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The aim of this research work is the optimization of the coagulation/flocculation process in the treatment of surface water for maximum dissolved organic matter (DOM) removal using response surface methodology (RSM). For this purpose, several jar test experiments were performed in order to identify the most influencing factors. Afterwards, RSM was done to investigate the effects and the interactions of three chosen variables (coagulant concentration, flocculant concentration, and initial pH), whereas the responses were the DOM removal in terms of chemical oxygen demand (COD), in terms of absorbance at the wavelength 254 nm (UV-254), and the final pH. The optimal conditions were as follows: 133 mg/L of coagulant, 60 mg/L of flocculant and an initial pH equal to 6.91. Under these conditions, the efficiency removals were 56% in terms of COD and 59% in terms of UV-254 with a final pH equal to 6.78. High variance coefficient R2 values, with 0.96 for the removal in terms of COD and 0.92 in terms of UV-254, confirm the reliability and the validity of the obtained model. HIGHLIGHTS Coagulation/flocculation is a very efficient process for removing dissolved organic matter from surface waters.; Response surface methodology approach is a very effective and powerful tool for optimizing the coagulation/flocculation process.; Optimization of the coagulation/flocculation process reduces the use of chemicals and protects the environment.

Quaternary compound Cu2ZnSnS4 (CZTS) is widely recognized as a promising candidate for use as an absorber layer for photovoltaic applications. However, its efficiency is limited by the high density of antisite defects that shorten the performance of CZTS-based solar cells. Cation substitution of copper by other elements has been proposed as a potential solution in order to control and eliminate the cation disorder within the kesterite structure. In this work, Ag2ZnSnS4 (AZTS) and Cu2ZnSnS4 (CZTS) powders were successfully synthesized by solid state reaction. XRD and Raman measurements were performed to study the crystallographic structures and their lattice vibration spectrum. The results confirmed the presence of the pure phase of CZTS and the stannite phase of AZTS with an occurrence of the secondary phase Ag8SnS6. Morphological properties and the composition analysis of synthesized powders were analyzed by scanning electron microscopy and energy dispersive x-ray analysis. A significant change is noticed in the band gap energy value established by the diffuse reflectance spectroscopy from 1.44 eV for CZTS to 2.55 eV for AZTS. Lastly, measurements with the hot probe method indicate the p-type conductivity of CZTS and the n-type conductivity for AZTS as predicted by theoretical studies. These results highlight that the substitution of silver for copper in CZTS leads to significant changes in the properties of CZTS.

In this study, we propose the development of a rapid and reliable method to control and to monitor microbial water quality. The methylene blue (MB) decolorization assay was based on the analysis of spectral profiles of dye in interaction with a different bacterial concentration. The determination of dye decolorization rate (DDR) shows a correlation between the MB reduction rate and the bacterial density. Moreover, the kinetic of the monomer and dimer equilibrium of MB in water mainly, the monitoring of bounded MB species in relationship with a knowed concentration of target bacteria, was allowed to establish a relationship between MB decolorization rate and bacterial density. Furthermore, this method was applied to evaluate the water quality after photocatalysis. Based on this method, the photocatalytic effects on bacterial density was highlighted by the decrease in DDR after photocatalytic treatment with fractioned times (0 to 5 h); this increase was followed by a decrease of bounded MB species and, an increase in free MB forms miming the reduction of bacterial density due to the biocide effects of photocatalysis process. However, the analysis of spectra profiles shows a weak but a continuous decrease in bounded MB dimer and monomer forms in the treated water samples exempt of culturable bacteria. Moreover, the MB spectra profiles were tended toward a negative control spectrum without superposition. Thus, the possibility of the presence of viable but non-culturable bacteria was expected; therefore, to optimize this tertiary water treatment process, an extending on proceeding time was recommended to avoid the bacterial resuscitation after photocatalysis.

The bacterial cells dwelling within the biofilm usually develop resistance against common disinfectants. In this current study, to improve the effectiveness of photocatalytic treatment, a natural sensitizer in combination with unsupported titanium dioxide nanoparticles (TiO2-NPs) was used to optimize the absorbance of NPs in the visible region and, to enhance the catalytic activity of the semiconductor. Different kinetic parameters were determined according to the first-order and the biphasic models to evaluate the ability of tested bacteria to form biofilm under different photocatalytic treatment conditions. As a result, the addition of red cabbage anthocyanins (RCA) as photosensitizer allows the enhancement of biocide activity of TiO2-NPs and the reduction of biofilm formation by tested bacteria.

We purpose in this study to develop a reliable and low-cost method for the detection of Viable but nonculturable (VBNC) bacteria. Indeed, after water disinfection, injured-VBNC bacteria can be underestimated using conventional assessment methods, causing false-negative results and, posing a significant and potential health risk. The VBNC bacterial survival strategy can hide the real microbial quality of treated water. To overcome this bacterial assessment limitation, we were used a specific and lytic phage to monitor the presence of active bacteria

It is well established that the performance of communication systems is improved when deploying multiple antennas at one or both of the transmit/receive sides; and the amount of the gained improvement depends on the level of multipath richness of the propagation channel. In ship-to-ship overwater channels, quantifying such an improvement is not an easy task due to the effect of evaporation duct on imposing complex rangeand height-dependent patterns of the received signal level. In this study, based on the parabolic equations (PE) method and using realistic evaporation duct distributions, we conduct extensive simulations in order to quantify the link-level improvement achieved when using 2 × 2 vertically-spaced Multiple-Input Multiple-Output (MIMO) systems against 1 × 2 Single-Input Multiple-Output (SIMO) and Single-Input Single-Output (SISO) systems. Then, we analyze the implication of such link improvement on the performance of a system comprised of a network of randomly distributed ships. When evaluating the outage throughput at the 2nd percentile using realistic system parameters, it was found that 2 × 2 MIMO-MRC (maximum ratio combining) systems with 1 m antenna spacing are able to improve the outage throughput by three-fold compared to SISO systems. This improvement increases to one order of magnitude when the antenna spacing increases to 10 m. It was also found that, in all cases, assuming using the same vertical spacing, 1 × 2 SIMO-MRC systems capture about 60% of the improvement achieved by 2 × 2 MIMO-MRC systems. On the other hand, 1 × 2 SIMO-DIV (diversity combining) systems are very sensitive to antenna spacing, and when assuming using the same vertical spacing, they can capture from 20% and up to 55% of the improvement achieved by 2 × 2 MIMO-MRC systems if the antenna spacing increases from 1 m to 10 m, respectively.

