Biofiltration d'air pollué par du xylène sur un nouveau lit à base de cellulose

2000 ◽  
Vol 27 (4) ◽  
pp. 814-828 ◽  
Author(s):  
L Bibeau ◽  
G Viel ◽  
M Heitz
Keyword(s):  
Carbon Dioxide ◽  
Organic Solvents ◽  
Degradation Process ◽  
Atmospheric Emissions ◽  
A Value ◽  
Volatile Organic ◽  
Different Types ◽  
Micro Organisms ◽  
Air Biofiltration ◽  
Air Discharge

The problem related to air discharge contaminated with volatile organic solvents (VOS) is the scope of numerous researches. Throughout the last decades, the development of different types of bioreactors to treat atmospheric emissions contaminated with VOS has been observed, such as: the bioscrubber, the percolating filter and the biofilter. These bioreactors are processes that use microorganisms in order to degrade the VOS into carbon dioxide, water, and biomass. This paper presents the results of a study on degradation by biofiltration of xylene contained in air, with a new filtering bed composed of cellulose. We have studied the conversion, the capacity of elimination of xylene with respect to the inlet load and the production of carbon dioxide. An elimination capacity of 75 g·m-3·h-1 for an inlet con centration to the biofilter of 1.7 g·m-3 of xylene has been obtained, which is a value that is superior to values mentioned in the literature. Measurements of temperature, pressure drop, and moisture content have been taken regularly so as to evaluate the influence of these parameters in the degradation process of xylene by microorganisms. Counts of bacteria and yeast/mould present in the filtering bed have been performed in order to follow the evolution of these micro organisms. At last, modeling based on the Ottengraf's model (1986) has been developed with the experimental data.Key words: treatment, air, biofiltration, xylenes, cellulose, volatile organic solvents.

scholarly journals The effect of oxygen on fermentation of sucrose by rumen micro-organisms in vitro

1969 ◽  
Vol 23 (1) ◽  
pp. 67-80 ◽  
Author(s):  
J. W. Czerkawski ◽  
Grace Breckenridge
Keyword(s):  
Carbon Dioxide ◽  
Organic Matter ◽  
Gas Phase ◽  
Particulate Organic Matter ◽  
Measurable Effect ◽  
A Value ◽  
Net Uptake ◽  
Effect Of Oxygen ◽  
Micro Organisms

1. The effect of oxygen on the fermentation of sucrose by mixed rumen micro-organisms in vitro was studied by adding oxygen to the gas phase in three ways: at the beginning of incubation, at two hourly intervals during incubation and continuously.2. The additions of oxygen had no measurable effect on the utilization of sucrose or on the production of carbon dioxide, steam-volatile acids and particulate organic matter by the micro-organisms. The addition of oxygen at the beginning of incubation inhibited methane production and increased the accumulation of hydrogen. Similar but much less pronounced changes occurred when the oxygen was infused continuously.3. In all the experiments there was a net uptake of oxygen by micro-organisms. When large amounts of oxygen were present in the gas phase the rates of uptake were proportional to these amounts. When small amounts of oxygen were added, the rates of uptake were independent of the amount added and had a value of approximately 5 ml/h when 100 ml of strained rumen contents were incubated.

Generic method for determination of volatile organic solvents in cosmetics

2014 ◽  
Vol 32 (11) ◽  
pp. 1251
Author(s):  
Jing DA ◽  
Xianglu HUANG ◽  
Gangli WANG ◽  
Jin CAO ◽  
Qingsheng ZHANG
Keyword(s):  
Organic Solvents ◽  
Volatile Organic

scholarly journals Assigning a Value to Volunteering in Requests for Proposals

SAGE Open ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 215824402110095
Author(s):  
Jakub Dostál
Keyword(s):  
Czech Republic ◽  
Theoretical Basis ◽  
Economic Value ◽  
European Economic Area ◽  
The Czech Republic ◽  
A Value ◽  
Economic Area ◽  
Different Types ◽  
The Relationship ◽  
Volunteer Time

The economic value of volunteering is an increasingly important part of volunteering management. It has become part of public policies. Some requests for proposals (RFP) enable nonprofits to include the value of volunteer time in compulsory co-financing. These RFP include the European Economic Area (EEA) Grants and Norway Grants. This article addresses the relationship in the value of volunteering, also called in-kind volunteering contributions. The research includes two case studies of finances from EEA and Norway Grants in the Czech Republic: the Czech NGO Programme, responsible for allocating grants between 2009 and 2014, and the Active Citizens Fund, responsible for allocating grants between 2014 and 2021. They share elements through the EEA and Norway Grants rules. However, they use different types of specialist replacement wages. The article summarizes the arguments for including in-kind volunteering contributions. It presents the possible values of these contributions in the selected cases, including the relationship between the type of volunteering and the number of hours necessary to achieve these values. The article defines the theoretical basis for calculating the value of in-kind volunteer contributions and illustrates this with real examples of allocations from EEA and Norway Grants.

