An integrated hybrid process has been developed to treat olive mill wastewater. This process is an improvement over simple ultrafiltration by the introduction of an ultrasonication step. The results obtained are very promising, the elimination rates were 88% for chemical oxygen demand, 85% for total organic carbon, 74% for polyphenols and 91% for ammonium nitrogen. Total elimination of germs (fungi and Sulfite-reducing anaerobes) and fatty acids was achieved. Changes in the dynamic properties, such as viscosity, of the olive mill wastewater under the action of the ultrasounds allowed an increase of the permeate flux through the ultrafiltration membrane. These results indicate that the addition of an ultrasonic process significantly improves the performance of ultrafiltration during the treatment of the heavily loaded olive mill wastewater.

The purpose of this paper is to design an efficient and low cost electrocoagulation reactor in which aluminum microbipolar electrodes are used and kept in suspension by an axial helical agitator. When compared to a conventional electrocoagulation reactor operated in the same conditions, the new electrocoagulation reactor shows significantly improved performance in batch mode. The use of this new electrocoagulation reactor in continuous mode and at the optimum operating conditions, Viz. Rotation speed = 300 rpm, C NaCl = 1 g/L, i = 180 A/m 2 , R = 10 mg dye/g of aluminum particles, allowed the dye concentration to reach a plateau with an abatement percentage of approximately 96%. The flocs that were formed appeared to be stable after 1 h.

A new photocatalyst delta-Fe2O3/MgAl-LDH elaborated by impregnation method with a different iron amount (2, 5, 10 and 20 wt.%) were used to improve the photocatalytic activity of delta-Fe2O3 under visible light. The synthesized samples were characterized by XRF, XRD, SEM, ATG/DSC, RDs and FTIR techniques. Structural studies revealed the formation of layered double hydroxyl structure (LDH) for unmodified materials and the existence of the iron oxide phase with allotropic delta for the modified material. The reconstruction of calcined LDH by the structural memory effect was verified by XRD. Optical studies confirmed the narrower band gap energy suitable for the visible light absorbance. The effect of iron loading, photocatalyst dose, dye concentration and pH were examined to enhance the photodegradation of methylene blue. The degradation rate over delta-Fe2O3/MgAl-LDH calcined at 400, 500 and 600 degrees C was also discussed. Under visible irradiation, the photocatalysts exhibited an efficient photoreactivity where the removal values increasing from similar to 19 to 60% upon increasing the% delta-Fe2O3 amount from 2 to 10%. Whereas, using MB concentration of 50 mg/L and a catalyst amount of 0.5 g/L, the photocatalyst with the% delta-Fe2O3 of 10% shown only a yield 67%. The prepared photocatalyst exhibited better reactivity compared to the MgAl-LDHc (less than 10%) and to the iron oxide (26%). A path of degradation based on a mechanism of hollow radicals is proposed.

The inactivation of microorganisms by an electric field was the purpose of this study. It was found that the application of an electric field had a lethal effect on Escherichia coli cells suspended in brain heart infusion broth. Experimental results indicated that the survival rate of E. coli decreased when an electric field with an intensity of 3A was applied during a time equal to 30 min. Mechanisms involved in the sterilization process were discussed. The concentration of proteins and N-acetylglucosamine (NAG) liberated by the cells during the experiment was recorded. The results indicated that the concentration of liberated proteins was 2.21 µg/ml after 5 min, and this concentration increased twofold after 45 min (4.10 µg/ml). The initial concentration of NAG was 0.084 µg/ml. It increased to 0.1 µg/ml after 5 min, to 0.2 µg/ml after 10 min and to 1.3 µg/ml after 30 min.

Received : 04/11/2016 Accepted :10/06/2017 Abstract: Demineralization (DM) and deproteinization (DP) of shrimp shell Parapenaeus longirostris using Lactobacillus helveticus, depends on the composition of culture medium, and temperature of incubation. In a synthetic medium containing glucose, completely different conditions are required for chitin recovery: 300 g/L of glucose and 35°C for maximal DM (60%) and 80 g/L of glucose and 30°C for a maximum of DP (70%). The use of date’s juice shows that it is possible to extract chitin, in a single step, unlike the simple medium. The richness of the dates juice in mineral elements and the high concentration of reducing sugars (200 g/L) allowed for a maximum activity of proteolytic enzymes favored by a pH maintained constant at around pH 6 for 29h of fermentation, and a significant acidification expressed by a minimum pH of 4.7 which are reflected by rates of 83% and 63% of deproteinization and demineralization, respectively.

