Reactive Dye Degradation by AOPs; Development of a Kinetic Model for UV/H2O2 Process

An application of UV/H2O2 process for the treatment of model wastewater containing organic reactive azo dye C.I. Reactive Blue 137 (RB137) was studied. The efficiency of applied process for decolorization and mineralization of RB137 model solution is discussed. The influence of operating process parameters, initial pH and initial concentration of H2O2, as well as initial dye mass concentration on process effectiveness was investigated. Both direct UV photolysis and OH radical attack were assumed as RB137 degradation mechanisms and a detailed kinetic model for dye degradation by UV/H2O2 process was proposed. The predicted system behavior was compared with experimentally obtained results of decolorization and mineralization of RB137 wastewater. A sensitivity analysis for the evaluation of importance of each reaction used in the model development was also included

Reactive Dye Degradation by AOPs; Development of a Kinetic Model for UV/H2O2 Process

An application of UV/H2O2 process for the treatment of model wastewater containing organic reactive azo dye C.I. Reactive Blue 137 (RB137) was studied. The efficiency of applied process for decolorization and mineralization of RB137 model solution is discussed. The influence of operating process parameters, initial pH and initial concentration of H2O2, as well as initial dye mass concentration on process effectiveness was investigated. Both direct UV photolysis and OH radical attack were assumed as RB137 degradation mechanisms and a detailed kinetic model for dye degradation by UV/H2O2 process was proposed. The predicted system behavior was compared with experimentally obtained results of decolorization and mineralization of RB137 wastewater. A sensitivity analysis for the evaluation of importance of each reaction used in the model development was also included

Surveillance sanitaire des cocoteraies adultes en Afrique de l'Ouest. I. Contrôles ordinaires

La plupart des ravageurs connus dans les cocoteraies d'Afrique de l'Ouest passent le plus souvent inaperçus, bien qu'ils soient toujours présents. Dans certaines conditions, difficiles à définir, il y a pullulation d'un ou de plusieurs d'entre eux et, en conséquence, des dégâts importants peuvent alors se produire. Des contrôles sanitaires fréquents sont nécessaires pour la conduite de la méthode de lutte intégrée, généralement adoptée à présent en défense des cultures, ce qui suppose une bonne connaissance des ravageurs, de leur biologie et de leurs ennemis naturels. Comme pour le palmier à huile, il y a deux types de contrôles phytosanitaires : - les contrôles ordinaires, décrits dans ces " Conseils ", qui permettent de suivre l'ensemble des populations de ravageurs, d'insectes auxiliaires, et de détecter toute anomalie susceptible de se traduire par des dégâts préjudiciables ; - les contrôles spéciaux, spécifiques d'un ravageur donné, qui feront l'objet d'une autre page de Pratique agricole (1 ), et sont réalisés sur un échantillon d'observation plus important. Ils permettent de suivre plus précisément l'évolution de ce ravageur, l'intensité et l'étendue des dégâts qu'il provoque. Toutefois, la décision d'intervention par traitement ne peut être prise à bon escient qu'après examen attentif des résultats d'un ou de plusieurs contrôles spéciaux réalisés après détection de l'attaque par un contrôle ordinaire. La présente " Page de pratique agricole " traite de la conduite des contrôles phytosanitaires en cocoteraie de plus de quatre ans, entrée en production. La surveillance des jeunes cocoteraies, beaucoup plus vulnérables, fera également l'objet d'autres " Conseils ". (Résumé d'auteur

Long-term results from the EARLY study of bosentan in WHO functional class II pulmonary arterial hypertension patients.

Abstract BACKGROUND: The double-blind phase of the EARLY study of bosentan remains the only randomized controlled trial of a PAH-targeted therapy in World Health Organization functional class (FC) II patients. We report on the efficacy, safety, disease worsening, survival and prognostic factors in mildly symptomatic pulmonary arterial hypertension (PAH) patients treated with bosentan in the open-label extension phase of the EARLY study. METHODS: Exploratory efficacy outcomes included 6-minute walk distance (6 MWD) and WHO FC. Adverse events were recorded. Kaplan-Meier analysis was used to estimate time to first PAH worsening event (death, initiation of intravenous or subcutaneous prostanoids, atrial septostomy or lung transplantation) and survival. Cox regression analysis determined factors prognostic of survival. RESULTS: Median exposure to bosentan (n=173) was 51 months. At the end of the bosentan-treatment assessment period, 77.8% of patients were in WHO FC I/II. Adverse events led to discontinuation of bosentan in 20.2% of patients. Aminotransferase elevations>3 7 upper limit of normal occurred in 16.8%. Four-year PAH-event-free survival and survival were 79.5% (95% confidence intervals [95% CI] 73.4, 85.6) and 84.8% [95% CI 79.4, 90.2], respectively. Low 6 MWD, low mixed venous oxygenation, high N-terminal pro hormone of brain natriuretic peptide levels and PAH associated with connective tissue disease were associated with a higher risk of death. CONCLUSIONS: The majority of patients exposed to long-term bosentan maintained or improved their functional class. Approximately 20% of the patients discontinued treatment because of adverse events, which were most commonly PAH worsening and elevated liver enzymes

Prediction of biodegradability of aromatics in water using QSAR modeling

International audienceThe study was aimed at developing models for predicting the biodegradability of aromatic water pollutants. For that purpose, 36 single-benzene ring compounds, with different type, number and position of substituents, were used. The biodegradability was estimated according to the ratio of the biochemical (BOD5) and chemical (COD) oxygen demand values determined for parent compounds ((BOD5/COD)0), as well as for their reaction mixtures in half-life achieved by UV-C/H2O2 process ((BOD5/COD)t1/2). The models correlating biodegradability and molecular structure characteristics of studied pollutants were derived using quantitative structure-activity relationship (QSAR) principles and tools. Upon derivation of the models and calibration on the training and subsequent testing on the test set, 3- and 5-variable models were selected as the most predictive for (BOD5/COD)0 and (BOD5/COD)t1/2, respectively, according to the values of statistical parameters R2 and Q2. Hence, 3-variable model predicting (BOD5/COD)0 possessed R2=0.863 and Q2=0.799 for training set, and R2=0.710 for test set, while 5-variable model predicting (BOD5/COD)1/2 possessed R2=0.886 and Q2=0.788 for training set, and R2=0.564 for test set. The selected models are interpretable and transparent, reflecting key structural features that influence targeted biodegradability and can be correlated with the degradation mechanisms of studied compounds by UV-C/H2O2