High-rate anaerobic treatment of purified terephthalic acid wastewater

During production of purified terephthalic acid (PTA) a concentrated waste stream is generated, containing both readily (acetate and benzoate) and slowly (terephthalate and para-toluate) degradable organic substrates. Based on our experimental experiences with the anaerobic treatment of this waste stream, this paper presents an optimized concept for start-up and operation of a two-stage anaerobic bioreactor system. Based on considerations concerning the optimal conditions for cultivation of the specific types of biomass degrading the different substrates, and considerations concerning sodium-hydroxide requirements for pH control, a gradual transition between initial operation in parallel to operation in series is suggested.