The main purpose of this work is to study the ability of the enzymatic reaction. For the performance of the experiment, it is desirable to control variations so that they are minimized to the maximum extend and therefore an optimum operating point can be maintained. To achieve this target, the central composite design takes into account all interaction effects that may be useful for creating a mathematical model in agreement with the validity criteria. The model showed to be more suitable for the saccharification experiments in batch mode than in continuous mode. In batch mode, a correlation coefficient close to unity (R-2=.98) was obtained. Moreover, the resulting mathematical model was satisfactory in accordance with the validation criteria. For continuous mode, the coefficient value obtained was R-2=.83 indicating that the model to study the ability of the enzymatic reaction was inferior than the batch mode conditions of the analysis. Practical applications The ability of the enzymatic reaction to maintain its performance at small experimental condition variations was studied. The central composite design conformed to criterion validity. A correlation coefficient close to unity (R2 5.98) was obtained.

In this study, the application of full factorial design and a surface response methodology was used to model the two-factor influence. Time and current intensity on bacterial biomass, color, turbidity, and natural organic matter (NOM) removal from Oued El Harrach River were discussed. A factorial experimental design was used to investigate the bacterial biomass and color removal from Oued El Harrach River situated in northern Algeria which is treated by electrocoagulation using iron plate electrodes. However, a response surface methodology (RSM) was used to reduce the turbidity and NOM. The bacteria removal efficiency was determined after 30min of treatment. The combined effects of operating parameters on removal turbidity and NOM were also analyzed. A regression model was found to fit the experimental data very well. Besides, the results were statistically analyzed using the student's t-test, analysis of variance, F-test, and lack of fit in order to define the most important process variables affecting the removal of bacteria biomass, color turbidity, and NOM from Oued El Harrach River. The predicted results using factorial regression model showed high regression coefficient values (i.e.[GRAPHICS]=0.9687 and[GRAPHICS]=0.9983) which are in substantial agreement with experimental data. On the other hand, predicted values of turbidity and NOM obtained from central composite model were in close agreement with the experimental values (i.e.[GRAPHICS]=0.9442 and[GRAPHICS]=0.9432). This study proved that factorial design and RSM could efficiently be applied for the wastewater treatment modeling by electrocoagulation process.

The main purpose of the present study is to investigate the mechanism which governs the adsorption of the pesticide onto electro-granular activated carbon (GAC). The operating conditions assessed are: electrical potential, electro-activation time, the initial metribuzin—electro-activated GAC concentration ratio (R =Cp/CGAC). In the first step, it has been confirmed using an experimental design that the C/C0 ratio is much more affected by the electrochemical potential application than by R ratio. The mathematical model indicates that the electrochemical potential has a significant effect during the metribuzin adsorption during the first half an hour on GAC and thereby demonstrates the electroactivation beneficial effect. In the second step, a mass transfer model has been applied in order to evaluate the effect of the electro-activation of GAC on the kinetic constant. Indeed, the results showed that the electro-activation accelerates the process with kinetic constants 2–3 times higher than those obtained without the electro-activation of GAC.

The present study aims to investigate the performance of Moringa oleifera seed extract as natural coagulant in clarification of secondary wastewater treatment plant (MWWTP) located in East of Algiers, Algeria. Coagulation flocculation performance of Moringa oleifera was evaluated through supernatant residual turbidity after jar test trials. Various influence parameters namely Moringa oleifera dosage and pH have been considered. Tests on Reghaia wastewater, having 129 NTU of initial turbidity, showed a removal of 69.45% of residual turbidity with only 1.5 mg/l of Moringa oleifera. This sufficient removal capability encourages the use of this bioflocculant for treatment of turbid waters. Indeed, Moringa oleifera which is a natural resource available locally (South of Algeria) coupled to the non-toxicity, biocompatibility and biodegradability, may be a very interesting alternative to the conventional coagulants used so far. Keywords—Coagulation flocculation, colloids, Moringa oleifera, secondary wastewater.

