Influence de l'ordre d'introduction des solutés (Naphtol-2 et Calcium) sur l'adsorption des tensioactifs sur charbon actif F400

L'effet de l'ordre d'introduction des solutés Naphtol-2 et Calcium (N-2 et Ca) sur l'adsorption de tensioactifs par le charbon actif en poudre (CAP) F400 brut a été étudié en discontinu. Les mélanges étudiés sont: le tensioactif anionique dodécyl-sulfate de sodium (DSS) et le N-2; le DSS, le N-2 et le Ca; le tensioactif cationique bromure de benzyldodécyldiméthylammonium (BBDDA) et le N-2 et enfin le BBDDA et Ca. Les résultats expérimentaux montrent tout d'abord que quel que soit l'ordre d'introduction des solutés N-2 et Ca, les concentrations en DSS à l'équilibre sont sensiblement identiques. Par ailleurs, la cinétique d'adsorption du DSS et du BBDDA croît en présence des ions Ca.Cependant, la cinétique d'adsorption du N-2 en présence du DSS diminue ce qui se traduit par une inhibition de l'adsorption du N-2 par le DSS. Quant à l'adsorption du BBDDA en présence du N-2 pour différents ordres d'introduction, le tracé des isothermes de LANGMUIR montre que la capacité maximale d'adsorption Г∞ du BBDDA ne change pas tandis que la constante de LANGMUIR (K) diminue. Par contre la capacité maximale d'adsorption du N-2 ** varie légèrement et passe de 1,67 à 1,5 mmol/g pour différent ordre d'introduction du BBDDA. On note également que Г∞ du N-2 en présence de concentrations croissantes en BBDDA diminue fortement et passe de 1,67 à 0,8 mmol/g.L'ajout de N-2 après 3 heures de contact du BBDDA /CAP ne provoque pas la désorption de ce dernier. Le même comportement a été observé avec le N-2, alors que l'ajout du DSS au mélange N-2/CAP provoque la désorption de celui ci.The effect of the introduction order of naphtol-2 and calcium (N-2 and ca) on the adsorption of surfactants by raw powdered activated carbon (PAC) F 400 has been studied in a static system, studied mixtures included the anionic surfactant: sodium dodecyl-sulfate (SDS) with N-2 or with N-2 + Ca, and the cationic surfactant beniyldodecyldimethylarnmoniurn bromide (BDDAB) with N-2, or with Ca. The experimental results demonstrate that whatever the order of solute introduction, the SDS concentrations at equilibrium are almost identical. Moreover, the adsorption kinetics of SDS and BDDAB increase in the presence of calcium ions. The adsorption kinetics of N-2 decrease in the presence of SDS, suggesting inhibition of N-2 adsorption by SDS. Concerning the adsorption of BDDAB the presence of N-2, for different introduction orders, plotting of the LANGMIIIR isotherms shows that the maximal BDDAB adsorption capacity Г∞, does not change but the LANGMUIR constant (K) decreases. For naphtol-2, however the maximal adsorption capacity Г∞, does vary slightly, going from l,67 to l.5 mmol/g for different BDDAB introduction orders. In the presence of increasing BDDAB concentrations, the maximum adsorption capacity of N-2 decreases from 1.67 to 0.8 mmol/g.The addition of N-2 after 3 hours of BDDAB/PAC contact does not lead to BDDAB desorption. similar behavior is observed on addition of N-2 after 3 hours of SDS/PAC contact, even though the addition of SDS to a N-2/PAC mixture leads to N-2 desorption

Étude de la performance de la STEP du centre emplisseur de la société Salam Gaz – Skhirat, Maroc

Le présent travail a pour but de vérifier l’efficacité du fonctionnement de la STEP de la société Salam Gaz. Les eaux traitées sont réutilisées durant le procédé de production de la société. Les résultats de la caractérisation physicochimique des eaux usées brutes ont montré que les paramètres analysés dépassent les valeurs limites de rejets directes ou indirectes. Les valeurs moyennes en MES, DBO5 et DCO de l’eau brute sont respectivement 3429, 447 et 698 mg/L. Les rendements d’éliminations des paramètres MES, DCO et DBO5 par la STEP sont respectivement 99%, 86%, et 84% alors que l’abattement de la teneur en chrome, cuivre, cadmium et plomb dépasse 90%. Ceci montre que la STEP fonctionne correctement. Toutefois, des améliorations sont nécessaires pour améliorer d’avantages la performance de la STEP. En outre, les eaux usées épurées ont montré un pH acide variant autour de 5 ce qui nécessite une optimisation de la dose du coagulant injecté et une neutralisation avant rejet des eaux traitées dans le milieu récepteur.Mots-clés : eaux usées, diagnostic, performances, recyclage, Salam Gaz – Skhirat, Maroc.Study of the performance of the WWTP filling station company Salam Gas - Skhirat MoroccoThe present work designed to verify the operating effectiveness of society Step Salam Gas. The treated water is reused in the production process of the company. The characterization results at selected tapping points show that the majority of the analyzed parameters exceed the limit values for discharges. The mean values of TSS, BOD5 and COD of raw water are respectively 3429, 447 and 698 mg/l. Yields eliminations parameters TSS, COD and BOD5 by STEP are respectively 99%, 86% and 84% while the reduction of chromium, copper, cadmium and lead in excess of 90%. This shows that STEP is working properly. However, improvements are needed to improve the performance benefits of STEP. In addition, the treated wastewater showed an acidic pH ranging around 5 which requires an optimization of the dose of coagulant injection and neutralization prior to discharge treated wastewater into the receiving environment.Keywords : Wastewater, diagnostic, performance, recycling performance, Salam Gaz – Skhirat, Morocco

