Metabolic pathway of anaerobic digestion and reaction rate limiting step of 2,4,5-TCP

✍ Scribed by Szu-Kung Tseng; Cheng-Hsin Lin

• Book ID: 103934796
• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 521 KB
• Volume: 11
• Category: Article
• ISSN: 0921-3449
• DOI: 10.1016/0921-3449(94)90095-7

✦ Synopsis

A study of the effluent of an anaerobic fluidized bed reactor acclimated to 2,4,5-TCP was made in order to determine the metabolic pathway and reaction rate limiting step of 2,4,5-TCP. The wastewater with about 2500 mg L-~ COD and 50 mg L-~ 2,4,5-TCP was biodegraded by anaerobic digestion, and the intermediate analyzed by HPLC and GC/MS. The results showed the degradative metabolic pathway of 2,4,5-TCP, under anaerobic conditions, to be: 2,4,5-TCP-*3,4-DCP~3-CP~phenol~benzoate. For the rate limiting step, the accumulated concentration of 3,4-DCP was higher than other intermediates for Anaerobic Toxicity Assay (ATA) and Biochemical Methane Potential (BMP) tests. From the anaerobic fluidized bed reactor, analyses showed the chloride at the ortho-position was removed very quickly after 2,4,5-TCP entered the reactor. As for the intermediate products, 43% of 3,4-DCP was not decomposed and of the 3-CP only 6.4% left. This shows that the rate limiting step of 2,4,5-TCP was the dechlorination of 3,4-DCP.