Optimization of coagulation-flocculation process for pastas industry effluent using response surface methodology

The goal of this study was to characterize and then optimize the treatment process of effluent generated from couscous and pasta industry. The crude effluent is characterized by a high level of organic concentration (from 2269 to 4383 mg/l). The optimization of coagulation-flocculation process was then performed to minimize chemical oxygen demand (COD). The experiments were carried out using the response surface methodology (RSM). A central composite design (CCD) was used to evaluate the effects and the interactions of three factors; coagulant dosage, flocculant dosage and pH on the wastewater treatment efficiency. Quadratic models was developed for the response variables and it successfully describes the experimental data (R2= 0.728). Analysis of variance (ANOVA) showed that only the coefficients corresponding to the flocculant dosage were significant (p < 0.0001). In order to take into account the variability of the initial organic concentration of the effluent, the CCD was repeated thrice by using a wastewater having initially different organic charges (530, 1775 and 2722 mg/l). Whatever was the initial organic charge of the wastewater, the optimal coagulant dosage was found constant (about 50 mg/l) and the optimal pH value was about 11.0. On the contrary, the optimal flocculant dosage varied linearly (from 24 to 50 mg/l) with the initial COD (from 529 to 2722 mg/l). These optimal conditions allow a COD removal varying from 78 to 93%. Irrigation and germination tests were carried out with treated and untreated wastewater and they showed that these effluents could be adequately recycled in culture irrigation.Key words: Couscous and pasta industry effluent, COD removal, central composite design, response surface methodology (RSM), irrigation tests

Phoenix dactylifera L. sap enhances wound healing in Wistar rats : Phytochemical and histological assessment

Acknowledgment Financial support of the Tunisian Ministry of Higher Education and Scientific Research is gratefully acknowledged.Peer reviewedPostprin

Influence of Doping and Nanostructuration on n-Type Bi2(Te0.8Se0.2)3 Alloys Synthesized by Arc Melting

In competitive thermoelectric devices for energy conversion and generation, high-efficiency materials of both n-type and p-type are required. For this, Bi2Te3-based alloys have the best thermoelectric properties in room temperature applications. Partial replacement of tellurium by selenium is expected to introduce new donor states in the band gap, which would alter electrical conductivity and thermopower. We report on the preparation of n-type Bi2(Te1-xSex)3 solid solutions by a straightforward arc-melting technique, yielding nanostructured polycrystalline pellets. X-ray and neutron powder diffraction was used to assess Se inclusion, also indicating that the interactions between quintuple layers constituting this material are weakened upon Se doping, while the covalency of intralayer bonds is augmented. Moreover, scanning electron microscopy shows large surfaces perpendicular to the c crystallographic axis assembled as stacked sheets. Grain boundaries related to this 2D nanostructuration affect the thermal conductivity reducing it below 0.8 Wm−1K−1 at room temperature. Furthermore, Se doping increases the absolute Seebeck coefficient up to −140 μV K−1 at 400 K, which is also beneficial for improved thermoelectric efficiency.This research was funded by the Spanish Ministry of Economy and Competitivity for granting the project MAT2013-41099-R.Peer reviewe

Biological properties of carotenoids extracted from Halobacterium halobium isolated from a Tunisian solar saltern

Background: Bioactive molecules have received increasing attention due to their nutraceutical attributes and anticancer, antioxidant, antiproliferative and apoptosis-inducing properties. This study aimed to investigate the biological properties of carotenoids extracted from Archaea. Methods: Halophilic Archaea strains were isolated from the brine of a local crystallizer pond (TS7) of a solar saltern at Sfax, Tunisia. The most carotenoid-producing strain (M8) was investigated on heptoma cell line (HepG2), and its viability was assessed by the MTT-test. The cells were incubated with different sub-lethal extract rates, with carotenoid concentrations ranging from 0.2 to 1.5 μM. Antioxidant activity was evaluated through exposing the cells to sub-lethal extract concentrations for 24 hours and then to oxidative stress induced by 60 μM arachidonic acid and 50 μM H2O2. Results: Compared to non-treated cells, bacterial carotenoid extracts inhibited HepG2 cell viability (50%). A time and dose effect was observed, with cell viability undergoing a significant (P < 0.05) decrease with extract concentration. After exposure to oxidative stress, control cells underwent a significant (P < 0.05) decrease in viability as compared to the non-treated cells. Conclusions: The bacterial extracts under investigation were noted to exhibit the strongest free radical scavenging activity with high carotenoid concentrations. The carotenoid extract also showed significant antiproliferative activity against HepG2 human cancer cell lines

