Treatment and reuse method of purified terephthalic acid refining wastewater

Abstract

The invention provides a treatment and reuse method of purified terephthalic acid refining wastewater. In the method, neutralization and solid-liquid separation is adopted as pretreatment before film treatment, and a double-film method technology combining ultrafiltration and two-level reverse osmosis is used to conduct film treatment, therefore, suspended matters in wastewater are efficiently removed, the removal rate of metal ions, such as cobalt, manganese and the like, as well as organic substances, such as 4-carboxybenzaldehyde, benzoic acid, p-toluic acid and the like, which are soluble in water, are above 99 percent, the effluent electric conductivity is less than 5muS / cm, and the water using requirement of a production system refining unit is achieved. Because the efficient pretreatment before film treatment technology is adopted, the process of the film treatment can stably run for a long term with reliable treatment effect and low running cost.

Description

technical field [0001] The invention relates to a treatment method of industrial waste water, more specifically, to a membrane treatment and recycling method of purified terephthalic acid waste water. Background technique [0002] Purified terephthalic acid (PTA) is an important chemical intermediate and the main raw material for the production of polyester and poly-p-phenylene terephthalamide fibers (aramid II). There are many processes for the industrial production of PTA, among which the high-temperature oxidation of p-xylene is the most important production process for the preparation of PTA. [0003] The process method uses p-xylene as raw material, and includes production processes such as air catalytic oxidation, hydrogenation refining, crystallization and separation. The 4-hydroxybenzaldehyde (4-BCA) that has not yet reacted completely in the process of p-xylene oxidation is converted into water-soluble p-toluic acid by hydrofining, and the hydrogenated product is o...

AI Technical Summary

Problems solved by technology

[0018] Combined with the water quality characteristics of PTA refining wastewater and the water quality requirements for the process water reused in the PTA production and refining unit, in order to solve the problems of unstable operation of the membrane system, poor treatment effect and high treatment costs, the present invention adopts "neutralization + solid-liquid Separation" is used as a pre-membrane pretreatment method, and the double-membrane process of "ultrafiltration + two-stage reverse osmosis" removes suspended solids, inorganic ions and organic matter in PTA refining wastewater. water requirements

Images