The Experts below are selected from a list of 37752 Experts worldwide ranked by ideXlab platform
Guangxue Wu - One of the best experts on this subject based on the ideXlab platform.
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effect of anoxic to Aerobic duration ratios on nitrogen removal and nitrous oxide emission in the multiple anoxic Aerobic Process
Environmental Technology, 2019Co-Authors: Huoqing Wang, Guangxue Wu, Yuntao GuanAbstract:ABSTRACTCharacteristics of nitrogen removal and nitrous oxide (N2O) emission in the multiple anoxic/Aerobic (AO) Process were examined in three sequencing batch reactors (SBRs) with different anoxi...
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color and nitrogen removal from synthetic dye wastewater in an integrated mesophilic hydrolysis acidification and multiple anoxic Aerobic Process
Chemosphere, 2018Co-Authors: Mengqi Gu, Zhongzhong Wang, Kai He, Guangxue WuAbstract:Abstract Dye wastewater is one kind of refractory pollutant and it is commonly treated by the integrated anAerobic and Aerobic Process. A new integrated hydrolysis/acidification and multiple anoxic/Aerobic (AO) Process was proposed for the removal of color and nitrogen from azo dye wastewater. System performance, the degradation pathway of azo dye and nitrogen metabolic pathway were investigated with quadrupole-time-of-flight and metagenomic analyses. The proposed Process removed color and nitrogen efficiently, with the removal percentages of 89.4% and 54.0%, respectively. A colorful intermediate C16H11N3O7S2 during the degradation of azo dye was detected. Controlling a low dissolved oxygen concentration in the multiple AO Process could enhance nitrogen removal. The detected bacteria possessing azoreductase for the azo dye degradation included Desulfovibrio aminophilus, Thermoanaerobacter, Lactococcus raffinolactis, Ruminiclostridium and Rhodopirellula. The nitrifying genes of amo and hao were mainly detected in Nitrosomonas, while the denitrifying genes were detected in Thauera, Candidatus Accumulibacter and Rhodothermus marinus.
Pierre Strehaiano - One of the best experts on this subject based on the ideXlab platform.
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microbial decolorization of reactive azo dyes in a sequential anAerobic Aerobic system
Chemical Engineering Journal, 2004Co-Authors: Nuttapun Supaka, Kanchana Juntongjin, Somsak Damronglerd, Marieline Delia, Pierre StrehaianoAbstract:A sequential anAerobic–Aerobic treatment Process based on mixed culture of bacteria isolated from textile dye effluent-contaminated soil was used to degrade reactive azo dyes Remazol Brilliant Orange 3R. Remazol Black B and Remazol Brilliant Violet 5R. Treating synthetic dye wastewater with the combination anAerobic and Aerobic Process showed that the majority of colors were removed by the anAerobic Process, on the other hand the majority of chemical oxygen demand (COD) was removed in the subsequent Aerobic Process. Samples from combined anAerobic–Aerobic system at the beginning of anAerobic Process, after anAerobic Process and after subsequent Aerobic Process were analyzed by high performance liquid chromatography (HPLC). The results suggested that under anAerobic conditions, the azo dyes were reduced and the aromatic amines were generated by the bacterial biomass. After re-aeration of the synthetic dye wastewater, these amines were further degraded by the same isolates. Thus, total degradation of reactive azo dyes was achieved by using an anAerobic–Aerobic treatment.
Xavier Lefebvre - One of the best experts on this subject based on the ideXlab platform.
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combined thermophilic Aerobic Process and conventional anAerobic digestion effect on sludge biodegradation and methane production
Bioresource Technology, 2010Co-Authors: Claire Dumas, Etienne Paul, Serge Perez, Xavier LefebvreAbstract:Abstract The efficiency of hyper-thermophilic (65 °C) Aerobic Process coupled with a mesophilic (35 °C) digester was evaluated for the activated sludge degradation and was compared to a conventional mesophilic digester. For two Sludge Retention Time (SRT), 21 and 42 days, the Chemical Oxygen Demand (COD) solubilisation and biodegradation Processes, the methanisation yield and the Aerobic oxidation were investigated during 180 days. The best results were obtained at SRT of 44 days; the COD removal yield was 30% higher with the Mesophilic AnAerobic Digestion/Thermophilic Aerobic Reactor (MAD–TAR) co-treatment. An increase of the sludge intrinsic biodegradability is also observed (20–40%), showing that the unbiodegradable COD in mesophilic conditions becomes bioavailable. However, the methanisation yield was quite similar for both Processes at a same SRT. Finally, such a Process enables to divide by two the volume of digester with an equivalent efficiency.
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Combined thermophilic Aerobic Process and conventional anAerobic digestion: effect on sludge biodegradation and methane production
Bioresource Technology, 2010Co-Authors: Claire Dumas, Etienne Paul, Serge Perez, Xavier LefebvreAbstract:The efficiency of hyper-thermophilic (65 degrees Celsius) Aerobic Process coupled with a mesophilic (35 degrees Celsius) digester was evaluated for the activated sludge degradation and was compared to a conventional mesophilic digester. For two Sludge Retention Time (SRT), 21 and 42 days, the Chemical Oxygen Demand (COD) solubilisation and biodegradation Processes, the methanisation yield and the Aerobic oxidation were investigated during 180 days. The best results were obtained at SRT of 44 days; the COD removal yield was 30% higher with the Mesophilic AnAerobic Digestion/Thermophilic Aerobic Reactor (MAD-TAR) co-treatment. An increase of the sludge intrinsic biodegradability is also observed (20-40%), showing that the unbiodegradable COD in mesophilic conditions becomes bioavailable. However, the methanisation yield was quite similar for both Processes at a same SRT. Finally, such a Process enables to divide by two the volume of digester with an equivalent efficiency.
