Influence of ground tire rubber on the transient loading response of a peat biofilter

ABSTRACT. Ethyl acetate, n-hexane and toluene removal from an air stream was carried out using a flat composite membrane bioreactor. The composite membrane consisted of a dense polydimethylsiloxane top layer with an average thickness of 1.5 µm supported by a polyacrylonitrile layer (50 µm). The membrane bioreactor (MBR) was operated during 4 months under continuous and intermittent loading conditions. Removal efficiencies higher than 99% were obtained for inlet loads up to 200 g m -3 h -1 and empty bed residence times as short as 15 s for ethyl acetate. A maximum elimination capacity of 75 g m -3 h -1 (RE ~ 66%) at an EBRT of 60 s was obtained for toluene. The system was unable to degrade n-hexane when a 1:1:1 ethyl acetate:n-hexane:toluene was supplied. The intermittent loading experiments illustrated the capacity of the MBR to put up with intermittent feeding conditions (16 h day ) and recover quickly after a period without VOC feeding. Ethyl acetate was not detected in the membrane gas outlet. CO 2 production recovered within 1 -2 h and 12 h when organic compound supply turned off during a night and a weekend, respectively.

Section: Resultssupporting

confidence: 70%

Removal of ethyl acetate, n‐hexane and toluene from waste air in a membrane bioreactor under continuous and intermittent feeding conditions

Álvarez‐Hornos

Volckaert

Heynderickx

et al. 2012

“…During transient emissions of toluene in a stirred tank bioreactor, the presence of styrene‐butadiene co‐polymer beads provided significant buffering to the system during imposed step changes, demonstrating the enhancement of performance arising from the presence of the polymer beads . Also, the effect of using ground tire rubber under different intermittent conditions in a biofilter was investigated, demonstrating that its use as bulking material can attenuate the effect of high pollutant concentrations in the emissions . However, in our particular case, the consideration of other types of bioreactors such BTFs with polymers for the treatment of α‐pinene could be limited, at least under steady‐state conditions.…”

Section: Resultsmentioning

confidence: 94%

Influence of polymeric materials on the performance of a mesophilic biotrickling filter treating an α‐pinene contaminated gas stream

Montes

Veiga

Kennes

2015

BACKGROUND: Recent studies have characterized the most effective absorbent polymers for the removal of volatile hydrophobic pollutants from air. This study evaluates the performance of a laboratory scale -pinene-degrading biotrickling filter (BTF) packed with lava rock. A second solid phase, Hytrel ® G3548L (5%, v/v), was added in order to check its effect on the performance of the system during long-term operation. RESULTS: The biodegradation profile was similar in both bioreactor configurations, with or without solid polymers, reaching a maximum elimination capacity (ECmax ) around 25.6 g m −3 h −1 when an inlet loading rate of 57.2 g m −3 h −1 was applied. Tracer studies were carried out in order to determine the effect of the liquid and gas velocities, and to analyze the gas distribution with the different packing materials. CONCLUSIONS: Deviation from ideal flow caused by channelling of the fluid was observed from tracer studies. No better performance was observed under steady-state conditions in the presence of polymeric Hytrel material. Further considerations are needed for the selection of an appropriate absorbent polymer for -pinene removal. Industry 50 cm in height, while the filter bed volume was 0.4 L. The column also had three equidistant gas sampling ports along its height. At the beginning of each experiment, the clean air inlet flow was mixed with the test compound. The waste-gas stream and the J Chem Technol Biotechnol 2015; 90: 658-668

“…Álvarez‐Hornos et al ,5 using ground rubber tire in a biofilter treating VOCs, encountered difficulties in maintaining appropriate moisture content in the packing material, due to the poor water‐holding capacity of this material.…”

Section: Resultsmentioning

confidence: 99%

“…This material is responsible for helping to control pressure drop, sorption and contaminant distribution. Some recent studies have shown the use of rubber tire as support, for example Ik Oh et al 4 used ground rubber tire (GRT) mixed with compost and granular activated carbon (GAC) to treat toluene vapors; Álvarez‐Hornos et al 5 used GRT mixed with peat treating VOCs.…”

Section: Introductionmentioning

confidence: 99%

Biofiltration of increasing concentration gasoline vapors with different ethanol proportions

Rizzolo

Woiciechowski

Santos

et al. 2012

BACKGROUND: Brazil is one of the largest exporters and producers of ethanol. The local commercialization of flex fuel cars (vehicles that can run with pure gasoline or pure ethanol or the mixed gasoline) increases annually. Biofiltration technology can treat ethanol and gasoline vapors, mineralizing contaminants. The aim of this research was to evaluate biofiltration technology treating ethanol-gasoline vapor mixtures, considering different proportions of the two pollutants and of the mixture in increasing concentrations. Two bench scale biofilters (System 1 and System 2) were evaluated, each of 2.72 L. Packing material was a mixture of compost and granulated rubber tire at 2 : 1 (v/v). The gas flow rate was 450 mL min −1 , resulting in an empty bed retention time of 6.04 min. Inlet pollutant concentration ranged from 1.3 and 59 g m −3 (System 1) and 1.25 g m −3 and 55 g m −3 (System 2). Gasoline/ethanol ratios applied were (%): 80/20, 60/40, 40/60, 20/80 and 100% of ethanol. RESULTS: Removal efficiency and elimination capacity increased with ethanol load augmentation. During the six phases of study the removal efficiency average remained above 70% and the maximum elimination capacity achieved was 587 g m −3 h −1 (biofilter system 1) with neat ethanol.CONCLUSIONS: This study showed that biofiltration is an excellent option for gasoline amended ethanol vapors treatment.