PILOT-STUDY OF UASB PROCESS TREATING PTA MANUFACTURING WASTE-WATER

A pilot-scale upflow anaerobic sludge blanket (UASB) reactor was emplo yed to treat the wastewater of a purified-terephthalic-acid (PTA) manu facturing factory. The performance of UASB reactor in terms of COD rem oval was achieved 62% at the volumetric loading rate of 2.93 kg COD/m( 3)/day. One of the major constituents, p-toluic acid in PTA wastewater was the refractory component due to the methyl substituent on the aro matic ring, which restricted the biodegradation performance. Moreover, from our study, it was surprising that high concentration of acetic a cid would retard the degradation of aromatics in the sludge bed. A con trol strategy of acetic acid level in the sludge bed was suggested dur ing the start-up period. Comparison of the anaerobic biodegradability of aromatic substituents in PTA wastewater was concluded as the follow ing sequence: -COOH > -CHO greater than or equal to -CH3 in terms of t he derivative functional groups based on the benzoic acid. Observation of bacterial population of the sludge granules showed high diversity of syntrophic structure on the biogranular surface as well as acetocla stic methanogens. (C) 1997 IAWQ. Published by Elsevier Science Ltd.