Novel membrane concentration system, process thereof and high-power concentration device

Abstract

The invention discloses a novel membrane concentration system which comprises a pretreatment device, a reverse osmosis device, a high-power concentration device, an ion exchange device and an advanced oxidation device, wherein high-multiple concentration can be realized; besides, the operation pressure is low, and the operation energy consumption of the system is greatly reduced. According to the novel membrane concentration process, the characteristics of reverse osmosis membranes are fully utilized, and part of concentrated water of a next-stage weak reverse osmosis membrane flows back to the water production side of a previous-stage weak reverse osmosis membrane, so that the inorganic salt content of the water production side of the previous-stage weak reverse osmosis membrane is increased, and the osmotic pressure difference between the concentrated water side and the water production side of the weak reverse osmosis membrane is reduced; furthermore, high-multiple concentration is realized under relatively low operation pressure. The invention further discloses a high-power concentration device, and the content of inorganic salt in concentrated water is gradually increased through a multi-stage weak reverse osmosis membrane; wherein, a backflow water inlet is formed in the water production side of each previous-stage weak reverse osmosis membrane, so that part of concentrated water flows back, and finally, high-multiple concentration is realized.

Description

Technical field: [0001] The invention relates to the field of wastewater treatment, in particular to a novel membrane concentration system, its technology and a high-power concentration device. Background technique: [0002] A large amount of wastewater will be produced in coal chemical industry, electronic products and other industrial production processes. Its main feature is that it contains inorganic salt ions, suspended solids, polluting impurity ions, organic matter, etc., and the content of each substance varies greatly. between 5000mg / L and 15000mg / L; the content of suspended solids is between 30mg / L and 500mg / L; the polluting impurity ions are mainly calcium ions, magnesium ions, silicon dioxide and other substances that are prone to scaling, and the content ranges from tens to Hundreds of mg / L, or even thousands of mg / L; organic matter is the most difficult to remove among pollutants, and its content ranges from tens to hundreds of mg / L, resulting in large fluctuat...

AI Technical Summary

Problems solved by technology

However, restricted by the current development level of membrane technology at home and abroad, the traditional membrane concentration technology has a single membrane concentration equipment with a limited concentration ratio. For example, the conventional brackish water membrane can only be concentrated to 25,000-30,000 mg / L, and the seawater desalination membrane can be concentrated to 55,000 mg / L. ~60000mg / L, high pressure reverse osmosis can concentrate to 90000~100000mg / L, high pressure flat membrane can concentrate to 110000~120000mg / L

Moreover, the concentration of the membrane system is mainly to achieve high concentration of inorganic salts in wastewater by increasing the operating pressure, that is, to operate multiple membrane systems in series under high pressure conditions. The existing problems are high operating pressure, high investment cost, and poor operation stability.

[0004] Some scholars try to directly use high-pressure flat membranes to concentrate wastewater to 100,000mg / L-120,000mg / L to shorten the process flow, but a large amount of low-concentration wastewater directly enters high-pressure flat membranes, resulting in a large processing load and high energy consumption for high-pressure flat membranes. It affects the economy of the membrane concentration system; and the water quality of the high-pressure flat membrane is not good, and it needs to be retreated, which further increases the complexity of the system

In addition, affected by the performance of the membrane technology itself, the traditional membrane technology can only concentrate the inorganic salt ions in water to 100,000 mg / L-120,000 mg / L. If the concentration factor needs to be further increased, an evaporation system is required, resulting in high energy consumption, such as , to evaporate 1kg of water, 0.45kg of steam or 2-4kwh of electricity is required, which greatly affects the economic benefits of the enterprise

Therefore, a new type of membrane concentration technology is developed, which can directly concentrate the inorganic salts in the wastewater at a high rate under low operating pressure conditions, avoiding the problems of long process flow, poor stability, and high energy consumption caused by the traditional operation of multiple membranes in series. It will be an important way to solve the current industrial wastewater treatment

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