Water Treatment "Part 22": Pressure Filtration.

Designed to remove impurities, a pressure filter is a closed tank with a single or multiple filter medium. The same filtering technique used by quick gravity filters serves as the foundation for pressure filters, but they differ from them in that the raw floating water and the bottom of the support filter within the pressure filter's surface are enclosed in a tight iron cylinder. A maximum diameter of 5 metres and a maximum capacity of 1000 cubic metres per hour are the dimensions of the metal cylinder. The high pressure allows for strong filtration resistance and prevents level decline, this offers high filtration rates and lengthy filter runtimes.

Membrane filtration under pressure:

In this system, pumps are utilised to introduce the water to be treated into the membranes and these pumps create pressure that enables the flow to continue through the membranes. Membranes are placed within casings that have the ability to withstand high pressure. An extra pump can be employed to circulate the concentrated solution within the membrane group, and the presence of flow regulators allows the pressure differential and yield to be controlled.

The membrane model is submerged in the water basin to be treated, with one side of it receiving raw water under pressure and the other receiving a partial vacuum. Water flowing adjacent to the membrane slows down the build-up of sediment on its surface.

- How to choose the treatment system and the quality of the membrane?

Many variables influence the selection of a treatment system, technique, or membrane quality, the most significant of which are the intended purpose of employing the membrane filtration: desalination, or removal of biological contaminants, or other objectives. Also, the method used depends on the flows to be handled as well as the available energy sources. The permeability velocity limitations and pressure difference for various membrane filtration systems are shown in Table 1, which are crucial considerations when choosing the treatment approach.

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References:

• [Introduction to Water Chemistry (Pollution- Treatment- Analysis). Dr. Nasser Al-Hayek. Publication of the Higher Institute for Applied Sciences and Technology (HIAST). Syrian Arab Republic, 2017.]
• Taparhudee, Wara (2002). "Applications of Paddle Wheel Aerators and Diffused-Air System in Closed Cycle Shrimp Farm System" (PDF). Witthayasan Kasetsart (Sakha Witthayasat). 36: 408–419. Retrieved 26 April 2020.
• Unsafe water kills more people than war, Ban says on World Day". UN News. 22 March 2010. Retrieved 10 May 2018
• Raymond Desjardins- Livre: Le traitement des eaux- 2éme edition- Ecole Polytechnique de Montréal- 1997- ISBN 2-553-00643-8
• Drinking Water Treatment- EDX- Delft University of Technology.
• Book- Drinking Water: Principles and Practices- by Hans J C Van Dijk (Author), Jasper Q J C Verberk (Author), Peter J De Moel.