Publications by authors named "Gerardo Buelna"

35 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

Microwave-assisted one-pot conversion of agro-industrial wastes into levulinic acid: An alternate approach.

Bioresour Technol 2018 Oct 7;265:471-479. Epub 2018 Jun 7.

Université Laval, Department of Civil Engineering and Water Engineering, Pavilion Adrien-Pouliot, 1065, avenue de la Médecine, Quebec G1V 0A6, Canada.

Brewery liquid waste (BLW), brewery spent grain (BSG), apple pomace solid wastes (APS), apple pomace ultrafiltration sludge (APUS) and starch industry waste (SIW) were evaluated as alternative feedstocks for levulinic acid (LA) production via microwave-assisted acid-catalyzed thermal hydrolysis. LA production of 204, 160, 66, 49 and 12 g/kg was observed for BLW, BSG, APS, APUS, and SIW, respectively, at 140 °C, 40 g/L substrate concentration (SC), 60 min and 2 N HCl (acid concentration). Based on the screening studies, BLW and BSG were selected for optimization studies using response surface methodology. Maximum LA production of 409 and 341 g/kg for BLW and BSG, respectively were obtained at 160 °C, 4.5 M HCl, 85 g/L SC and 27.5 min. Results demonstrated the possibility of using brewery wastes as promising substrates for economical and higher yield production of LA, a renewable platform chemical and versatile precursor for fuels and chemicals.
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http://dx.doi.org/10.1016/j.biortech.2018.06.012DOI Listing
October 2018

Removal of Pollutants in Different Landfill Leachate Treatment Processes on the Basis of Organic Matter Fractionation.

J Environ Qual 2018 Mar;47(2):297-305

A combination of processes was required for the proper treatment of old landfill leachate, as it contained a high concentration of pollutants. Humic substances comprised half of the total organic carbon in the raw leachate. Mobility of di(2-ethylhexyl) phthalate (DEHP) and metals could depend on the fate of these substances. Characterization of carbon in raw leachate and effluent of the membrane bioreactor, biofiltration, electro-oxidation, electro-coagulation, and nanofiltration showed complete removal of suspended solids and colloids. Physical processes could not remove the hydrophilic fraction due to its lower molecular weight. However, high removal of the hydrophilic fraction with a molecular weight <500 Da was expected in the biological process. In comparison with fulvic acid, larger sized humic acid resulted in complete removal by physicochemical processes. Because of DEHP partitioning on dissolved organic matter, especially on humic substances, its removal could be correlated with total organic carbon removal. Metals such as iron, aluminum, magnesium, and lead showed removal efficiency >80% in biological processes. Electro-deposition on the surface of an electrode and precipitation by hydroxide resulted in removal efficiencies >90 and >50% in electro-coagulation and electro-oxidation, respectively. Rejection of metals by nanofiltration was >80% and depended on the size and charge of cation. All in all, a combination of membrane bioreactor and nanofiltration seems to be the optimal process configuration for efficient treatment of old landfill leachate.
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http://dx.doi.org/10.2134/jeq2017.09.0360DOI Listing
March 2018

Performance of a membrane bioreactor in extreme concentrations of bisphenol A.

Water Sci Technol 2018 Mar;77(5-6):1505-1513

Centre de Recherché Industrielle du Québec (CRIQ), 333 rue Franquet, Québec, QC, Canada, G1P 4C7.

In this study, a submerged membrane bioreactor was used to study the effect of low and high bisphenol A (BPA) concentration on the sludge biological activity. The pilot was operated over 540 days with hydraulic retention time and solid retention time of 5.5 hours and 140 days, respectively. As a hydrophobic compound, BPA was highly adsorbed by activated sludge. In lower concentrations, the biodegradation rate remained low, since the BPA concentration in the sludge was lower than 0.5 mg/g TS; yet, at an influent concentration up to 15 mg/L, the biodegradation rate was increasing, resulting in 99% BPA removal efficiency. The result for chemical oxygen demand removal showed that BPA concentration has no effect on the heterotrophic bacteria that were responsible for the organic carbon degradation. In higher concentrations, up to 16 mg of BPA was used for each gram of sludge as a source of carbon. However, the activity of autotrophic bacteria, including nitrifiers, was completely halted in the presence of 20 mg/L of BPA or more. Although nitrification was stopped after day 400, ammonia removal remained higher than 70% due to air stripping. Assimilation by bacteria was the only removal pathway for phosphorus, which resulted in an average 35% of P-PO removal efficiency.
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http://dx.doi.org/10.2166/wst.2018.011DOI Listing
March 2018

Evaluation of Ficus benjamina wood chip-based fungal biofiltration for the treatment of Tequila vinasses.

