Ferrrate(VI) and freeze-thaw treatment for oxidation of hormones and inactivation of fecal coliforms in sludge
WATER SCIENCE AND TECHNOLOGY
Authors: Diak, James; Ormeci, Banu
Abstract
This study examined the individual and combined effects of potassium ferrate(VI) additions and freezethaw conditioning for the treatment and dewatering of wastewater sludge in cold climates, with particular focus on the inactivation of fecal coliforms and oxidation of estrogens, androgens, and progestogens. The first phase of the study evaluated the effects of potassium ferrate(VI) pre-treatment followed by freeze-thaw at -20 degrees C using a low (0.5 g/L) and high (5.0 g/L) dose of potassium ferrate(VI). The results showed that pre-treatment of anaerobically digested sludge with 5 g/L of potassium ferrate(VI) reduced the concentration of fecal coliforms in the sludge cake to below 100 MPN/g DS. The second phase evaluated the ability of ferrate(VI) to oxidise selected hormones in sludge. Anaerobically digested sludge samples were spiked with 10 different hormones: estrone (E1), 17 alpha-estradiol, 17 beta-estradiol (E2), estriol (E3), 17 alpha-ethinylestradiol (EE2), equilin, mestranol, testosterone, norethindrone and norgestrel in two groups of low (3-75 ng/mL) and high (12-300 ng/L) concentration ranges of hormones. The samples were treated with either 0.5 or 1.0 g/L of potassium ferrate(VI), and hormone concentrations were measured again after treatment. Potassium ferrate(VI) additions as low as 1.0 g/L reduced the concentration of estrogens in sludge. Potassium ferrate(VI) additions of 0.5 and 1.0 g/L were less effective at reducing the concentrations of androgens and progestogens. Increasing ferrate(VI) dose would likely result in more substantial decreases in the concentrations of fecal coliforms and hormones. The results of this study indicate that the combined use of freeze-thaw and ferrate(VI) has the potential to provide a complete sludge treatment solution in cold regions.
Isolation and characterization of a new highly effective 17 beta-estradiol-degrading Gordonia sp. strain R9
3 BIOTECH
Authors: Liu, Na; Shi, Yue-e; Li, Jialu; Zhu, Meiling; Zhang, Tingdi
Abstract
In this report, Gordonia sp. strain R9 isolated from an enrichment culture of chicken leachate was confirmed to degrade 17 beta-estradiol (E2), which can also use other estrogens (estrone, estriol, and 17 alpha-ethynylestradiol) and testosterone as sole carbon and energy sources. Optimization of growth conditions showed that Gordonia sp. strain R9 can tolerate a very wide range of temperature (4-40 degrees C) and pH (1.0-11.0), and is sensitive to antibiotics including kanamycin, ampicillin, chloramphenicol, and carbenicillin. Optimal culture conditions for E2 degradation were 30 degrees C and pH 7.0 with almost 100% degradation of E2 concentrations ranging from 50 mu g/L to 5 mg/L within 24 h. The E2 intermediates so generated included estrone (E1), estratriol (E3), (3Z)-3-(3-hydroxy-3a-methyl-7-oxododecahydro-6H-cyclopenta[a]naphthalen-6-ylidene) propanoic acid and 3-hydroxy-3a-methyl-7-oxododecahydro-1H-cyclopenta[a]naphthalene-6-carboxylic acid. These results indicate that the highly effective E2-degradative ability of Gordonia sp. strain R9 merits further investigation as a candidate for large-scale estrogen biodegradation.