reduce capital cost as well asrnthe equipment’s required footprint, the latter of which is becoming more of a challenge forrnwastewater treatment plants located in landlocked urban communities.