Water Sci Technol 2018 Mar;77(5-6):1449-1459

Instituto Mexicano de Tecnología del Agua, Jiutepec, Mor., Mexico E-mail:

This study was focused on the application of an aerobic biofiltration (BF) with Ficus benjamina wood chips as support medium, inoculated with two basidiomycete fungi, Phanerochaete chrysosporium (BF 1) and Trametes versicolor (BF 2), to treat Tequila vinasses from a Tequila industry. The biofiltration system was compared with a biofilter system without basidiomycete fungi (BF W), in order to determine the influence of fungi on the treatment of vinasses. Three different vinasses/water ratios (30/70, 40/60, and 50/50) were evaluated. The maximum removals of chemical oxygen demand (COD) obtained during each operation step were 72% (BF 1), 72% (BF 2), and 8% (BF W) for 30 vinasses/70 water; 72% (BF 1), 73% (BF 2), and 66% (BF W) for 40 vinasses/60 water; and 22% (BF 1), 20% (BF 2), and 18% (BF W) for 50 vinasses/50 water. The total organic carbon (TOC) removal was significantly increased using a volumetric organic load of 5.5 kg COD md. During the operation of the biofilters, the enzymatic activity of laccase was present, even at the step of highest concentration of vinasses.
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http://dx.doi.org/10.2166/wst.2018.023DOI Listing
March 2018

Hybrid process, electrocoagulation-biofiltration for landfill leachate treatment.

Waste Manag 2018 May 21;75:391-399. Epub 2018 Feb 21.

Centre de Recherche Industrielle du Québec (CRIQ), 333 rue Franquet, Québec, QC G1P 4C7, Canada. Electronic address:

Landfill leachates are known for their high and complex composition of organic, inorganic and microbial pollutants. As a result, it is quite challenging to treat these effluents by using only one treatment process. A combining approach is generally required to treat efficiently these wastewaters and comply with the discharge standards. In this present study, electrocoagulation (EC) and biofiltration (BF) processes were sequentially used to treat landfill leachate. EC process has been able to remove 37 ± 2% of the initial total COD. A fractionation of organic compounds showed that EC was particularly efficient to remove insoluble COD and humic acids. In addition, other pollutants such as turbidity, true color, Zn and phosphorus were significantly reduced by EC with 82 ± 2.7%, 60 ± 13%, 95 ± 2.6% and 82 ± 5.5% of removal respectively. The subsequent treatment by BF process led to completely removal of ammonia pollution (>99% of NH removal) and a partial removal of dissolved organic compounds (42 ± 7% of COD removal). The hybrid process EC/BF could form the basis of a process capable of removing organic and inorganic pollutants from many refractory wastewaters (mature landfill leachates, industrial and municipal wastewaters).
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http://dx.doi.org/10.1016/j.wasman.2018.02.016DOI Listing
May 2018

Synthetic hospital wastewater treatment by coupling submerged membrane bioreactor and electrochemical advanced oxidation process: Kinetic study and toxicity assessment.

Chemosphere 2018 Feb 4;193:160-169. Epub 2017 Nov 4.

Centre de Recherche Industrielle du Québec (CRIQ), 333 Franquet, Québec City, QC, G1P 4C7, Canada.

In this work, the combination of membrane bioreactor (MBR) and electro-oxidation (EO) process was studied for the treatment of a synthetic hospital wastewater fortified with four pharmaceutical pollutants namely carbamazepine (CBZ), ibuprofen (IBU), estradiol (E-E) at a concentration of 10 μg L venlafaxine (VEN) at 0.2 μg L. Two treatment configurations were studied: EO process as pre-treatment and post-treatment. Wastewater treatment with MBR alone shows high removal percentages of IBU and E-E (∼90%). Unlikely for CBZ and VEN, a low elimination percentage (∼10%) was observed. The hydraulic and the solid retention times (HRT and SRT) were 18 h and 140 d respectively, while the biomass concentration in the MBR was 16.5 g L. To enhance pharmaceuticals elimination, an EO pretreatment was conducted during 40 min at 2 A. This configuration allowed a 92% removal for VEN, which was far greater than both treatments alone, with lower than 30% and 50% for MBR and EO, respectively. The MBR-EO coupling (EO as post-treatment) allows high removal percentages (∼97%) of the four pharmaceutical pollutants after 40 min of treatment at a current intensity of 0.5 A with Nb/BDD as electrodes. This configuration appears to be very effective compared to the first configuration (EO-MBR) where EO process is used as a pre-treatment. Toxicity assessment showed that the treated effluent of this configuration is not toxic to Daphnia magna except at 100% v/v. The MBR-EO coupling appears to be a promising treatment for contaminated hospital effluents.
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http://dx.doi.org/10.1016/j.chemosphere.2017.11.010DOI Listing
February 2018

Hydrolytic pre-treatment methods for enhanced biobutanol production from agro-industrial wastes.

