The Experts below are selected from a list of 121020 Experts worldwide ranked by ideXlab platform
A Seco - One of the best experts on this subject based on the ideXlab platform.
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Methane Recovery Efficiency in a Submerged Anaerobic Membrane Bioreactor (SAnMBR) treating sulphate-rich urban wastewater: Evaluation of methane losses with the effluent
2020Co-Authors: J B Gimenez, N Marti, J Ferrer, A SecoAbstract:Elsevier Ferrer, J.; Abstract The present paper presents a submerged anaerobic membrane bioreactor (SAnMBR) as a sustainable approach for urban wastewater treatment at 33ºC and 20ºC, since greenhouse gas emissions are reduced and energy Recovery is enhanced. Compared to other anaerobic systems such as UASB reactors, the membrane technology allows the use of biogas-assisted mixing which enhances the methane stripping from the liquid phase bulk. The methane saturation index obtained for the whole period (1.00 ± 0.04) evidenced that the equilibrium condition was reached and the methane loss with the effluent was reduced. The methane Recovery Efficiency obtained at 20ºC (53.6%) was slightly lower than at 33ºC (57.4%) due to a reduction of the treatment Efficiency, as evidenced by the lower methane production and the higher waste sludge per litre of treated wastewater. For both operational temperatures, the methane Recovery Efficiency was strongly affected by the high sulphate concentration in the influent wastewater. 2 Keywords Dissolved methane; methane saturation index; submerged anaerobic membrane bioreactor (SAnMBR); urban wastewater; sulphate-rich wastewate
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methane Recovery Efficiency in a submerged anaerobic membrane bioreactor sanmbr treating sulphate rich urban wastewater evaluation of methane losses with the effluent
Bioresource Technology, 2012Co-Authors: J B Gimenez, N Marti, J Ferrer, A SecoAbstract:Abstract The present paper presents a submerged anaerobic membrane bioreactor (SAnMBR) as a sustainable approach for urban wastewater treatment at 33 and 20 °C, since greenhouse gas emissions are reduced and energy Recovery is enhanced. Compared to other anaerobic systems, such as UASB reactors, the membrane technology allows the use of biogas-assisted mixing which enhances the methane stripping from the liquid phase bulk. The methane saturation index obtained for the whole period (1.00 ± 0.04) evidenced that the equilibrium condition was reached and the methane loss with the effluent was reduced. The methane Recovery Efficiency obtained at 20 °C (53.6%) was slightly lower than at 33 °C (57.4%) due to a reduction of the treatment Efficiency, as evidenced by the lower methane production and the higher waste sludge per litre of treated wastewater. For both operational temperatures, the methane Recovery Efficiency was strongly affected by the high sulphate concentration in the influent wastewater.
R J Schotting - One of the best experts on this subject based on the ideXlab platform.
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analysis of Recovery Efficiency in high temperature aquifer thermal energy storage a rayleigh based method
Hydrogeology Journal, 2014Co-Authors: Gilian Schout, Benno Drijver, Mariene Gutierrezneri, R J SchottingAbstract:High-temperature aquifer thermal energy storage (HT-ATES) is an important technique for energy conservation. A controlling factor for the economic feasibility of HT-ATES is the Recovery Efficiency. Due to the effects of density-driven flow (free convection), HT-ATES systems applied in permeable aquifers typically have lower Recovery efficiencies than conventional (low-temperature) ATES systems. For a reliable estimation of the Recovery Efficiency it is, therefore, important to take the effect of density-driven flow into account. A numerical evaluation of the prime factors influencing the Recovery Efficiency of HT-ATES systems is presented. Sensitivity runs evaluating the effects of aquifer properties, as well as operational variables, were performed to deduce the most important factors that control the Recovery Efficiency. A correlation was found between the dimensionless Rayleigh number (a measure of the relative strength of free convection) and the calculated Recovery efficiencies. Based on a modified Rayleigh number, two simple analytical solutions are proposed to calculate the Recovery Efficiency, each one covering a different range of aquifer thicknesses. The analytical solutions accurately reproduce all numerically modeled scenarios with an average error of less than 3 %. The proposed method can be of practical use when considering or designing an HT-ATES system.
Yinhu Wu - One of the best experts on this subject based on the ideXlab platform.
