Membrane Water Treatment Volume 10, Number 4, July 2019 , pages 277-286 DOI: https://doi.org/10.12989/mwt.2019.10.4.277 |
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Autopsy of Nanofiltration membrane of a decentralized demineralization plant |
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Soufian El-ghzizel, Hicham Jalté, Hajar Zeggar, Mohamed Zait, Sakina Belhamidi,
Fathallah Tiyal, Mahmoud Hafsi, Mohamed Taky and Azzedine Elmidaoui
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Abstract | ||
In 2014, the first demineralization plant, using nanofiltration (NF) membrane coupled with renewable energies was realized at Al Annouar high school of Sidi Taibi, Kenitra, Morocco. This project has revealed difficulties related to the membrane performances loss (pressure increase, flux decline, poor water quality of the produced water and increase of energy consumption), as consequences of membrane fouling. To solve this problem, an autopsy of the membrane was done in order to determine the nature and origin of the fouling. The samples of membrane and fouling were then analyzed by scanning electron microscopy using a scanning electron microscope (SEM) connected with an energy dispersive X-ray (EDX) detection system and X-ray diffractometer (XRD). Moreover, three cleaning solutions (hydrochloric acid, nitric acid and sulfuric acid) were tested and assessed in a single cleaning step to find the suitable one for the fouled membrane to regain its initial permeability and performances. The analysis of the experimental results showed that the fouling layer is mainly composed of calcium carbonate (inorganic fouling). Results showed also that the permeability is improved by the hydrochloric acid cleaning (pH=3) with a cleaning efficiency of 93%. Cleaning efficiency did not exceed 75 % with nitric acid (pH=3) and 40 % with sulfuric acid (pH= 3). | ||
Key Words | ||
nanofiltration; desalination plant; fouling; autopsy; demineralization; membrane cleaning | ||
Address | ||
Soufian El-ghzizel, Hicham Jalté, Hajar Zeggar, Mohamed Zait, Sakina Belhamidi, Fathallah Tiyal, Mohamed Taky and Azzedine Elmidaoui\" Laboratory of Separation Processes, Department of Chemistry, Faculty of Sciences, Ibn Tofail University, Kenitra 14000, Morocco Mahmoud Hafsi: International Institute for Water and Sanitation, National Office of Electricity and potable Water ONEE-IEA, Rabat, Morocco | ||