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In this paper, the feasibility of hybrid nanofiltration-reverse osmosis (NF-RO) process to remove hardness in brackish water at higher recovery rate and concentrate minimization is investigated. Two nanofiltration (NF) membranes are tested in the first stage for selecting the appropriate membrane on the basis of lower applied pressure and higher permeate flow. Then the evaluation of the performances of hybrid NF-RO system of each stage is studied in terms of recovery rate and Langelier saturation index (LSI) values to prevent the corrosion potential. The blending strategy is adopted with NF brine and reverse osmosis (RO) permeate in order to bring the RO permeate characteristics in accordance with drinking water standards and to minimize the volume of NF brine. Also, energy consumption performance of conventional nanofiltration (NF-NF) and NF-RO hybrid system in hardness removal is compared. The results show that the NF-RO hybrid system combined to blending strategy provides the simplest process but most energy efficient process compared to a single conventional NF-NF. Moreover, including NF upstream of RO is responsible of the increasing of the overall water recovery rate (95 %) and of the permeate quality with lower total dissolved solids (TDS). However, less water with lower salinity treated by RO increases significantly the recovery rate in RO stage up to 80 %. The portion rate of NF brine blending with RO permeate is equal to 32.45 %, corresponding to 240 L/h, which meet the water quality regulations for drinking water. Hybrid NF-RO system has a lower energy cost per m3 than NF-NF, it is around of 0.055 $/m3. At the same time, this procedure minimizes the fraction of brine disposal dumping to sewage, making it environmentally friendly.

Nitrate groundwater contamination is of major interest all over the world. This problem arises in agricultural regions across Morocco. An excess amount of nitrate causes a serious problem in urban water networks and human health. Because of these health risks, considerable attention has been paid to find effective treatment processes to reduce nitrate concentrations to safe levels. The World Health Organization has set an acceptable level for nitrate in drinking water at 50 mg/L. The aim of this study is to reduce the nitrate concentration from groundwater using two membrane processes: Electrodialysis (ED) and Nanofiltration (NF). Efficiencies of these two technologies are compared in respect to nitrate ions removal, cost process and final quality of water. The results of technologies show that, for electrodialysis standards level can be achieved for a demineralization rate of 15% and the physico-chemical quality of the produced water is satisfactory. For nanofiltration we obtain a nitrate removal of 90% but the produced water is very de-mineralized and must be remineralized.

The present study aims to investigate desalination processes of surface water of M’rirt city located in the Middle Atlas in Morocco. Membrane-based processes, including NF and RO single combinations and NF-RO hybrid system. The performances of these combinations were evaluated and compared in terms of TDS and chloride ion reduction. The membranes used are NF270 as NF membrane and BW30 as RO membrane. ROSA software was applied to simulate and to compare the filtration design of two proposed combinations in terms of specific energy consumption, water recovery rate, number of membranes and pressure tubes. The study also investigated the technico-economical performances of two coagulants such as ferric chloride and aluminum sulphate in terms of turbidity removal in the pretreatment step. The obtained results showed that the NF-RO hybrid system is a very flexible design and the application of NF upstream of RO process is favorable where the satisfactory permeate quality required for human consumption is obtained right after a slight post-remineralization to rebalance it again. The simulation results by ROSA software showed that the hybrid NF-RO system requires less membrane elements and lower specific energy consumption than RO process while single RO system requires 3 and 2 times more membranes than NF-RO hybrid system and single combination NF system respectively. On the other hand, the results of the coagulation pretreatment reveal that the ferric chloride is more efficient in terms of turbidity removal at lower doses in comparison with aluminum sulphate and with a cheaper cost estimated at 0.032 $/m3.

In 2014, the first nitrate removal plant, using nanofiltration (NF) coupled to an electrochemical disinfection system, supplied with renewable energies (Photovoltaic and wind energies) was realized at Al Annouar high school of Sidi Taibi (Kenitra, Morocco). This project was designed to supply the 1200 students of the school with potable water, based on the production capacity of 500 L/h (3 L/Day/student). The local underground water, which is slightly brackish and nitrated, was treated by nanofiltration, using a hybrid renewable energy system, photovoltaic and wind; just before the distribution, an electrochemical disinfection setup was used to disinfect the nanofiltered water. In the first part of this work, the feasibility of the processes combination (nanofiltration- electrochemical water disinfection step) is verified by assessing the main factors which have determined the electrolysis performance (Volumetric flow rate, temperature, chloride concentration, energy…). This part of the study is carried out during two years of operation (from April 2014 to February 2016). The second part focused mainly on the optimization of a new membrane treatment plant. The purpose of this installation is twofold; firstly, the objective was to correct the concentration of chloride ions at the inlet of electrolysis. Secondly, it was meant to avoid the quality deterioration of the produced water (nitrates in particular). The results of this study confirmed the feasibility of the process combination: nanofiltration and electrochemical water disinfection, especially with the use of renewable energies (Photovoltaic and wind). On other hand, this installation will be more attractive by blending raw water with the nanofiltered water in order to increase the performances of the plant hydraulically, energetically, and to correct the chloride concentration for safe disinfection of water. Hence, the produced water by the new installation (process bypass blending) is totally mineral for human consumption and slightly corrosive for pipes and equipments.

