The aim of this work is to evaluate the use of phenalenone (PN) grafted to sand in the photodegradation of tebuconazole (TEB). PN was covalently attached to sand via click reactions between functionalized sand and PN derivatives. The... more
The aim of this work is to evaluate the use of phenalenone (PN) grafted to sand in the photodegradation of tebuconazole (TEB). PN was covalently attached to sand via click reactions between functionalized sand and PN derivatives. The photodegradation study was conducted in an annular reactor equipped with immersed UV and visible lamps. In the first step the photodegradation of TEB was studied in presence of free PN. The influence of the molar ratio = PN/TEB was investigated; a maximal effect was observed with R close to 769; beyond this value a shielding effect appeared. The use and the lifetime of the sand-bound PN were studied and the photodegradation mechanism was investigated. Covalent binding of photosensitizer to sand resulted in a 80 nm red shift of the PN absorption band in the visible region along with an important increase in degradative efficiency. PN-Sand was more stable under visible irradiation. The main mechanism was the type II with some contribution of type I.
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Adsorption of the herbicide diuron and its three degradation products: 3-(3,4-dichlorophenyl)- 1-methylurea, 1-(3,4-dichlorophenyl) urea and 2,4-dichloroanilin on three organoinorgano-clay minerals, was investigated. These... more
Adsorption of the herbicide diuron and its three degradation products: 3-(3,4-dichlorophenyl)- 1-methylurea, 1-(3,4-dichlorophenyl) urea and 2,4-dichloroanilin on three organoinorgano-clay minerals, was investigated. These surfactant-modified pillared ...
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Filtration of polluted aqueous solutions is performed by activated carbon membranes. The adsorption capacities are determined in batch reactors. Classic models are applied and kinetic constants are calculated. A comparison with grains and... more
Filtration of polluted aqueous solutions is performed by activated carbon membranes. The adsorption capacities are determined in batch reactors. Classic models are applied and kinetic constants are calculated. A comparison with grains and powders of activated carbon is made. The performances of the membranes in continously fed reactors are also studied. The breakthrough curves are plotted for different concentrations of organic compounds and fluid velocities. A simple model of mass transfer into the porous volume of the membrane is put forward and used to predict the outlet concentrations as a function of time. The model parameters are correlated to the fluid velocities and the inlet concentrations.
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La production d'eau potable nécessite parfois une filtration sur charbon actif en vue d'éliminer des micropolluants organiques. Afin de développer un modèle prévisionnel de la durée de vie de ces filtres, il est nécessaire de bien... more
La production d'eau potable nécessite parfois une filtration sur charbon actif en vue d'éliminer des micropolluants organiques. Afin de développer un modèle prévisionnel de la durée de vie de ces filtres, il est nécessaire de bien connaître les caractéristiques des charbons influençant l'adsorption. Des caractéristiques de la structure physique (porosité et surface) et chimiques (fonction de surface), le potentiel zêta et les constantes thermodynamiques de neuf charbons actifs ont été déterminées et des essais de corrélation ont indiqué une certaine ligne de conduite pour l'utilisation de charbons de différentes origines. Des cinétiques et des isothermes d'adsorption de l'atrazine et du phénol ont été réalisées, ceci afin de mieux comprendre l'influence de la structure et des caractéristiques physico-chimiques des charbons sur les mécanismes d'adsorption. L'étude a mis en évidence les points suivants : (i) le nombre de sites primaires polaires d&#...
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This research reports on phosphate removal from aqueous solution using ZVI/sand packed columns. The influence of column preconditioning, consisting of ZVI pre-oxidation before feeding the columns with phosphate solution, revealed that a... more
This research reports on phosphate removal from aqueous solution using ZVI/sand packed columns. The influence of column preconditioning, consisting of ZVI pre-oxidation before feeding the columns with phosphate solution, revealed that a column aged for 1 day was more efficient than un-conditioned column, 5-days and 10-days preconditioned columns. The distribution of phosphate trapped inside the columns was evaluated by measuring phosphate concentration in the solids at different levels (P1, P2 and P3) along the depth of the columns. The distribution of phosphate inside the columns was determined for a time period up to 46 days, corresponding to column saturation. Results showed heterogeneous trapping along the column before saturation and homogeneous distribution upon saturation. The maximum cumulative trapped phosphate after column dismantling was determined before saturation (after 17 days running) at 130, 68 and 31 mgP/gFe at the inlet-P1, P1-P2 and P2-P3 layers, respectively, wh...
