Membrane integration process for desalinizing sea water

Abstract

The invention discloses a seawater desalinating technique through film integrated method, which comprises the following steps: passing the seawater through self-rinsing filter; predisposing the rinsed seaward into hyperfilter device; boosting the seawater through the boost pump; removing possible micro-particle in the inlet water of counter-osmosis system of the seawater through seawater safety filter; elevating the inlet pressure of the counter-osmosis system of the seawater; desalinating through counter-osmosis system of the seawater; removing micro-particle in the inlet water of counter-osmosis system of the fresh water through fresh water safety filter; elevating the inlet pressure of the counter-osmosis system of the fresh water; desalinating through counter-osmosis system of the fresh water. The invention reduces the adding quantity of the chemicals and rinsing times of reverse osmosis membrane effectively, which improves automatic degree with stable property and small equipment occupying area.

Description

technical field [0001] The invention relates to a seawater desalination process, in particular to a membrane-integrated seawater desalination process for seawater and brackish water desalination. Background technique [0002] The seawater desalination treatment process with reverse osmosis as the core technology generally includes: pretreatment, reverse osmosis core treatment and post-treatment. Among them, pretreatment has a great influence on the treatment efficiency, service life and operation cost of reverse osmosis, and the flow chart of conventional reverse osmosis pretreatment in the prior art is shown in FIG. 1 . It mainly includes flocculation, sedimentation, filtration, disinfection, security filtration, etc. [0003] Conventional pretreatment methods are widely used in seawater desalination, but the main problems are: [0004] (1) The cost is high and the space occupied is large. Among them, the multi-media filtration process is usually relatively complicated, ...

AI Technical Summary

Problems solved by technology

The multi-media filtration process is usually complicated, and the quality of the filtered water depends on the physical properties of the particles to be removed, the filter medium and the entire filtration system, often due to the difference in the quality of the influent water, resulting in fluctuations in the quality of the effluent water

At the same time, due to the structural problems of the filter itself, part of the filter material is lost, which blocks the security filter, shortens its life, and frequently replaces the filter element.

[0005] (2) The raw water sterilization treatment generally adopts the method of continuous chlorine addition, but the amount of chlorine addition is not easy to control. If the chlorine addition is insufficient, the sterilization will not be complete. If the chlorine addition is too much, it will easily cause irreversible damage to the RO membrane.

However, activated carbon also adsorbs COD while dechlorinating. Mn etc., provide a nutrient source for bacteria, and fine activated carbon particles can also clog security filters

[0006] (3) Sodium hexametaphosphate is usually used as antiscalant, but sometimes it may also constitute a nutrient source for bacteria

[0007] (4) Conventional pretreatment methods cannot form an effective barrier to bacteria and colloidal particles, protect the RO membrane, and prolong its life. Moreover, the flow rate and water quality of the produced water vary with the quality of the raw water, which cannot meet the requirements of constant RO feed water quality.

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