The municipality of M’rirt located in the eastern part of central Morocco, in response to the scarcity of water resources in food, the national Office of Drinking Water has used the coagulation-flocculation for water treatment of Oum Errabia River, process of removing the most delicate phase in suspension by the addition of a body chemical called coagulant. The application of coagulation flocculation process for the treatment of surface water is an interesting alternative as the treatment is fast, cheap and allows obtaining perfectly clear water can fill the deficit in water. In the case of our study, we chose the coagulation-flocculation with aluminum sulphate and ferric chloride in order to compare their effectiveness in the elimination or reduction of turbidity on the one hand, and On the other hand see the effectiveness of aluminum sulfate in an acid pH range. The tests are performed in the laboratory and were conducted using a jar test. Ferric chloride showed an effective reduction of the turbidity of water from the aluminum sulfate at low concentrations. The reduction in turbidity of the water by the aluminum sulphate is higher in acid pH (pH 5.5) according to the results obtained from the tests.

Desalination technique is among the focused theme of the Moroccan kingdom’s universities. The implementation of reverse osmosis (RO) technology at the industrial level has proved that this RO technology delivers an affordable production of good water quality and quantity. The conception of mid-size to large RO (FILMTEC™ product) desalination plants are performed by means of reverse osmosis system analysis (ROSA) software. This study shed the light on how realistic the predictions are done by means of ROSA software to the real daily performance of the RO (FILMTEC™XLE440) membranes. The results obtained are then compared against the real industrial data collected from Khenifra desalination plant. This RO plant is designed to produce 36.290 m3/d of drinking water at the horizon of the year 2030. The performances collected are the pressure, temperature, permeate flow and permeate conductivity. The brackish water RO desalination plant has operated successfully and showed a steady behavior from the second half of 2013. The data collected within around 400 days showed that the ROSA modeling prediction matches in a conservative way to the real performance data collected from the plant at about 97%.

The recovery of polyphenols from olive mill wastewaters (OMWs) provides the double opportunity to obtain high-added value biomolecules and to reduce the phytotoxicity of the effluent. The purpose of this study is to gain information about the hygienic quality of the raw material by performing a microbiological analysis of olive mill wastewater, from an extraction system of three phases. The determination of total coliforms,fecal coliforms,aecal streptococci, and another group of microorganisms have been explored, namely yeasts, molds and total aerobic mesophilic flora. We examined the results of the confrontation of olive mill wastewater polyphenols with certain strains known for their pathogenicity, and the minimum concentrations inhibiting bacteria and the minimal bactericidal concentration (MBC) were determined by the dilution method. Polyphenols are particularly the delipidated fraction of OMW extracts according to liquid–liquid phase. The overall yield is 1.367 ± 0.108 %. The quantitative estimation of total polyphenols was assessed by the colorimetric reagent Folin–Ciocalteu, gallic acid and tyrosol, tannic acid and total flavonoids catechin (the method using aluminum trichloride). The results of microbiological analysis confirmed that there is no fecal contamination. For the in vitro bioassay, polyphenols showed a variable antimicrobial activity against six bacteria: Escherichia coli, Proteus sp., Pseudomonas aeruginosa, Enterroccus feculis, Staphylococcus aureus, and Klebsiella pneumoniae. This variability depends essentially on the microorganism tested and the nature of the product tested. Indeed, we found complete inhibition of the growth of Proteus sp. and E. fecalis by the sinks method. Some microorganisms were sensitive to phenols with MBC values between 1/50 and 1/25.

