The surface treatment industry is likely to bring pollution, nuisances and hazards that require a rigorous treatment of the effluent. The membrane technologies Wake great interest in the treatment of industrial waters, it depends on membrane type, the effluent to be treated and the operating conditions, the membranes may lose its characteristics over time. Clogging or fouling is the most important problem related to the use of the membranes, which results in an allows flow and decrease in an increase in passage of salts and of the differential pressure. In addition to the deterioration of the reverse osmosis, fouling can damage irreversibly the membranes and prevent effective cleaning it. For a better recovery of the membranes, it is necessary to have all information related to the deposited material is for this reason that the realization of an autopsy is becoming a necessity in order to undertake a comprehensive review of the filing of the membrane and the integrity of all components of the same. Definitely, the autopsy of the membrane allows to study the reasons clogging detail that can be used to develop the best cleaning conditions and manner of the avoided in the future. The objective of this work is to conduct a study deepens on the material deposited on the active layer of the membrane previously used in the treatment of effluents from a surface treatment plant with the completion of an autops

Gutiérrez Ruiz, S.

isaad, jalal

Maria Quiroga Alonsoc, J.

Tarik, C.

Zerrouk Mohammeda, H.

English

Revues Scientifiques Marocaines

 H. Zerrouk & al. / Mor. J. Chem. 4 N°2 (2016) 308-314  308      Investigation of membrane fouling in surface treatment plant using reverse osmosis process  H. Zerrouk Mohammeda, Isaad Jalala, Santiago Gutiérrez Ruizc, , Chafik Tarikb, José Maria Quiroga Alonsoc   (a) Université Mohamed 1er, Faculté des Sciences et Techniques d’Al Hoceima. BP 34, 32003 Ajdir – Maroc. (b) Université Abdelmalek Essaadi. Faculté des Sciences et Techniques de Tanger. Ancienne Route de l'aéroport, Km 10, Ziaten. BP : 416. Tanger - Maroc (c) Universidad de Cadiz – Gerencia, C/. Ancha, 10, 11001 - Cádiz. España  *Corresponding author. E-mail : jisaadjalal@gmail.com  Received 20 Dec 2015, Revised 22 Fev 2016, Accepted 07 May 2016  Abstract   The surface treatment industry is likely to bring pollution, nuisances and hazards that require a rigorous treatment of the effluent. The membrane technologies Wake great interest in the treatment of industrial waters, it depends on membrane type, the effluent to be treated and the operating conditions, the membranes may lose its characteristics over time. Clogging or fouling is the most important problem related to the use of the membranes, which results in an allows flow and decrease in an increase in passage of salts and of the differential pressure. In addition to the deterioration of the reverse osmosis, fouling can damage irreversibly the membranes and prevent effective cleaning it. For a better recovery of the membranes, it is necessary to have all information related to the deposited material is for this reason that the realization of an autopsy is becoming a necessity in order to undertake a comprehensive review of the filing of the membrane and the integrity of all components of the same. Definitely, the autopsy of the membrane allows to study the reasons clogging detail that can be used to develop the best cleaning conditions and manner of the avoided in the future. The objective of this work is to conduct a study deepens on the material deposited on the active layer of the membrane previously used in the treatment of effluents from a surface treatment plant with the completion of an autopsy.  Keywords: membrane, reverse osmosis; fouling; wastewater.  1. Introduction  Liquid effluents of the surface treatment industry a source of chemical pollution, organic and mineral [1], therefore they must be treated before being discharged into the natural environment, to respect the limits imposed by national regulations in force for the protection of the environment, and if given a refinement of treated effluent treatment this water can be reused in various activities. Between the  H. Zerrouk & al. / Mor. J. Chem. 4 N°2 (2016) 308-314  309   technologies used in the regeneration of water in the surface treatment industry [2-7], reverse osmosis has found its largest uses for water reuse in other applications of the plant [8,9]. The success of the application of reverse osmosis, and had to its reliability and ability to reduce the cost of operation and maintenance. For cons, the clogging of the membranes is a very significant barrier to the use of this technology, it depends on membrane type, the effluent to be treated and the operating conditions, the membranes may lose its characteristics over time. This blockage is caused by the deposition of fine particles, colloidal deposition and biological and microbiological growth. Sometimes the autopsy of the membrane is the only way to determine clogging of the nature conclusively. The membrane allows the dissection of a rigorous examination of the membrane and composition of contaminant in addition to flow testing and cleaning of parts of the sacrificed membrane for effective cleaning solutions [8,9]. The purpose of an autopsy is first find out why a blockage occurred, and how to avoid it, and also know the best solutions and cleaning conditions and membrane recoveries.  