Publications by authors named "Moletta R"

A thermochemical pretreatment, i.e. saponification, was optimised in order to improve anaerobic biodegradation of slaughterhouse wastes such as aeroflotation grease and flesh fats from cattle carcass.

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High strength milk permeate derived from ultra-filtration based cheese making process was treated in an anaerobic moving bed biofilm reactor (AMBBR) under mesophilic (35 degrees C) condition. Total chemical oxygen demand (TCOD) removal efficiencies of 86.3-73.

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The treatment of reconstituted whey wastewater was performed in a 400 L digester at 20 degrees C, with an anaerobic digestion step, followed by a step of aerobic treatment at low oxygen concentration in the same digester. In a first set of 48 cycles, total cycle time (T(C)) of 2, 3 and 4 days were tested at varying organic loading rates (OLR). The COD removal reached 89+/-4, 97+/-3 and 98+/-2% at T(C) of 2, 3 and 4 days and OLR of 0.

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Bioaugmentation experiments with the aerobic denitrifier Microvirgula aerodenitrificans were performed in an aerobic continuous stirred tank reactor (CSTR) treating urban wastewater. The fate of the added bacteria was monitored by a specific fluorescent oligonucleotide probe targeting 16S rRNA. The first addition of the strain led to its rapid disappearance because of grazing.

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An anaerobic fixed bed reactor, filled with small floating supports of polyethylene material (Bioflow 30) as inert media, was operated for 6 months to treat vinasse (wine residue after distillation). Bioflow 30 has a density of 0.93 and a specific area of 320 m2/m3.

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Wine distillery wastewater, commonly called vinasses, was treated by an anaerobic moving bed biofilm reactor (AMBBR) with 32.9 litre available volume. The reactor was filled with 66% cylindrical polyethylene supports with density 0.

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A proof of concept was performed in order to verify if the coupling of anaerobic and aerobic conditions inside the same digester could efficiently treat a reconstituted whey wastewater at 21 degrees C. The sequencing batch reactor (SBR) cycles combined initial anaerobic phase and final aerobic phase with reduced aeration. A series of 24 h cycles in 0.

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The anaerobic treatment of saline effluents using halophilic and halotolerant microbial consortia is of major interest. Inhibition of anaerobic digestion is known to occur at high salt content. However, it seems that the suitable adaptation of an anaerobic sludge makes possible the treatment of saline wastewater.

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Many industrial sectors are likely to generate highly saline wastewater: these include the agro-food, petroleum and leather industries. The discharge of such wastewater containing at the same time high salinity and high organic content without prior treatment is known to adversely affect the aquatic life, water potability and agriculture. Thus, legislation is becoming more stringent and the treatment of saline wastewater, both for organic matter and salt removal, is nowadays compulsory in many countries.

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A bacterial culture-based inventory with 16S rDNA identification of the isolates was carried out on an anaerobic digestor microbial ecosystem to compare to the 16S rDNA sequences directly retrieved from the ecosystem by a molecular inventory previously made in our laboratory. Twenty OTUs (Operational Taxonomic Units) belonging to five of the major bacterial groups were identified from 338 isolated colonies. The sequences of 13 of the 20 OTUs were not closely related to any hitherto published sequences (less than 96% sequence identity).

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Pichia stipitis efficiently converts glucose or xylose into ethanol but is inhibited by ethanol concentrations exceeding 30 g/L. In Saccharomyces cerevisiae, ethanol has been shown to alter the movement of protons into and out of the cell. In P.

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In contrast to conventional wastewater treatment plants and saline environments, little is known regarding the microbial diversity of hypersaline wastewater. In this study, the microbial communities of a hypersaline tannery effluent, and those of three treatment systems operating with the tannery effluent, were investigated using 16S rDNA phylogenetic markers. The comparative analysis of 377 bacterial sequences revealed the high diversity of this type of hypersaline environment, clustering within 193 phylotypes (> or = 97% similarity) and covering 14 of the 52 divisions of the bacterial domain, i.