Results from physicochemical analysis of olive mill wastewater (OMW) have shown that total suspended solids (5.170 to 0.658 g/L), chemical oxygen demand (124.400 ± 25.442 g/L), biochemical oxygen demand (60.593 ± 6.276), total organic carbon (3.317 ± 0.350 g/L), and Kjeldahl nitrogen (0.126 ± 0.044 g/L) far exceed discharge standards. The concentrations of the major constituents of phenolic extracts of OMW can cause mortality of the pests Euphyllura olivina and Aphis citricola. Analysis of variance and use of the Sheffe test showed that exposure for 24 h to olive mill wastewater polyphenol extracts had a significant (P

The inhibition effect of polyphenols extracted from olive mill wastewater (PP) on carbon steel in 1.0 M HCl solution was studied. Inhibition efficiency of PP was carried out by using chemical (weight loss method) and electrochemical techniques [potentiodynamic polarization and electrochemical impedance spectroscopy (EIS)]. The effect of temperature and immersion time on the corrosion behavior of carbon steel in 1.0 M HCl with addition of an extract was also studied. The results show that PP acts as a very good inhibitor, and the inhibition efficiency increases with the concentration of PP and decreases with rising temperature. Polarization curves show that PP behaves as a mixed-type inhibitor in hydrochloric acid. Data, obtained from EIS measurements, were analyzed to model the corrosion inhibition process through an appropriate equivalent circuit model; a constant phase element has been used. EIS shows that charge-transfer resistance increases and the capacitance of double layer decreases with the inhibitor concentration, confirming the adsorption process mechanism. The activation energy as well as other thermodynamic parameters for the inhibition process were calculated. The adsorption of PP obeys the Langmuir adsorption isotherm.

Economic evaluation was carried out for a plant of fluoride removal by nanofiltration having a capacity of 2400 m 3 /d (100 m 3 /h) corresponding to a water consumption for 50.000 capita following the Moroccan considerations in rural medium. The design of this plant was carried out for the predetermined optimized conditions corresponding to a recovery rate of 84%, a fluoride rejection of 97.8% and a pressure pump of 10 bar. The capital cost was estimated to 748,003 € and the calculated operating cost to 0.212 €/m 3 . These costs were briefly compared to other ones.

An economic study was conducted to evaluate the costs of fluoride removal by electrodialysis on the basis of industrial and economic data. The investment and operating costs were estimated for an industrial plant with a capacity of 2200 m 3 /d water consumption for 50,000 per capita according to Moroccan standards for rural areas. The capital cost was estimated to be € 833,207 and the calculated operating cost to be € 0.154/m 3 .

Fluoride contamination of groundwater becomes more and more a worldwide preoccupation, especially in Morocco. With the decrease in water resources, especially underground water, and the frequent excess observed during these last decades, the dilution solution becomes unattainable in a short term. So to prevent this situation, the National Office of Potable Water (ONEP) has initiated studies in collaboration with Ibn Tofail University to investigate remedial options. The study on the comparison of the performances of electrodialysis and nanofiltration in the fluoride removal was started two years ago. In previous works, results of electrodialysis performances and preliminary results of nanofiltration performances have been presented. In this work, comparison of the performances of three commercial membranes in fluoride removal by nanofiltration in continuous mode was carried out. The pilot used (supplied by the French Company TIA, Techniques Industrielles Appliquees) is an industrial nanofiltration pilot plant having two modules equipped with various spiral commercial membranes with an area of 7.6 m2. Many configurations were tested: simple pass, double pass with one type of membranes and combination of two types of membranes and supplied batch configuration. The water parameters were followed as a function of the running conditions (time, pressure, fluoride content, etc.) in order to follow the behaviour of the membranes tested.

Studies have been conducted on a groundwater containing 850–1100 mg/l of total dissolved solids (TDS) and 80 mg/l of nitrate to remove nitrate by coupling electrodialysis and bioreactor. The performances of the pilot plant during the period of the tests (more than one year) were proved. The optimisation of recovery rates was carried out by the study of the influence on the water recoveries of the addition of acid and antiscalant to the brine stream. The moderated performances of the bioreactor were shown.

Nitrate content in surface water and especially in ground water have increased in Morocco and other areas of the world. Several processes including degradation processes and separation processes can remove nitrate from water. As separating processes, an electrodialysis operation was performed to remove nitrate from a ground water. Preliminary a brief reviews of the nitrate ground water pollution in Morocco was presented. A preselection of several commercial membranes was carried out to determine the best anionic exchange membrane for nitrate removal. The selected membrane transports anions in the following order: NO3− > Cl− > HCO3− > SO42−. The results show that a desired product water quality can easily be obtained by electrodialysis. The electrodialysis is a simple process to remove nitrate from ground water.

Studies have been conducted to reduce fluorine by electrodialysis from a brackish water containing 3000 ppm of total dissolved solids (TDS) and 3 ppm of fluoride. Two methods have been proposed and described to minimize the precipitation risks of the bivalent salts in the concentrate compartment. Measurements indicate that after electrodialysis, the targets concerning the quality of produced water were all achieved. The method without chemical pretreatment seems more simple to conduct and more adapted to environmental requirements than the method with pretreatment. From these studies it is demonstrated that electrodialysis is a reasonable process for removing fluoride from brackish water.

