Molecular sieve ion exchange method and application thereof

Abstract

The invention provides a molecular sieve ion exchange method. The method comprises the following steps: conducting bipolar membrane electrodialysis on an aqueous solution containing ions in a bipolar membrane dialyzer to obtain an acid liquid, wherein the bipolar membrane dialyzer comprises a positive electrode, a negative electrode, bipolar membranes, a cation exchange membrane and an anion exchange membrane, and the bipolar membranes, the cation exchange membrane and the anion exchange membrane are located between the positive electrode and the negative electrode, and the cation exchange membrane and the anion exchange membrane are in pairs to separate the bipolar membranes in pairs, enabling the molecular sieve containing a template agent to be in contact with the acid liquid to conduct ion exchange so as to obtain a molecular sieve slurry subjected to the iron exchange; conducting solid liquid separation on the t molecular sieve slurry subjected to the iron exchange to obtain a solid phase and liquid phase; regulating the pH of the liquid phase to be more than 8, then conducting solid liquid separation to obtain a processing liquid, and circulating the processing liquid to the bipolar membrane electrodialysis step to conduct bipolar membrane electrodialysis. The method reduces the power consumption of a bipolar membrane electrodialysis device, and acquires higher ion exchange efficiency. The invention further provides application of an alkaline liquid prepared by the method and used in the preparation of the molecular sieve.

Description

technical field [0001] The invention relates to a molecular sieve ion exchange method and its application, in particular to a clean and low-cost ion exchange method for molecular sieves and its application. Background technique [0002] According to the data of the Ministry of Water Resources in 2005, 78% of the river sections flowing through cities in the country are no longer suitable for drinking water sources, and 50% of urban groundwater is polluted. Water pollution will not only directly affect industrial and agricultural production, but also cause serious harm to human health. In order to achieve the sustainable development of the country and the harmonious coexistence between man and nature, the country has formulated the national standard GB8978-1996 for industrial sewage discharge, which stipulates that the primary discharge standard of ammonium nitrogen in the petrochemical industry is 15mg / L, and the secondary discharge standard is 50mg / L. [0003] Molecular s...

AI Technical Summary

Problems solved by technology

However, the common problem with the ammonium exchange method is that the raw molecular sieve powder needs to be exchanged with ammonium to produce NH 4 Type molecular sieves can be transformed into hydrogen type molecular sieves by roasting again. However, due to the limitation of chemical balance, NH 4 + Cannot completely replace Na at one time + , to get low Na 2 Molecular sieve with O content, the ammonium exchange process needs to be repeated many times, resulting in a large amount of ammonium nitrogen waste water exceeding the standard

In order to meet the national standard that the discharge of ammonium nitrogen is less than 15mg / L, wastewater needs to be treated, but the process of treating the wastewater not only consumes a lot of energy but also costs a lot

In addition, the conventional ammonium ion exchange method needs to repeatedly adjust the acidity and alkalinity of the environment, the operation is complicated and the efficiency is low

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