Assessment of organo-mineral fraction during storage of oil refinery sludge

The biotransformation during storage of petroleum refinery sludge was evaluated by physicochemical and spectroscopy analyses. The abatement rate of organic matter  has reached 50.5% after 14 months of storage. The humic substances have decreased of about 49% at the end of storage indicating that the OM was mineralized into inorganic compounds (CO2, N2…). The XRD of dried samples shows the presence of a large proportion of silica (SiO2), carbonate (CaCO3), Hercynite (Al2FeO4) and hemihydrate calcium sulphate (2CaSO4.H2O).  Hematite (Fe2O3) and anhydrite (CaSO4) were found as a new appeared phase. Pb, Cd, Cr, Cu, Ni and Zn were the most identified heavy metals in the petroleum samples. Their increase at the end of storage was explain by the organic matter degradation. FTIR analysis show that the carbonate, sulphate and silica are the most identified compounds beside the organic matter

Recent Advances in Physicochemical and Biological Techniques for the Management of Discharges Loaded with Surfactants

The spectacular evolution of the urban and industrial sector today poses real environmental challenges of water pollution that requires immediate attention. Surfactants are emerging contaminants that pose a significant problem in wastewater treatment, and their presence causes difficulty in traditional treatment processes. In this context, the present work critically reviews the impacts of surfactants and their toxicity on the environment and human health while presenting the various techniques used in wastewater treatment plants to reduce their effects. Surfactants are removed from wastewater using different techniques, including physical, chemical, biological, and membrane treatment. The choice of the most appropriate technique for wastewater treatment is based on many criteria, such as effluent quality, standards to be respected, investment and operating costs, and environmental footprint. Adsorption and coagulation-flocculation are the most suitable techniques for removing detergents from wastewater due to their effectiveness, ease of use, environmental friendliness, and cost-effectiveness. This work is licensed under a Creative Commons Attribution 4.0 International License

Assessment of groundwater quality in Berrechid Aquifer, Morocco

The aquifer of the Berrechid plain is the most important of Morocco. He sustains many activities closely linked to regional and national socio-economic development (farming, industrial). High concentrations of chlorides, nitrates, electrical conductivity in the soil, and the risks to the environment and public safety are the subject of increased interest in the Berrechid aquifer. The main objective of this study was to analyze the quality of groundwater in the region of Berrechid. This region is subject to high agricultural and industrial activity.The mapping of physicochemical parameters was realized with ArcGIS Software, Version 10.3. These distribution maps were generated by Distance Weighted Inverse interpolation (DWI). For comparison analyses, the simplified groundwater quality grid was used. The physicochemical and bacteriological characterization of the Berrechid aquifer showed high values for electrical conductivity (EC) (7100 μS/cm), Chlorides (Cl-) (2409 mg/l), nitrates (NO3-) (190 mg/l), ammoniacal nitrogen (NH4+) (0.02 mg/l), organic matter (OM) (4.55 mg/l), fecal coliforms (FC) (40000 UFC/100ml). Generally, the approaches developed in this work proved to be promising for real-time and low-cost groundwater quality prediction by using physicochemical parameters

Évaluation de la pollution des eaux usées mixtes collectées par le réseau d’assainissement de la ville de Mohammedia : Cas d’un collecteur principal

