Etude de la reactivite microbiologique et de l’effet toxique sur carassius auratus du glutaraldehyde

p.p. 177-185Le ‘’glutaraldéhyde’’ est un composé largement utilisé dans l’industrie, comme biocide efficace.L’hygiène hospitalière l’utilise en grande quantité, pour ses propriétés physicochimiques (réactivité, tension de vapeur). Le ‘’glutaraldéhyde’’ se montre toxique pour la santé humaine et animale. L’étude des effets du ‘’glutaraldéhyde’’ sur le Carassius auratus, de la famille des cyprinadae d’eaux douces, met en évidence son extrême nuisance sur l’environnement. La Concentration Létale (CL50) déterminée en fonction du poids de ‘’cyprin doré’’, souligne la nocivité des solutions à base du glutaraldéhyd

ASPECT TOXICOLOGIQUE ET PHYSICOCHIMIQUE DU 1,5-DIPENTANAL

The 1,5-dipentanal is an important organic molecule: pedagogically, the molecule provides a range of interesting chemical reactions (Aldolisation, Michael, glycolysis, Cannizzaro, Mannich ...). It has the same reaction mechanisms for teaching the fundamentals of ecotoxicology in particular and chemistry in the environment in general. The extent of these applications between the fine disciplines (medical sciences, pharmacological chemistry, enzyme technology, technology of biological membranes and tissues, cytochemistry, histochemistry, immunochemistry, microscopy, X-ray ...) generates a rich multidisciplinary education first. Glutaraldehyde reacts with proteins, sugars and lipids feature free groups (-NH2). The amine group (NH2) reacts with the nucleophilic carbonyl electrophilic aldehyde (- CHO). The consequences of this mechanism in vivo are at the heart important pathophysiological (diabetes, renal failure, ...). Moreover, the miscibility with water (100%), high reactivity in physiological, highly evaporable terms (air contamination), chemical intermediate in industry and a must for all disinfection and sterilization of equipment. A good compromise between advantage and disadvantage impose a regulated management of the molecule as effluent or residue. It can not be rejected in sanitation, or natural mitan. The development of processes requested by the practical interest of the molecule and its management as harmful liquid waste is required

ASPECT TOXICOLOGIQUE ET PHYSICOCHIMIQUE DU 1,5-DIPENTANAL

The 1,5-dipentanal is an important organic molecule: pedagogically, the molecule provides a range of interesting chemical reactions (Aldolisation, Michael, glycolysis, Cannizzaro, Mannich ...). It has the same reaction mechanisms for teaching the fundamentals of ecotoxicology in particular and chemistry in the environment in general. The extent of these applications between the fine disciplines (medical sciences, pharmacological chemistry, enzyme technology, technology of biological membranes and tissues, cytochemistry, histochemistry, immunochemistry, microscopy, X-ray ...) generates a rich multidisciplinary education first. Glutaraldehyde reacts with proteins, sugars and lipids feature free groups (-NH2). The amine group (NH2) reacts with the nucleophilic carbonyl electrophilic aldehyde (- CHO). The consequences of this mechanism in vivo are at the heart important pathophysiological (diabetes, renal failure, ...). Moreover, the miscibility with water (100%), high reactivity in physiological, highly evaporable terms (air contamination), chemical intermediate in industry and a must for all disinfection and sterilization of equipment. A good compromise between advantage and disadvantage impose a regulated management of the molecule as effluent or residue. It can not be rejected in sanitation, or natural mitan. The development of processes requested by the practical interest of the molecule and its management as harmful liquid waste is required

Thiamethoxam removal by Fenton and biological oxidation

BACKGROUND: Thiamethoxam (TMX) is a potential insecticide pollutant of hydric resources that must be removed. Advanced oxidation processes (AOPs) are usually effective, but expensive to implement. Combining Fenton's reagent with biological oxidation circumvents the shortcomings of Fenton technology, facilitating the biodegradation of the resulting effluents in a sequencing batch reactor (SBR). RESULTS: Fenton-like oxidation of TMX with variable hydrogen peroxide (H2O2) doses afforded total organic carbon (TOC) conversion and chemical oxygen demand (COD) removal by (respectively) 40% and 80% from pure TMX, and 40% and 60% from commercial TMX. The effluents from Fenton oxidation using substoichiometric H2O2 doses were less ecotoxic and more biodegradable than the initial solution and, therefore, susceptible to a biological treatment. Biological oxidation of effluents obtained from 50% and 75% H2O2 doses was accomplished for different organic loads in 6-h cycles. Coupling Fenton and biological oxidation of TMX afforded TOC conversion and COD removal of 80% for the effluent obtained with a 75% H2O2 dose. CONCLUSIONS: Coupling Fenton–biological oxidation efficiently reduces the amounts of H2O2 needed and produces biodegradable effluents. In addition, the biological treatment increases COD and TOC removal by ≤80% for the overall treatment. © 2019 Society of Chemical IndustryThe authors wish to thank Spain's MINECO and Madrid's Regional Government for funding this research through Projects CTM2016-76564-R and S2013/MAE-2716, respectively