The present study is focused on the effect of chitin derivatives against human cancer cell lines RD and Hep2. As an outcome from this research, chitin was cytotoxic at IC50 = 400 μg/ml and 200 μg/ml against Hep2 cells and RD cells lines, respectively. Irradiated chitin had an IC50 value of 450 μg/ml for Hep2 and an IC50 of 200 μg/ml for RD. The lowest IC50 is attributed to chitosan, 300 μg/ml in Hep2 and 190 μg/ml in RD.

The Opuntia ficus-indica cactus (also known as the nopal or prickly pear) indigenous from Mexico is being tested as a flocculating agent. The performance of coagulation-flocculation and the quality of treated water was evaluated by measuring the residual turbidity. The results showed the effectiveness of different solutions of Opuntia with the best removal of 0.5 NTU for the most turbid water, by using 0.2 mg/L of cactus concentration. This natural coagulant functions by means of adsorption mechanism followed by charge neutralization or polymeric bridging effect. Utilization of this coagulant represents important progress in sustainable environmental technology. (C) 2015 Elsevier B.V. All rights reserved.

The economic evaluation of defluoridation of Sahara groundwater is presented for three processes: electrodialysis, reverse osmosis and the electrochemical bipolar reactor (EBR). The economic study was accomplished for a drinking water unit production of 100 m(3)/h. One of the findings was that the costs per cubic metre of treated water obtained with different processes were not too costly for the states of the North African region. The results also indicated that the most efficient process uses the EBR, followed by the electrodialysis and reverse osmosis process. However, the water produced by the first process does not have the required quality for drinking water; therefore, it has to be utilised for agricultural purposes. On the other hand, the electrodialysis unit do produce quality drinking water and appears to be an interesting solution to the fluorisis disease. Reverse osmosis method technique provides higher quality of drinking water with a salinity not exceeding 0.1 g(salts)/l.

This work aims to evaluate the potential use of chitosan as an eco-friendly flocculant in chemical conditioning of municipal-activated sludge. Chitosan effectiveness was compared with synthetic cationic polyelectrolyte Sedipur CF802 (Sed CF802) and ferric chloride (FeCl₃). In this context, raw sludge samples from Beni-Messous wastewater treatment plant (WWTP) were tested. The classic jar test method was used to condition sludge samples. Capillary suction time (CST), specific resistance to filtration (SRF), cakes dry solid content and filtrate turbidity were analyzed to determine filterability, dewatering capacity of conditioned sludge and the optimum dose of each conditioner. Data exhibit that chitosan, FeCl₃and Sed CF802 improve sludge dewatering. Optimum dosages of chitosan, Sed CF802 and FeCl₃allowing CST values of 6, 5 and 9 s, were found, respectively, between 2-3, 1.5-3 and 6 kg/t ds. Both polymers have shown faster water removal with more permeable sludge. SRF values were 0.634 × 10¹², 0.932 × 10¹² and 2 × 10¹² m/kg for Sed CF802, chitosan and FeCl₃respectively. A reduction of 94.68 and 87.85% of the filtrate turbidity was obtained with optimal dosage of chitosan and Sed CF802, respectively. In contrast, 54.18% of turbidity abatement has been obtained using optimal dosage of FeCl₃.

Chitosan is naturally bio-polymer obtained through chitin deacetylation. Chitosan can be molded in several shapes, such as membranes, microspheres, gel beads and films, and is able to use for wide application including food and nutrition, cosmetic, pharmaceutical, biomedicai, water treatment and other purposes. The aim of this work was to characterize the properties of biopolymer prepared by freeze-drying technique. Cylindrical foams were formed and then characterized and tested for their ability to water treatment. The surface morphology and topographic analysis of the polymer samples was examined by Scanning Electron Microscope and Fourier transform infrared spectroscopy (FTIR) was investigated.

Chitosan is naturally bio-polymer obtained through chitin deacetylation. Chitosan can be molded in several shapes, such as membranes, microspheres, gel beads and films, and is able to use for wide application including food and nutrition, cosmetic, pharmaceutical, biomedicai, water treatment and other purposes. The aim of this work was to characterize the properties of biopolymer prepared by freeze-drying technique. Cylindrical foams were formed and then characterized and tested for their ability to water treatment. The surface morphology and topographic analysis of the polymer samples was examined by Scanning Electron Microscope and Fourier transform infrared spectroscopy (FTIR) was investigated.

