Electrodialyzer

Abstract

The invention discloses an electrodialyzer. The electrodialyzer comprises an anode plate, a membrane stack, a cathode plate and compaction plates for fixing and sealing the membrane stack; the membrane stack comprises monovalent selective anion exchange membranes for monovalent anions to selectively permeate, cation exchange membranes for monovalent cation and polyvalent cations to permeate, and separator plates; the quantity of the monovalent selective anion exchange membranes is n, the quantity of the cation exchange membranes is n+1, and the cation exchange membranes and the monovalent selective anion exchange membranes are alternately arranged between the compaction plates; every separator plate comprises an intermediate plate and support plates, a compartment is arranged in the middlepart of the intermediate plate, and a channel communicates every water flow hole with the corresponding communication hole; and the support plates at two sides of the intermediate plate cover the remaining part of the channel. The electrodialyzer can selectively separate and concentrate the easily-deposited polyvalent anions and polyvalent cations to prevent electrodialyzer fouling.

Description

technical field [0001] The invention relates to an electrodialyzer, in particular to an electrodialyzer for preventing fouling. Background technique [0002] With the deteriorating problem of water shortage in our country, the problem of overexploitation of groundwater in northern China is serious. Industrial water is a major user of water resources in my country. my country's long-term plan is to achieve a reuse rate of more than 80% for industrial wastewater, but currently it is generally only about 50%. Therefore, there will be a lot of room for growth in the reuse of industrial wastewater. At the same time, my country's environmental protection policy requires thermal power plants, electroplating, coal chemical industry and other industries to achieve zero discharge of wastewater. [0003] When dealing with saline wastewater, the electrodialyzer has the advantages of high concentration multiple, low operating pressure and high recovery rate. However, in many saline was...

AI Technical Summary

Problems solved by technology

However, in many saline wastewater, such as desulfurization wastewater, reverse osmosis concentrated water and circulating cooling tower sewage, etc., the wastewater solution to be treated contains a variety of ions, mainly A n+ , B n- 、C + and D - , where A n+ Represents multivalent cations including calcium ions, magnesium ions, iron ions, copper ions, etc., B n- Represents sulfate ions, phosphate ions, carbonate ions and other polyvalent anions, C + Represents monovalent cations such as sodium ions, potassium ions, ammonium ions, etc., D - Represents monovalent anions such as chloride ions and nitrate ions. Calcium ions, magnesium ions, and sulfate ions, phosphate ions, and carbonate ions are easy to combine to form precipitates, which is easy to cause scaling of electrodialysis equipment

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