Removal of Acetone Vapor from Air Using a Biotrickling Filter Packed with Polymeric Bioballs

Acetone released into the atmosphere can adversely affect human health and the environment. The aim of this work was to evaluate the performance of a laboratory-scale biotrickling filter (BTF) with bioball packing material to remove acetone vapor from contaminated air. The acetone removal efficiency was investigated in two different scenarios: with and without the inoculation of microorganisms. Three strains of bacteria, Pseudomonas putida, Rhodococcus aerolatus, and Aquaspirillum annulus, were used in the BTF. In both cases, the filter units were simultaneously operated for 100 days under three different inlet acetone concentrations (0.18 ± 0.01 g/m3, 0.25 ± 0.01 g/m3, and 0.40 ± 0.02 g/m3) and two different gas flow rates (2.54 and 5.09 m3/h). The results showed that acetone removal was greater in the filter with the inoculated bacteria. In the filter operated without inoculum, the acetone removal efficiency gradually decreased with filtration time from 90.1% to 6.1%. While employing three types of bacteria in the BTF, the efficiency of acetone removal remained relatively stable and varied between 70.2% and 97.6%. The study also revealed that bioballs can be successfully used as a packing material in air biofiltration systems designed for acetone removal from the air.

EXPERIMENTAL REEARCH ON APPLYING LAVSAN IN THE AIR BIOFILTRATION PROCESS / LAVSANO TAIKYMO ORO BIOFILTRACIJOS PROCESE EKSPERIMENTINIAI TYRIMAI

Air cleaning efficiency tests on placing material load into the lavsan biofilter were carried out. Testing included butanol vapour-contaminated air stream pulled during the boot. The studies were conducted by the Department of Environmental Protection at VGTU that developed a biofilter – an experimental biological air cleaning device. Measurements were done using 60 l/min and 90 l/min air volume aspirators under the initial pollutant concentration making 180, 305, 350, 440 and 545 mg/m3. Before measuring the concentrations of butanol lavsan cartridge, loading was periodically irrigated with nutrient-rich solution. In order to evaluate the influence of microorganisms on genus Pseudomonas, cleaning efficiency tests were repeated – Boot was moistened with water only, which allowed measuring butanol vapour concentrations after the cartridge. At the concentration of 180±9 mg/m3, efficiency reached 41% at a speed of 0,07 m/s and 46 % at a speed of 0,10 m/s. Measuring the performance of the initial concentration of 545±67 mg/m3, efficiency was 54% at 0,07 m/s and 53 % at 0,10 m/s respectively. Article in Lithuanian. Santrauka Atlikti oro valymo efektyvumo tyrimai į lašelinį biofiltrą įkrovus lavsano medžiagos įkrovą. Bandymų metu pro įkrovą buvo traukiamas butanolio garais užterštas oro srautas. Tyrimai atliekami naudojant VGTU Aplinkos apsaugos katedroje sukurtą eksperimentinį biologinį oro valymo įrenginį – biofiltrą. Matavimai atlikti leidžiant 60 l/min. ir 90 l/min. oro kiekį aspiratoriumi. Pradinės teršalo koncentracijos – 180, 305, 350, 440, 545 mg/m3. Prieš matuojant butanolio koncentracijas panaudojant lavsano medžiagos kasetę, įkrova buvo periodiškai drėkinama maistinių medžiagų prisotintu tirpalu. Pseudomonas genties mikroorganizmų įtakai valymo efektyvumui įvertinti tyrimai buvo pakartoti – įkrovos sudrėkinamos tik vandeniu, leidžiami butanolio garai, ir matuojamos koncentracijos panaudojus lavsano medžiagos kasetę. Esant 180±89 mg/m3 koncentracijai biofiltro oro valymo efektyvumas siekė 41 %, kai per įkrovą leidžiamo dujų srauto greitis buvo 0,07 m/s, ir 46 %, kai greitis 0,10 m/s. Nustatyta valymo efektyvumas. Esant 545±55 mg/m3 pradinei koncentracijai jis siekė 54 % (0,07 m/s) ir 53 % (0,10 m/s).

Biofiltration d'air pollué par du xylène sur un nouveau lit à base de cellulose

The problem related to air discharge contaminated with volatile organic solvents (VOS) is the scope of numerous researches. Throughout the last decades, the development of different types of bioreactors to treat atmospheric emissions contaminated with VOS has been observed, such as: the bioscrubber, the percolating filter and the biofilter. These bioreactors are processes that use microorganisms in order to degrade the VOS into carbon dioxide, water, and biomass. This paper presents the results of a study on degradation by biofiltration of xylene contained in air, with a new filtering bed composed of cellulose. We have studied the conversion, the capacity of elimination of xylene with respect to the inlet load and the production of carbon dioxide. An elimination capacity of 75 g·m-3·h-1 for an inlet con centration to the biofilter of 1.7 g·m-3 of xylene has been obtained, which is a value that is superior to values mentioned in the literature. Measurements of temperature, pressure drop, and moisture content have been taken regularly so as to evaluate the influence of these parameters in the degradation process of xylene by microorganisms. Counts of bacteria and yeast/mould present in the filtering bed have been performed in order to follow the evolution of these micro organisms. At last, modeling based on the Ottengraf's model (1986) has been developed with the experimental data.Key words: treatment, air, biofiltration, xylenes, cellulose, volatile organic solvents.