2. Materials and methods  The material used is a reverse osmosis membrane previously clogged after its use in the sector of effluent treatment of a surface treatment plant. Before the effluent reaches the membrane it has been previously pretreated by physical-chemical processes, which consists in a ferric chloride by coagulation for removing suspended matter and organic matter in suspension, followed by a metal precipitation by pH adjustment, flocculation anionic polyelectrolyte, a lamellar settling is a water softener to remove the calcium and magnesium. The reverse osmosis and has a 5 .mu.m cartridge filter to protect the membrane potential insoluble impurities which have not been eliminated in the physic-chemical treatment. For its consideration of the membrane, they were used the scanning electron microscopy (SEM) coupled with microanalysis Energy Dispersive X-ray (EDX) to analyze inorganic materials deposited on the membrane. Similarly, there was used the Steric Exclusion Chromatography which separates macromolecules according to their hydrodynamic volume. For physicochemical characterization he completed a gravity survey and analysis of metals such as Al, Fe, Si, Mn, and Total Organic Matter.  The object of study membrane was selected to detect if there is a blockage of biological origin, for that reason it was taken the first module first membrane. The membrane was transported to the laboratory in an opaque moist packaging and stored in a sodium bisulfite solution and a temperature of 4 ° C to prevent bacterial growth. Before beginning the autopsy was performed an external inspection of the diaphragm to see the integrity of the membrane and also have an idea about the effectiveness of pretreatment system. After opening of the membrane was performed for internal inspection of observing the integrity of the sheets, the carrier and the adhesive lines and the deposition distribution on the surface of the membrane. After they were pray samples pulp deposited on the surface of the membrane for analysis. Using a sterile scalpel it was cut pieces of the membrane for analysis previously detriment  3. Results and Discussions  3.1. External inspection Visual observation of the membrane shows no particular default on the level of integrity, and it was not observed any effects or telescoping structural irregularity. The permeate collector does not present  H. Zerrouk & al. / Mor. J. Chem. 4 N°2 (2016) 308-314  310   significant cracks or damage. The state of supply and seals laze permeate pipes in good condition rings, for it was observed against a light brown and slime at the collectors join permeate (Figure 1).   Figure 1. Reverse osmosis membrane and connector.  3.1. Internal inspection After the opening and running of the membrane, it is observed the support and the seal lines, the module wasn't presenting any fracture or deformation, and the seal lines were in very good conditions. The membrane surface was covered with a layer of orange brown color and a mucilaginous texture. The distribution layer on the surface of the membrane was homogeneous occupying the entire surface. (Figure 2). Concerning the spacer, it did not show any significant deposit. The deposit scraped off at the surface of the leaflets showed a significant amount of fouling which was dark brown in color. Part of this deposit was resuspended in ultra pure water to determine the chemical nature. Observed characteristics are typical of the majority formed organic and colloidal material layer. Autopsy of the membrane is characterized by the visual lack of bacterial and fungal colonies.  Figure 2. The stages of the autopsy  3.3 Deposition analyzes 3.3.1 Scanning Electron Microscopy (SEM-EDX) Using a sterile scalpel was snuffing a piece of membrane and spacer. For the SEM-EDX observation, the samples were fixed and pulverized Gold to protect the active layer of the aromatic polyamide  H. Zerrouk & al. / Mor. J. Chem. 4 N°2 (2016) 308-314  311   membrane against the increase in temperature produced by the electronic microscope spindle. The Figure 3 represents a micrograph representative of what could be observed from the membrane and spacer.  Micrograph formed on the surface of the membrane shows the presence of a large proportion of microorganisms and various organic nature of materials with some inlaid minerals (fig 3: A, B, D). This shows that the hydrodynamic conditions at the active layer of the membrane were not sufficient to prevent the deposition and bacterial growth on the membrane. The significant presence of microorganisms seriously affects the performance of the unit. The micrograph also shows mineral precipitates that occupy a good portion of the deposit.   Figure 3.  Observation Scanning Electron Microscopy  The review by EDX (Figure 4) shows that the mineral elements are embedded in the deposit Iron, Aluminium and Silica. These inorganic precipitations are obliged to concentration polarization taking place in the intermediation of the membrane; the increase of certain salts on the active layer produced their crystallization on the effect of the system pressure and low water turbulence Treaty.  H. Zerrouk & al. / Mor. J. Chem. 4 N°2 (2016) 308-314  312    Figure 4. The examination of EDX results   Similarly, at the spacer (Figure 3 C), observation by SEM-EDX shows the significant presence of organic matter, mineral and microorganism in the intersections; for a small hydropower area that promotes their membership, and therefore facilitates the clogging. The rate of permeability of reverse osmosis membranes can also occur that the hydrodynamic force resulting from the convective flow membrane silk worm above the electrostatic repulsive force between the particles and the surface of the membrane, thereby resulting ease of deposition of particles and the occurrence of clogging.  