Publications by authors named "G Buelna"

43 Publications

Bioelimination of low methane concentrations emitted from wastewater treatment plants: a review.

Crit Rev Biotechnol 2021 Jul 14:1-18. Epub 2021 Jul 14.

Department of Chemical Engineering and Biotechnological Engineering, Faculty of Engineering, Université de Sherbrooke, Sherbrooke, Canada.

Sewage from residents and industries is collected and transported to wastewater treatment plants (WWTPs) with sewer networks. The operation of WWTPs results in emissions of greenhouse gases, such as methane (CH), mostly due to sludge anaerobic digestion. Amounts of emissions depend on the source of influent, i.e. municipal and industrial wastewater as well as sewer systems (gravity and rising). Wastewater is the fifth-largest source of anthropogenic CH emissions in the world and represents 7-9% of total global CH emissions into the atmosphere. Global wastewater CH emission grew by approximately 20% from 2005 to 2020 and is expected to grow by 8% between 2020 and 2030, which makes wastewater an important CH emitter worldwide. This review initially considers the emission of CH from WWTPs and sewer networks. In the second part, biotechniques available for biodegradation of low CH concentrations (<5% v/v) encountered in WWTPs have been studied. The paper reviews major bioreactor configurations for the treatment of polluted air, i.e. biotrickling filters, bioscrubbers, two-liquid phase bioreactors, biofilters, and hybrid reactor configurations, after which it focuses on CH biofiltration systems. Biofiltration represents a simple and efficient approach to bio-oxidize CH in waste gases from WWTPs. Major factors influencing a biofilter's performance along with knowledge gaps in relation to its application for treating gaseous emissions from WWTPs are discussed.
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http://dx.doi.org/10.1080/07388551.2021.1940830DOI Listing
July 2021

Acclimatization of microbial community of submerged membrane bioreactor treating hospital wastewater.

Bioresour Technol 2021 Jan 8;319:124223. Epub 2020 Oct 8.

Investissement Québec - CRIQ, 333, rue Franquet, Quebec, QC G1P 4C7, Canada.

This study was performed to understand the dynamics of the microbial community of submerged membrane bioreactor during the acclimatization process to treat the hospital wastewater. In this regard, three acclimatization phases were examined using a mixture of synthetic wastewater (SWW) and real hospital wastewater (HWW) in the following proportions; In Phase 1: 75:25 v/v (SWW: HWW); Phase 2: 50:50 v/v (SWW: HWW); and Phase 3: 25:75 v/v (SWW: HWW) of wastewater. The microbial community was analyzed using Illumina high throughput sequencing to identify the bacterial and micro-eukaryotes community in SMBR. The acclimatization study clearly demonstrated that shift in microbial community composition with time. The dominance of pathogenic and degrading bacterial communities such as Mycobacterium, Pseudomonas, and Zoogloea was observed at the phase 3 of acclimatization. This study witnessed the major shift in the micro-eukaryotes community, and the proliferation of fungi Basidiomycota was observed in phase 3 of acclimatization.
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http://dx.doi.org/10.1016/j.biortech.2020.124223DOI Listing
January 2021

Simultaneous biodegradation of methane and styrene in biofilters packed with inorganic supports: Experimental and macrokinetic study.

Chemosphere 2020 Aug 17;252:126492. Epub 2020 Mar 17.

Department of Chemical Engineering and Biotechnological Engineering, Faculty of Engineering, 2500 boulevard de l'Université, Université de Sherbrooke, Sherbrooke, J1K 2R1, Quebec, Canada. Electronic address:

Four upflow 0.018 m biofilters (3 beds), B-ME, B-200, B-500 and B-700, all packed with inorganic materials, were operated at a constant air flow rate of 0.18 m h to eliminate methane (CH), a harmful greenhouse gas (GHG), and styrene (CH), a carcinogenic volatile organic compound (VOC). The biofilters were irrigated with 0.001 m of recycled nutrient solution (NS) every day (flow rate of 60 × 10 m h). Styrene inlet load (IL) was kept constant in each biofilter. Different CH-ILs varying in the range of 7-60 gCH m h were examined in B-ME (IL of 0 gCH m h), B-200 (IL of 9 gCH m h), B-500 (IL of 22 gCH m h) and B-700 (IL of 32 gCH m h). Finally, the effect of CH on the macrokinetic parameters of CH biofiltration was studied based on the Michaelis-Menten model. Average CH removal efficiencies (RE) varying between 64 and 100% were obtained at CH-ILs increasing from 7 to 60 gCH m h and for CH-ILs range of 0-32 gCH m h. More than 90% of CH was removed in the bottom and middle beds of the biofilters. By increasing CH-IL from 0 to 32 gCH m h, maximal EC in Michaelis-Menten model and macrokinetic saturation constant declined from 311 to 39 g m h and from 19 to 2.3 g m, respectively, which confirmed that an uncompetitive inhibition occurred during CH biofiltration in the presence of CH.
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http://dx.doi.org/10.1016/j.chemosphere.2020.126492DOI Listing
August 2020

Statistical optimization of arsenic removal from synthetic water by electrocoagulation system and its application with real arsenic-polluted groundwater.

Environ Technol 2020 Mar 2:1-12. Epub 2020 Mar 2.

Departamento de Biotecnología y Ciencias Alimentarias, Instituto Tecnológico de Sonora (Centro de Investigación e Innovación Biotecnológica, agropecuaria y ambiental), Ciudad Obregón, México.

Arsenic presence in the water has become one of the most concerning environmental problems. Electrocoagulation is a technology that offers several advantages over conventional treatments such as chemical coagulation. In the present work, an electrocoagulation system was optimized for arsenic removal at initial concentrations of 100 µg/L using response surface methodology. The effects of studied parameters were determined by a 2 factorial design, whereas treatment time had a positive effect and current intensity had a negative effect on arsenic removal efficiency. With a -value of 0.1629 and a confidence of level 99%, the type of electrode material did not have a significant effect on arsenic removal. Efficiency over 90% was reached at optimal operating conditions of 0.2 A of current intensity, and 7 min of treatment time using iron as the electrode material. However, the time necessary to accomplish with OMS arsenic guideline of 10 µg/L increased from 7 to 30 min when real arsenic-contaminated groundwater with an initial concentration of 80.2 ± 3.24 µg/L was used. The design of a pilot-scale electrocoagulation reactor was determined with the capacity to meet the water requirement of a 6417 population community in Sonora, Mexico. To provide the 1.0 L/s required, an electrocoagulation reactor with a working volume of 1.79 m, a total electrode effective surface of 701 m, operating at a current intensity of 180 A and an operating cost of 0.0208 US$/day was proposed. Based on these results, electrocoagulation can be considered an efficient technology to treat arsenic-contaminated water and meet the drinking water quality standards.
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http://dx.doi.org/10.1080/09593330.2020.1732472DOI Listing
March 2020

Passive phosphorus capture in biofiltration context: nitrate impact on the performance.

Environ Technol 2020 Dec 3;41(28):3682-3694. Epub 2019 Jun 3.

Centre de Recherche Industrielle du Québec (CRIQ), Québec, Canada.

Research on the development of a passive phosphorus entrapment process characterized by biofilters with active wood-based media impregnated with iron hydroxide has been conducted. Phosphorus removal was done by sorption which includes adsorption, exchange of ions and precipitation. Experiments were performed in order to investigate the effect of nitrate, generally present at the end of secondary treatment, on the phosphorus removal performance. Columns tests were performed with anaerobic activated wood-based media and immersion over a period of 150 days. Columns were fed for 32 days with a synthetic solution of 5 mg P L. Different concentrations of nitrate (5, 10 and 25 mg N-NO L) were then applied on three columns (C, C and C), column C serving as a control. Results showed total phosphorus (TP) removal efficiencies of 96.9%, 81.7%, 70.6% and 75.7%, respectively, for C, C, C and C. Addition of nitrate increases the oxidoreduction potential (ORP). This results in an inhibition of the reductive dissolution, characterized by a decrease in the release of ferrous ions. Simultaneous denitrification occurs within the columns. It is both biological and chemical through the oxidation of ferrous ions by NO, produced during biological denitrification. Furthermore, bacterial identification tests have highlighted the presence of iron-related bacteria (, , , e.g. ), slym forming bacteria, sulphate reducing bacteria and denitrifying microorganisms such as and in biofilters.
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http://dx.doi.org/10.1080/09593330.2019.1618921DOI Listing
December 2020
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