The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Yves Waché - One of the best experts on this subject based on the ideXlab platform.
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WITHDRAWN: Dataset on solid state fermentation for the production of lactones by Yarrowia lipolytica
Process Biochemistry, 2018Co-Authors: Sophal Try, Joëlle De-coninck, Andrée Voilley, Thavarith Chunhieng, Yves WachéAbstract:The data presented in this article are related to the original article entitled “Solid state fermentation for the production of γ-decalactones by Yarrowia lipolytica” (Try et al. 2008). In this work, the potential of solid state fermentation (SSF) is investigated for the production of γ-lactones with Y. lipolytica W29. The investigation focused on the impact of Aeration on metabolites. In that goal, experiments were carried out in three different SSF reactor types, wide-mouth Erlenmeyer flask (static Aeration), forced Aeration mini-reactor, and small-headspace bottle (without Aeration). From the present work, an alternative process is proposed as a novel model for lactone production.
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Use of a Doehlert factorial design to investigate the effects of pH and Aeration on the accumulation of lactones by Yarrowia lipolytica.
Journal of Applied Microbiology, 2007Co-Authors: E Escamilla García, J.-m. Belin, Yves WachéAbstract:AIMS: To detect rate-limiting steps in the production of lactones by studying the combined effect of pH and Aeration on their accumulation. METHODS AND RESULTS: A Doehlert experimental design was chosen to evaluate the accumulation of four lactones in the pH (3.5-7.3) and K(L)a (4.1 h(-1) to 26 h(-1)) experimental domain. The accumulation of gamma-decalactone was higher at pH around 5 and increased at low Aeration reaching 496 mg l(-1) at pH 6.35 and K(L)a 4.5 h(-1). The specific accumulation increased at low Aeration. The 3-hydroxy-gamma-decalactone accumulation was higher at low pH and high Aeration conditions: 660 mg l(-1) at pH 4.4 and 26 h(-1). For dec-2-en-4-olide and dec-3-en-4-olide, lower amounts were reached (104 mg l(-1) and 66 mg l(-1), respectively). CONCLUSIONS: Although the accumulation of the four lactones should be related to catalytic steps requiring oxygen, the accumulation of gamma-decalactone was higher in low Aeration conditions whereas the one of 3-hydroxy-gamma-decalactone was promoted for high Aeration. Decenolides accumulate independently of pH or Aeration. SIGNIFICANCE AND IMPACT OF THE STUDY: This study gives new insights into the catabolism of lipids, such as the role of co-factor regulation and the fact that the 3-hydroxylactone dehydration step is insensitive to pH or Aeration.
Hai Zhang - One of the best experts on this subject based on the ideXlab platform.
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Determination of the optimal Aeration for nitrogen removal in biochar-amended aerated vertical flow constructed wetlands.
Bioresource technology, 2018Co-Authors: Xu Zhou, Lei Gao, Hai ZhangAbstract:Abstract Nitrogen removal in vertical flow constructed wetlands (VFCWs) is still a key problem especially for treating low C/N wastewaters. In this study, nitrogen removal and nitrous oxide (N 2 O) emission in biochar-amended aerated VFCWs were evaluated under the varying intermittent Aeration (different Aeration times and Aeration rates). The results indicated that the optimal Aeration time and rate were 2 h d −1 and 0.6 L min −1 , which could create alternant of aerobic and anaerobic conditions for the simultaneous nitrification and denitrification in VFCWs. Much higher removal efficiency of COD (95.9%), NH 4 + -N (96.6%), and TN (74.7%) was achieved under the optimal conditions, and moderate N 2 O emission (282 μg m −2 ·h −1 ) was observed simultaneously. The results can be used to select the optimal Aeration in the further design and application of biochar-amended aerated CW treatments.
Weidong Chen - One of the best experts on this subject based on the ideXlab platform.