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Ordered mesoporous silica with hexagonal and cubic structure, type MCM-41 and MCM-48 respectively, were synthesized under basic media using pure silica, cetyltrimethylammonium bromide and tetramethylammonium hydroxide, for MCM-41 and... more
Ordered mesoporous silica with hexagonal and cubic structure, type MCM-41 and MCM-48 respectively, were synthesized under basic media using pure silica, cetyltrimethylammonium bromide and tetramethylammonium hydroxide, for MCM-41 and tetraethylorthosilica, cetyltrimethylammonium and NaOH for MCM-48. The expanded materials were prepared by post-synthesis method with N-N dimethyldodecylamine (DMDDA) and dodecylamine (DDA). Small angle X-ray diffraction, nitrogen adsorption-desorption measurements, FT-IR and thermogravimetry were used to characterize the samples. The expanded materials were tested for adsorption of Cd(2+), Co(2+), Cu(2+) and Pb(2+) in aqueous solution. Aminated materials were found to be fast adsorbents for metallic ions cation with affinity for Cu(2+), Pb(2+), than for Cd(2+) and Co(2+) from single solution. In mixed metallic ions cation solutions, competition by the adsorption sites is likely to occur, the adsorption preference is for Cu(2+)and Pb(2+). The kinetic of the reaction is very rapid and follow pseudo-second order and clearly indicated that Langmuir model describe better the for metal ions adsorption on aminated mesoporous material than Freundlich model.
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Research Interests: Kinetics, Modeling, Two Phase Flow, Multidisciplinary, Bioreactor, and 15 moreNitrification, Potassium, Laplace Transform, Steady state, Transfer Function, Residence Time Distribution, Continuous Flow, Fresh water, Biofilter, Batch Reactor, Unsaturated Flow, Flow Rate, Residence Time, Packed Bed, and Functional Equation
Research Interests: Adsorption and Pesticide
Research Interests: Engineering, Kinetics, Morphology, Adsorption, Models, and 15 moreDiffusion, Ph, Modification, Mechanism, Equation, Difusion, CHEMICAL SCIENCES, Encapsulation, Diffusion Coefficient, Infrared Spectrometry, Aqueous Solution, Non linear regression, Langmuir Isotherm, Freundlich Isotherm, and Adsorption isotherm
Research Interests: Engineering, Carbon, Environmental Monitoring, Eutrophication, France, and 15 moreBiological Sciences, Mobility, Environmental Sciences, Pesticide, Copper, Environmental Technology, Laboratory experiment, Environmental Conditions, Dissolved Organic Carbon, Decontamination, Organic Matter, Biological Availability, Geologic Sediments, Copper sulfate, and Organic Chemicals
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... l'appliquer aux SBR et simuler les systèmes discontinus afin d'optimiser les performances ... Lamodélisation de la mortalité englobe les phénomènes de métabolisme endogène, de ... que le procédé présenté aboutit à des... more
... l'appliquer aux SBR et simuler les systèmes discontinus afin d'optimiser les performances ... Lamodélisation de la mortalité englobe les phénomènes de métabolisme endogène, de ... que le procédé présenté aboutit à des rendements moyens d'épuration extrêmement satisfaisants ...
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The rheological behaviour of granular sludges (diameter 20-315 ¿m) originating from different anaerobic reactors was carried out using rotation tests. The sieved granular sludges suspensions display a non-Newtonian rheological behaviour... more
The rheological behaviour of granular sludges (diameter 20-315 ¿m) originating from different anaerobic reactors was carried out using rotation tests. The sieved granular sludges suspensions display a non-Newtonian rheological behaviour and the limit viscosity was therefore used as a rheological parameter. The values obtained, which depend on the shear rate used, were strongly influenced by the total suspended solids (TSS)
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ABSTRACT A new diatomite-based composite is prepared and used for environmental remediation. The Algerian diatomite has been used for the first time for this application. Preparation conditions showed increased surface area with improved... more
ABSTRACT A new diatomite-based composite is prepared and used for environmental remediation. The Algerian diatomite has been used for the first time for this application. Preparation conditions showed increased surface area with improved sorption properties. This composite consisting of diatomite (Dia) and activated carbon (C) was prepared using a mixture of diatomaceous earth and glucose. Effects of thermal and chemical treatments are studied. methylene blue (MB), methyl orange (MO) and para-nitro-phenol (PNP) from aqueous solution were chosen as pollutants to test retention capacity. Physical, chemical and structural properties of these new hybrid materials have been investigated by several methods. The surface areas of pure and modified diatomite are estimated to be (22 m2 g−1) and (100-173 m2 g−1), respectively. Sorption kinetics and isotherms for MB, MO and PNP were carried out in order to determine their respective adsorption capacity. The surface charges (negatives) and macroporosity of diatomite did not allow the adsorption of PNP and MO. However, modified diatomite (Dia/C) showed ability to eliminate these pollutants, despite their dominant inorganic nature. The pseudo-second-order kinetics and the Langmuir model described sorption data reasonably well. The study showed that the composite materials can be used as potential efficient sorbents.
