Keywords: alkali weight-reduction wastewater, TPA recovery, coagulation-sedimentation, carbon adsorption, terephthalic acid, high purity, PET waste recycling, environmental pollution
The study of the recovery of highly purified terephthalic acid from alkali weight-reduction wastewater
A new process has been developed for recovering the terephthalic acid (TPA) with high purity from alkali weight-reduction wastewater. Three methods were used to purify the mother liquor: coagulation-sedimentation, carbon adsorption and the combination of these two methods. The results show that the nature of the TPA is greatly improved by coagulation-sedimentation or by carbon adsorption, however, the combination of the two methods is more efficient than either one of them used alone, the purity of recovered TPA can reach 99.3%. This result is important not only in recovering TPA from the wastewater, but also in recycling PET wastes.