Abstract: ON THE ANAEROBIC BIODEGRADATION PATHWAY OF TA BY ~(14)C and ~3H DOUBLE-LABELLING METHODShen Lixian；Liu Mei（Beijing Municipal Research Institute of Environmental Protection,10037）Lin Zhongmin（Beijing Normal Umversity，100875）ABSRACT The mxiture of ~(14)C and ~3H labelled terephthalic acid TA-（Carbonyl-~(14)C）－（aromaticring－~3H）and non-labelled TA are used as the substrate to carry out the anaerobic test．The TA biodegradationprocess and main intermediate products are obtaind by examining the changes of the concentration of~(14)C and ~3H in methane and carbon dioxide and the analytical results of GC／MS．The main in termediatepreducts in the anaerobic reaction are benzoic acid，alkyl－benzenes，C_8－C_(13) saturated hydrocarbons，C_8－C_(12) olefin，cyclanes and small molecules of aldehyde，alcohol，organic acid and ester，etc．Theanaerobic biedegradation path way of TA is explained qualitatively．Key words ~3H ~(14)C double-labelling terephthalic acid an aerobic biodegradation pathway