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ABSTRACT New generations of hydrophobic composite geomaterials intended to sorb certain hazardous wastes are assembled by mixing surfactant-modified aluminum-pillared montmorillonite (Al-SMPM) with activated carbon (AC). The sorption of... more
ABSTRACT New generations of hydrophobic composite geomaterials intended to sorb certain hazardous wastes are assembled by mixing surfactant-modified aluminum-pillared montmorillonite (Al-SMPM) with activated carbon (AC). The sorption of 4-nitrophenol (4NP) and 2-nitrophenol (2NP) on these sorbents was studied in both single and binary component systems from aqueous solutions using batch tests. Results showed the efficiency of these composite sorbents relative to the two phenolic compounds, with a dominant contribution from Al-SMPM. In single-component systems, sorption isotherms of 4NP and 2NP as a function of pH were analyzed with the Freundlich equation, whose statistical interpretation was also developed. Sorption capacities sharply decreased when the solution pH value was raised from 3 to 9. In binary-component systems, the fit between measured and predicted simultaneous sorption capacities of both 4NP and 2NP indicated that the Sheindorf-Rebhun-Sheintuch model, an extended Freundlich model, is fully applicable. The 2NP favorably influences the sorption of 4NP. The synergistic effect between these two nitrophenol compounds has been confirmed by the higher competition coefficients, which increase with increasing pH. A number of hypotheses, based on the Abraham's solvation parameters model, have been advanced to discuss this mechanism.
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Removal of the amine template enhances the sorption of phenolic pollutants. The sorption capacity could be dependent of the pore size.
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The rheological behaviour of granular sludges (diameter 20-315 microm) originating from different anaerobic reactors was carried out using rotation tests. The sieved granular sludges suspensions display a non-Newtonian rheological... more
The rheological behaviour of granular sludges (diameter 20-315 microm) originating from different anaerobic reactors was carried out using rotation tests. The sieved granular sludges suspensions display a non-Newtonian rheological behaviour and the limit viscosity was therefore used as a rheological parameter. The values obtained, which depend on the shear rate used, were strongly influenced by the total suspended solids (TSS) content of granular sludge and an exponential relation was found between the TSS and the rheological parameter limit viscosity. The increase of viscosity as a function of TSS content of the granular sludge as well as the increase of granule size underlines the importance of the interaction between granules in the evolution of this rheological parameter. Significant differences in granular sludge limit viscosity were found for granular sludge of different origins. All measurements performed with 10 g.l(-1) TSS granular sludge indicate the ability of the chosen ...
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Rheological behaviour of filamentous sludges originated from activated sludge reactors was studied. Filamentous bulking was detected via a hysteresis loop developed from rheograms resulting from increasing-decreasing shear rates. The... more
Rheological behaviour of filamentous sludges originated from activated sludge reactors was studied. Filamentous bulking was detected via a hysteresis loop developed from rheograms resulting from increasing-decreasing shear rates. The rheological parameter reduced hysteresis area (rHa), corresponding to the loop area developed by rheograms was used to quantify filamentous bulking. Application to the evolution of several bulkings was carried out and it was shown that filaments proliferation and disappearance were correlated with, respectively, the increasing and decreasing of the value of the parameter rHa. In parallel with rheological measurement, parameters used for the study of sludge quality, such as sludge volume index (SVI) and settling initial flow (F0), were determined for comparison during the evolution of several bulkings. It was shown that rHa was more sensitive to the appearance of filamentous bulking than SVI and F0, therefore it was concluded that detection of filamentou...
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The use of a simulation model for setting up a control strategy for a sequencing batch reactor necessary for treating municipal wastewater is described. The model used is the ASM no 1 model. The objective of the pollution control... more
The use of a simulation model for setting up a control strategy for a sequencing batch reactor necessary for treating municipal wastewater is described. The model used is the ASM no 1 model. The objective of the pollution control treatment is the removal of carbon and nitrogen; the optimisation is concerned with the improvement in the biological removal of nitrogen. After experimental identification of the initialisation variables, the model enables different SBR control scenarios to be tested (time variation for each process) leading to the total elimination of nitrogen. The best simulation was tested in a laboratory reactor. On that scale, it was noted that denitrification is an endogenous process. Lastly, the control strategy was tested on a semi-industrial pilot working in a pollution control plant. Other control scenarios can be devised and tested by simulation, in order to improve the productivity of the reactor.
