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 m h and an average concentration of 1126 ± 470 mg-C Nm. 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 and 9.1·10. Biomass growth was prevented by periodical chemical cleaning; the average pressure drop was 165 Pa m. 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 by treating daily average organic loads up to 3.0 kg COD h, equivalent to 24 kg COD m bed d. 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.

Granulation and microbial community dynamics in the chitosan-supplemented anaerobic treatment of wastewater polluted with organic solvents

“…The bacterial and archaeal 16S rRNA were amplified by PCR using the primers proposed by Bravo et al (2017) under the following conditions: 94ºC for 5 min, 19 cycles at 94ºC for min, 65ºC for 0.5 min and 72ºC for min, followed by 12 cycles for bacteria and cycles for archaea of 94ºC for 1 min, 55ºC for 0.5 min, 72ºC for 1 min, and a final extension step at 72ºC for min. Denaturing gradient gel electrophoresis (DGGE) analysis, subsequent band excision, purification and sequencing were done by adapting the method used by Bravo et al (2017). In this work, a linear denaturant gradient from 25% to 60% was used and electrophoresis was performed at 60ºC and 100 V for 14 h. The V4 hyper-variable region of the extracted DNA was amplified with the universal primers 515F (5'-GTG CCA GCM GCC GCG GTA A-3') and 806R (5'-GGA CTA CHV GGG TWT CTA AT-3').…”

“…The high rate sludge bed reactors such as the Upflow Anaerobic Sludge Blanket reactor (UASB) and its derivatives are by far, the most popular anaerobic systems for the treatment of industrial wastewater because they achieve high biomass retention improving the treatment efficiency while applying high loading rates (van Lier et al, 2015;Zhou et al, 2006). Recently, this type of reactor has been successfully applied to the treatment of wastewater polluted with organic solvents (Bravo et al, 2017;Enright et al, 2009;Lafita et al, 2015;Oktem et al, 2007;Siggins et al, 2011;Wang et al, 2017).…”

Research of Modified Atomizers and Their Application for Moistening of Air-Cleaning Device Charges

“…Absorbers as waste air cleaning devices may be categorized as physical, chemical, and biological absorbers, and are mainly used for the abatement of polar compounds. Biological processes may be further categorized according to the amounts of water used for bioscrubbers (for polar compounds; big amounts of water [2]), biotrickling filters (both for polar and lipophilic compounds; moderate amounts of water [3]), and biofilters (mainly for lipophilic compounds and odor; low amounts of water [4]). The biological processes underline the relevance of optimal spraying conditions, both to the size of spray droplets to avoid an insufficient dispersion of the water phase as well as the volume of the water phase sprayed in total.…”

Capillary membrane bioreactor for abatement of low soluble compounds in waste gas

“…Different physicochemical techniques such as absorption, adsorption and thermal and catalytic oxidation have been used in order to reduce air pollutants. In the last decade, biological gas treatment techniques such as biotrickling filtration, bioscrubbing and membrane biofiltration have been widely studied and implemented as alternatives for the traditional physical–chemical techniques . Biological technologies present several advantages over conventional physical‐chemical ones, such as low operating cost, low energy requirements, and the absence of waste products that require further treatment or disposal.…”

“…In the last decade, biological gas treatment techniques such as biotrickling filtration, bioscrubbing and membrane biofiltration have been widely studied and implemented as alternatives for the traditional physical-chemical techniques. [2][3][4][5][6] Biological technologies present several advantages over conventional physical-chemical ones, such as low operating cost, low energy requirements, and the absence of waste products that require further treatment or disposal. However, these biotechniques have some limitations, such as large size reactors, difficult control of moisture and pH (biofilters), channelling and, especially, low removal efficiencies for highly hydrophobic pollutants (biotrickling filters).…”