The clinical relevance of oliguria in the critically ill patient : Analysis of a large observational database

Funding Information: Marc Leone reports receiving consulting fees from Amomed and Aguettant; lecture fees from MSD, Pfizer, Octapharma, 3 M, Aspen, Orion; travel support from LFB; and grant support from PHRC IR and his institution. JLV is the Editor-in-Chief of Critical Care. The other authors declare that they have no relevant financial interests. Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Urine output is widely used as one of the criteria for the diagnosis and staging of acute renal failure, but few studies have specifically assessed the role of oliguria as a marker of acute renal failure or outcomes in general intensive care unit (ICU) patients. Using a large multinational database, we therefore evaluated the occurrence of oliguria (defined as a urine output 16 years) patients in the ICON audit who had a urine output measurement on the day of admission were included. To investigate the association between oliguria and mortality, we used a multilevel analysis. Results: Of the 8292 patients included, 2050 (24.7%) were oliguric during the first 24 h of admission. Patients with oliguria on admission who had at least one additional 24-h urine output recorded during their ICU stay (n = 1349) were divided into three groups: transient - oliguria resolved within 48 h after the admission day (n = 390 [28.9%]), prolonged - oliguria resolved > 48 h after the admission day (n = 141 [10.5%]), and permanent - oliguria persisting for the whole ICU stay or again present at the end of the ICU stay (n = 818 [60.6%]). ICU and hospital mortality rates were higher in patients with oliguria than in those without, except for patients with transient oliguria who had significantly lower mortality rates than non-oliguric patients. In multilevel analysis, the need for RRT was associated with a significantly higher risk of death (OR = 1.51 [95% CI 1.19-1.91], p = 0.001), but the presence of oliguria on admission was not (OR = 1.14 [95% CI 0.97-1.34], p = 0.103). Conclusions: Oliguria is common in ICU patients and may have a relatively benign nature if only transient. The duration of oliguria and need for RRT are associated with worse outcome.publishersversionPeer reviewe

Use of the Genetic Algorithm for the Optimal Operation of Multi-Reservoirs on Demand Irrigation System

This study presents the application of a Genetic Algorithm (GA) model developed for computation of the optimal supply hydrographs in on demand irrigation systems aimed at the optimal regulation of the upstream storage reservoirs. The model was applied to an Italian irrigation scheme whe re the optimal inflows to five reservoirs were computed. The obtained result is characteris ed by two inflow values. In addition, the maximum discharge supplied by the upstream dam was redu ced by 10.65 %, and the maximum violation of reservoirs water levels was reduced to acceptable values. The optimal solution guarantees to satisfy the daily demand requirements, to minimize the maximum discharge delivered by the upstream dam, and to avoi d the reservoirs emptiness. In addition, the on- demand delivery schedule according to the actual demand hydrograph recorded downstream the reservoirs may be applied also during the peak periodCette \uc8tude pr\uc8sente l\uedapplication d\uedun Algorithme G\uc8n\uc8 tique (AG) d\uc8velopp\uc8 pour le calcul des hydrogrammes d'approvisionnement optimaux dans les syst\ucbmes d\uedirrigation \u2021 la demande vis\uc8 pour la r\uc8gulation optimale des r\uc8servoirs de stockage. Le mod\ucble a \uc8t\uc8 appliqu\uc8 pour un r\uc8seau d\uedirrigation italien o \u306 les apports optimaux \u2021 cinq r\uc8servoirs ont \uc8t\uc8 calcul\uc8s. Le r\uc8sultat obtenu est caract\uc8ris \uc8 par deux valeurs d\uedapports. En addition, le d\uc8bit maximal fourni par le barrage en amont a \uc8t\uc8 r\uc8duit par 10.65 %, et les violations maximales des niveaux d'eau de r\uc8servoirs ont \uc8t\uc8 r\uc8duites \u2021 des valeurs accepta bles. La solution optimale garantit de satisfaire les besoins jou rnaliers, de minimiser le d\uc8bit maximal de barrage en amont et d\ued\uc8viter la vidange des r\uc8se rvoirs. En outre, la livraison \u2021 la demande selon l'hydrogramme de la demande actuelle enregistr\uc8e en aval des r\uc8servoirs peut-\ucdtre \uc8galement appliqu\uc8s pendant la p\uc8riode de pointe