Wastewaters of the urban district of Mohammedia drained by the collector, is rejected without treatment in the sea have pH close relations of neutrality and is relatively saline with a content chloride of about 1207mg/l. The polluting load is included/understood between 32 mg/l and 312 mg/l for the BDO5, 1144.27 mg/l and 2743.12 mg/l for the DOC and between 329 mg/l and 632 mg/l for the suspended matters. Calculated report/ratio DOC/BDO5 is 16.4, very high value, which shows that this wastewaters is characterized by an inorganic pollution in particular related to the rejection of the effluents of an industry of textile and tannery connected to this collector. These effluents are used to irrigate the cultures of the perimeter of sea and constitute an environmental risk for the subjacent ground water and for water of the Oued El maleh.Les eaux usées de la commune urbaine de Mohammedia, drainées sans traitement dans la mer ont des pH proches de la neutralité avec une teneur en chlorures de l'ordre de 1207mg/l. Les teneurs en matières polluantes sont comprises entre 32 mg/l et 312 mg/l pour la DBO5, 1144.27mg/l et 2743.12 mg/l pour la DCO et entre 329 mg/l et 632 mg/l pour les matières en suspension. Le rapport DCO/DBO5 est de 16.4, ce qui est lié à la pollution industrielle notamment au rejet des effluents de l’industrie textile et des rejets de tannerie raccordées au collecteur. Ces effluents servent à irriguer les cultures du périmètre de la mer et constituent un risque environnemental pour la nappe phréatique sous-jacente et pour les eaux de surface  d’Oued El maleh

Triage et valorisation des déchets solides à la décharge publique de la ville de Mohammedia

This work is part of the evaluation of solid waste in landfills in Morocco. It can first show, the importance of triage and valorization and help develop other opportunities in the various sectors of solid waste. The latter is relevant in overcoming the constraints identified and exploiting the opportunities      identified. The results obtained during the triage conducted showed that the dump of Mohammedia is a source of raw material (plastic, glass, paper ...). The study showed an estimated quantity  T/day between 10 and 16 tones of plastic to value, 10 to 6 tons of  paper... The activity of plastic recycling mainly responds to the demand and supply products with an annual deposit within a range from 30000 to 40000 tones (1). The circuit recovery and recycling of solid waste the plastic glassware ... knows a problem of organization and precarious working conditions of scavengers in particular:   hygiene and sanitation and health risk.Ce travail entre dans le cadre de la valorisation des déchets solides triés dans des décharges publiques au Maroc. Il peut d’une part montrer l’importance de triage et valorisation et d’autre part aider  au développement des débouchés des différentes filières de récupération des déchets. Ce dernier présente les actions pertinentes à même de dépasser les contraintes relevées et d’exploiter les opportunités identifiées. Les principaux résultats obtenu durant le triage réalisé a montré que la décharge publique de Mohammedia constitue une source de matière première (plastiques, verreries, papiers cartonnées….). L’étude réalisée a montré qu’on estime une quantité en T/ jour variant entre 10  et 16 tonnes de plastiques à valoriser, 10 à 6 tonnes de papiers,… L’activité de recyclage du plastique répond principalement à l’offre et la demande des produits dont le gisement annuel se situe dans une fourchette de 30 000 à 40 000 tonnes (1). Le circuit de récupération et de valorisation des déchets tel que le plastique la verrerie… connaît un véritable problème d’organisation et de précarité des conditions de travail en particulier des récupérateurs : manquement aux règles de base d’hygiène et de salubrité, risque pour la santé, etc

Pollution reduction and biodegradability index improvement of tannery effluents

Al2 (SO4)3, 18H2O, FeCl3 and Ca (OH)2 were used for the treatment of tannery wastewaters. The influences of pH and coagulant dosages were studied. Conditions were optimised according to the pollutant removal efficiencies, the volume of decanted sludge and the biodegradability index improvement. The results indicate that 6771% of total COD, 76-92% of color and 79-97% of Cr can be removed using the optimum coagulant dosages at the optimum pH range. Al2 (SO4)3, 18H2O and Ca (OH)2 produced better results than FeCl3 in terms of COD, color and Cr removal as well as in terms of biodegradability improvement. Moreover, Al2 (SO4)3, 18H2O and FeCl3 produced the least amount of sludges for a given amounts of COD, color and Cr removed in comparison with Ca (OH)2. Al2 (SO4)3, 18H2O seems to be suitable for yielding high pollutant removals and corresponding low volumes of decanted sludges in addition to improving wastewaters biodegradability index

REMOVAL OF PHENOL AND SURFACTANT FROM LANDFILL LEACHATE BY COAGULATION-FLOCCULATION PROCESS

Following the action of rainfall and natural fermentation, the stored waste produces a liquid fraction called leachate. This leachate is rich in organic matter (biodegradable but also refractory) and trace elements. There are many techniques of treating the leachate, in particular, biological, physicochemical, membrane processes. The choice of a technique instead of another depends on several parameters including: the age of the leachate, composition... In this work we applied a coagulation-flocculation process to treat intermediate landfill leachate of Rabat city with a combined ferric chloride coagulant and a polymer flocculant. We were inspired by full factorial design, including twenty five experiments, to determine optimal dosages of coagulant and flocculant. We operate at pH 8.4, the best removal efficiencies obtained were 88 % for Turbidity, 98 % for Phenol and 82 % for surfactant. The optimum dosages values determined by this study were 13.2 g∙L-1 of coagulant, 62 mL∙L-1 of flocculant