Bioresour Technol 2018 Feb 5;249:673-683. Epub 2017 Oct 5.

Bioprocess Engineering and Biotechnology Department, Federal University of Paraná, Centro Politécnico, Usina Piloto B, CEP 81531-990 Curitiba, Paraná, Brazil.

Brewery industry liquid waste (BLW), brewery spent grain (BSG), apple pomace solid wastes (APS), apple pomace ultrafiltration sludge (APUS) and starch industry wastewater (SIW) have been considered as substrates to produce biobutanol. Efficiency of hydrolysis techniques tested to produce fermentable sugars depended on nature of agro-industrial wastes and process conditions. Acid-catalysed hydrolysis of BLW and BSG gave a total reducing sugar yield of 0.433 g/g and 0.468 g/g respectively. Reducing sugar yield from microwave assisted hydrothermal method was 0.404 g/g from APS and 0.631 g/g from APUS, and, 0.359 g/g from microwave assisted acid-catalysed SIW dry mass. Parameter optimization (time, pH and substrate concentration) for acid-catalysed BLW hydrolysate utilization using central composite model technique produced 307.9 g/kg glucose with generation of inhibitors (5-hydroxymethyl furfural (20 g/kg), furfural (1.6 g/kg), levulinic acid (9.3 g/kg) and total phenolic compound (0.567 g/kg)). 10.62 g/L of acetone-butanol-ethanol was produced by subsequent clostridial fermentation of the substrate.
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http://dx.doi.org/10.1016/j.biortech.2017.09.132DOI Listing
February 2018

Efficiency of an upflow anaerobic sludge blanket reactor treating potato starch processing wastewater and related process kinetics, functional microbial community and sludge morphology.

Bioresour Technol 2017 Sep 4;239:105-116. Epub 2017 May 4.

Centre de Recherché Industrielle du Québec (CRIQ), 333 Franquet, Sainte-Foy, Québec G1P 4C7 Canada. Electronic address:

Herein, an upflow anaerobic sludge blanket reactor was employed to treat potato starch processing wastewater and the efficacy, kinetics, microbial diversity and morphology of sludge granules were investigated. When organic loading rate (OLR) ranging from 2.70 to 13.27kgCOD/m.d was implemented with various hydraulic retention times (72h, 48h and 36h), COD removal could reach 92.0-97.7%. Highest COD removal (97.7%) was noticed when OLR was 3.65kgCOD/m.d, but had declined to 92.0% when OLR was elevated to 13.27kgCOD/m.d. Methane and biogas production increased from 0.48 to 2.97L/L.d and 0.90 to 4.28L/L.d, respectively. Kinetics and predictions by modified-Gompertz model agreed better with experimental data as opposed to first-order kinetic model. Functional population with highest abundance was Chloroflexi (28.91%) followed by Euryarchaeota (22.13%), Firmicutes (16.7%), Proteobacteria (16.25%) and Bacteroidetes (7.73%). Compared with top sludge, tightly-bound extracellular polymeric substances was high within bottom and middle sludge. Morphology was predominantly Methanosaeta-like cells, Methanosarcina-like cells, rods and cocci colonies.
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http://dx.doi.org/10.1016/j.biortech.2017.04.124DOI Listing
September 2017

Valorization of crude glycerol and eggshell biowaste as media components for hydrogen production: A scale-up study using co-culture system.

Bioresour Technol 2017 Feb 2;225:386-394. Epub 2016 Dec 2.

Centre de recherche industrielle du Québec (CRIQ), Québec (QC), Canada.

The properties of eggshells (EGS) as neutralizing and immobilizing agent were investigated for hydrogen (H) production using crude glycerol (CG) by co-culture system. Eggshells of different sizes and concentrations were used during batch and repeated-batch fermentation. For batch and repeated-batch fermentation, the maximum H production (36.53±0.53 and 41.16±0.95mmol/L, respectively) was obtained with the EGS size of 33μm
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http://dx.doi.org/10.1016/j.biortech.2016.11.114DOI Listing
February 2017

Review on fate and mechanism of removal of pharmaceutical pollutants from wastewater using biological approach.

Bioresour Technol 2017 Jan 15;224:1-12. Epub 2016 Nov 15.