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an efficient microalgal biomass harvesting method with a high concentration ratio using the polymer surfactant aggregates process
Algal Research-Biomass Biofuels and Bioproducts, 2018Co-Authors: Yinhu Wu, Licheng Shen, Hongying Hu, Nicholas P Hankins, Wei E HuangAbstract:Abstract The high cost and energy consumption related to the downstream harvesting and dewatering process is one of the most important bottlenecks limiting the commercial production of microalgal bioenergy. In this study, a novel microalgal biomass harvesting technique has been developed using polymer surfactant aggregates (PSAs). This approach has been applied to three different microalgal strains and two cynobacterial strains with a Recovery Efficiency of over 80%. In particular, the Recovery Efficiency of Chlorella sp. ZTY4 with a biomass concentration of 1.43 g·L− 1 can be as high as 99.9% using 360 mg·L− 1 poly (acrylic acid) (PAA) and 4 mM (1432 mg·L− 1) cetylpyridinium chloride (CPC). In addition, with this PAA and CPC dosage, the Recovery Efficiency of Chlorella sp. ZTY4 remains above 90% for biomass concentrations up to 2.5 g·L− 1. Furthermore, the water content in the harvested biomass is below 70% with a corresponding concentration ratio of 231. The total flocculation time needed for this technique is 20 min. The optimum dosage ratio for PAA to CPC ranges from 90 to 100 mg/mmol. Based on these results, an efficient harvesting method with a high concentration ratio is proposed to simplify the whole downstream harvesting and dewatering processes of microalgal biomass.
J B Gimenez - One of the best experts on this subject based on the ideXlab platform.
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Methane Recovery Efficiency in a Submerged Anaerobic Membrane Bioreactor (SAnMBR) treating sulphate-rich urban wastewater: Evaluation of methane losses with the effluent
2020Co-Authors: J B Gimenez, N Marti, J Ferrer, A SecoAbstract:Elsevier Ferrer, J.; Abstract The present paper presents a submerged anaerobic membrane bioreactor (SAnMBR) as a sustainable approach for urban wastewater treatment at 33ºC and 20ºC, since greenhouse gas emissions are reduced and energy Recovery is enhanced. Compared to other anaerobic systems such as UASB reactors, the membrane technology allows the use of biogas-assisted mixing which enhances the methane stripping from the liquid phase bulk. The methane saturation index obtained for the whole period (1.00 ± 0.04) evidenced that the equilibrium condition was reached and the methane loss with the effluent was reduced. The methane Recovery Efficiency obtained at 20ºC (53.6%) was slightly lower than at 33ºC (57.4%) due to a reduction of the treatment Efficiency, as evidenced by the lower methane production and the higher waste sludge per litre of treated wastewater. For both operational temperatures, the methane Recovery Efficiency was strongly affected by the high sulphate concentration in the influent wastewater. 2 Keywords Dissolved methane; methane saturation index; submerged anaerobic membrane bioreactor (SAnMBR); urban wastewater; sulphate-rich wastewate
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methane Recovery Efficiency in a submerged anaerobic membrane bioreactor sanmbr treating sulphate rich urban wastewater evaluation of methane losses with the effluent
Bioresource Technology, 2012Co-Authors: J B Gimenez, N Marti, J Ferrer, A SecoAbstract:Abstract The present paper presents a submerged anaerobic membrane bioreactor (SAnMBR) as a sustainable approach for urban wastewater treatment at 33 and 20 °C, since greenhouse gas emissions are reduced and energy Recovery is enhanced. Compared to other anaerobic systems, such as UASB reactors, the membrane technology allows the use of biogas-assisted mixing which enhances the methane stripping from the liquid phase bulk. The methane saturation index obtained for the whole period (1.00 ± 0.04) evidenced that the equilibrium condition was reached and the methane loss with the effluent was reduced. The methane Recovery Efficiency obtained at 20 °C (53.6%) was slightly lower than at 33 °C (57.4%) due to a reduction of the treatment Efficiency, as evidenced by the lower methane production and the higher waste sludge per litre of treated wastewater. For both operational temperatures, the methane Recovery Efficiency was strongly affected by the high sulphate concentration in the influent wastewater.
Gregory F Piepel - One of the best experts on this subject based on the ideXlab platform.
