Cover Chem. Eng. Technol. 10/2011

Terephthalic acid recovered from alkali reduction wastewater A process for the recovery and purification of terephthalic acid (TA) from alkali reduction wastewater was developed. The process consisted of two steps: TA was first precipitated from alkali reduction wastewater by acidification. After that, the crude TA produced was dissolved into dimethylacetylamide and purified by cooling crystallization. The results indicated that acidification could reduce the chemical oxygen demand of the wastewater by 83 %, and the purity of TA by crystallization could reach 99.9 %. Furthermore, at an average cooling rate of 1.18 K min^–1, the particle size of TA was uniform and the average size was about 100 µm. The isolated terephthalic acid can be recycled as raw material for polyethylene terephthalate production. S.‐C. Wu, Z.‐M. Cheng*, S.‐D. Wang, X.‐L. Shan Chem. Eng. Technol. 2011 , 34 (10), 1614–1618. DOI: 10.1002/ceat.201100096