Kinetics of Aerobic Biological Oxidation of Purified Terephthalic Acid Plant Waste

The kinetics of aerobic biological oxidation of a PTA (terephthalic acid) plant waste was investigated for plant effluent (initial COD: 7000–8000 ppm) and anaerobically treated plant effluent (initial COD: 1500–2500 ppm). Experiments were performed at three different Dissolved oxygen (DO) levels viz. low (0.05–0.1 ppm), intermediate (1.00–3.00 ppm) and high (>6.00 ppm). For each DO level at least three mixed liquor suspended solids (MLSS) loadings were studied in the range of 2000–10 000 ppm. Care was taken to eliminate mass transfer resistance for oxygen transfer at gas–liquid and liquid–solid interfaces. An attempt has been made to propose the kinetics of reaction. In order to confirm the rate equation, experiments were also performed in continuous mode of operation over a wide range of MLSS and dissolved oxygen level. A comparison between batch and continuous mode results has been presented.