Zero-wastewater discharge system and method for preparing ultrapure water

Abstract

The invention discloses a zero-wastewater discharge system for preparing ultrapure water. The system comprises a pretreatment subsystem, a desalination subsystem, a precision treatment subsystem and a regenerated wastewater pretreatment subsystem. The pretreatment subsystem comprises a raw water storage tank, a water pump, a softening filter, a pH value regulating tank, a quartz sand filter, an active carbon filter, a zeolite filter and a pretreatment water storage tank which are sequentially connected through pipelines. The desalination subsystem comprises a primary reverse osmosis main machine and a secondary reverse osmosis main machine. The precision treatment subsystem is a mixed bed system. The regenerated wastewater pretreatment subsystem comprises a regenerated wastewater neutralization pond and an evaporative crystallization device. By means of the system and method for preparing the ultrapure water, zero-wastewater discharge in the preparing process of the ultrapure water is realized; the system for preparing the ultrapure water comprises a mixed bed, a large amount of acid-alkali wastewater produced in the regeneration process of cation resin and anion resin in the mixed bed is treated in the system instead of being discharged into a sewage pipe network just like in an existing treatment mode, and the ultrapure water is obtained ultimately.

Description

technical field [0001] The invention relates to a method for preparing pure water, in particular to a system and method for preparing ultrapure water with zero waste water discharge in the production process. Background technique [0002] Water is one of the most common chemical compounds. It is not only the source of life, but also an important resource indispensable to modern industry. With the development of science and technology, the requirements for water quality in many fields are getting higher and higher, and pure water preparation technology has become a hot research field. [0003] Pure water includes drinking pure water and industrial pure water. Industrial pure water is divided into three types according to the conductivity, as shown in Table 1 below. [0004] Table 1 Classification of industrial pure water (25°C) [0005] [0006] Ultrapure water is widely used in many industrial fields such as electronics, medicine, electric power, and chemical industry ...

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Problems solved by technology

[0009] The above-mentioned ultrapure water preparation processes all use a mixed bed. During the operation of the mixed bed, frequent acid-base regeneration is required, resulting in a large amount of acid-base waste liquid. The above-mentioned literature does not mention the treatment method of the acid-base waste liquid; currently the mixed bed The treatment of the acid-base wastewater generated by regeneration is to neutralize it and then discharge it to the municipal sewage pipe network. This treatment method is also a waste of water resources.

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