BIODEGRADATION OF TRIETHANOLAMINE

Triethanolamine production in me United States exceeds 100,000 metric tons per year. Given this magnitude of production and widespread distr ibution to consumer product, specialty chemical, and agricultural chem ical markets, an understanding of the environmental fate and lifetime of this chemical is warranted. Studies were conducted to determine the fate and lifetime of [C-14] triethanolamine in an aerobic surface soi l, freshwater river systems, and in activated sludge waste treatment, The half-life determined for biodegradation of triethanolamine ranged from 0.02 to 0.10 d in reactions containing 818 mg/L mixed liquor acti vated sludge solids from a municipal wastewater treatment facility. Th e half-life of triethanolamine in a sandy loam surface soil ranged fro m 0.5 to 1.8 d for initial concentrations ranging from 0.01 to 13.4 mm ol/kg (1.4-2,000 mg/kg dry wt.). Biodegradation was also measured in t wo different river waters, with an average half-life (+/- 1 SD) of 1.2 +/- 0.5 d determined for initial triethanolamine concentrations of 0. 67 and 3.28 mu mol/L (99 and 489 mu g/L). The kinetics of both primary biodegradation and mineralization were shown to be generally first-or der in triethanolamine and biomass concentrations (second-order overal l) for the matrices and range of triethanolamine concentrations tested . When these relatively short half-lives are related to typical chemic al residence times in various environmental compartments, it can be co ncluded that biodegradation would prevent accumulation of triethanolam ine and its associated degradation products in the environment.