Influence factor of 17β-estradiolphotodegradation by heterogeneous Fenton reaction

Abstract

The photocatalytic degradation of 17beta-estradiol (E2), by Fenton like reaction was investigated as a function of E2 concentrations, organic co-solvents and co-existing estrogens, humic acid (HA) and other background anions. E2 degradation was effectively achieved by hydroxyl radicals that were generated in the heterogeneous photo-Fenton process. The degradation kinetics were fitted to Langmuir-Hinshelwood model with kr = 0.3140 microM/h and Kads = 2.2146L/micromol. The removal kinetics of E2 were initiated by a rapid decay and then followed by a much slower one in acetonitrile-water solutions while in methanol-water solutions they followed the first-kinetic model for the diffusion-control of hydroxyl radicals and competition between E2 and co-solvents. In addition, the lower level of co-existing substances did not significantly influence the oxidation efficiency of E2. The degradation rates of E2 were found to depend not only on the concentrations of hydrogen peroxide and iron content as reported before but also on pH, E2 concentrations and composition of co-solvents. Thus it is very important to look for the optimum conditions for the purpose of most efficiently eliminating E2 from drinking water.

Ciprofloxacin degradation from aqueous solution by Fenton oxidation: reaction kinetics and degradation mechanisms

“…An oxidation number of 0, +1, +0.5, +2 were considered for the C-C sand p-bonds; C]C sand p-bonds and; C]O sand p-bonds, respectively. 27 It gave net 'zero' oxidation number of carbons in both piperazine ring and cyclopropyl group.…”

Fast degradation of estrogen hormones in environmental matrices by photo-Fenton oxidation under simulated solar radiation

“…They reported 86% and 100% conversion after 480 min of reaction at pH o = 6.5-7.5, 272 g/L E2, 330 mg/L H 2 O 2 and 5 g/L ␣-FeOOH [22] or ␤-FeOOH [23], respectively. E2 conversion remained unchanged when the experiment was repeated in drinking water with ␣-FeOOH, while several degradation by-products were identified [24]; moreover, the degradation rate could be described by the L-H kinetic model [25].…”

Effect of Thermal Conditioning on Combustion and Pollutant Emissions Characteristics of Sewage Sludge

“…Previous studies show that production solid fuel employing some pretreatment technologies can significantly reduce the operating cost. Generally speaking, these sludge-derived solid fuel technologies can be classified into three types: combination of thermal drying and physical mixing [10,12]; the chemical conditioning [3][4][13][14]; thermal conditioning [1,2]. This work investigates on the influence of the thermal conditioning on the sludge combustion performance from the view of the ignition, burnout characteristics and pollutant emission characteristics.…”