W irk un gs gra d 100 hyp othe t w irku ngs gra d 40

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Unformatted text preview: in toluene degradation 35 -1 -3 hy po the t. W irk un gs gra d= 100 % hyp othe t. W irku ngs gra d= 40 Eliminationsleistung [g C org m h ] 50 % 45 30 25 20 Raumgeschwindigkeiten: -1 15 30 h 60 h-1 118 h-1 176 h-1 10 5 0 0 10 20 30 40 50 60 70 80 90 100 110 Spez. Volumenbelastung [g C org m-3 h-1 ] 120 130 140 150 160 Advantages and limits (= research areas!) • formerly: BWAP plants were used for odour reduction – mainly: bioscrubbers, soil biofilters • recently: increasing use in the `high Cconcentration area` ([C] >/ 1g/m3 – mainly: closed biofilters and biotricklingfilters • prerequisites for ready use of BWAP techniques: – biodegradability of waste air compounds / suited microorganisms !! – Moderate temperatures (hopefully <= 35oC) Limitations of biological exhaust-air processing • 40 14 35 12 30 10 Mesitylenmasse Mesitylene Mass 25 Mesitylen-Konzentration Mesitylene Conc. 8 20 CH3 6 15 4 10 H3 C 5 CH3 2 0 0 20 40 60 80 100 120 140 Zeit [h] Fig. by Reinhard Schmidt in „Thermisch unterstützte Bodenluftabsaugung (TUBA) zur in-situ-Mobilisierung von Schadstoffen in Phase“ 160 180 200 Time [h] 0 220 Konzentration [g/m3] High fluctuations in type and/or concentration of the components Peak loads in temp., dust, disinfectants, steam or other parameters Average Total-C-Conc. >> 2000 mg/m3 in simultaneity with high volume flow rates Poorly water-soluble components (perhaps also highly concentrated) Masse [kg] • • • • • • • Gasoline Vapor Treatment at a Soil Vapor Extraction Site (Ref.: Devinny, Deshusses and Webster „Biofiltration for air pollution control“) v Remediation site: Exxon service station; Hayward, CA, USA v Contaminants: (methyl) alkanes, cycloalkanes (C6 – C9), BTEX v Initial concentration (1995): 2,7 g/m³ v Characteristics of the biofilters : • Biofilter: 4 cubic containers, vol. of medium 1,2 m³ each • Medium type: perlite and compost (50:50) • Air flow rate: 13 – 32 m³/h, after 8 months 44 – 47 m³/h • Additionally: two 100 kg GAC canisters (downstream) Gaso...
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This document was uploaded on 03/25/2014.

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