In this paper, a new design single feed multi-band antenna is presented. The proposed antenna is designed to operate at the 1.278GHz, 2.8GHz, 5.7GHz, and 10GHz frequency bands which cover the Galileo satellite positioning system (1.278GHz), WLAN (2.8GHz), WIMAX (5.7GHz) and the radar applications (10GHz), respectively. The antenna has a compact size, it is printed on an FR4 substrate of dimensions (60mm×27.5mm×1.67mm) placed on a ground plane of 60mm×17.5mm×0.035mm dimensions. To improve the radiation performance of the proposed antenna, an artificial magnetic conductor (AMC) was used as a reflector plane with dimensions of 13.5mm6×613.5mm6×61mm. The simulated and measured results are in good agreement and show the significant improvement of the gain value of the multiband antenna with AMC which is a required propriety for novel wireless communications systems.

The considerable genetic variability of salt tolerance in Hordeum vulgare L. and its wild relative species Hordeum marinum Huds. (sea barley) is a potentially useful trait to develop well-adapted v...

The decentralized wastewater treatment systems including collection, treatment, and recycling of treated wastewater are an efficient integrated water management solution to overcome the shortage of freshwater and to reduce pollutant emissions. In this study, life cycle assessment was performed in order to evaluate a decentralized alternative allowing the recycling of treated greywater (TGW) in a multi-family dwelling. The adopted treatment system is the moving bed biofilm reactor (MBBR). The biological treatment with MBBRs was found the main contributor to the majority of the investigated impact categories. The integration of the tertiary treatment led to an increase in the environmental load ranging between 6 and 30.4% depending on the impact category in comparison with the scenario integrating only the biological treatment. However, the final environmental profile of both scenarios presented a minor difference. Moreover, the recycling of the TGW allowed a reduction ranging between 3.9 and 17% on five impact categories compared to the no recycling scenario. It is concluded that the decentralized approach for greywater treatment and recycling is beneficial for the environment as the distribution system and the tertiary treatment didn’t increase drastically the environmental load of the plant allowing water saving. Moreover, it is recommended to use renewable energy to reduce the environmental impact associated with the energy requirement for the biological treatment which affects the global warming potential and the acidification impact categories and to substitute the polyvinylchloride pipes with polyethylene pipes to reduce emissions related to the human toxicity impact category.

A re-circulating horizontal flow constructed wetland (RHFCW) system was developed in a greenhouse. This system was operated with Typha domingensis to study the phytoremediation capacity of this macrophyte species in different developing stages for synthetic textile wastewater with the pollutant type, the amaranth (AM) azo dye. Experiments were applied with a fixed flow rate Q = 10 L/h corresponding to a theoretical residence time of 3 h. The synthetic feeding to the RHFCW container was re-circulated back until the required water quality was achieved. The performance of this pilot-scale system was compared to an unplanted RHFCW. The effect of the initial dye concentration was studied using four dye concentrations (10, 15, 20, and 25 mg/L). The following parameters pH, color, COD, BOD5, NO3−, NO2−, and NH4+ were monitored during treatment. The maximum efficiencies obtained for discoloration, COD, NO3−, and NH4+ were 92 ± 0.14%, 56 ± 1.12%, 92 ± 0.34%, and 97 ± 0.17% respectively. Experiences demonstrate a decrease of removal efficiencies of studied parameters with the increase of dye concentrations, leading to an increase of the duration of treatment. Changes in activities of antioxidant enzymes (superoxide dismutase (SOD), guaiacol peroxidase (GPX), catalase (CAT), ascorbic peroxidase (APX), and glutathione reductase (GR)) and their relation to plant defense system against stress were studied. Enzymes were evaluated in leaves of T. domingensis during the remediation of the azo dye (amaranth). During treatment, an increase of enzymes activities was observed in accordance with the high removal efficiency.

International audience; Metals Organic Frameworks (MOFs) are promising crystalline, embrittled materials generally produced in powdering form with varied remarkably functionalities. In contrary, polymer are flexible and processable materials. Therefore, obtaining shaped solids gathering polymer malleability and MOFs properties such as their photocatalytic activities, have attracked many reasearchers attention. This work, report the successful fruitful incorporation of two different Fe-based MOFs into a polymer matrix via a facile and cheap photopolymerization process upon mild visible light irradiation at 405 nm. The as-prepared photocomposites displayed excellent stability and photocalytic performance for several Acid Black degradation cycles. Hence, approximatively, 95% of this model dye was decomposed by the two MIL-100(Fe)/polymer and MIL-88A(Fe)/polymer composites under juste 30 min of UV lamp irradiation. Incorporation of the MOFs into the polymer was confirmed by several techniques including Scanning Electron Microscopy (SEM), Energy-dispersive X-ray analysis 2 (EDX), Transmission Electron Microscopy (TEM), X-Ray Diffraction analysis (DRX), Fourier-Transform Infrared Spectroscopy (FTIR). Furthermore, these photocatalysts exhibited a high thermal stability, excellent rigidity and low band gap energy characterized by Thermogravimetric Analysis (TGA) Atomic Force Microscopy (AFM), Dynamic Mechanical Analysis (DMA) and UV-Visible diffuse reflectance spectroscopy, respectively.

International audience; Nowadays water scarcity represents a threat for human and living beings. Therefore, to satisfy the demands of people for clean and safe water, new technologies for wastewater treatment have been developed. Thus, photocatalysis has emerged as a green chemical approach for such treatment. In this context, new polyoxometalate (POM)/polymer composites with relevant photocatalytic properties have been developed via an easy and cheap photopolymerization process upon mild visible light irradiation at 405 nm. This fruitful association between POM and polymer allowed the obtention of shaped materials facile to collect and reuse at the end of the photocatalytic treatment avoiding then the usual time-consuming regeneration methods. The prepared photocomposites displayed excellent photocatalytic performance for the removal of bisphenol-A from water under different sources of irradiation. Hence, 100%, 88%, and 50% of this model compound were decomposed by the phosphomolybdic composite under just 90 min of UV lamp, solar and LED@375 nm irradiations, respectively. The effectiveness of these developed photocatalysts towards the degradation of other organic compounds, as well as the degradation mechanism based on the generation of highly reactive chemicals such as •OH radicals promoting the degradation were already reported. Bisphenol-A degradation pathway and the identification of the photoproducts were discussed using mass spectroscopy technique. Therefore, this paper highlighted the photocatalytic efficiency of the new manufactured materials for the photodegradation of the bisphenol-A, thus expanding their application fields, under different sources of irradiation and under pure solar irradiation which make their applications more interesting and less energy consuming.

