碱减量废水膜法集成处理技术

TREATMENT OF ALKALI REDUCTION WASTEWATER WITH MEMBRANE INTEGRATION TECHNIQUE

研究了膜法集成技术在碱减量废水处理中的应用。通过膜技术可以将碱减量废水中的对苯二甲酸钠分离成浓缩液,经过酸析处理,不仅可以从浓缩液中回收得到纯度90%以上的对苯二甲酸,而且加酸量仅为直接酸析法的1/3。同时,碱减量废水经膜处理和酸析后,COD可以降低70%以上。膜法集成技术还能够将含有乙二醇的碱液从碱减量废水中分离出来,乙二醇可以通过反渗透等膜技术分离回收,而碱液可以通过添加液碱的方法重新用于碱减量过程。

In this work, application of membrane integration technique in alkali reduction wastewater treatment was studied. Sodium terephthalate was separated and enriched from wastewater. The enriched solution was then treated by acidation. The purity of recovered terephthalic acid （TA） reached to over 90% and the acid dosage was only one third of that by direct acidation. In addition, COD of alkali reduction wastewater could be reduced by 70% after the treatments of membrane integration technique and acidation. The lye containing glycol could also be separated from wastewater. Glycol could be recovered by reverse osmosis while lye could be reused in alkali reduction by adding alkali.