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

Due to research advancement and discoveries in the field of medical science, maintains and provides better human health and safer life, which lead to high demand for production of pharmaceutical compounds with a concomitant increase in population. These pharmaceutical (biologically active) compounds were not fully metabolized by the body and excreted out in wastewater. This micro-pollutant remains unchanged during wastewater treatment plant operation and enters into the receiving environment via the discharge of treated water. Persistence of pharmaceutical compounds in both surface and ground waters becomes a major concern due to their potential eco-toxicity. Pharmaceuticals (emerging micro-pollutants) deteriorate the water quality and impart a toxic effect on living organisms. Therefore, from last two decades, plenty of studies were conducted on the occurrence, impact, and removal of pharmaceutical residues from the environment. This review provides an overview on the fate and removal of pharmaceutical compounds via biological treatment process.
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http://dx.doi.org/10.1016/j.biortech.2016.11.042DOI Listing
January 2017

Insight into the adsorption mechanisms of trace organic carbon on biological treatment process.

Environ Technol 2017 Sep 28;38(18):2324-2334. Epub 2016 Nov 28.

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

The presence of recalcitrant dissolved organic matter (DOM) could have a significant effect on the adsorption mechanism and capacity of the sludge for many trace organic carbons (TrOCs). In this study, adsorption of three TrOCs on the sludge and HA was investigated. The results revealed that neutral hydrophilic compounds had an insignificant interaction with both sludge and HA. Positively charged compounds, such as fluoranthene, had more affinity toward HA than sludge with solid/liquid partitioning of 57 and 3.2 L/g, respectively. The adsorption intensity (K) of di-2-ethyl hexyl phthalate was 0.5 and 1.13 for the HA and the sludge, respectively. By introducing the sludge to the solution of HA and TrOCs that already reached equilibrium, the sludge adsorption capacity in the presence of HA was investigated. The finding showed that at the lower concentration, adsorption of HA on the sludge was considered as the main removal pathway for the adsorbed emerging contaminants, as 70 mg of HA was adsorbed by a gram of sludge. For the higher concentration, desorption of TrOCs from DOM into the sludge comprised 15-30% of total removal efficiency.

Abbreviations: CBZ: carbamazepine; DEHP: di-2-ethyl hexyl phthalate; DOM: dissolved organic matter; FLAN: fluoranthene; f: fraction of organic carbon; HA: humic acid; Log Kow: octanol-water partition coefficient; PAH: polycyclic aromatic hydrocarbon TS: total solid; TrOCs: trace organic carbons VS: volatile solid.
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http://dx.doi.org/10.1080/09593330.2016.1259355DOI Listing
September 2017

Electrocoagulation of bio-filtrated landfill leachate: Fractionation of organic matter and influence of anode materials.

Chemosphere 2017 Feb 4;168:1136-1141. Epub 2016 Nov 4.

E2Metrix Inc, 3905 Rue Lesage, Sherbrooke, QC, J1L 2Z9, Canada. Electronic address:

Electrocoagulation (EC) was employed to treat residual organic matter from a landfill leachate pretreated by an aerated bio-filter system. Organic matter (humic acids (HA), fulvic acids (FA) and hydrophilic compounds (Hyl)) was fractionated using DAX-8 resin in order to estimate the efficiency of EC on each fraction. Initial characterization of the bio-filtrated landfill leachate showed that humic substances (HA + FA) represented nearly 90% of TOC. The effects of current densities, type of anode (Aluminum versus iron), and treatment time on the performance of COD removal were investigated. The best COD removal performances were recorded at a current density ranging between 8.0 and 10 mA cm during 20 min of treatment time. Under these conditions, 70% and 65% of COD were removed using aluminum and iron electrodes, respectively. The fractionating of organic matter after EC treatment revealed that HA was completely removed using either aluminum or iron anode. However, FA and Hyl fractions were partially removed, with the percentages varying from 57 to 60% and 37-46%, respectively. FA and Hyl removal were quite similar using either aluminum or iron anode. Likewise, a significant decrease in 254-nm absorbance was recorded (UV removal of 79-80%) using either type of anode. These results proved that EC is a suitable and efficient approach for treating the residual refractory organic matter from a landfill leachate previously treated by a biological system.
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http://dx.doi.org/10.1016/j.chemosphere.2016.10.092DOI Listing
February 2017

Landfill leachate treatment by sequential membrane bioreactor and electro-oxidation processes.

J Environ Manage 2016 Dec 10;184(Pt 2):318-326. Epub 2016 Oct 10.

Centre de Recherche Industrielle du Québec (CRIQ), 333 rue Franquet, Québec, QC, G1P 4C7, Canada.

