The study on recovery of highly purified terephthalic acid

In those traditional ways of treating alkali weight-reduction wastewater, the COD removal is greatly considered, while recovering the valuable resource according to the principles of sustainable development is less involved. In this study, the recovery of high pure TA from alkali weight-reduction has been researched by purified mother liquid with coagulation-sedimentation. The characters of TA obtained was investigated by various methods, results has shown that the purity of TA was great improved in view of high recovery rate by coagulation-sedimentation on conditions of pH 7.0-7.5 of wastewater and 300-400mg/l in quantity of Al2(SO4)3.18H2O, thermogravimetric analysis (TGA) spectrums proved this. Particle size analysis revealed the crystal size of recovered TA became greater, it contained few impurities. So coagulation-sedimentation by pretreatment is an effective method. The study is also very useful in recycling of PET and treating TA industrial wastewater. © 2011 IEEE.