A method for preparing acid-base from viscose fiber sodium sulfate waste liquid by bipolar membrane electrodialysis

Abstract

The invention discloses a method for preparing acid base from waste liquid of viscose sodium sulphate by a bipolar membrane electrodialysis method, which comprises the following steps of performing crystallization, pH adjustment, primary pre-filtration, O3 oxidation of reducing substances, secondary pre-filtration, organism removal by active carbon, zinc ion removal by ion exchange resin and pp micro-porous filtration and refined filtration on the waste liquid of viscose sodium sulphate in which a sodium sulphate concentration is 5-20%; then, feeding a product into a sodium sulphate runner of a bipolar membrane electrodialysis membrane device; and feeding demineralized water serving as absorption liquid into an acid runner and a base runner of the bipolar membrane electrodialysis membrane device respectively to obtain a sulphuric acid solution and a sodium hydroxide solution, wherein the working pressure of the bipolar membrane electrodialysis membrane device is 0.03-0.08MPa. The method disclosed by the invention improves the regeneration recovery rate of acid and base in the waste liquid of viscose, reduces the damage of a bipolar membrane caused by impurities of the waste liquid, prolongs the service life of the bipolar membrane, and guarantees the electrodialysis of the bipolar membrane as well as the smooth operation of follow-up processes.

Description

technical field [0001] The present invention relates to a method for material treatment in chemical production, more specifically, the present invention relates to a bipolar membrane electrodialysis method for producing acid-base from viscose fiber sodium sulfate waste liquid, which belongs to viscose fiber production technology field. Background technique [0002] In the viscose fiber forming process in the chemical fiber industry, the viscose and the acidic coagulation bath interact to neutralize the alkali, decompose the sodium cellulose sulfonate and regenerate hydrated cellulose, and the cellulose sulfonate in the viscose during this process Ester, free NaOH, and Na produced by side reactions 2 CS 3 Side reaction products such as polysulfides and polysulfides will react with sulfuric acid in the coagulation bath to generate sodium sulfate. Viscose fiber production includes the acid bath process that consumes sulfuric acid, and also includes the pulp soaking process t...

AI Technical Summary

Problems solved by technology

[0011] The present invention aims to solve the existing problems and defects in the existing technology of recovering acid and alkali through bipolar membrane electrodialysis for waste liquid produced in the process of forming viscose fiber strands, and provides a bipolar membrane electrodialysis method from The method for producing acid-base from viscose fiber sodium sulfate waste liquid is only aimed at the process of producing acid-base from waste liquid produced in the process of forming viscose fiber strands through bipolar membrane electrodialysis, and adopts a specific recovery method. The pretreatment step in the recovery method handles the waste liquid produced in the viscose fiber strand molding process, and then enters the bipolar membrane electrodialysis process, which improves the regeneration recovery rate of acid and alkali in the viscose fiber waste liquid, reduces Eliminate the damage to the bipolar membrane caused by waste liquid impurities, improve the service life of the bipolar membrane, and ensure the smooth progress of bipolar membrane electrodialysis and subsequent processes