Combination of high performance membrane bioreactor (MBR) equipped with ultrafiltration and electro-oxidation process (EOP) by boron-doped diamond electrode (BDD) was used to effectively treat highly contaminated old landfill leachate. MBR and EOP were optimized for raw and pretreated landfill leachate. Seasonal changes dramatically affected the both processes' performance, as the landfill leachate was ¾ more concentrated in winter. For MBR, organic load rate of 1.2 gCOD/L/day and sludge retention time of 80 days was considered as the optimum operating condition in which COD, TOC, NH and phosphorous removal efficiencies reached the average of 63, 35, 98 and 52%, respectively. The best performance of EOP was in current intensity of 3 A with treatment of time of 120 min. Effluent of electro-oxidation was more toxic due to the presence of radicals and organochlorinated compounds. These compounds were removed by stripping or assimilation of sludge if EOP was used as a pretreatment method. Furthermore, the energy consumption of EOP was decreased from 22 to 16 KWh/m for biologically treated and raw landfill leachate, respectively.
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http://dx.doi.org/10.1016/j.jenvman.2016.10.010DOI Listing
December 2016

Coupling biofiltration process and electrocoagulation using magnesium-based anode for the treatment of landfill leachate.

J Environ Manage 2016 Oct 5;181:477-483. Epub 2016 Aug 5.

E2Metrix Inc, 3905 Rue Lesage, Sherbrooke, QC, J1L 2Z9, Canada. Electronic address:

In this research paper, a combination of biofiltration (BF) and electrocoagulation (EC) processes was used for the treatment of sanitary landfill leachate. Landfill leachate is often characterized by the presence of refractory organic compounds (BOD/COD < 0.13). BF process was used as secondary treatment to remove effectively ammonia nitrogen (N-NH4 removal of 94%), BOD (94% removed), turbidity (95% removed) and phosphorus (more than 98% removed). Subsequently, EC process using magnesium-based anode was used as tertiary treatment. The best performances of COD and color removal from landfill leachate were obtained by applying a current density of 10 mA/cm(2) through 30 min of treatment. The COD removal reached 53%, whereas 85% of color removal was recorded. It has been proved that the alkalinity had a negative effect on COD removal during EC treatment. COD removal efficiencies of 52%, 41% and 27% were recorded in the presence of 1.0, 2.0 and 3.0 g/L of sodium bicarbonate (NaHCO3), respectively. Hydroxide ions produced at the cathode electrode reacted with the bicarbonate ions to form carbonates. The presence of bicarbonates in solution hampered the increase in pH, so that the precipitation of magnesium hydroxides could not take place to effectively remove organic pollutants.
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http://dx.doi.org/10.1016/j.jenvman.2016.06.067DOI Listing
October 2016

The effect and biological mechanism of COD/TN ratio on nitrogen removal in a novel upflow microaerobic sludge reactor treating manure-free piggery wastewater.

Bioresour Technol 2016 Jun 5;209:360-8. Epub 2016 Mar 5.

Centre de Recherche Industrielle du Québec, 333 Franquet, Québec G1P 4C7, Canada.

A novel upflow microaerobic sludge reactor (UMSR) was constructed to treat manure-free piggery wastewater with high NH4(+)-N concentration and low COD/TN ratio, and the effect and biological mechanism of COD/TN ratio on nitrogen removal were investigated at a constant hydraulic retention time of 8h and 35°C. The results showed that the UMSR could treat the wastewater with a better synchronous removal of COD, NH4(+)-N and TN. The microaerobic UMSR allowed nitrifiers, and heterotrophic and autotrophic denitrifiers to thrive in the flocs, revealing a multiple nitrogen removal mechanism in the reactor. Both the nitrifiers and denitrifiers would be restricted by an influent COD/TN ratio more than 0.82, resulting in a decrease of TN removal in the UMSR. To get a TN removal over 80% with a TN load removal above 0.86kg/(m(3)·d) in the UMSR, the influent COD/TN ratio should be less than 0.70.
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http://dx.doi.org/10.1016/j.biortech.2016.03.008DOI Listing
June 2016

Performance of electrochemical oxidation process for removal of di (2-ethylhexyl) phthalate.

Environ Sci Pollut Res Int 2016 Jun 14;23(12):12164-73. Epub 2016 Mar 14.

Industrial research center of Quebec, 333 rue Franquet, Québec, QC, G1P 4C7, Canada.