3.3.2 Chemical and microbiological analyzes deposit The results of chemical analyzes performed on the deposit scraped from 100 cm2 of the membrane are shown in the table 1.  Table 1: Chemical analyzes of the deposit Gravimetric  Solidsat 105 ° C 37  % Volatiles at550 °C 85  % MS Mineralsat 550 °C 15 % MS Mineralelements   Si  0,20 μg/cm² Al 0,13 μg/cm² Fe 0,20 μg/cm² Mg 0,50 μg/cm² Ca 0,40 μg/cm² Organic materials(μg/cm2)   COD 6,4 μg/cm² Aerobic22Cº 0,9 102 UFC/ cm² Aerobic37Cº 1,1 102 UFC/ cm²  The test results show that the deposition of the membrane is formed mainly by organic matter. The mineral fraction shows that the majority of detected elements are Ca, Mg, Fe, Si and Al. The presence  H. Zerrouk & al. / Mor. J. Chem. 4 N°2 (2016) 308-314  313   of Ca and Mg may be had to the quality of water used in the trial, in the presence of SO42- and CO32- in saturation condition determined produce a loss of membrane permeability due to the crystallization of calcium carbonate and calcium sulfate resulting in a yield loss of the unit [10]. The presence of iron, Si and Al in the slurry is forced to not total elimination element in the physicochemical treatment of the effluent, and because of the effect of concentration polarization generated on the surface of the membrane that this inorganic salt is insoluble in the deposit. Similarly, it is possible that some type of microorganisms present in the deposit can induce precipitation of ions dissolved by biochemical transformation. They exist various microorganisms such as alter the valence state of certain metal ions dissolved and its resultant deposition directly in the wall. For example oxidizing bacteria Iron and Manganese (Gaillonella ferrginea and Sphearotilus natans) and other microorganism promoted the oxidation of reduced form (Fe2+, Fe3+) which is deposited as a metal hydroxide on the cell wall surface. All these shows that we are talking about a biofouling associated with an inorganic overlay. For the microbiological content analytical results show that despite the hydrodynamic conditions that occur on the membrane of microorganisms manage to colonize even in small amounts and consequently affects wield significant performance of the unit. The attached microorganisms excrete extracellular polymeric substances (EPS), wherein they are packed, and form organic layer called biofilms [11,12]. With time begins to produce yield losses of the unit.  3.3.3 Analysis by LC-SEC-OCD The results of the analyses realised by the liquid chromatography LC-SEC-OCD show that the dissolved organic substance extracted from the membrane deposit is constituted essentially of organic compounds of high molecular masses.   Figure 5. Results of analysis by LC-SEC-OCD  Likewise, we notice a low detection, which characterises polysaccharides and proteins involved essentially in the structure of the bacterial wall.  4. Conclusion The results of various analyzes carried out on the membrane revealed the following: The autopsy of the membrane can be studied in detail the type and clogging reasons and help develop  H. Zerrouk & al. / Mor. J. Chem. 4 N°2 (2016) 308-314  314   the best cleaning conditions and manner of the avoided in the future. The microorganisms present in the effluent to seriously affect the membrane may be used as the soluble organic matter as a power source, which promotes attachment, proliferation and colonization of bacteria and fouling to the membrane. Colonization of the membrane by microorganisms affects the hydrodynamic conditions at the active layer of the membrane; the flow becomes less turbulent thereby promoting the acceleration of development of biofouling of a part, and the crystallization of dissolved salts at the active layer on the other. The metal ions present in the effluent can be fixed in fouling under the effect of concentration polarization, thus forming a more complex deposition.  References [1] Z Amjad,. Reverse Osmosis, Membrane Technology, Water Chemistry and Industrial Application; Van Nostrand Reinhold: New York, NY, USA, 1992. [2] J.S. Vrouwenvelder, D. van der Kooij. Desalination 153 (2002), 121–124.  [3] F.A. Abd El Aleem.; K.A. Al-Sugair, M.I. Alamad, Int. Biodeterior. Biodegrad. 41 (1998), 19–23. [4] H.F Ridgway, Parekh, B.S., Ed.; Marcel Dekker: New York, NY, USA, 1988; pp. 429–481. [5] H.F Ridgway, J Safarik, Verlag: Heidelberg, Germany, 1991; pp. 81–111.  [6] H.-C Flemming,. Membrane Technology; Amjad, Z., Ed.; Van Nostrand Reinhold: New York, NY, USA, 1992; pp. 163–209.  [7] A.P Murphy, C.D Moody, R.L Riley, S.W Lin, B Murugaverl, P Rusin, J. Membr. Sci. 193 (2001), 111–121. [8] M. Hassani Zerrouk, J. M. Quiroga Alonzo. J.A. Lopez Ramirez. Tecnologias del Agua. 259 (2005) 21-29. [9] O. Cornstock, W. wcsson. Tecnología de las Membranas, Energía, 2003. [10] S Gutierrez Ruiz, J. A Lopez Ramirez, J. M. Quiroga Alonzo, M Hassani Zerrouk. Tecno Ambiente, 207 (2010), 21-29. [11] Z. Asif Matin, S.M.J. Khan., M. Zaidi. C. Boyce. Desalination, 281 (2011) 1–16. [12] T. Nguyen, F.A. Roddick, L Fan. Membranes, 2 (2012), 804-840  

Investigation of membrane fouling in surface treatment plant using reverse osmosis process

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Investigation of membrane fouling in surface treatment plant using reverse osmosis process

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