G Lyberatos - One of the best experts on this subject based on the ideXlab platform.
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exploitation of olive oil mill wastewater for combined biohydrogen and biopolymers production
Bioresource Technology, 2009Co-Authors: Ioanna Ntaikou, Constantina Kourmentza, E C Koutrouli, K Stamatelatou, A Zampraka, Michael Kornaros, G LyberatosAbstract:Abstract The present study aimed to the investigation of the feasibility of the combined biohydrogen and biopolymers production from OMW (Olive oil Mill Wastewater), using a two stage system. H2 and volatile fatty acids (VFAs) were produced via anAerobic fermentation and subsequently the acidified wastewater was used as substrate for Aerobic biodegradable polymer production. Two different bioreactors, one of CSTR type and a SBR were used for the anAerobic and the Aerobic Process respectively. The anAerobic reactor was operated at different hydraulic retention times (HRTs) with OMW, diluted 1:4 (v/v) with tap water, as feed. The main VFAs produced were acetate, butyrate and propionate, in different ratios depending on the HRT. Valerate, isovalerate and isobutyrate were also detected in small quantities. Selective effluents of the acidogenic/hydrogen producing reactor were subsequently used as feed for the Aerobic reactor. The Aerobic reactor was inoculated with an enriched PHAs producing bacteria culture, and was operated in sequential cycles of nitrogen offer (growth phase) and nitrogen limitation (PHAs accumulation phase). The operational program of the SBR was determined according to the results from batch test, and its performance was evaluated for a period of 100 days. During the accumulation phase butyrate was consumed preferably, indicating that the dominant PHA produced is polyhydroxybutyrate. The higher yield of PHAs observed was 8.94% (w/w) of dry biomass weight.
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combined and separate Aerobic and anAerobic biotreatment of green olive debittering wastewater
Journal of Agricultural Engineering Research, 2001Co-Authors: George Aggelis, Hariklia N Gavala, G LyberatosAbstract:Abstract Wastewater generated from olive Processing comes either from olive oil or edible olive producing industries. Both types of wastewater constitute a major environmental concern since they are characterized by high organic content and are generated in large quantities for a specific period of the year. Furthermore, they contain compounds such as polyphenols, that are toxic to plants and/or soil microbes when discarded to soil receptors. This study aims at investigating the potential for biological treatment of a green olive debittering wastewater (GOW). The performance of a separate anAerobic, Aerobic and a combined anAerobic–Aerobic Process was evaluated. AnAerobic digestion of GOW reached a 49% maximum efficiency of organic matter removal with a polyphenolic reduction of about 12%. The Process seemed to be severely influenced by an inhibitory factor as suggested by the limited chemical oxygen demand (COD) removal, volatile fatty acids accumulation and low biogas production. The Aerobic biotreatment of the GOW was more efficient than its anAerobic counterpart, resulting in a degradation efficiency of 71·6–75·9%. However, it hardly affected the polyphenolic compounds, with the additional disadvantages of the requirement for pH correction of the influent and the high production of biomass. On the other hand, Aerobic treatment of the anAerobic effluent achieved a COD and polyphenolics reduction by 74 and 19·6% resulting in an overall reduction by 83·5 and 28%, respectively. Furthermore, the combined anAerobic–Aerobic treatment results in a smaller amount of Aerobic sludge and does not require a pH correction of the anAerobic or the Aerobic influent.
Cavacopaulo Artur - One of the best experts on this subject based on the ideXlab platform.
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biodegradation of textile azo dyes by a facultative staphylococcus arlettae strain vn 11 using a sequential microaerophilic Aerobic Process
International Biodeterioration & Biodegradation, 2009Co-Authors: Franciscon Elisangela, Zille Andrea, Dias Guimaro Fabio, Ragagnin De Menezes Cristiano, Durrant Lucia Regina, Cavacopaulo ArturAbstract:Abstract A facultative Staphylococcus arlettae bacterium, isolated from an activated sludge Process in a textile industry, was able to successfully decolourize four different azo dyes under microaerophilic conditions (decolourization percentage >97%). Further aeration of the decolourized effluent was performed to promote oxidation of the degradation products. The degradation products were characterized by FT-IR and UV–vis techniques and their toxicity with respect to Daphnia magna was measured. The amine concentrations as well as the total organic carbon (TOC) levels were monitored during the biodegradation Process. The presence of aromatic amine in the microaerophilic stage and its absence in the Aerobic stage indicated the presence of azoreductase activity and an oxidative biodegradation Process, respectively. TOC reduction was ∼15% in the microaerophilic stage and ∼70% in the Aerobic stage. The results provided evidence that, using a single Staphylococcus arlettae strain in the same bioreactor, the sequential microaerophilic/Aerobic stages were able to form aromatic amines by reductive break-down of the azo bond and to oxidize them into non-toxic metabolites.