Di (2-ethylhexyl) phthalate (DEHP) is the most detected and concentrated plasticizer in environment and wastewaters, worldwide. In this study, different operating parameters such as current intensity, treatment time, type of anodes, and supporting electrolytes were tested to optimized the electro-oxidation process (EOP) for the removal of DEHP in the presence of methanol as a dissolved organic matter. Among the anodes, the Nb/BDD showed the best degradation rate of DEHP, at low current intensity of 0.2 A after 90 min of treatment time with a percentage of degradation recorded of 81 %, compared to 70 % obtained with the Ti/IrO2-RuO2. Furthermore, due to the combination of direct and indirect oxidation, the removal of DEHP in the presence of 1 g/L Na2SO4 was higher than NaBr, even though the oxidant production of NaBr was 11.7 mmol/L against 3.5 mmol/L recorded in the presence of sulfate at 0.5 A and after 60 min of electrolysis time. Under optimal condition (current intensity = 0.5 A, time = 120 min, using Nb/BDD anode and Na2SO4 as supporting electrolyte), the removal of 87.2 % of DEHP was achieved. The total cost of 0.106 US$/m(3) of treated water was achieved based on economical optimization of reactor with current intensity of 0.2 A and 1 g/L Na2SO4.
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http://dx.doi.org/10.1007/s11356-016-6304-2DOI Listing
June 2016

Tylosin effect on methanogenesis in an anaerobic biomass from swine wastewater treatment.

Water Sci Technol 2016 ;73(2):445-52

Mexican Institute of Water Technology, Paseo Cuauhnahuac 8532, Progreso, Jiutepec, Morelos C.P. 62550, Mexico E-mail:

The effect of different concentrations of tylosin on methane production was investigated: first methanogenesis in a biomass without contact with the antibiotic, and later the ability of the sludge to adapt to increasing concentrations of tylosin. Results showed that, for biomass that had no contact with the antibiotic, the presence of tylosin inhibits the generation of methane even at concentrations as small as 0.01 mg L(-1), and samples at concentrations above 0.5 mg L(-1) produced practically no methane, whereas, in the digesters acclimated in the presence of tylosin at a concentration of 0.01 to 0.065 mg L(-1), methanogenesis is not inhibited in the presence of antibiotic and the generation of methane is improved. This behaviour suggests the microorganisms have developed not only resistance to the antibiotic but also an ability to metabolize it.
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http://dx.doi.org/10.2166/wst.2015.507DOI Listing
May 2016

Efficiency and bacterial populations related to pollutant removal in an upflow microaerobic sludge reactor treating manure-free piggery wastewater with low COD/TN ratio.

Bioresour Technol 2016 Feb 24;201:166-73. Epub 2015 Nov 24.

Centre de Recherche Industrielle du Québec, 333 Franquet, Québec G1P 4C7, Canada.

A novel upflow microaerobic sludge reactor (UMSR) had proved excellent in nitrogen removal from manure-free piggery wastewater characterized by high concentration of ammonium (NH4(+)-N) and low chemical oxygen demand (COD) to total nitrogen (TN) ratio, but the biological mechanism in the UMSR was still indeterminate. With a constant nitrogen loading rate of 1.10kg/(m(3)d) at hydraulic retention time 8h, the UMSR was kept performing for 67days in the present research and the average load removal of COD, NH4(+)-N and TN was as high as 0.72, 0.76 and 0.94kg/(m(3)d), respectively. Compared with the inoculated sludge, the acclimated sludge was richer in genera responsible for the biological removal of carbon, nitrogen and phosphorus. Ammonium oxidation bacteria, heterotrophic denitrifiers, autotrophic denitrifiers and phosphate accumulating organisms coexisted perfectly in the microaerobic system, and their synergistic action made the UMSR perform well in COD, NH4(+)-N, TN and phosphate removal.
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http://dx.doi.org/10.1016/j.biortech.2015.11.054DOI Listing
February 2016

A combined upflow anaerobic sludge bed and trickling biofilter process for the treatment of swine wastewater.

Environ Technol 2016 20;37(10):1265-75. Epub 2015 Nov 20.

b Centre de Recherche Industrielle du Québec , Québec , Canada.

A combined upflow anaerobic sludge blanket (UASB)-trickling biofilter (TBF) process was constructed to treat swine wastewater, a typical high-strength organic wastewater with low carbon/nitrogen ratio and ammonia toxicity. The results showed that the UASB-TBF system can remarkably enhance the removal of pollutants in the swine wastewater. At an organic loading rate of 2.29 kg/m(3) d and hydraulic retention time of 48 h in the UASB, the chemical oxygen demand (COD), Suspended Solids and Total Kjeldahl Nitrogen removals of the combined process reached 83.6%, 84.1% and 41.2%, respectively. In the combined system the UASB served as a pretreatment process for COD removal while nitrification and denitrification occurred only in the TBF process. The TBF performed reasonably well at a surface hydraulic load as high as 0.12 m(3)/m(2) d. Since the ratio of influent COD to total mineral nitrogen was less than 3.23, it is reasonable to suggest that the wood chips in TBF can serve as a new carbon source for denitrification.
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http://dx.doi.org/10.1080/09593330.2015.1111426DOI Listing
November 2016

Investigation on removal pathways of Di 2-ethyl hexyl phthalate from synthetic municipal wastewater using a submerged membrane bioreactor.