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International audience; In the last few years, pharmaceutical compounds classified as emerging pollutants have attracted the attention of many researchers, due to their massive presence in soil, surface, sewage, groundwater and drinking water, as well as to their harmful effects on human health and the environment. In this context, the degradation of four drugs with different chemical structures, Ciprofloxacin, Oxytetracycline, Ibuprofen and Erythromycin was investigated. Indeed, in this paper, we studied the impact of the presence in the aqueous solution of a newly developed POM/polymer composite on the removal of these different drugs from water. Synthesis details and characterizations of these materials have already been reported within our group. The various experiments carried out during this study revealed that the presence of the phosphomolybdic acid-based composite was not essential for the total degradation of Ciprofloxacin and Oxytetracycline which could be totally removed from water by simple photolysis under UV-Visible lamp irradiation. However, under the same experimental conditions, the use of this photocatalyst was indispensable for the total mineralization of Ibuprofen, more recalcitrant than the other selected drugs. In fact, only 20% of this pharmaceutical was degraded by simple photolysis vs. 100% and 94% upon respectively, 90 min of UV-Visible lamp and solar irradiation, in the presence of the phosphomolybdic acid-based composite which was more pertinent than the usually used photocatalyst, namely titanium dioxide. The Ibuprofen degradation pathway was identified thanks to mass spectrometry analysis, conducted at different time intervals. The obtained results demonstrated also that POM/polymer composite inhibits the degradation of Erythromycin through the formation of more toxic intermediates than the original drug

Recently, many researchers have focused their attentions on associating perovskites with polymers in order to enhance their processability and rigidity while protecting their interesting environmental properties. Therefore, this work reports the successful development of two different Perovskites/polymer composites via a simple, rapid, low-cost and eco-friendly photopolymerization process under mild visible Light Emitting Diode LED@405 nm irradiation. The as-synthesized composites exhibit excellent photocatalytic activity towards the removal of the Acid Black dye from water, reaching approximately 95% under just 30 min of UV light irradiation. The fruitful hybridization between the perovskites and the acrylate monomer allowed the collect and reuse of this photocatalyst for several successive cycles without external usual time-consuming methods. Furthermore, the new as-fabricated shaped materials were fully characterized by numerous characterization techniques including, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-Ray Analysis (EDX), X-Ray Diffraction Analysis (XRD), Atomic Force Microscopy (AFM), Dynamic Mechanical Analysis (DMA) and Thermogravimetric Analysis (TGA), which have verified on one side the successful immobilization of the perovskites into the polymer and the structural stability of the photocatalysts after hybridization and in the other side the high rigidity and thermal stability of the obtained molded composites.

We investigate estimation in Poisson regression model when the count response is right-censored and the censoring indicators are missing at random. We propose several estimators based on the regression calibration, multiple imputation and augmented inverse probability weighting methods. Under appropriate regularity conditions, we prove the consistency of our estimators and we derive their asymptotic distributions. Simulation experiments are carried out to investigate the finite sample behaviour and relative performance of the proposed estimates. These estimates are illustrated on a real data set.

This study deals with the electrochemical degradation of Amaranth in aqueous solution by means of stainless steel (SS) electrodes coated with a SiOx interlayer deposited by Plasma Enhanced Chemical Vapour Deposition and a modified PbO2 top layer deposited by continuous galvanostatic electrodeposition. The morphological characterization of the PbO2 top-layer performed by Field Emission Scanning Electron Microscope put in evidence that the SiOx, interlayer allows obtaining a more integrated PbO2/SS electrode with a very homogeneous PbO2 film. The composition of the lead oxide layer was investigated by X-ray Diffractometry, showing that the β-PbO2/α-PbO2 ratio in the top layer deposited on the SiOx film was four times higher respect to the one deposited directly on the stainless steel surface. In addition, the electrochemical behaviour of SS/SiOx/PbO2 interfaces was studied by electrochemical impedance spectroscopy (EIS). The EIS results showed that the presence of SiOx favors electron transfer within the oxide layer which improves electro-oxidation capability. Moreover, bulk electrolysis showed that over 100% colour removal and 84% COD removal, using SS/SiOx/PbO2 at acidic pH were reached after 300 min. High Performance Liquid Chromatography analysis was used for the quantitative determinations of initial Amaranth dye molecule removal and to evaluate its specific degradation rate. In order to evaluate the phototoxicity of treated solution with different by-products, different tests of germination were performed and proved that the electrochemical treatment with modified PbO2 could be as an efficient technology for reducing hazardous wastewater toxicity and able to produce water available for reuse.

In this study, the Activated Sludge Model No. 3 (ASM3) was applied for the simulation of the removal of organics and nitrogen in a multistage moving bed biofilm reactor (MBBR) used for biological greywater treatment. The data related to the characterization of the greywater were collected over a period of 5 months to be investigated in the model. The reactor showed a high performance for the removal of chemical oxygen demand (COD), dissolved organic carbon (DOC), biological oxygen demand (BOD5), ammonia (NH4-N), and total nitrogen (TN) with a removal efficiency of 93%, 80.7%, 99%, 89%, and 77%, respectively. The results of modeling showed a good correlation between simulated and experimental concentrations of COD issued from different reactors of the MBBR system. The adaptability of the ASM3 model to fit other parameters such as TN, NH4-N, total suspended solids (TSS), and the dissolved oxygen (DO) was also investigated for two selected reactors: reactor (R1) and the reactor (R5). The simulation results showed an acceptable correlation regarding the evolution of the investigated parameters in R1 and R5 and in the effluent except for total nitrogen TN. The adjustment of the stoichiometric parameters led to a satisfactory simulation of TN concentrations.

Water disinfection using visible light-active photocatalyst has recently attracted more attention due to its potential to inactivate microbes. In this study, we have investigated the efficiency of ...

Methylene blue (MB) desorption from alkali-treated orange tree sawdust (ATOS) adsorbent was investigated under different experimental conditions. For an initial MB adsorbed amount of 63.78 mg g−1 and an initial aqueous pH of 6.0, the experimental data showed that MB desorption is time dependent and increases with NaCl concentration. A maximal desorption yield of 65% was reached after 120 min for a 1 M NaCl concentration. These experimental data were successfully fitted by the pseudo-second-order kinetic model (R2 ≈ 1 and APE < 1.155%), indicating that MB desorption mechanism involved mainly an ion exchange process between liquid and solid phases. Moreover, the effect of initially adsorbed dye concentration on MB desorption efficiency was apprehended for five successive desorption steps. The experimental results showed that MB release in the bulk solution followed a non-singular adsorption/desorption isotherm that become more intense with the increase in the initially retained dye amounts onto ATOS. The theoretical required number of MB desorption steps for a total regeneration of ATOS noticeably decreased from 575 when using distilled water to only 50 steps with NaCl aqueous solutions (0.5 M) as desorbing eluent. FTIR analysis showed the involvement of the hydroxyl and carboxylic functional groups in the sorption process. Ionic chromatography analysis presented a decrease in the aqueous solution concentration in Na+ and Cl− ions by 46% and 48%, respectively, which emphasizes on their migration onto the solid phase. These results confirmed that MB desorption is most likely driven by a cationic exchange mechanism between dye molecules and sodium ions.

