Purification of exhaust air containing organic pollutants in a trickle-bed bioreactor

Abstract

S u m m a r y . This paper reports experiments on the purification of exhaust air containing organic pollutants by a new biological process using a trickle-bed reactor. Pollutant-specific microorganisms in high concentration were fixed to a suitable bed. The absorption and conversion of propionaldehyde as a model pollutant was measured by systematic variation of the gas and liquid flow rates in the reaction system. At a space velocity of 1000 h -1, it was possible to achieve conversion rates of between 68 and 96%, depending on the trickling density. The degradation capacity of the biological trickle bed is over 500 g propionaldehyde/m 3 of reactor per hour. By using a tube bundle (honeycomb tube), it was possible to ensure continuous operation of the reactor with reduced conversion and pressure loss.

Activity of toluene-degrading Pseudomonas putida in the early growth phase of a biofilm for waste gas treatment

“…Biofiltration is an attractive technique for purification of emissions in low concentrations because of its simplicity and cost-effectiveness. General experiences with the technique are satisfactory, but major problems with clogging of the filters due a high biomass or extracellular polymer production are often reported (Diks and Ottengraf, 1994;Govind et al, 1993;Jol et al, 1994;Kirchner et al, 1991). To prevent clogging of the filters and to optimize and control the purification process, investigations of the biofilm growth in the filters are needed.…”

Controlled biomass formation and kinetics of toluene degradation in a bioscrubber and in a reactor with a periodically moved trickle-bed

“…Thus, a desired volumetric capacity for waste gas treatment can be obtained when a low specific microbial degradation rate is compensated by an equivalent increase in cell mass. High concentrations of biomass in a trickle-bed reactor, however, raise problems of clogging and channel formation resulting in a reduction of interfacial area for mass transfer and an increased requirement for air compression (Kirchner et al, 1991;Weber and Hartmans, 1996). Therefore, controlled formation of biomass in a trickle-bed reactor is a prerequisite to estimate its capacity and the continuity for waste gas treatment.…”

A High Performance Biofilter for VOC Emission Control

“…1 The bioscrubber and biotrickling filters have also received increased attention due to their low pressure drops and better control of reaction conditions (pH, nutrients). [1][2][3][4][5][6] Some studies have shown that biotrickling filters, possibly due to high internal biomass concentrations, may provide greater performances than biofilters at high VOC loading. For example, only 20 g/m 3 .hr of elimination capacity for toluene was obtained in a biofilter, 7 while 200-250 g/m 3 .hr was achieved by use of a biotrickling filter.…”

“…In recent years, considerable progress has been made on the first and second aspects. [1][2][3][4][5][6][7][8][9][10][11][12][13] Due to this intensive research, much progress has been made in isolating, selecting or constructing strains or mixed cultures of microorganisms, which can degrade some of the recalcitrant compounds to a considerable extent. 1 The bioscrubber and biotrickling filters have also received increased attention due to their low pressure drops and better control of reaction conditions (pH, nutrients).…”