Reduction of haloacetic acids in natural surface water by integrated treatment: coagulation and membrane processes

The objectives of this research were to study the elimination of dissolved organic carbon (DOC) and the reduction in the formation of haloacetic acid potential (HAAFP) when natural water from La Pedrera reservoir was treated with a single process of coagulation or filtration membrane, and a combined process (coagulation followed by treatment with membranes). In this research two coagulants, aluminium sulfate and polyaluminium chloride, and four membranes, two nanofiltration membranes (NF 90 and DESAL HL) and two ultrafiltration membranes (PES 5000 and PES 10000) were studied. The highest reduction in DOC was obtained when the natural water underwent the combined treatment of coagulation followed by NF90 membrane filtration. With this combined treatment the values of DOC rejection were over 82% independently of the coagulant used. For the single treatment with nanofiltration membranes, HAAFP rejection was 81% for NF 90 and 76% for Desal HL. However, a single treatment with coagulation or ultrafiltration membranes showed results for HAAFP rejection of under 35% and 26%, respectively. When a combined treatment of aluminium sulfate followed by ultrafiltration with the PES 5000 membrane was used, HAAFP rejection reached values of 80% approximately. These values are very similar to the results obtained from a single treatment with NF 90 but with the advantage that the flux of PES 5000 is 4,000 times the flux of the NF 90 membrane. Therefore, this treatment should be given due consideration

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

Etude de la reactivite microbiologique et de l’effet toxique sur carassius auratus du glutaraldehyde

Le ‘’glutaraldéhyde’’ est un composé largement utilisé dans l’industrie, comme biocide efficace.L’hygiène hospitalière l’utilise en grande quantité, pour ses propriétés physicochimiques (réactivité, tension de vapeur). Le ‘’glutaraldéhyde’’ se montre toxique pour la santé humaine et animale. L’étude des effets du ‘’glutaraldéhyde’’ sur le Carassius auratus, de la famille des cyprinadae d’eaux douces, met en évidence son extrême nuisance sur l’environnement. La Concentration Létale (CL50) déterminée en fonction du poids de ‘’cyprin doré’’, souligne la nocivité des solutions à base du glutaraldéhyd

Mass transfer in pervaporation: The key component approximation for the solution-diffusion model

International audienceA simple mass transfer model for the pervaporation process. the key component model, is described. in pervaporation the selectivity is often of the sorption type, which means that at the upstream side of the membrane, one of the components is much more sorbed than the others. The diffusivity of each component in this model does only depend on the volume fraction occupied by the key component. With this approximation when to solvents are involved in the pervaporation process the classical 6-parameter model becomes a four-parameter model. We develop the mass transfer equations in a special case where the diffusivity of each pure component follows Long's equation with a common plastization coefficient. The key component model is checked with data concerning pervaporation of ethanol-water mixtures through a PVA based membrane that follows these conditions. The limiting diffusivities and piastization coefficient are obtained from equilibrium and pervaporation data (at nil downstream pressure). The model allows the prediction of the pervaporation fluxes at growing downstream pressure. (c) 2009 Elsevier B.V. All rights reserved

Mass transfer in pervaporation: The key component approximation for the solution-diffusion model

International audienceA simple mass transfer model for the pervaporation process. the key component model, is described. in pervaporation the selectivity is often of the sorption type, which means that at the upstream side of the membrane, one of the components is much more sorbed than the others. The diffusivity of each component in this model does only depend on the volume fraction occupied by the key component. With this approximation when to solvents are involved in the pervaporation process the classical 6-parameter model becomes a four-parameter model. We develop the mass transfer equations in a special case where the diffusivity of each pure component follows Long's equation with a common plastization coefficient. The key component model is checked with data concerning pervaporation of ethanol-water mixtures through a PVA based membrane that follows these conditions. The limiting diffusivities and piastization coefficient are obtained from equilibrium and pervaporation data (at nil downstream pressure). The model allows the prediction of the pervaporation fluxes at growing downstream pressure. (c) 2009 Elsevier B.V. All rights reserved