In recent years, as a consequence of climatic changes, the leafminer Liriomyza cicerina had emerged as a serious pest in chickpea crops causing considerable damage in Tunisia. Thus, the search of control methods is necessary. The aim of this research was to monitor and identify the naturally occurring parasitoids of the chickpea leafminer Liriomyza cicerina in insecticide-free chickpea-growing areas located in North-Western Tunisia. Chickpea leaves with mines were weekly sampled from Beja and Kef sites during 2016 and 2017 and kept to observe and count emerging leafminer and parasitoid adults in the laboratory. Results revealed that L. cicerina parasitoids complex species included three hymenopteran parasitoids namely Opius monilicornis (Fisher, 1962) (Braconidae); Diglyphus isaea (Walker, 1838) (Eulophidae) and Diaulinopsis arenaria (Erdos, 1951) (Eulophidae). These parasitoids were identified and recorded for the first time in Tunisia on L. cicerina with parasitism rate varied between 13% and 52.5%. The most common species was O. monilicornis. The correlation between infestation rate on chickpea plants and number of emerged three parasitoids was calculated revealing high significant and positive correlations. The diversity index (H′) was also calculated. The three parasitoids were found in two sites Beja and Kef; while the diversity differed during the developmental stage of chickpea crops.

In this study, both TiO2 and WO3 were synthetized using controlled hydrolysis followed by dialysis. The produced transparent emulsions were dried into powders. Then, TiO2–WO3 photocatalyst films were deposited by pulsed electrophoretic deposition. The substrates were made of stainless steel pre-functionalized in a conversion bath. The conversion layer played an important role in the adhesion of the composite film into the substrate. Film surface morphology, crystallinity, roughness, thickness, and elemental composition were determined from XRD, optical profilometry and SEM–EDX measurements. The mechanical properties were resolute by nano-indentation test and adhesion was investigated using a scratch test. The photocatalytic decolorization of the Amido Black-10B dye was studied over TiO2–WO3 coatings under UV irradiation. TiO2 film doped 5% WO3 film exhibited the best photocatalytic activity due to its crystalline size and three-phase structure as well as a synergetic effect of TiO2–Fe2O3 and TiO2–WO3. This film showed also good adhesion properties.

International audience; Hybrid H3PMo12O40/polymer composites were proposed here for the simple photocatalytic decomposition of erythrosine B and rose Bengal because of their unwanted effect on the environmental microorganism. Interestingly, the composite exhibited efficient photocatalytic activity for the decomposition of dyes under both mild near UV irradiation and solar irradiation. High final conversions were obtained for both of dyes reaching 81% and 86% for the erythrosine B and rose Bengal respectively after 120 min of LED@375 nm illumination and 90% for both dyes after only 30 min of solar exposure. The photocatalytic stability was also demonstrated. The photoluminescence technique was used to prove hydroxyl radicals implication into the photo-decomposition reaction using H3PMo12O40/polymer. The efficiency of the proposed treatment was confirmed by the evaluation of the ecotoxicity effect of by-products of each dye on two bacterial strains.

In this study, TiO2 was synthesized using controlled hydrolysis of TiCl4, followed by dialysis. We produced a transparent emulsion that was later dried into TiO2 powder. TiO2 photocatalyst films were deposited applying the technique of pulsed electrophoretic deposition, which decreased bubble formation caused by direct current. The substrates were bare stainless steel (SS) and stainless steel pre-functionalized in a conversion bath. Film surface morphology, crystallinity, elemental composition, and wettability were determined using XRD, SEM–EDAX, and contact angle measurements. The mechanical properties were determined by nano-indentation test. The adhesion was investigated using scratch test. The obtained results showed that the TiO2 film over a conversion layer had better adhesion and mechanical properties than TiO2 over bare SS. The optical characteristics of TiO2 films were tested using PL measurement. The photocatalytic decolourization of the amido black-10B dye was studied over TiO2 coating under UV and visible light irradiation. TiO2 film over a conversion layer without heat treatment exhibited the best photocatalytic activity as a result of its crystalline size and three-phase structure as well as the synergetic effect of TiO2 and Fe2O3.

This paper deals with the methylene blue molecule (MB) removal from synthetic and real textile wastewaters by alkali-treated orange tree sawdust (ATOS) under different dynamic conditions. Experimental results showed that MB removal efficiencies by ATOS increased when increasing initial dye concentrations and bed depths but decreased with the increase of the applied flow rates with a maximum adsorption capacity of about 110 mg g−1. Moreover, various empirical models were applied to predict the experimental breakthrough curves (BTCs) and to determine the characteristic adsorption parameters. The applied models successfully fitted data in the following order: Thomas ( $$ {\overset{-}{R^2}}_{Th} $$ = 0.969), dose response ( $$ {\overset{-}{R^2}}_{D- R} $$ = 0.949), and Clark ( $$ {\overset{-}{R^2}}_{\mathrm{Clark}} $$ = 0.874). ATOS was also found to efficiently remove dyes and other mineral pollutants such as chlorides, nitrates, and phosphates from real wastewaters. MB removal by ATOS involved not only cationic exchange but also complexation with acidic and basic functional groups. Moreover, important MB desorption yields from ATOS (more than 93%) were obtained when using saline solutions. All these results confirmed that NaOH-treated orange tree sawdust can be considered as a promising material for the removal of cationic dyes from industrial wastewaters.

Titanium dioxide (TiO2) nanostructed films were obtained on stainless steel by electrophoretic deposition in aqueous media. After the sintering stage, crystalline phases were investigated by X-ray ...

In this paper we present a 5G design and deployment framework within the 5G-EVE European project which aims at interconnecting multiple sites in order to form a single 5G end-to-end facility. Each partner of the project proposes 5G solution elements that will host use-cases brought by verticals. In this paper we present Plug'in as a design framework allowing different partners of the 5G-EVE project and verticals to create and test innovative components for 5G. We also present how components such as VNFs are on-boarded within 5G-EVE and finally we give a quick overview of a vertical's workflow.