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The leather industry occupies a place of prominence in the Indian economy due to its massive potential for employment, growth and exports. The potential environmental impact of tanning is significant. This study focuses on tannery soak liquor, generated by the soaking of hides and skins, which is characterised by high organic load and high salinity.

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Hypersaline wastewater (i.e. wastewater containing more than 35 gl(-1) total dissolved solids (TDS)) is generated by various industrial activities.

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The long start-up period of fluidized bed biofilm reactors is a serious obstacle for their wide installation in the anaerobic treatment of industrial wastewater. This paper presents the results of an anaerobic inverse turbulent bioreactor treating distillery wastewater during 117 days of operation at a laboratory scale. The pre-colonized bioparticles for this work were obtained from a similar reactor processing the same wastewater and which had a start-up period of 3 months.

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Anaerobic digestion is widely used for wastewater treatment, especially in the food industries. Generally after the anaerobic treatment there is an aerobic post-treatment in order to return the treated water to nature. Several technologies are applied for winery wastewater treatment.

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In France, small goat's cheese dairies using traditional craft methods often have no profitable solution for dealing with the whey byproduct of their cheesemaking activity: it is usually mixed with the cleaning wastewater which, in the absence of other possibilities, is then discharged directly into the environment. The volume of such wastewater is small but it has a high COD of around 12-15 g/L. An aerobic SBR was proposed as a method for treating the mixture of wastewater and whey and the first installation was set up on a farm with 170 goats.

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Microbial consortia in a two-phase, anaerobic bioreactor using a mixture of fruit and vegetable wastes were established. Bacterial and archaeal communities obtained by a culture-independent approach based on single strand conformation polymorphism analysis of total 16S rDNA showed the adaptation of the microflora to the process parameters. Throughout the 90 d of the study, the species composition of the bacterial community changed significantly.

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Hypersaline effluents are produced by various industrial activities. Such wastewater, rich in both organic matter and salt (> 35 g l(-1)), is difficult to treat by conventional wastewater treatment processes. It is necessary to use halophilic bacteria.

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This paper describes the application of the inverse fluidization technology to the anaerobic digestion of dairy wastewater. Two reactors were investigated: the inverse fluidized bed reactor and the inverse turbulent reactor. In these reactors, a granular floating solid is expanded by a down-flow current of effluent or an up-flow current of gas, respectively.

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The aim of the study was to determine the performances of a combined ozone/anaerobic digestion system for waste activated sludge reduction. The objective was the estimation of the process efficiency and stability when keeping constant influent flow while increasing recycled chemically treated flow. The ozonation step consisted in a partial oxidation (0.

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A study of the anaerobic biodegradability of the three categories of water separated from extracted crude oil (Venezuelan oilfields)--light, medium or heavy crude--was carried out at laboratory scale using UASB reactors working at mesophilic conditions. Chemical oxygen demand (COD) removal in a low loaded UASB reactor fed with water separated from extracted light crude was high, with an average 87% purification efficiency. The remaining COD was made up of the nonbiodegradable and the very slowly biodegradable fractions of the organic matter in the water.

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Treatment of winery wastewater was investigated using an anaerobic sequencing batch reactor (ASBR). Biogas production rate was monitored and permitted the automation of the bioreactor by a simple control system. The reactor was operated at an organic loading rate (ORL) around 8.

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This paper describes the variation of the methane yield during the start-up period of an anaerobic fluidized bed reactor. After a lag phase, with acclimatized sludge, the methane yield increased with time during biofilm development up to the theoretical steady yield value, reported to be around 0.351 CH4/g CODdeg.

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A group of Gram-negative denitrifying bacteria has been isolated from a denitrifying reactor treating landfill leachate. The new isolates produced both oxidase and catalase and showed growth on acetate, butyrate, n-caproate, i-butyrate, i-valerate, propionate, n-valerate, lactate, alanine, benzoate, phenylalanine and ethanol. No growth was observed on sugars.

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