How switching the substituent of a pyrene derivative from a methyl to a butyl affects the fluorescence response of polystyrene randomly labeled with pyrene

2010 ◽  
Vol 88 (3) ◽  
pp. 217-227 ◽  
Author(s):  
Mark Ingratta ◽  
Manoj Mathew ◽  
Jean Duhamel
Keyword(s):  
Organic Solvents ◽  
Excellent Agreement ◽  
Fluorescence Spectra ◽  
Series Solutions ◽  
Specific Nature ◽  
Polymer Backbone ◽  
Excimer Fluorescence ◽  
Fluorescence Response ◽  
Different Types ◽  
Blob Model

A series of polystyrenes randomly labeled with 1-pyrenebutanol were prepared by copolymerizing styrene and 1-pyrenebutylacrylate yielding the CoBuE–PS series. Solutions of CoBuE–PS were prepared in nine organic solvents having viscosities ranging from 0.36 to 5.5 mPa·s and the fluorescence spectra and pyrene monomer and excimer fluorescence decays were acquired. Analysis of the fluorescence spectra yielded the IE/IM ratio, whereas analysis of the fluorescence decays with the fluorescence blob model (FBM) yielded the parameters N blobo , <kblob × Nblob> , and k blobo . These parameters were compared to those obtained with two other series of pyrene-labeled polystyrenes, which had been studied earlier, namely CoA–PS and CoE–PS where pyrene was attached to the polymer backbone via a methylamide and benzyl methylether linker, respectively. Although the parameters IE/IM, N blobo , <kblob × Nblob>, and k blobo took different values according to the specific nature of the linker connecting pyrene to the polystyrene backbone, they exhibited trends that were quite similar for all the pyrene-labeled polystyrene constructs. The excellent agreement between the parameters retrieved for the three different types of pyrene-labeled polystyrenes suggests that the FBM accounts satisfyingly for differences in the nature of the label used, while still retrieving information pertinent to the polymer of interest.

Unsymmetrical phthalocyanines with cyclopalladated azo functions

2012 ◽  
Vol 16 (02) ◽  
pp. 192-199 ◽  
Author(s):  
H. Yasemin Yenilmez Akkurt ◽  
Ali ihsan Okur ◽  
Ahmet Gül
Keyword(s):  
Organic Solvents ◽  
Column Chromatography ◽  
Spectroscopic Analysis ◽  
Palladium Complex ◽  
Palladium Complexes ◽  
High Solubility ◽  
Synthetic Procedure ◽  
Different Types ◽  
New Compounds ◽  
Very High

In this study, a synthetic procedure for unsymmetrical metallophthalocyanines of the form M[Pc(AB3)], where A and B refer to two different types of peripheral functionality, has been developed and the new compounds have been converted to monomeric and dimeric palladium complexes. Asymmetrically substituted phthalocyanines were synthesized with the well-known statistical condensation method, by using two differently substituted precursors, namely 4-(2-ethoxyethoxy)-1-2-dicyanobenzene (1) and 4-{4-[Z/E]-phenylazo]-1-naphthyl}oxy-1,2-dicyanobenzene (2). Consequently, electron-donating 2-ethoxyethoxy groups and electron-withdrawing palladium complex are present in the same structure. Cyclopalladation was performed with [Pd(PhCN)2Cl2] to yield the bis-μ-chloro-bridged dimers and subsequently, the corresponding monomers were obtained by refluxing with three equivalents of potassium acetylacetonate. The resulting products were purified by column chromatography and characterized by several chemical and spectroscopic analysis methods. All compounds have very high solubility in organic solvents due to the presence of 2-ethoxyethoxy moiety.

scholarly journals Some chemical and bacterial characteristics of bottom deposits from lakes and estuaries

1953 ◽  
Vol 51 (2) ◽  
pp. 185-194 ◽  
Author(s):  
L. A. Allen ◽  
J. Grindley ◽  
Eileen Brooks
Keyword(s):  
Bacteriological Examination ◽  
Surface Layers ◽  
Digested Sludge ◽  
Faecal Pollution ◽  
Bottom Deposits ◽  
Low Concentrations ◽  
Different Types ◽  
Different Depths ◽  
Micro Organisms ◽  
Reducing Bacteria

Chemical and bacteriological examination of muds from sources differing widely in the degree of pollution to which they were subject showed great differences in the contents of carbon, nitrogen and sulphide. These differences were not correlated with differences in the severity of faecal pollution. The amount of organic matter available for growth of micro-organisms in the mud of different depths was not reflected in the figures for organic carbon. A convenient index of this factor was obtained by measuring the volume of gas evolved during anaerobic digestion over a prolonged period of incubation. The rate of evolution was increased by the addition of an inoculum of digested sludge from a sewage works.Sulphate-reducing bacteria appeared to be of two different types. In samples of mud from fresh-water lakes much higher counts were usually obtained in a medium containing comparatively low concentrations of inorganic salts and of lactate than in a medium containing much higher concentrations of these constituents. In samples from locations where conditions were more saline the reverse was usually true.Counts of Bact. coli and of Strep, faecalis together probably constitute the best index of faecal pollution in the examination of samples of mud. These organisms are, however, largely confined to the surface layers.

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