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effect of artificial Aeration on the performance of vertical flow constructed wetland treating heavily polluted river water
Journal of Environmental Sciences-china, 2012Co-Authors: Huiyu Dong, Zhimin Qiang, Hui Jin, Weidong ChenAbstract:Three lab-scale vertical-flow constructed wetlands (VFCWs), including the non-aerated (NA), intermittently aerated (IA) and continuously aerated (CA) ones, were operated at different hydraulic loading rates (HLRs) to evaluate the effect of artificial Aeration on the treatment efficiency of heavily polluted river water. Results indicated that artificial Aeration increased the dissolved oxygen (DO) concentrations in IA and CA, which significantly favored the removal of organic matter and NH4+-N. The DO grads caused by intermittent Aeration formed aerobic and anoxic regions in IA and thus promoted the removal of total nitrogen (TN). Although the removal efficiencies of CODCr, NH4+-N and TN in the three VFCWs all decreased with an increase in HLR, artificial Aeration enhanced the reactor resistance to the fluctuation of pollutant loadings. The maximal removal efficiencies of CODCr, NH4+-N and total phosphorus (TP) (i.e., 81%, 87% and 37%, respectively) were observed in CA at 19 cm/day HLR, while the maximal TN removal (i.e., 57%) was achieved in 1A. Although the improvement of artificial Aeration on TP removal was limited, this study has demonstrated the feasibility of applying artificial Aeration to VFCWs treating polluted river water, particularly at a high HLR.
Fabrice Béline - One of the best experts on this subject based on the ideXlab platform.
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Estimation of nitrogen removal from swine wastewater in activated sludge systems using activated sludge model simulation
2018Co-Authors: M. Waki, Fabrice Béline, T Yasuda, Y. Fukumoto, A. MagriAbstract:Livestock waste has a lot of influence on nitrogen contamination in public water body, in Japan, because it is produced as much as 20% of the total amount of industrial waste generated in the country. Commonly, liquid fractions that was produced by solid-liquid fraction of livestock waste, is treated by activated sludge process and then discharged to public water body. According to government sources, 61% of such swine wastewater is aerobically treated. An activated sludge model (ASM)-type model considering BOD and N removal was implemented including nitrite as intermediate, free ammonia and free nitrous acid as potential inhibitors and temperature as process parameter during swine wastewater treatment. Aeration condition is a key factor on nitrogen removal in the activated sludge process. Therefore, simulations were performed with focusing on Aeration conditions: continuous and intermittent Aeration with various Aeration intensity; influent swine wastewater BOD/N ratio of 2, 3 and 4. In the continuous Aeration condition, when DO was low, N was mainly removed through the nitrite short cut in simultaneous nitrification-denitrification. In intermittent Aeration condition, N was removed at broader DO conditions during Aeration than previously assessed for continuous Aeration. However, electrical energy consumption to achieve satisfactory N removal was almost same between two Aeration conditions. When the BOD/N ratio was set at 4, achieving satisfactory N removal was easier than BOD/N ratio of 3, and 2, at both conditions. When the BOD/N ratio was set at 2, critical DO control was required to achieve satisfactory N removal, therefore in such case, adding post-treatment for nitrogen removal like anammox process, after the activated sludge process would be practical.
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Nitrogen Removal from Swine Wastewater in Activated Sludge Systems Using an ASM for Continuous and Intermittent Aeration
2018Co-Authors: M. Waki, Fabrice Béline, T Yasuda, Y. Fukumoto, A. MagriAbstract:An ASM-type model considering BOD and N removal was implemented including nitrite as intermediate, free ammonia and free nitrous acid as potential inhibitors and temperature as process parameter during swine wastewater treatment. Simulations were performed at various conditions: continuous and intermittent Aeration; influent swine wastewater BOD/N ratio of 2, 3 and 4. Under continuous Aeration and low DO, N was mainly removed through the nitrite short cut in simultaneous nitrification-denitrification. Under intermittent Aeration, N was removed at broader DO conditions during Aeration than previously assessed for continuous Aeration. In both Aeration conditions, critical DO control was required to achieve satisfactory N removal, particularly when the BOD/N ratio of the wastewater was set at 2. This study assesses those conditions needed to meet the N effluent standards in AS swine wastewater treatment plants, and to identify those cases when post-treatment will be needed.