J Environ Sci (China) 2015 Nov 2;37:37-50. Epub 2015 Jul 2.

National Institute of Scientific Research, Water, Earth and Environment (INRS-ETE), University of Quebec, Quebec City, Quebec G1K 9A9, Canada.

Highly hydrophobic Di 2-ethyl hexyl phthalate (DEHP) is one of the most prevalent plasticizers in wastewaters. Since its half-life in biological treatment is around 25days, it can be used as an efficiency indicator of wastewater treatment plant for the removal of hydrophobic emerging contaminants. In this study, the performance of submerged membrane bioreactor was monitored to understand the effect of DEHP on the growth of aerobic microorganisms. The data showed that the chemical oxygen demand (COD) and ammonia concentration were detected below 10 and 1.0mg/L, respectively for operating conditions of hydraulic retention time (HRT)=4 and 6hr, sludge retention time (SRT)=140day and sludge concentration between 11.5 and 15.8g volatile solid (VS)/L. The removal efficiency of DEHP under these conditions was higher and ranged between 91% and 98%. Results also showed that the removal efficiency of DEHP in biological treatment depended on the concentration of sludge, as adsorption is the main mechanism of its removal. For the submerged membrane bioreactor, the pore size is the pivotal factor for DEHP removal, since it determines the amount of soluble microbial products coming out of the process. Highly assimilated microorganisms increase the biodegradation rate, as 74% of inlet DEHP was biodegraded; however, the concentration of DEHP inside sludge was beyond the discharge limit. Understanding the fate of DEHP in membrane bioreactor, which is one of the most promising and futuristic treatment process could provide replacement for conventional processes to satisfy the future stricter regulations on emerging contaminants.
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http://dx.doi.org/10.1016/j.jes.2015.03.025DOI Listing
November 2015

Potential Application of Biohydrogen Production Liquid Waste as Phosphate Solubilizing Agent-A Study Using Soybean Plants.

Appl Biochem Biotechnol 2016 Mar 5;178(5):865-75. Epub 2015 Nov 5.

Centre de Recherche Industrielle du Québec (CRIQ), Québec, QC, G1P 4C7, Canada.

With CO2 free emission and a gravimetric energy density higher than gasoline, diesel, biodiesel, and bioethanol, biohydrogen is a promising green renewable energy carrier. During fermentative hydrogen production, 60-70 % of the feedstock is converted to different by-products, dominated by organic acids. In the present investigation, a simple approach for value addition of hydrogen production liquid waste (HPLW) containing these compounds has been demonstrated. In soil, organic acids produced by phosphate solubilizing bacteria chelate the cations of insoluble inorganic phosphates (e.g., Ca3 (PO4)2) and make the phosphorus available to the plants. Organic acid-rich HPLW, therefore, has been evaluated as soil phosphate solubilizer. Application of HPLW as soil phosphate solubilizer was found to improve the phosphorus uptake of soybean plants by 2.18- to 2.74-folds. Additionally, 33-100 % increase in seed germination rate was also observed. Therefore, HPLW has the potential to be an alternative for phosphate solubilizing biofertilizers available in the market. Moreover, the strategy can be useful for phytoremediation of phosphorus-rich soil.
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http://dx.doi.org/10.1007/s12010-015-1914-6DOI Listing
March 2016

Nitrogen removal from low COD/TN ratio manure-free piggery wastewater within an upflow microaerobic sludge reactor.

Bioresour Technol 2015 Dec 16;198:884-90. Epub 2015 Sep 16.

Centre de Recherche Industrielle du Québec, 333 Franquet, Québec G1P 4C7, Canada.

An upflow microaerobic sludge reactor (UMSR) was constructed in treating manure-free piggery wastewater with high ammonium concentration and a COD/TN ratio as low as 0.84. The UMSR offered an outstanding removal of NH4(+)-N and TN at 35°C and hydraulic retention time 8h subsequent to inoculated sludge acclimation. A short NO2(-)-N accumulation phase was observed whenever there was a considerable increase in TN loading rate (NLR), but decreased rapidly along with an evident increase in TN removal. Fed with raw wastewater at a NLR of 1.10 kg/(m(3)d), the average COD, NH4(+)-N and TN removal reached 0.72, 0.76 and 0.94 kg/(m(3)d), respectively. Inference drawn from stoichiometry based on the potential nitrogen removal pathways and the C/N ratio required by denitrification indicated that anammox was the main mechanism for NH4(+)-N and TN removal in the UMSR.
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http://dx.doi.org/10.1016/j.biortech.2015.09.023DOI Listing
December 2015

Biohydrogen production by co-fermentation of crude glycerol and apple pomace hydrolysate using co-culture of Enterobacter aerogenes and Clostridium butyricum.