Solar photocatalytic inactivation of Gram-negative bacteria with immobilized TiO2-P25 in a fixed-bed reactor was modeled with simplified kinetic equations. The kinetic parameters are the following: the photocatalytic inactivation coefficient (kd,QUV), the initial bacterial reduction rate (A) in the contact with the disinfecting agent, and the threshold level of damage (n) were determined to report the effect of QUV/TiO2-P25 on bacterial cultivability and viability and to compare the response of bacterial strains to photocatalytic treatment. In addition, the integration of the reactivation coefficient (Cr) in the photocatalytic inactivation equation allowed evaluating the ability of bacterial reactivation after photocatalytic stress. Results showed different responses of the bacteria strains to photocatalytic stress and the ability of certain bacterial strains such as Escherichia coli ATCC25922 and Pseudomonas aeruginosa ATCC4114 to resuscitate after photocatalytic treatment.

The consideration of nonclassical beam theories beyond Timoshenko beam model is necessary in applications involving complex yarns subjected to transverse compaction, for which the section dilatation and in-plane shear require a detailed kinematic and static modeling. In the present work, new enriched beam elements with additional degrees of freedom are derived from the mechanics of generalized continua, allowing a representation of the in plane-shear and dilatation of sections. As a novel aspect, enriched beam model called macrodilatation, macroshear, and macrostrain have been constructed on the basis of generalized beam theories but with a more condensed kinematics, assuming uniform hyperstress tensor within the beam. The choice of the adequate extended continuum for a given beam depends on its macroscopic deformation mechanisms. As a result, the developed beam models include modified material parameters (the tensile, shear and bulk moduli for an isotropic beam) involving additional microstructural parameters. These macrobeam models are expected to better describe the in plane-shear and dilatation of the beam sections along its mean line in comparison to classical beam theories. Numerical illustrative examples show that the microdilatation beam model has the ability to capture the local deformation field around holes, in contrast to Timoshenko beam model. The parameters of the microdilatation beam model provide a very good estimate of the overall porosity.

The effect of stainless steel (SS) electrode shape on electrochemical treatment of pharmaceutical pollutant has been studied. Anodes consisting of SS plate and SS grid coated with lead dioxide (PbO2) were prepared by different deposition techniques: electrodeposition (ED), sol gel method (SG) using spin-coating (SC) and dip-coating (DC) depending on the electrode shape. The influence of the substrate shape and the deposition method on the oxidizing performance of the elaborated electrode was studied. The surface morphology and the composition of the PbO2 layer were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). XRD analysis revealed the presence of β -PbO2 form with both deposition techniques in addition to the chromium (Cr) phase attributed to the SS substrate. Electrochemical Impedance Spectroscopy (EIS) measurements were performed for assessing the electrochemical behavior of the SS/PbO 2 anodes. EIS results demonstrated a smaller charge transfer resistance with PbO2 ED coating compared to PbO2 SG . The degradation of ampicillin as pharmaceutical pollutant was evaluated with high performance liquid chromatography and chemical oxygen demand (COD) for overall mineralization of organic matter and to evaluate the related average current efficiency (ACE) and energy consumption (EC). This study demonstrated that SS grid /PbO 2 ED is the most efficient electrode for electrochemical treatment with 100% of ampicillin removal after 120 min of treatment.

International audience; Hybrid Metal Organic-Frameworks (MOF)/polymer materials have gathered many researcher's consideration thanks to their varied functionalities and high processability. Herein, Metal Organic Frameworks (MOFs) have been successfully incorporated into an acrylate polymer network by photopolymerization upon mild visible light irradiation at 405 nm. The synthesized MOF/polymer composites were very efficient for Acid Black removal from water reaching 96% of decomposition after 30 and 45 min of UV-Lamp irradiation in the presence of MIL-53(Cr)/polymer and HKUSTI-1(Cu)/polymer composites, respectively. Probing further, the photo-composites were characterized by several techniques including Thermogravimetric Analysis (TGA), Fourier-Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy-dispersive X-ray 2 analyses (EDX), X-Ray Diffraction analysis (DRX), Brunauer, Emmett and Teller (BET) specific surface area, Atomic Force Microscopy (AFM), Dynamic Mechanical Analysis (DMA) and UV-Visible diffuse reflectance spectroscopy. The different methods used to characterized the MOF-containing polymers revealed these polymers to exhibit a high rigidity, an excellent thermal stability, an interesting band gap energy as well as an exceptional stability after their reuse for many photocatalytic treatment cycles.

Electrochemical denitrification of highly concentrated synthetic wastewaters was investigated using bipolar Boron-Doped Diamond on silicone substrate (Si/BDD) electrodes under various experimental conditions. The effects of the key operational parameters on the removal efficiency of nitrates were assessed using the Response Surface Methodology. Results showed that the efficiency of removal of nitrates was mostly sensitive to the applied current density and the duration of treatment, which are optimized, respectively, at 35.7 mA cm − 2 and 120 min. Under these experimental conditions, the removal yield of nitrates was evaluated at 91% with formation of by-products of 0.4% and 3.6% of nitrites and ammonia, respectively. Furthermore, average current efficiency is optimized at 59% with an energy consumption estimated at 0.35 × 10 − 3 kWh(g-N) − 1 . To better understand the role of BDD anode/cathode, by-products electrogeneration and disappearance, as well as the effect of chloride ions on pathway electrochemical denitrification, series of experiments were carried out at three concentrations of NaCl. The kinetic constants were calculated using a pseudo first-order kinetic model based on the fitting of the experimental data to established numerical approximations using Matlab software. At first, we noted that the direct reduction to N 2 in the absence of NaCl was very low ( k = 1.7 × 10 − 9 s − 1 ) compared to NH 3 and NO 2 − electrogeneration ( k = 1.7 × 10 − 5 and 5.4 × 10 − 4 s − 1 , respectively), where N 2 seemed to be the result of a reduction in by-products. The presence of hypochlorous species had a negligible effect on the kinetic rates of NO 3 − reduction.

