Search results for "achat"
showing 10 items of 89 documents
Aerobic Granular Sludge for Leachate Treatment
2014
The treatment of municipal landfill leachate by means of aerobic granular sequencing batch reactors (GSBRs) was investigated. The paper reports the results from an experimental campaign lasted 100 days, which has been divided into three periods: cultivation of granular sludge (70 days), operation with semi-fresh (15 day) and diluted landfill leachate (15 day). Two different GSBR configurations were used: a Sequencing Batch Bubble Column reactor and a Sequencing Batch Airlift Reactor. All reactors were operated at Volume Loading Rates (VLRs) between 4.8 and 7.2 g COD /(m 3 ·d). The Chemical Oxygen Demand (COD) removal efficiency varied between 80% and 90% under operation with synthetic waste…
Mathematical modelling of biogas from municipal solid waste landfil
2016
Sanitary landfills for municipal solid wastes can be considered as large biological reactors where the organic fraction of municipal solid waste undergoes anaerobic digestion producing gas and liquid emissions. Leachate production from municipal sanitary landfills is currently recognized as a major environmental burden associated with municipal solid waste management and it may be responsible for local pollution of groundwater and soil. Moreover, the fate of the organic compounds within the landfill body is of primary importance since it directly influences the production of landfill gas. The aim of the paper is to propose an integrated mathematical model able to simulate, on one hand, the …
Effect of micro-aeration and leachate replacement on COD solubilization and VFA production during mono-digestion of grass-silage in one-stage leach-b…
2010
The effect of micro-aeration and leachate replacement with fresh water on chemical oxygen demand (COD) solubilization and volatile fatty acid (VFA) production during the mono-digestion of grass-silage in one-stage leach-bed reactors (LBRs) was investigated in four LBRs, L0 (control), L1, L2 and L3 in batch mode at 35 + or - 1 degrees Celsius for 57 days. Results showed that leachate replacement without pH adjustment (L3) resulted in 2.7 and 1.3 times more SCOD in the leachate compared to control (L0) or leachate replacement with initial pH adjustment (L1), respectively. Micro-aeration at flow rate of 1 L min(-1) (2.5 L of air) in L2 resulted in 4-fold increase in VFA production (from 2.2 to…
Effect of macro and micro nutrients addition during anaerobic mono-digestion of grass silage in leach-bed reactors
2019
The effect of macro- (NH4Cl) (set I) and micro-nutrients (Fe, Ni, Co and Mo) (set II) addition on chemical oxygen demand (COD) solubilisation during anaerobic mono-digestion of grass silage was investigated in two sets of leach bed reactor experiments at 35°C. Results showed that addition of NH4Cl and micro-nutrients improved COD solubilisation by 18% (0.56 g SCOD g−1 volatile solids) and 7% (0.45 g SCOD g−1 VS), respectively than control. About 20–50% of the added micro-nutrients were bioavailable in the produced leachates, while the rest (50–80%) were adsorbed onto the grass silage. Results of biological methane potential assays showed that, specific methane yields of grass silage were im…
The Tortricidae described by J. C. Fabricius (Lepidoptera)
2011
The identity and nomenclature of the 88 species of Tortricidae (Lepidoptera) described by J. C. Fabricius are reviewed. Type material deposited in the Natural History Museum Denmark is illustrated. Lectotypes for Tinea compositella (Fabricius, 1775), Pyralis rivellana (Fabricius, 1775) and P. strigana (Fabricius, 1775) are designated. Two new synonymies are proposed: Pyralis marmorana (Fabricius, 1798), syn. n., of Ancylis achatana (Denis and Schiffermuller, 1775), and P. rusticana (Fabricius, 1794), syn. n., of Epinotia solandriana (Linnaeus, 1758). In an appendix, the identity and nomenclature of the 49 species of non-Tortricidae described by Fabricius in the genus Pyralis Linnaeus, 1758 …
Organic carbon, water repellency and soil stability to slaking under different crops and managements: a case study at aggregate and intra-aggregate s…
2014
This research studies the distribution of organic C and intensity of water repellency in soil aggregates with different size and in the interior of aggregates from Mediterranean soils under different crops (apricot, citrus and wheat) and management (con- 5 ventional tilling and no tilling/mulching). For this, undisturbed aggregates were sampled and carefully divided in size fractions (0.25–0.5, 0.5–1, 1–2, 2–5, 5–10 and 10–15 mm) or peeled to obtain separated aggregate layers (exterior, transitional and interior). Organic C content in the fine earth fraction of soils under different crops did not show important variations, although it increased significantly from conventionally tilled to 10…
Vers une clarification théorique de la notion de valeur perçue en marketing
2012
International audience; La valeur perçue par les consommateurs occupe une place significative dans les réflexions actuelles des praticiens et des chercheurs en marketing. Cependant, la diversité des recherches et l'absence d'un cadre théorique unifié nécessitent un travail de clarification. Cet article propose ainsi d'identifier, à partir des définitions et approches de la valeur, des critères de classification et de caractérisation de cette notion. Puis, la comparaison avec d'autres concepts proches amène à resituer la valeur perçue au sein d'un réseau de relations. Enfin, les implications managériales, liées à l'analyse de la valeur perçue, sont soulignées.
Dynamics of copper and zinc sedimentation in a lagooning system receiving landfill leachate.
2013
9 pages; International audience; This study characterises the sediment dredged from a lagooning system composed of a settling pond and three lagoons that receive leachates from a municipal solid waste (MSW) landfill in France. Organic carbon, carbonate, iron oxyhydroxides, copper (Cu) and zinc (Zn) concentrations were measured in the sediment collected from upstream to downstream in the lagooning system. In order to complete our investigation of sedimentation mechanisms, leachates were sampled in both dry (spring) and wet (winter) seasonal conditions. Precipitation of calcite and amorphous Fe-oxyhydroxides and sedimentation of organic matter occurred in the settling pond. Since different di…
The 2010 Eyjafiallajokull volcanic summit eruption: evidences from ash-leachates analysis and ground deposition fluxes
2012
The Eyjafjallajökull 2010 eruption was an extraordinary event in that it led to widespread over Europe. Volcanic processes which lead to eruptions can be investigated by monitoring a variety of parameters, including the composition of ash leachates. Fine-grained tephra erupted from active vents, and transported through volcanic plumes, can adsorbs, and therefore rapidly scavenge, volatile elements such as S, halogens, and metal species in the form of soluble salts adhering to ash surfaces. Analysis of such water-soluble phases is a suitable complement for the remote sensing of volcanic gases at inaccessible volcanoes, like Eyjafjallajökull. The 2010 Eyjafjallajökull eruption developed in fo…
Leachate Analyses of volcanic ashes from the 2010 Eyjafjallajökull eruption
2011
Volcanic processes which lead to eruptions can be investigated by monitoring a variety of parameters, including the composition of ash leachates. Fine-grained tephra erupted from active vents, and transported through volcanic plumes, can adsorb, and therefore rapidly scavenge, volatile elements such as sulphur, halogens, and metal species in the form of soluble salts adhering to ash surfaces. Analysis of such water-soluble surface materials is a suitable complement for the remote sensing of volcanic gases at inaccessible volcanoes. The April 2010 Eyjafjallajökull eruption has been characterised by several distinct phases, with an initial effusion of alkali basalt on the volcano's northeast …