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Reduction of methane emissions during storage of slurry using Aeration
2004Co-Authors: Fabrice BélineAbstract:The aim of this work was to develop and evaluate Aeration as a strategy to reduce methane emissions during the storage of cattle slurry. For this purpose, a laboratory pilot including 3 storage reactors (9 litres each) was developed. One of them was equipped with an oxydo-reduction potential (ORP) probe in order to control Aeration level. Methane (CH4) and ammonia (NH3) emissions were determined during all experiments. Aerobic storage with low level of Aeration allow to reduce CH4 emissions during storage (>85%). However, NH3 emissions are promoted by Aeration and the level of Aeration should be minimized.
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Nitrogen transformations during biological aerobic treatment of pig slurry: effect of intermittent Aeration on nitrous oxide emissions
Bioresource Technology, 2002Co-Authors: Fabrice Béline, José MartinezAbstract:A laboratory scale Aeration treatment system was built to study the fate of nitrogen during Aeration of pig slurry. For each run evaluated, the nitrogen mass balance was determined including measurement of the nitrous oxide gas Emissions. Intermittent Aeration led to a nitrogen removal about 53% of the total nitrogen content of the raw slurry. About 18% of the total nitrogen content of the raw slurry was emitted as N2O during Aeration with an aerobic to anoxic ration equal to 0.625. In contrast, the extension of the anoxic period (aerobic to anoxic ratio = 0.375) allowed complete denitrification and avoided N2O emissions.
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Reduction of nitrous oxide emissions during aerobic treatment of pig slurry using intermittent Aeration
2000Co-Authors: Fabrice Béline, José MartinezAbstract:A laboratory treatment system was designed to study the fate of nitrogen during aerobic treatment of pig slurry. Different Aeration processes, continuous and intermittent, were evaluated. For each of the four runs evaluated, the nitrogen mass balance was determined including measurement of the gaseous nitrogen forms (ammonia and nitrous oxide). For continuous Aeration, nitrogen removal could rise up to 66% of the total nitrogen content of the raw slurry (redox control = 0 mVAg/AgCl) but was less important (34.5%) with redox potential control = -50 mVAg/AgCl due to oxygen limitation for ammonium oxidation. Concurrently, intermittent Aeration with Aeration sequences of 9 and 15 hours/day led to a nitrogen removal of about 53% of the total nitrogen content of the raw slurry. Between 21-24% of the total nitrogen content of the raw slurry was emitted as N2O during continuous Aeration while N2O emissions could be reduced from 18.4% of the total nitrogen content of the raw slurry during intermittent Aeration (Aeration: 2.5 hours, anoxic: 1.5 hours) to 0 using anoxic period longer (Aeration: 1.5 hours, anoxic: 2.5 hours).
Roland A Muller - One of the best experts on this subject based on the ideXlab platform.
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hydraulic characterization and optimization of total nitrogen removal in an aerated vertical subsurface flow treatment wetland
Bioresource Technology, 2014Co-Authors: Johannes Boog, Jaime Nivala, Manfred Van Afferden, Scott Wallace, Thomas Aubron, Roland A MullerAbstract:Abstract In this study, a side-by-side comparison of two pilot-scale vertical subsurface flow constructed wetlands (6.2 m2 × 0.85 m, qi = 95 L/m2 d, τn = 3.5 d) handling primary treated domestic sewage was conducted. One system (VA-i) was set to intermittent Aeration while the other was aerated continuously (VAp-c). Intermittent Aeration was provided to VA-i in an 8 h on/4 h off pattern. The intermittently aerated wetland, VA-i, was observed to have 70% less nitrate nitrogen mass outflow than the continuously aerated wetland, VAp-c. Intermittent Aeration was shown to increase treatment performance for TN while saving 33% of running energy cost for Aeration. Parallel tracer experiments in the two wetlands showed hydraulic characteristics similar to one Continuously Stirred Tank Reactor (CSTR). Intermittent Aeration did not significantly affect the hydraulic functioning of the system. Hydraulic efficiencies were 78% for VAp-c and 76% for VA-i.