Bioresour Technol 2015 Oct 25;193:297-306. Epub 2015 Jun 25.

CO(2) Solutions Inc., 2300, Rue Jean-Perrin, Québec, QC G2C 1T9, Canada.

Co-substrate utilization of various wastes with complementary characteristics can provide a complete medium for higher hydrogen production. This study evaluated potential of apple pomace hydrolysate (APH) co-fermented with crude glycerol (CG) for increased H2 production and decreased by-products formation. The central composite design (CCD) along with response surface methodology (RSM) was used as tool for optimization and 15 g/L of CG, 5 g/L of APH and 15% (v/v) inoculum were found to be optimum to produce as high as 26.07 ± 1.57 mmol H2/L of medium. The p-value of 0.0017 indicated that APH at lower concentration had a significant effect on H2 production. By using CG as sole carbon source, reductive pathway of glycerol metabolism was favored with 19.46 mmol H2/L. However, with APH, oxidative pathway was favored with higher H2 production (26.07 ± 1.57 mmol/L) and decrease in reduced by-products (1,3-propanediol and ethanol) formation. APH inclusion enhanced H2 production, and decreased substrate inhibition.
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http://dx.doi.org/10.1016/j.biortech.2015.06.095DOI Listing
October 2015

Novel spectrophotometric method for detection and estimation of butanol in acetone-butanol-ethanol fermenter.

Talanta 2015 Aug 4;141:116-21. Epub 2015 Apr 4.

Bioprocess Engineering and Biotechnology Department, Federal University of Paraná, Centro Politécnico, Usina Piloto B, CEP 81531-990 Curitiba, Paraná, Brazil.

A new, simple, rapid and selective spectrophotometric method has been developed for detection and estimation of butanol in fermentation broth. The red colored compound, produced during reduction of diquat-dibromide-monohydrate with 2-mercaptoethanol in aqueous solution at high pH (>13), becomes purple on phase transfer to butanol and gives distinct absorption at λ520nm. Estimation of butanol in the fermentation broth has been performed by salting out extraction (SOE) using saturated K3PO4 solution at high pH (>13) followed by absorbance measurement using diquat reagent. Compatibility and optimization of diquat reagent concentration for detection and estimation of butanol concentration in the fermentation broth range was verified by central composite design. A standard curve was constructed to estimate butanol in acetone-ethanol-butanol (ABE) mixture under optimized conditions. The spectrophotometric results for butanol estimation, was found to have 87.5% concordance with the data from gas chromatographic analysis.
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http://dx.doi.org/10.1016/j.talanta.2015.03.062DOI Listing
August 2015

A novel anaerobic two-phase system for biohydrogen production and in situ extraction of organic acid byproducts.

Bioprocess Biosyst Eng 2015 Jun 10;38(6):1097-102. Epub 2015 Jan 10.

Institut National de la Recherche Scientifique (INRS), Centre Eau, Terre and Environnement, 490, Rue de la Couronne, Quebec, QC, G1K 9A9, Canada.

Owing to CO2-free emission, hydrogen is considered as a potential green alternative of fossil fuels. Water is the major emission of hydrogen combustion process and gravimetric energy density of hydrogen is nearly three times more than that of gasoline and diesel fuel. Biological hydrogen production, therefore, has commercial significance; especially, when it is produced from low-cost industrial waste-based feedstock. Light independent anaerobic fermentation is simple and mostly studied method of biohydrogen production. During hydrogen production by this method, a range of organic acid byproducts are produced. Accumulation of these byproducts is inhibitory for hydrogen production as it may result in process termination due to sharp decrease in medium pH or by possible metabolic shift. For the first time, therefore, a two-phase anaerobic bioreactor system has been reported for biohydrogen production which involves in situ extraction of different organic acids. Among different solvents, based on biocompatibility oleyl alcohol has been chosen as the organic phase of the two-phase system. An organic:aqueous phase ratio of 1:50 has been found to be optimum for hydrogen production. The strategy was capable of increasing the hydrogen production from 1.48 to 11.65 mmol/L-medium.
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http://dx.doi.org/10.1007/s00449-015-1352-4DOI Listing
June 2015
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