A novel SS (Stainless steel)/SiOx/PbO2 anode for dye removal in water electrolysis was studied. SiOx interlayer was deposited by plasma enhanced chemical vapor deposition (PECVD) in plasma fed with argon, oxygen and tetraethoxysilane (TEOS) in different ratios. Lead oxide was deposited by pulsed electrodeposition. Well-adherent and homogeneous SiOx film, characterized by high hydrophobicity, were deposited in oxygen rich plasma onto the SS substrate as confirmed by the morphological characterization performed by means of Field Emission Scanning Electron Microscopy (FESEM). The composition of PbO2 layer was investigated by X-ray diffractometry (XRD) and evidenced that β-PbO2 crystallites nucleation was promoted by the SiOx interlayer. Additionally, Electrochemical Impedance Spectroscopy (EIS) measurements were performed for assessing the electrochemical behaviour of the SS/SiOx/PbO2 anodes. Results confirmed that the increase in the presence of the β-PbO2 form, increases the conductivity of the PbO2 film. Finally, the anode, with SiOx interlayer deposited in oxygen rich plasma, showed the best efficiency in removing the azoic dye from aqueous solution in terms of COD and color removal.

This work investigated the electrochemical treatment of four real effluents which were municipal wastewater (MWW), human urine (HU), river water (Wadi), and slaughterhouse wastewater (SHWW). The treatment was performed on a Boron-Doped Diamond (BDD) as anode/cathode material with an applied current density of 35.7 mA cm−2 and without any reagent addition. Effluent characterization before treatment indicated that nitrogen pollution existed essentially as ammonium/ammonia ions, low level of nitrate, and in some cases as nitrite form. Organic pollution was also determined by COD values which were 920, 7300, 320, and 2280 mg O2 L−1 for MWW, HU, Wadi, and SHWW effluents, respectively. The effectiveness of the electrochemical oxidation/reduction was assessed by nitrogenous compounds and COD removals. Obtained removals underlined the simultaneous oxidation and reduction at the BDD interfaces of the main species present in the real effluents as well as the electro-generated ones. Results confirmed the high performance of BDD electrode for removal of coexistent pollutants from the studied matrix. The oxidation of organic matter and ammonium/ammonia as well as the kinetic of COD degradation was rapid in acidic medium (HU case) than that in neutral and alkaline medium (MWW, Wadi, and SHWW). Moreover, the phytotoxicity test showed less toxic behavior only in the cases of MWW and SHWW with a Germination Index equal to 58.8 and 72.2 %, respectively. The EC and ACE were also evaluated for all studied wastewaters, and the lowest EC value (0.03 kWh (g COD)−1) was obtained for the more charged effluent (HU).

Electrophoretic deposition was used to produce titanium dioxide (TiO2) nanostructured films on copper substrate in aqueous media for photocatalytic application. Polyvinyl pyrrolidone (PVP) with a weight rate from 0 to 15% was added to TiO2 P25 suspension in order to enhance film adhesion. The films were characterized by X-ray diffraction, optical microscopy, contact angle measurement, nanoindentation, scratch test and photoluminescence. The photocatalytic activity of the films was tested with amido black 10B under UV irradiation. The results indicated that the morphology and the mechanical properties of films depended on the added PVP amount. Scratch test showed that adhesion strength rose with increased PVP amount. The photocatalytic activity indicated that TiO2 film synthesized with 13% PVP had the highest efficiency.

Southern Mediterranean area, particularly the Middle East and North Africa (MENA), has been facing social, economic, environmental and political challenges related to the water scarcity and quality. Within the European SWMED project, a socio-economic survey was conducted in Palestine and Tunisia, in order to explore the water conditions, and the social and economic situations of local families. The article illustrates the research design and implementation, as well as the main results that were used to select the appropriate sustainable water management solutions to respond to the hydropolitical issues. Due to the huge use of water in agriculture and the difficulty of reducing the water consumption in this sector, fostering tools for domestic water saving may be a winning strategy for facing water scarcity in MENA region. Fil: Anzera, Giuseppe. Università degli studi di Roma "La Sapienza"; Italia Fil: Belotti, Francesca. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Università degli studi di Roma "La Sapienza"; Italia Fil: Bousselmi, Latifa. Centre des Recherches et des Technologies des Eaux; Túnez Fil: Rabi, Ayman. Palestinian Hydrology Group; Palestina (ANP)

The present study investigates the combination of electrocoagulation (EC) and electrochemical treatment (ET) for a simultaneous removal of nitrates and phosphates from synthetic wastewater. In the EC process, four parallel mild steel electrodes in a batch reactor were used. The increase of the current density from 1 to 40 mA cm−2 led to a total removal rates of both nitrates and phosphates at natural pHs (6 and 7). However, at high current density a rise of the electric energy consumption from 0.32 kW h m-3 for 1 mA cm−2 to 105.78 kW h m−3 for 40 mA cm−2 was recorded. Whereas the EC process is an inefficient method that generated ammonia as by-product, which needs additional treatment. ET process using boron doped diamond (BDD), which was evaluated as one of the most promising methods for the removal of nitrogenous compounds. Combining the two processes offers a practical hybrid treatment. Such combination resulted in the oxidation of the elector-generated ammonia and therefore enhanced the final quality of the treated wastewater. Additionally, the combined EC-ET method offer a low energy consumption per unit of removed pollutant (about 0.99 kW h (kg-N)−1). The kinetic modeling showed that phosphates adsorption fit the pseudo-second order, while nitrates fit the pseudo-first order. However, the nitrogenous products oxidation/reduction fit the pseudo-first order on mild steel as well on BDD electrodes.

Bacteria are able to construct biofilm adjacent to carbon steel surface and leading to the biocorrosion and metal deterioration. The impact of wasterwaters’ indigenious bacteria on biocorrosion of carbon steel was evaluated under different pH values (3,7 and 9), two chloride concentrations (0.5 g/L and 1.5 g/L), and for two wastewaters. In tannery wastewaters (TWW) and under pH 3, Pseudomonas aeruginosa sp. (MN788665) and Enterobacter aerogenes sp. (MN788688) were able to establish an irreversible adhesion on the first stage of biofilm formation on the carbon steel surface due to hydrophobic behaviour of the bacteria. However, under the same pH, bacteria from industrial wastewaters (IWW) such us Brevundimonas diminuta sp. (MN788672) and Enterobacter aerogenes sp. (MN788689) promote the reversible adhesion followed by a continuous attachment and consequently a limited biofilm. Subsequently, in TWW and 0.5 g/L of chlorides, indigenious bacteria like Enterobacter aerogenes sp. (MN790737) and Raoultella ornithinolytica sp. promote an irreversible attachment of biofilm enhanced by their hydrophobic property contrarily to the bacteria isolated in the medium at chloride concentration of 1.5 g/L. In IWW, 1.5 g/L of chlorides the biofilm attachment is reversible and therefore its inhibition role is of little influence.