This study’s main purpose is to contribute to the Oued Smar landfill leachate decontamination. To achieve this aim, the advanced oxidation process (AOP) via heterogeneous photocatalysis (TiO2/UV) was coupled with seeded bioreactors with different inoculums types (raw leachate, soil extract and activated sludge). The results obtained after heterogeneous photocatalysis show that the reduction is comprised between 50 and 84% of the initial COD maintained at pH 5. However, this treated leachate cannot be reused or discharged without another treatment into the environment. The new BOD5/COD ratio ranging between 0.045 and 0.18 are favorable for biological treatment. The AOP–bioreactor coupling allowed an abatement of 90% of the initial BOD5 and 87% of the initial COD leachate surface reduction with a final value of 1000mgO2/L. However, this value is not yet conformed to the norm. The biological treatment has shown the landfill indigenous microorganism's ability to degrade the irradiated leachate since, the mineralization dissolved organic carbon (DOC) rate is almost identical to the value obtained by activated sludge. These results encourage the supposition to recycle the irradiated leachate in the landfill which now possess a biopile behavior (loop AOP+landfill).

The main purpose of this study was the chitin enzymatic hydrolysis enhancement by a pretreatment, consisting of chitin exposure to gamma radiation at several doses, ranging from 15kGy to 210kGy. The solid chitin molecular weight reduction achieved by Co-60 gamma rays treatment reached a 90% rate at the t used, with a dose of 210kGy. The partial depolymerization of chitin was realized by irradiation allowing an enzyme affinity increase toward this substrate. The monomers and oligomers obtained from their radiated chitin production rate were almost 100%. It was also demonstrated that the NAG production by enzymatic hydrolysis of irradiated chitin at 210Gy follows Michaelis–Menton kinetics.

The purpose of this study is to investigate the possible purification of Oued El Harrach river water, which introduces significant chemical and biological pollution into the Algiers Bay ecosystem and threatens public health. This study determines the feasibility of river water treatment by electrocoagulation (EC) with aluminum electrodes. In batch tests, chemical oxygen demand (COD) and turbidity were reduced of about 80% and 95%, respectively, within 30 mm. Analysis of the water before and after EC also indicates a significant reduction of microbial load. Indeed, a 99% reduction in fecal coliforms and Escherichia coli was observed. Almost total destruction of fungi was obtained. (C) 2013 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Microbial fuel cells can be used to reduce the organic load of a wastewater, while producing electricity at the same time. However, most tests on MFCs are done in controlled laboratory environments using synthetic wastewaters, and MFCs that contain expensive catalysts and membranes. In this work, we studied the performances of a low-cost microbial fuel cell that was made with stainless steel electrodes and no catalysts, and The COD removal in the MFC was compared to the one obtained in an aerated activated sludge bioreactor. It was found that the MFC could be used for water treatment, an 80% COD removal was reached after 15 days, compared to 90% after 10 days in the aerated reactor. However, the power densities were quite low, a maximum of 2.5 mW/m2 could be reached, this was due to high activation losses, a high internal resistance, and the presence of few electrogenic bacteria in the biocatayst.

Chitosan is a biopolymer, biodegradable, non-toxic and widely abundant in nature. Our study presents an investigation on the application of this biopolymer in treatment of Beni- Amrane dam water by coagulation flocculation process. In this study, the raw water from Beni-Amrane dam characterized by high turbidity was treated using chitosan as primary flocculant and as coagulant aid with aluminum sulfate (alum). The performance of this process was evaluated by measuring the supernatant residual turbidity for various values of chitosan concentrations. The obtained results are in favor of chitosan. With low concentrations, chitosane used alone is able to reducing 85% of initial turbidity. In the case of using chitosane in combination with alum, highest turbidity removal (97%) was carried out with 0. 15mg/l of chitosan and 20mg/l after 45minutes of settling time. At this value, a very low residual aluminum (0, 02mg/l) was registered. The organic carbon contribution on the turbidity coagulation flocculation performance is negligible because chitosan is used in small doses. Hence, chitosan could be used as natural coagulant aid for drinking water treatment with lowest risks of organic release. These properties, combined with its non-toxicity, make the chitosan as the best substitute to conventional synthetic polyelectrolytes used so far.