Regulation issues and prediction of natural estrogen loads for wastewater treatment plants

A model was developed for the fate of the natural estrogens estrone (E1) and estradiol (E2) in municipal sewage collection systems. Six municipalities throughout the Northern Hemisphere provided data to aide in the calculation of the biotransformation/degradation kinetics of the natural estrogens estrone (E1) and estradiol (E2) in wastewater collection systems. The mean pseudo-first-order kinetic constant for the biotransformation of E2 into E1, kE2, was 0.030 hr-1 (ranging from -0.080 to 0.49 hr-1) and the mean value of the pseudo-first-order kinetic constant for the biodegradation of E1, kE1, was -0.18 hr-1(ranging from 0.44 to 0.38 hr-1) The mean total suspended solids concentration was 0.256 g/L (ranging from 0.103 to 0.450 g/L), and mean temperature was 16.8oC (ranging from 12 to 24.5 oC). Biodegradation k values were not found to be temperature sensitive within this range. Values for kE2 and kE1 displayed a trend of increasing with total suspended solids concentration.