Several Advanced Oxidation Processes (AOPs) including O3/H2O2, O3/TiO2, O3/activated carbon (AC), O3/Al2O3, O3/Fe2+/H2O2 and UV/TiO2 have been investigated and compared for the removal of diethyl phthalate (DEP), an endocrine disrupting compound, in aqueous solutions. Hydroxyl radicals were the main species responsible for DEP degradation and this was supported by computational chemistry calculation, scavenger experiments, and LC/MS/MS analysis. The change of the abundance of reaction products over time was determined. Organic acids as well as anhydride and hydroxylated products were found to accumulate in solution even after long reaction time (2 h). Careful choice of the operating parameters (pH, ozone concentration and catalyst dosage) was crucial to achieve enhanced performance of the combined processes above what each oxidant and catalyst can achieve alone. O3/AC process was found to reduce the oxidation efficiency of O3 at high ozone concentrations. Heterogeneous catalytic ozonation with Al2O3 was the most effective process for DEP removal (∼100% removal in about 15 min) and based on pseudo-first-order kinetics at pH7, the studied oxidation processes followed the order: O3/Al2O3(0.093 min−1)>O3/H2O2/Fe2+(0.076 min−1)>O3/AC(0.069 min−1)>O3/H2O2(0.053 min−1)>O3/TiO2(0.050 min−1)> O3 alone (0.039 min−1)>UV/TiO2(0.009 min−1).

9 pages, The main goal of the present study was to enhance the rhizobacterium potential in a horizontal subsurface flow constructed wetland system planted with Phragmites australis, through environmentally friendly biological approaches. The bioinoculation of antagonist bacteria has been used to promote higher rhizosphere competence and improve pathogenic bacteria removal from wastewater. The experiment was performed both with single and sequential bioinoculation. The results showed that strain PFH1 played an active role in pathogenic bacteria removal, remarkably improving inactivation kinetics of the pathogenic tested bacterium Salmonella typhi in the plant rhizosphere. The single bioinoculation of selected bacteria into the rhizosphere of P. australis improved the kinetics of S. typhi inactivation by approximately 1 U-Log10 (N/N0) (N is the number of viable cultured bacteria at time t, N0 is the number of viable and cultivable bacteria at time t0) compared to the control. By a series of multi-bioinoculations, the enhancement of pathogenic bacteria reduction compared to the inhibition rate in the pilot-scale control was of 2 U-Log10(N/N0). These findings suggested that this strain represents a promising candidate to enhance water purification in constructed wetlands

The attraction of foreign direct investment is a common objective in developing countries, and this broad aim is carried out with different approaches in public policies. Corporate social responsibility is very common in international corporations, and it tends to produce a positive image for investors and in the surrounding society. This study aims to clarify the influence of the enhancement of corporate social responsibility by companies established in Tunisia as a consequence of the host country government general policies on the attraction of direct foreign investment. We propose the testing of a conceptual framework that describes this influence and explains the benefits of the social commitment, especially when it will be encouraged by public policies which can favor the attraction of foreign investments. The paper opted for an exploratory analysis on a sample of foreign companies with subsidiaries in the country. It contains a descriptive analysis, a study of the reliability of the scales of measurement and a principal components analysis. This approach is completed by an analysis of moment structures (AMOS) through a structural equation model linking the interactions of public policies with the development of strategies in social responsibility in companies, and their induced effects on the investment decisions in their subsidiaries. This approach tends to be associated with the sustainability and the commitment in the country, which is especially important in the present moment, with the political changes in the Maghreb region. With the models proposed, it has been shown that public policies, in addition to having a direct impact on investment decisions, can produce positive effects when they are carried out with the aim of promoting sustainable growth, and using indirect tools like the promotion of corporate social strategies in the companies that are already established in the country.

Microbiologically influenced corrosion (MIC) of bare and silane-TiO2 sol-gel coated stainless steel (SS) was studied in treated urban wastewater (TUWW). Combining the electrochemical impedance spectroscopy (EIS) and the scanning vibrating electrode technique (SVET) showed that SS surface colonization occurs, at earlier stages, by iron-oxidizing bacteria (IOB), and later by sulphate-reducing bacteria (SRB). The SVET results showed that chemical corrosion process and bacterial respiration led to the depletion of dissolved oxygen, creating a differential aeration cell and thus a localized corrosion phenomenon. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) showed that the growth of a bacterial biofilm on 304L SS was a dynamic process, stimulating the localized oxidation of SS. To improve corrosion protection, a silane-TiO2 sol-gel coating for SS is proposed. SEM showed that the coating reduced bacterial adhesion and EIS study demonstrated that the coating improved the barrier properties and corrosion resistance of 304L SS in TUWW over a short period of immersion.

Freshwater availability is increasingly under pressure from growing demand, resource depletion and environmental pollution. Desalination of saline wastewater is an option for supplying households, industry and agriculture with water, but technologies such as reverse osmosis, evaporation or electrodialysis are energy intensive. By contrast, membrane distillation (MD) is a competitive technology for water desalination. In our study, response surface methodology was applied to optimize the direct contact membrane distillation (DCMD) treatment of synthetic saline wastewater. The aim was to enhance the process performance and the permeate flux Jp (L/m2·h) by optimizing the operating parameters: temperature difference ΔT, feed velocity Vf, salt concentration [NaCl], and glucose concentration [Gluc]. The results are a high permeate quality, with 99.9% electrical conductivity reduction and more than 99.9% chemical oxygen demand (COD) removal rate. The predicted optimum permeate flux Jp was 34.1 L/m2·h at ΔT = 55.2 °C and Vf = 0.086 m/s, the two most significant parameters. The model created showed a high degree of correlation between the experimental and the predicted responses, with high statistical significance.

Agri-food wastewaters are characterized by high contents of hardly biodegradable organics and large amounts of inorganics especially nitrogen and phosphorus. The present work investigates the efficiency of two electrochemical treatment processes, namely electrochemical oxidation/reduction (EOR), electrocoagulation (EC) and their combination for the treatment of two types of effluents collected from poultry slaughterhouse (SHWW) and dairy (DWW) industries. The optimization of these treatment systems in terms of pollutant performance removal and energy cost were carried out. The EOR treatment was assessed on a bipolar cell with Boron-Doped Diamond (BDD) supported on silicon electrodes. While, the EC treatment was performed on a reactor containing mild steel electrodes with parallel configuration. The simultaneous removal efficiencies of the organic matter in term of the chemical oxygen demand (COD), nitrates, ammonium/ammonia and phosphates, as well as the electric energy consumption (EEC), were evaluated for the different electrochemical scenarios. Results indicated that the EOR treatment shows the highest removal efficiencies of COD, nitrates and ammonia from the two studied wastewaters. While, the phosphates were removed only by the EC process. On the other hand, the EC process shows a relatively low cost in term of EEC (0.01 kWh/g COD-1), which is about 13 times lower than the one consumed during the EOR process. The combination of the two processes leads to the improvement of the removal rate of all coexistent pollutants when the EC technology was used as a pre-treatment step. While, this coupling mode has the highest EEC. However, when the EOR process was used before the EC one, the removal rates of COD and nitrates were globally similar to the EOR process alone with a relatively low EEC.