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To monitor the ability of flocs to settle in Sequencing Batch Reactor sludge, two methods were tested during two operation cycles. Firstly, an automated image analysis procedure has been tested to quantify the floc size and the length and... more
To monitor the ability of flocs to settle in Sequencing Batch Reactor sludge, two methods were tested during two operation cycles. Firstly, an automated image analysis procedure has been tested to quantify the floc size and the length and number of filaments. Secondly, rheological measurements (Bingham viscosity and shear stress) have been used to characterise the dispersion of the sludge which can reflect the cohesive strength of aggregates and so the influence of filamentous bacteria on rheological properties. These results were compared with settling parameters such as Sludge Volume Index or settling velocity. Correlations between the measured parameters with image analysis and parameters such as Sludge Volume Index have been obtained. If it is more difficult to analyze rheological results, it seems however that the thixotropy and the Bingham viscosity distinguish poor settlement owing to some filamentous bulking. The first results are promising, although they require confirmatio...
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A simulation of a SBR using Benchmark procedure was done prior to field operation in order to optimize the cycle and phases lengths. The accurate identification of ASM1 variables is a prerequisite to achieve a good prediction. A... more
A simulation of a SBR using Benchmark procedure was done prior to field operation in order to optimize the cycle and phases lengths. The accurate identification of ASM1 variables is a prerequisite to achieve a good prediction. A fractionation procedure was applied to samples, corresponding to dry and rainy weather conditions, for taking into account the ASM1 state variable characteristics of specific wastewater (mixture of domestic and industrial wastewater), which differ largely from the default ones used in ASM1. The choice of the ASM1 state variables identification methodology is very important as it influences the results. Two methods were carried out: a batch test in closed reactors, and a coagulation/flocculation procedure. An optimal 12‑hour cycle length was determined, in terms of discharged water quality and reactor productivity. The described methodology led to valuable results in terms of carbon and nitrogen removal: respectively more than 90% of COD removal and more than...
This work studied the combination of a chemical coagulation/flocculation step with an aerobic biological process, using feed-batch operation, to treat real paint manufacturing wastewater (PMW). The results indicate that the combination of... more
This work studied the combination of a chemical coagulation/flocculation step with an aerobic biological process, using feed-batch operation, to treat real paint manufacturing wastewater (PMW). The results indicate that the combination of coagulation flocculation and biological process is an efficient alternative in the treatment of PMW. For initials COD of 18590 mg/L, BOD of 1492 mg/L and colour of 0.9 absorbency, coagulation flocculation using iron chloride and chimec 5161 allows 92% of COD, 97% of colour and 44.5% of BOD removals, and residuals COD and BOD of 1553 and 828 mg/L, respectively. However, the combination of chemical and biological process generates a clear effluent with residuals COD and BOD of 680 and 112 mg/L, corresponding to 96 and 92.5% removal rates, respectively. Aerobic biological treatment using feed batch operation permits a COD removal rate of rCOD = 873 mg/L, and an average growth yield coefficient of 0.3 g of biomass / g COD.
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In arid regions such as near Sfax (Tunisia), treated wastewater effluents (TWE) are often applied as agricultural irrigation. Irrigation TWE usually contain large amounts of carbon, nitrogen and sodium. The objective of this study was to... more
In arid regions such as near Sfax (Tunisia), treated wastewater effluents (TWE) are often applied as agricultural irrigation. Irrigation TWE usually contain large amounts of carbon, nitrogen and sodium. The objective of this study was to evaluate the impact of TWE irrigation on soil salinity and sodicity. In the city of Sfax, two sites were selected with two soil types (fluvisol and calcisol) having been irrigated for 4 and 15 years respectively. Soils were sampled at three different depths (0-30, 30-60 and 60-90 cm) in the TWE irrigated area and in a non-irrigated control area. Irrigated and non-irrigated study soils were analyzed for pH, nitrate and ammonia, electrical conductivity (ECs), exchangeable sodium percentage (ESP), sodium absorption ratio (SAR) and soil organic matter. The fluvisol, irrigated for only four years, is more affected by salinity than the calcisol irrigated for 15 years. In the upper fluvisol layer irrigated by the treated wastewater, ECs reach 8 mS•cm-1 and...
