생물환경연구실

논문 초록 (Abstract)

Two-stage upflow anaerobic sludge blanket (UASB) process was investigated as an efficient process configuration optionfo r the treatment of purified terephthalic acid (PTA) wastewater. To study its feasibility in a defined condition, synthetic wastewater con taining only the major pollutants (i.e., acetate, benzoate, terephth alate and p-toluate) was used. By focusing the role of the second stag e on the p-toluate degradation, improved overall COD and p-toluate re moval capacities of 4.18 and 1.35 g-thCOD/L. day could be achieved together with a complete COD removal efficiency. In this situation, a ll the pollutants except p-toluate were completely degraded in the first stage while 38 and 62% of p-toluate originally present inthe was tewater were consecutively degraded in the individual stages. The concom itant methane production rate in each stage was 0.91 and 0.35 L/L . day respectively, and the methane yield on p-toluate was determ ined to be 0.12 L/g-thCOD. Batch tests using the granules obtained fro m each stage revealed that the acidogenic microorganisms enriched in bot h stages had a universal ability to degrade all aromatic pollutants pres ent in the PTA wastewater. Moreover, image analysis using scanning ele ctron microscope and confocal laser scanning microscopy combined with fluorescence in situ hybridization technique elucidated th at the distribution of acidogens and methanogens within the granu le was varied in each stage, which influenced the mass transfer regime r esulting in the different pollutant degradation rates during the batch tests. (C) 2012 ElsevierLtd. All rights reserved.