International audience; In the present research, the optimization of the photocatalytic degradation of simulated textile effluent containing two pollutants (Methylene blue (MB) and Zinc) consisted of studying the variation of four parameters, namely initial MB concentration ([MB]I, mg/L), zinc concentration ([Zn2+]I, mg/L), sodium chloride concentration ([NaCl]I, M) and flow rate (Q, mL/min) through a design of experiment using the response surface methodology approach. Results showed that MB degradation depends by order of importance on NaCl concentration andgt; MB concentration andgt; ionic zinc concentration andgt; flowrate. Modeling results presented a good concordance between predicted and experimental values with acceptable correlation coefficients (R2 = 0.9879 and R2 (adjusted) = 0.9773). Desirability function was applied on the second-order polynomial equation to determine the optimal experimental condition for fastest total photocatalytic degradation and it was identified as follows For a maximal target of 85.91% and a desirability of d = 1.0, [MB] = 75 mg/L, [Zn2+] = 45 mg/L, [NaCl] = 0.125 M and Q = 500 mL/min. Moreover, results showed that zinc had a good affinity to cellulose material and contributed on enhancing the photocatalytic activity in terms of degradation. Mineralization of the dye was assessed for the optimal conditions using the TOC method. Moreover, special attention was also paid to better understand the effect of inorganic pollutant, scavenging effects of different molecules such as EDTA, isopropyl alcohol and CCl4 were examined and discussed.

Membrane distillation is getting increasing attention thanks to its advantages in terms of energy consumption and final permeate quality in addition to its resistance against highly corrosive media which forms an appealing solution for industrial wastewater treatment. Despite its advantages, one of the most challenging issues in direct contact membrane distillation (DCMD) is membrane fouling and wetting. In the present research work, saline dairy effluent discharged from hard cheese industry was pretreated by macrofiltration (MAF) and ultrafiltration (UF) and processed by DCMD to investigate the extent of the aforementioned issues. Effluents pretreated by UF have led the best process performance with stable flux values at different operating conditions. Fouling has occurred in all the experiments, though their effect on the flux behavior and membrane wetting was different from one feed to the other. Changing the flow rate and the temperature difference have affected slightly the membrane wettability for all feed qualities. In all experiments, the permeate has maintained a good quality with low electrical conductivity that did not exceed 70 µS/cm and low total organic carbon

The main goal of the present study was to enhance the rhizobacterium potential in horizontal subsurface flow constructed wetland system planted by Phragmites australis using biotechnology. The bioinoculation of denitrifier promoting rhizobacteria fluorescent Pseudomonas spp. has been used to confer higher rhizosphere competence by environmentally friendly biological approaches. In order to study the behaviour or the denitrifying potential of the inoculated bacteria ex situ and in situ, the models of Chick–Watson and Series-Event were used with modifications. The comparison of kinetic parameters: (k): the denitrifying coefficient (h−1) and the denitrifying rate at the first contact with a determined concentration of nitrate (A) for different bioassays has shown that the application of the bioinoculation increases remarkably the efficiency of the water treatment system for the reduction of nitrates even by an individual bioinoculated bacterium.

The effect of cyclic voltammetry (CV) on electrochemical behavior of PbO2 layer electrodeposited by pulsed method on stainless steel (AS30) has been studied. The field emission scanning electrons microscope and X-ray diffraction (XRD) were used to characterize the surface morphology and crystal structure of different electrodes with CV effect, respectively. The content of PbO2 particles has been tuned by altering the cycle number, of CV through which the content of PbSO4 also increased. It is related to reduction phenomena depending on electron transfer through the pores into β-PbO2 layer. Electrochemical behavior of the prepared samples was investigated in 0.5 M H2SO4 solution by CV and electrochemical impedance spectroscopy (EIS) techniques. EIS results revealed that the charge-transfer resistance significantly increased because the lead sulfate layer is more compact and the access of electrolyte ions to the internal layer is blocked. Anodic oxidation of solutions containing Amaranth as a dye mo...

PbO2 films are electrodeposited by the galvanostatic (G) and pulsed current (P) methods on lead and stainless steel (AS30), respectively. They are used as electrodes for electrochemical degradation of Amaranth dye. The scanning electron microscope, atomic force microscope, and X-ray diffraction analyses revealed the dominance of β-PbO2 form in two anodes and the absence of the form tet-PbO and PbSO4 in AS30 substrate that have more amorphous shape and less roughness (200 nm). A poor lead oxide adhesion on AS30 substrate is detected. Cyclic voltammetry results showed that the absence of oxidation peak in the case of AS30/PbO2 anode is related to the oxidation of PbSO4 to β-PbO2. EIS results demonstrated that the pH influences largely PbO2 layer. Concerning E123 degradation, 95 and 91% of color removal (82 and 76% of Chemical oxygen demand removals) were achieved using Pb/PbO2 and AS30/PbO2 anodes, respectively. In this case, current efficiency has kept relatively a high value assuming less energy c...

The present paper investigates the efficiency of coagulation/flocculation process using aluminum sulfate as coagulant and CHT industrial flocculent as coagulant aid/flocculent in the treatment of vegetable oil refinery wastewater (VORW). The process optimization was conducted in two steps, jar test experiments for preliminary evaluation to identify the most influencing factors and response surface methodology using Box–Behnken design to investigate the effects of three major factors and their interactions. The variables involved were the coagulant concentration (X1), flocculent dosage (X2), and initial pH (X3) of water samples, while the responses were COD removal (Y1) and residual turbidity (Y2). The optimal conditions obtained by solving the quadratic regression models, as well as by analyzing the response surface contour plots, were as follows: 2.4 g/L of coagulant (aluminum sulfate), 60.05 mg/L of flocculent, and about 9.23 as initial pH. Under these conditions, the coagulation/flocculation treatment was able to achieve 99% of COD removal with total turbidity elimination (100% removal). Analysis of variance showed high variance coefficient (R2) values of 0.929 and 0.836 for COD and turbidity removals, respectively, thus ensuring a satisfactory adjustment of the second-order regression model with the experimental data. This statistical design methodology was demonstrated as an efficient and feasible approach for the optimization of coagulation/flocculation treatment.