Research Interests: Irrigation and Wastewater
Watermilfoil genus Myriophyllum could be used in ecological surveys as in-situ biomonitors of metal pollution and water quality due to its ability to accumulate chemicals. The copper and cadmium sorption characteristics of Myriophyllum... more
Watermilfoil genus Myriophyllum could be used in ecological surveys as in-situ biomonitors of metal pollution and water quality due to its ability to accumulate chemicals. The copper and cadmium sorption characteristics of Myriophyllum alterniflorum have been investigated. The Langmuir and Freundlich isotherms were used to model the metal sorption isotherms and the monolayer sorption capacities, as obtained by the Langmuir
Research Interests: Water quality, Kinetics, Photosynthesis, Biomass, Environmental Monitoring, and 14 moreCarotenoids, Multidisciplinary, Adsorption, Water Supply, Copper, Chlorophyll, Cadmium, Photosynthetic Pigment, Time Dependent, Water Quality, Myriophyllum Spicatum, Langmuir Isotherm, Freundlich Isotherm, and Saxifragaceae
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Ce travail explore les performances de deux types de membranes de nanofiltration (Desal DK et NF200) dans l'élimination dans les eaux de certains pesticides (l'atrazine et son métabolite la déséthylatrazine (DEA), la simazine, la... more
Ce travail explore les performances de deux types de membranes de nanofiltration (Desal DK et NF200) dans l'élimination dans les eaux de certains pesticides (l'atrazine et son métabolite la déséthylatrazine (DEA), la simazine, la cyanazine, l'isoproturon et le diuron) et évalue l'influence de la présence de matière organique ou inorganique dans la matrice d'eau sur l'efficacité de ce traitement. Des eaux synthétiques, composées à partir d'eau distillée à laquelle a été ajoutée de la matière organique (acides humiques) ou inorganique (CaCl2 ou CaSO4), ont été traitées sur un pilote de nanofiltration durant 96 heures. Les taux rétention en pesticides et ceux de leur adsorption sur les membranes ont été calculés et comparés aux résultats obtenus sur une matrice d'eau distillée pure. Une influence du type de membrane et de la présence de la matière humique sur le taux d'abattement de certains pesticides a été constatée.…
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ABSTRACT The performance of a novel extra-loop fluidized bed bioreactor (EFBBR) in sequencing batch reactor mode (total 12 h: anaerobic 1.5 h, aerobic 5 h, anoxic 4.5 h, settle 1 h, and idle 1 h) and employing a PVC tube as a carrier... more
ABSTRACT The performance of a novel extra-loop fluidized bed bioreactor (EFBBR) in sequencing batch reactor mode (total 12 h: anaerobic 1.5 h, aerobic 5 h, anoxic 4.5 h, settle 1 h, and idle 1 h) and employing a PVC tube as a carrier medium for the simultaneous carbon, nitrogen, and phosphorus removal from synthetic wastewater is discussed. The EFBBR was operated and the system commissioning and optimization lasted for about 300 d. During the operation, the EFBBR was able to achieve chemical oxygen demand (COD), ammonia nitrogen (NH4-N), and phosphorus removal efficiencies of 90, 95, and 100%, respectively. The results presented that C/N was insignificant for COD removal. At C/P = 33.2, there were productions including NO2-N and NO3-N. However, at C/P = 10.4, nitrification was restrained with TKN/COD from 0.0805 to 0.139, and phosphorus was eliminated completely. The reactor operation can achieve nitrite accumulation successfully. Therefore, the EFBBR is a novel high-powered equipment for carbon and phosphorus removal simultaneously with a shortcut nitrification–denitrification process.
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Le traitement des effluents urbains par réacteurs discontinus séquentiels (SBR : Sequencing Batch Reactor) constitue une solution alternative aux traitements par systèmes à boue activée en effectuant le traitement du carbone, la... more
Le traitement des effluents urbains par réacteurs discontinus séquentiels (SBR : Sequencing Batch Reactor) constitue une solution alternative aux traitements par systèmes à boue activée en effectuant le traitement du carbone, la séparation liquide solide et l'élimination des nutriments au sein d'un bassin unique grâce à une gestion adéquate des cycles temporels de réaction. L'alternance de phases aérées et anoxiques suivie d'une période de décantation conduit en théorie à l'élimination quasi totale des ions nitrate formés lors de la phase de nitrification aérobie. Cependant, selon la charge appliquée, le carbone totalement dégradé lors de la phase préliminaire d'aération ne peut servir de source de carbone pour la dénitrification exogène. Afin d'accélérer la dénitrification, plusieurs solutions sont possibles : l'une consiste à allonger la deuxième phase d'anoxie suffisamment longtemps pour traiter les ions nitrate résiduels au cours…