Donnan Dialysis of Ag + and Zn 2+ was investigated through a cation exchange membrane (CMS Neosepta) when a proton concentration difference was maintained between the two sides of the membrane. Developed for the production of brine from sea water, CMS Neosepta showed a higher permeability to monovalent than to bivalent cations. Several physico-chemical parameters have been determined (electrical resistance, membrane potential, sorption of electrolytes, Zn 2+ and Ag + diffusion coefficients). The flux of Ag + and the diffusion potential in the membrane increase with HNO 3 concentrations. Ag + and Zn 2+ can be separated because of the preferential membrane transfer for Ag + .

In this work an electrodialysis process with bipolar membranes was used to generate HCl and NaOH from pure NaCl and Algerian rock salt from Hamraya. The current efficiency of this process was limited by the proton leakage through the anion exchange membrane: diffusion of HCl, NaOH, Na+ and Cl- through bipolar membranes. In this work two low-proton-leakage membranes, AAV and ACM, were used. NaOH and HCl solutions of high purity were obtained. The experimental values of the HCl and NaOH fluxes are compared with the values that could be calculated after integrating the Nernst–Planck electrodiffusion equations. This calculation required several parameters that were experimentally determined: ion diffusion coefficients, membrane conductance and amount of sorbed electrolytes. Regeneration de l'acide chlorhydrique et de la soude par electrodialyse avec une membrane bipolaire a partir du chlorure de sodium. Dans ce travail, nous avons utilise′ l'e′lectrodialyse avec une membrane bipolaire pour re′ge′ne′rer l'acide chlorhydrique a partir du chlorure de sodium pur et du mineral de sel d'Hamraya. Le rendement faradique de ce proce′de′ est limite′ par la fuite en protons au travers des membranes e′changeuses d'anions: la diffusion de HCl, NaOH, Na+ et Cl- a travers les membranes bipolaires. Dans ce travail, nous avons utilise′ les membranes AAV et les membranes ACM qui sont des membranes a faibles fuites en proton. Nous avons obtenu des solutions de HCl et de NaOH a haute purete′. Les valeurs expe′rimentales des flux de HCl et NaOH sont compare′es avec les valeurs calcule′es a partir de l'inte′gration des e′quations d'e′lectrodiffusion de Nernst–Planck. Ce calcul ne′cessite la connaissance de plusieurs parametres qui ont e′te′ de′termine′s expe′rimentalement: coefficients de diffusion des ions, conductance de la membrane et quantite′s d'e′lectrolytes sorbe′s.

Transport properties of chloride, fluoride and nitrate ions through AFN, AMX, ACS, ACM anion-exchange membranes (from Tokuyama Soda) and MA-40 membrane (from the Institute of Plastic Materials, Moscow) have been investigated by studying electroconductivity, transport numbers and current–voltage characteristics. On the basis of the micro-heterogeneous model proposed by Nikonenko and Zabolotsky describing the microstructure of the membrane material, the volume fractions of the different phases and the electroconductivity of the joint-gel phase have been determined. Good correlations have been founded between the electroconductivity of the anion-exchange membranes (AEMs) and their structural properties. Recommendations are provided to determine which kind of membrane has to be selected for a given application. For all the membranes, increase of the counter-ion mass transfer is observed above the limiting current.

Problem statement: Water quality of river Boufekrane is subject to he avy pollution exerted by population growth and industrial activity, inclu ding the OMW from the olive industry in which the presence of polyphenols and toxic effect dominant c haracter may generate a higher organic pollution. Approach: Our objective is to "study the impact of OMW by an alyzing the physicochemical parameters on seven sites along the bed of the Oued Boufekrane and value of Olive Mill Wastewater (OMW) polyphenols extracted as a biopesticide to contribute to environmental sustainability . Results: Results in quality that Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD 5), Total Solid (TSS) greatly exceeds the discharge standards of the WHO and the pollution of the Oued Boufekrane increases from Ain Maarouf (source control) and downstream, therefore, these waters may be used either for irrigation or for swi mming. Conclusion/Recommendations: The principal component analysis allowed us to confirm the spatiotemporal correlation between physicochemical parameters and stations of the rive r Boufekrane. Analysis of variance of OMW polyphenols against the pest aphid ( Aphis citricola ) found after 24 h exposure by ANOVA and followed by the self test at 1% used as polyphenols , compared with controls significantly affect the survival of stages in a statistically comparable ac cording to the concentration.