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false negative rate limit of detection and Recovery Efficiency performance of a validated macrofoam swab sampling method for low surface concentrations of bacillus anthracis sterne and bacillus atrophaeus spores
Journal of Applied Microbiology, 2016Co-Authors: Gregory F Piepel, Brett G Amidan, Christopher A Barrett, B Deatherage L Kaiser, Michael A. Sydor, Janine R HutchisonAbstract:AIMS: We sought to evaluate the effects of Bacillus species, low surface concentrations, and surface material on Recovery Efficiency (RE), false-negative rate (FNR) and limit of detection for recovering Bacillus spores using a validated macrofoam-swab sampling procedure. METHODS AND RESULTS: The performance of a macrofoam-swab sampling method was evaluated using Bacillus anthracis Sterne (BAS) and Bacillus atrophaeus Nakamura (BG) spores applied at nine low target surface concentrations (2 to 500 CFU per plate or coupon) to positive-control plates and test coupons (25·8064 cm(2) ) of four surface materials (glass, stainless steel, vinyl tile and plastic). The Bacillus species and surface material had statistically significant effects on RE, but surface concentration did not. Mean REs were the lowest for vinyl tile (50·8% with BAS and 40·2% with BG) and the highest for glass (92·8% with BAS and 71·4% with BG). FNR values (which ranged from 0 to 0·833 for BAS and from 0 to 0·806 for BG) increased as surface concentration decreased in the range tested. Surface material also had a statistically significant effect on FNR, with FNR the lowest for glass and highest for vinyl tile. Finally, FNR tended to be higher for BG than for BAS at lower surface concentrations, especially for glass. CONCLUSIONS: Concentration and surface material had significant effects on FNR, with Bacillus species having a small effect. Species and surface material had significant effects on RE, with surface concentration having a nonsignificant effect. SIGNIFICANCE AND IMPACT OF THE STUDY: The results provide valuable information on the performance of the macrofoam-swab method for low surface concentrations of Bacillus spores, which can be adapted to assess the likelihood that there is no contamination when all macrofoam-swab samples fail to detect B. anthracis.
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Recovery Efficiency false negative rate and limit of detection performance of a validated macrofoam swab sampling method with low surface concentrations of two bacillus anthracis surrogates
2015Co-Authors: Gregory F Piepel, Brett G Amidan, Brooke Deatherage L Kaiser, Michael A. Sydor, Janine R Hutchison, Christopher A BarrettAbstract:The performance of a macrofoam-swab sampling method was evaluated using Bacillus anthracis Sterne (BAS) and Bacillus atrophaeus Nakamura (BG) spores applied at nine low target amounts (2-500 spores) to positive-control plates and test coupons (2 in. × 2 in.) of four surface materials (glass, stainless steel, vinyl tile, and plastic). Test results from cultured samples were used to evaluate the effects of surrogate, surface concentration, and surface material on Recovery Efficiency (RE), false negative rate (FNR), and limit of detection. For RE, surrogate and surface material had statistically significant effects, but concentration did not. Mean REs were the lowest for vinyl tile (50.8% with BAS, 40.2% with BG) and the highest for glass (92.8% with BAS, 71.4% with BG). FNR values ranged from 0 to 0.833 for BAS and 0 to 0.806 for BG, with values increasing as concentration decreased in the range tested (0.078 to 19.375 CFU/cm2, where CFU denotes ‘colony forming units’). Surface material also had a statistically significant effect. A FNR-concentration curve was fit for each combination of surrogate and surface material. For both surrogates, the FNR curves tended to be the lowest for glass and highest for vinyl title. The FNR curves for BG tended tomore » be higher than for BAS at lower concentrations, especially for glass. Results using a modified Rapid Viability-Polymerase Chain Reaction (mRV-PCR) analysis method were also obtained. The mRV-PCR results and comparisons to the culture results will be discussed in a subsequent report.« less
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false negative rate and Recovery Efficiency performance of a validated sponge wipe sampling method
Applied and Environmental Microbiology, 2012Co-Authors: Paula Krauter, Brett G Amidan, Gregory F Piepel, Raymond M Boucher, Mathew Tezak, Wayne EinfeldAbstract:ABSTRACT Recovery of spores from environmental surfaces varies due to sampling and analysis methods, spore size and characteristics, surface materials, and environmental conditions. Tests were performed to evaluate a new, validated sponge wipe method using Bacillus atrophaeus spores. Testing evaluated the effects of spore concentration and surface material on Recovery Efficiency (RE), false-negative rate (FNR), limit of detection (LOD), and their uncertainties. Ceramic tile and stainless steel had the highest mean RE values (48.9 and 48.1%, respectively). Faux leather, vinyl tile, and painted wood had mean RE values of 30.3, 25.6, and 25.5, respectively, while plastic had the lowest mean RE (9.8%). Results show roughly linear dependences of RE and FNR on surface roughness, with smoother surfaces resulting in higher mean REs and lower FNRs. REs were not influenced by the low spore concentrations tested (3.10 × 10−3 to 1.86 CFU/cm2). Stainless steel had the lowest mean FNR (0.123), and plastic had the highest mean FNR (0.479). The LOD90 (≥1 CFU detected 90% of the time) varied with surface material, from 0.015 CFU/cm2 on stainless steel up to 0.039 on plastic. It may be possible to improve sampling results by considering surface roughness in selecting sampling locations and interpreting spore Recovery data. Further, FNR values (calculated as a function of concentration and surface material) can be used presampling to calculate the numbers of samples for statistical sampling plans with desired performance and postsampling to calculate the confidence in characterization and clearance decisions.
