title: Control of VOCs from printing press air emissions by anaerobic bioscrubber: Performance and microbial community of an on-site pilot unit.
abstract: A novel process consisted of an anaerobic bioscrubber was studied at the field scale for the removal of volatile organic compounds (VOCs) emitted from a printing press facility. The pilot unit worked under high fluctuating waste gas emissions containing ethanol, ethyl acetate, and 1-ethoxy-2-propanol as main pollutants, with airflows ranging between 184 and 1253 m3h-1and an average concentration of 1126 ± 470 mg-C Nm-3. Three scrubber configurations (cross-flow and vertical-flow packings and spray tower) were tested, and cross-flow packing was found to be the best one. For this packing, daily average values of VOC removal efficiency ranged between 83% and 93% for liquid to air volume ratios between 3.5·10-3and 9.1·10-3. Biomass growth was prevented by periodical chemical cleaning; the average pressure drop was 165 Pa m-1. Rapid initiation of anaerobic degradation was achieved by using granular sludge from a brewery wastewater treatment plant. Despite the intermittent and fluctuating organic load, the expanded granular sludge bed reactor showed an excellent level of performance, reaching removal efficiencies of 93 ± 5% at 25.1 ± 3.2 °C, with biogas methane content of 94 ± 3% in volume. Volatile fatty acid concentration was as low as 200 mg acetic acid L-1by treating daily average organic loads up to 3.0 kg COD h-1, equivalent to 24 kg COD m-3bed d-1. The denaturing gradient gel electrophoresis (DGGE) results revealed the initial shift of the domains Archaea and Bacteria associated with the limitation of the carbon source to a few organic solvents. The Archaea domain was more sensitive, resulting in a drop of the Shannon index from 1.07 to 0.41 in the first 123 days. Among Archaea, the predominance of Methanosaeta persisted throughout the experimental period. The increase in the proportion of Methanospirillum and Methanobacterium sp. was linked to the spontaneous variations of operating temperature and load, respectively. Among Bacteria, high levels of ethanol degraders (Geobacter and Pelobacter sp.) were observed during the trial.
authors.affiliation: Research Group GI(2)AM, Department of Chemical Engineering, University of Valencia, Avd. Universitat s/n, 46100, Burjassot, Spain; Pure Air Solutions, PB 135, 8440 AC, Heerenveen, The Netherlands.
authors.forename: D
authors.initials: D
authors.lastname: Bravo
authors.affiliation: Research Group GI(2)AM, Department of Chemical Engineering, University of Valencia, Avd. Universitat s/n, 46100, Burjassot, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Ferrero
authors.affiliation: Research Group GI(2)AM, Department of Chemical Engineering, University of Valencia, Avd. Universitat s/n, 46100, Burjassot, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Penya-Roja
authors.affiliation: Research Group GI(2)AM, Department of Chemical Engineering, University of Valencia, Avd. Universitat s/n, 46100, Burjassot, Spain.
authors.forename: F J
authors.initials: FJ
authors.lastname: Álvarez-Hornos
authors.affiliation: Research Group GI(2)AM, Department of Chemical Engineering, University of Valencia, Avd. Universitat s/n, 46100, Burjassot, Spain. Electronic address: carmen.gabaldon@uv.es.
authors.forename: C
authors.initials: C
authors.lastname: Gabaldón
mesh_terms: D000693:Anaerobiosis; D019149:Bioreactors; D008697:Methane; D011327:Printing; D012722:Sewage; D055549:Volatile Organic Compounds; D014865:Waste Disposal, Fluid
chemical_list: D012722:Sewage; D055549:Volatile Organic Compounds; D008697:Methane
keywords: Air emissions; Anaerobic bioscrubber; Denaturing gradient gel electrophoresis; Expanded granular sludge bed reactor; Volatile organic compounds