Biological vapor‐phase treatment using biofilter and biotrickling filter reactors: Practical operating regimes

Abstract

The biological treatment of volatile organic compounds (VOCs) and air toxics has received increased attention in recent years. Biotreatment of air‐borne contaminants offers an inexpensive alternative to conventional air treatment technologies such as carbon adsorption and incineration. Most biological air treatment technologies commercially available are fixed‐film systems that rely on growth of a biofilm layer on an inert organic support such as compost or peat (biofilters), or an inorganic support such as ceramic or plastic (biotrickling filters). If designed properly, these systems combine the advantages of high biomass concentration with high specific surface area for mass transfer. At economically viable vapor residence times (1 to 1.5 minutes), biofilters can be used for treating vapor streams containing up to approximately 1500 μg/L of readily biodegradable compounds. Biotrickling filters may offer greater performance than biofilters at high contaminant loadings, possibly due to higher internal biomass concentrations. Both systems are best suited for treating vapor streams containing one or two major compounds. If designed properly, biofilters are especially well suited for treating streams that vary in concentration from minute to minute.

Comparative Scale-Up and Cost Estimation of a Biological Trickling Filter and a Three-Phase Airlift Bioreactor for the Removal of Methylene Chloride from Polluted Air

“…21,22 Among the various types of bioscrubbers, biotrickling filters and three-phase airlift reactors are the most promising equipment. 7,20,23 Airlift reactors are extensively used for wastewater treatment, and have recently been shown highly effective for waste air treatment. 20,25 Although more complex and more expensive than biofilters, bioscrubbers have proven superior in eliminating acid-producing pollutants, such as chlorinated VOCs.…”

Two-Stage Biofilter for Effective NH3 Removal from Waste Gases Containing High Concentrations of H2S

“…12 The technique contains higher microbial content, environmental endurance, and operational stability at a lower treatment cost. 13 However, high H 2 S concentrations (120 ppmv) significantly suppress the NH 3 removal from waste gases in a coimmobilized cell biofilter. 14 Similar results have also been found by Kim et al 15 and Lee et al 16 This dramatic reduction in NH 3 removal is because of the simultaneous introduction of high H 2 S concentrations, which result in a large accumulation of acidic metabolites and creates substantial operational problems for traditional biofilters.…”

A Fundamental Study of Biofiltration Processes for VOC Removal From Waste Gas Streams

“…Therefore, a moving liquid phase exists in this system instead of the stationary phase of a natural nutritive bed biofilter. Biotrickling filters allow more uniform substrate and nutrient distribution, better pressure drop control, more consistent operation and higher VOC removal efficiency than conventional biofilters (Togna and Singh 1994). A major disadvantage, according to Severin, Shi, and Hayes (1993), is that VOC vapors must first be absorbed into the flowing liquid phase, which becomes the rate-limiting step for compounds with low water solubility.…”