THE EFFECTS OF HRT ON PTA REMOVAL USING AN ANAEROBIC BAFFLED REACTOR.

The objective was to investigate the feasibility of anaerobic baffled reactor (ABR) treating real purified terephthalic acid (PTA) wastewater. The anaerobic biological treatment of real PTA wastewater was conducted in a pilot-scale ABR of five compartments, and the performance of ABR was tested when the hydraulic retention time (HRT) decreased from 40.0 to 25.0 h. After approximately four months of operation, the chemical oxygen demand (COD) removal efficiencies ranged from 67 to 81% at 3.60-5.76 kgCOD/m³/d feeding. Further, the TA and COD removal efficiency markedly decreased in the 1st compartment when the HRT decreased, but both of them kept increasing in the following compartments, indicating that the ABR showed high removal efficiency of PTA wastewater and exhibited excellent stability to shock loads. Additionally, the production of volatile fatty acid (VFA) reduced, the pH value increased, and the oxidation-reduction potential (ORP) decreased in the latter compartments, demonstrating that the compartmentalization offered well staged multi-phase anaerobic environment to treat PTA wastewater. Therefore, it could be concluded that the compartmentalization characteristic could effectively protect from shock loads and keep the stability of the whole ABR system for treating real PTA wastewater. [ABSTRACT FROM AUTHOR]