Regeneration of activated carbon by fenton and photofenton oxidation for the treatment of phenol wastewater

Advanced Oxidation Processes have emerged as promising technologies for the recovery of carbons saturated with aromatic molecules, owing to their potency to degrade a wide range of organic pollutants by the generation of very reactive and non selective free hydroxyl radicals. The purpose of this work is to study the adsorption of phenol on activated carbons (ACs) and the consecutive in-situ regeneration of carbon by Fenton oxidation. Two different processes have been carried out: - the first one is based on a complete batch system in order to investigate the influence of Fe2+ and H2O2 concentrations; - the second one consists in a continuous fixed bed adsorption, followed by a batch circulation of the Fenton’s reagent through the saturated AC bed, to examine the efficiency of the real process. Two different activated carbons have been also studied: a both micro- and mesoporous AC (L27) and an only microporous one (S23). In the batch reactor containing a 1 g/L phenol solution, the optimal conditions found for pollutant mineralization in the homogeneous Fenton system (Fe2+ = 10 mmol/L, [H2O2] = 1000 mmol/L, corresponding to 6.5 times the stoechiometric amount for complete mineralization) are not the best for AC regeneration: a continuous reduction of adsorption capacity of L27 from 100% to 23% is observed after 3 oxidations, due to the decrease of both AC weight and surface area. Higher concentration of Fe2+ (20 mmol/L) and lower concentration of H2O2 (2 times the stoechiometry) lead to a 50% recovery of the initial adsorption capacity during at least 4 consecutive cycles for L27, while about 20% or less for S23. In the consecutive continuous adsorption/batch oxidation process, the regeneration efficiency reaches 30% to 40% for L27 after two cycles whatever the feed concentration (0.1 g/L or 1 g/L of phenol) and less than 10% for S23 (0.1 g/L of phenol). During oxidation step, Total Organic Carbon removal is found to reach a limit, probably due to the formation of Fe3+/organic acid complex, hindering Fe2+ regeneration. Such complexes are stable in usual Fenton conditions, but can be destroyed by UV radiation. A photo-Fenton test performed on L27 indeed shows almost complete mineralization and improved recovery of AC adsorption capacity although not complete (56% after two cycles)

Host habitat patchiness and the distance decay of similarity among gastro-intestinal nematode communities in two species of Mastomys (southeastern Senegal)

International audienceBeta-diversity, or how species composition changes with geographical distance, has seldom been studied for different habitats. We present here quantitative estimates of the relationship between geographic distance and similarity of parasitic nematode communities in two closely related rodent host species that live in habitats with very different spatial configurations. In southeastern Senegal Mastomys natalensis lives exclusively inside human villages whereas M. erythroleucus is continuously distributed outside villages. Both host species and their gastro-intestinal nematodes were sampled on the same spatial scale. Beta-diversity was found to be higher in parasite communities of M. erythroleucus than in those of M. natalensis, and significantly related to geographic distance in this first species. Even on the local spatial scale studied, host dispersal limitation, and stochastic events, may affect species turnover in nematode communities of M. erythroleucus. In M. natalensis, no relationship was found between geographic distance and nematode community similarity, however, suggesting low host dispersal rates between habitat patches. Together with previous population genetic results, this study illustrates the need for different approaches with regard to dispersal in natural populations and its effect on biodiversity

Trends in health facility deliveries and caesarean sections by wealth quintile in Morocco between 1987 and 2012.

OBJECTIVES: To examine trends in the utilisation of facility-based delivery care and caesareans in Morocco between 1987 and 2012, particularly among the poor, and to assess whether uptake increased at the time of introduction of policies or programmes aimed at improving access to intrapartum care. METHODS: Using data from nationally representative household surveys and routine statistics, our analysis focused on whether women delivered within a facility, and whether the delivery was by caesarean; analyses were stratified by relative wealth quintile and public/private sector where possible. A segmented Poisson regression model was used to assess whether trends changed at key events. RESULTS: Uptake of facility-based deliveries and caesareans in Morocco has risen considerably over the past two decades, particularly among the poor. The rate of increase in facility deliveries was much faster in the poorest quintile (annual increase RR: 1.09; 95% CI: 1.07-1.11) than the richest quintile (annual increase RR: 1.01; 95% CI: 1.02-1.02). A similar pattern was observed for caesareans (annual increase among poorest RR: 1.13; 95% CI: 1.07-1.19 vs. annual increase among richest RR: 1.08; 95% CI: 1.06-1.10). We found no significant acceleration in trend coinciding with any of the events investigated. CONCLUSIONS: Morocco's success in improving uptake of facility deliveries and caesareans is likely to be the result of the synergistic effects of comprehensive demand and supply-side strategies, including a major investment in human resources and free delivery care. Equity still needs to be improved; however, the overall trend is positive

Cross-cultural Adaptation And Validation Of The Teamwork Climate Scale

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)To adapt and validate the Team Climate Inventory scale, of teamwork climate measurement, for the Portuguese language, in the context of primary health care in Brazil. METHODS: Methodological study with quantitative approach of cross-cultural adaptation (translation, back-translation, synthesis, expert committee, and pretest) and validation with 497 employees from 72 teams of the Family Health Strategy in the city of Campinas, SP, Southeastern Brazil. We verified reliability by the Cronbach's alpha, construct validity by the confirmatory factor analysis with SmartPLS software, and correlation by the job satisfaction scale. RESULTS: We problematized the overlap of items 9, 11, and 12 of the "participation in the team" factor and the "team goals" factor regarding its definition. The validation showed no overlapping of items and the reliability ranged from 0.92 to 0.93. The confirmatory factor analysis indicated suitability of the proposed model with distribution of the 38 items in the four factors. The correlation between teamwork climate and job satisfaction was significant. CONCLUSIONS: The version of the scale in Brazilian Portuguese was validated and can be used in the context of primary health care in the Country, constituting an adequate tool for the assessment and diagnosis of teamwork.50Fundacao de Amparo a Pesquisa de Sao Paulo (FAPESP) [17685-3 2012]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Genetic structure of black rat populations in a rural plague focus in Madagascar

Correspondance: [email protected] genetic structure of reservoir populations is a key characteristic in understanding the persistence of infectious diseases in natural systems. In the Highlands of Madagascar, where plague has persisted since 1920, the black rat, Rattus rattus (L., 1758), is the sole species acting as a reservoir of the disease. Ecological surveys have shown a clear correlation between the locations of the plague-persistence area in Madagascar (above 800 m elevation) and the distribution area of one endemic plague vector, the flea Synopsyllus fonquerniei, which is found exclusively on rats living outdoors. This clear habitat segregation has led to the suggestion that R. rattus populations in the central highlands are divided into indoor- and outdoor-dwelling populations. Using eight microsatellite markers, we analysed the genetic structure of R. rattus populations living within a human plague focus in relation to habitat and geographic distance. We found that habitat by itself was not a structuring factor, unlike geographic distance. Nevertheless, the significant genotypic differentiation of R. rattus populations that was found at a fine spatial scale might relate to differences in population dynamics between rats in indoor and outdoor habitats