Particle interactions and removal of trace contaminants from water and wastewaters

Schäfer, A.I.; Mastrup, M.; Jensen, Ric

doi:10.1016/s0011-9164(02)00544-1

Cited by 65 publications

(37 citation statements)

References 11 publications

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“…Lai et al (5) observed increasing sorption onto river sediments with 0.3-3.3% organic carbon but also some 40% removal of estrogens sorbed to pure iron oxide, presumably through ion exchange between the surface hydroxyl group on the oxide and the polar phenolic steroids. Similar, although lower, sorption was observed by Schäfer et al (38) for E1 onto hematite and clays in the presence of natural organic matter. The influent to the enhanced primary STP, unlike the advanced STP, is pre-dosed with FeCl 2 upstream in the sewerage system to control sulfide odours before reaching the plant.…”

Section: Steroid Estrogen Concentration and Behaviour Within The Advasupporting

confidence: 86%

Fate of Steroid Estrogens in Australian Inland and Coastal Wastewater Treatment Plants

Braga

Smythe

Schäfer

et al. 2005

Environ. Sci. Technol.

178

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Environmental Science and Technology (Revised version January 2005): note also CORRECTION published in EST 39(18): 7344* Corresponding author: Phone +61 2 9385 5082, fax: +61 2 9313 8624, email: andrew.feitz@unsw.edu.au AbstractA comparison of estrone (E1), 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) removal at a coastal enhanced primary and inland advanced sewage treatment plant (STP) is reported. The average concentration of estrogens in the raw sewage is similar to reports in other studies. The sequential batch reactor at the advanced STP removed on average 85% of the incoming E1 and 96% of the E2. Further removal was observed during later microfiltration with the estrogen concentration below detection (<0.1 ng.L -1 ) after reverse osmosis. Some 6% of the influent E1+E2 was removed in the waste activated sludge. The detection of EE2 in the waste activated sludge (0.42 ng.g -1 solids dry weight), undetectable in the raw sewage, suggests that EE2 is resistant to biological treatment in the sequential batch reactor and is primarily removed due to sorption. Little estrogen removal was observed at the enhanced primary with only 7% of E1 and 0% of E2 removed. Low removal is expected based on the degree of estrogens partitioning in the organic fraction given the relatively low solids concentration, but surprisingly, some 43% of E2, 24% of E1 and 100% of EE2 remains associated with the solids fraction in the treated effluent. Further research is necessary to determine whether the low level of estrogen removal for the coastal treatment plant will adversely affect the receiving marine environment. 2 IntroductionThere are increasing concerns that the release of steroid estrogens post wastewater treatment is leading to abnormal reproductive systems in freshwater and marine dwelling animals (1-3). Human excretion is considered to be the primary source of steroid estrogens from the urban environment and are is released by individuals into sewerage system in both conjugated and unconjugated forms at µg levels per day (4-6). Johnson and Williams (6) recently developed a model to estimate the quantities of estrogens by the human population, taking in consideration conjugation and metabolism of natural and synthetic hormones in the body and the different quantities released by different population groups. The average human excretion of estrogens per head is reported to be 10.5 µg.d -1 for estrone (E1), 6.6 µg.d -1 for 17β-estradiol (E2), with an additional 3.3 µg.d -1 transformation of the E1 to E2 in the sewer (6). The population normalized concentration of the synthetic steroid 17α-ethinylestradiol, an active agent in the contraceptive pill, is 1 µg.d -1 per head (6).

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Section: Steroid Estrogen Concentration and Behaviour Within The Advasupporting

confidence: 86%

Fate of Steroid Estrogens in Australian Inland and Coastal Wastewater Treatment Plants

Braga

Smythe

Schäfer

et al. 2005

Environ. Sci. Technol.

178

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“…The partitioning of the compounds between the aqueous and solid phase was assumed to follow a linear isotherm with finite transfer rate as demonstrated by Schafer et al (2002). The result represented in Figs.…”

Section: Sorption Isotherms Of E2 and Ee2mentioning

confidence: 99%

Mechanistic evaluation of the sorption properties of endocrine disrupting chemicals in sewage sludge biomass

Ifelebuegu

Theophilus

Bateman

2010

Int. J. Environ. Sci. Technol.

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This study investigated the sorption behaviour of two endocrine disrupting chemicals; 17β-estradiol (E2) and 17β-ethinylestradiol and their thermodynamic properties in an activated sludge biomass. The partition coefficient values measured for E2 and EE2 at varying temperatures range from 245 -604 L/kg ( log K d 2.39 -2.78) and 267 -631 L/kg (Log K d 2.43 -2.80), respectively. The K d values were inversely related to temperature. The average percentages of E2 and EE2 adsorbed to the solid phase at 4.3 % dry solid were 87.2 % and 92.5 %, respectively. Sorption of E2 and EE2 to the activated sludge biomass was found to be spontaneous and entropy retarded with ∆G values in the range of -13 to -16 KJ/mol and ∆S value of -105.2J/mol/K and 96.7 J/mol/k for E2 and EE2, respectively. The enthalpy changes for E2 and EE2 were -45.7KJ/mol and -43.4KJ/mol respectively, demonstrating that the sorption process is exothermic. The values of the enthalpy changes also show that the mechanism of sorption is physisorption with some element of chemisorption.

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“…Removal is also effective when the xenobiotic adsorbs on the biomass suspended solids [59,60] and is later separated from the treated water by MF or UF. Adsorption on the sludge is found to be the highest at lower pH where there is less charge repulsion between the sludge and the xenobiotics [117,81]. Removal is also enhanced for xenobiotics with lower dipole moment or higher hydrophobicity [13,54].…”

Section: Xenobiotics Removal Using Membrane Bioreactorsmentioning

confidence: 96%

“…However studies show the occurrence of adsorption by some of the membrane polymers [117] leading to apparent high retention.…”

Section: Xenobiotics Removal By Mf and Ufmentioning

confidence: 99%

“…Removal is also enhanced for xenobiotics with lower dipole moment or higher hydrophobicity [13,54]. Due to gel formation or fouling on the membrane surface there is thought to be a shift of the membrane MWCO which can partly remove macromolecular organic carbon to which xenobiotics are adsorbed to [117,76,81].…”

Section: Xenobiotics Removal Using Membrane Bioreactorsmentioning

confidence: 99%

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Xenobiotics Removal by Membrane Technology: An Overview

Semiao

Schäfer

2009

Environmental Pollution

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Small molecular weight xenobiotics are compounds of extreme concern in potable water applications due to their adverse human health and environmental effects. However, conventional water treatment processes cannot fully and systematically remove them due to their low concentrations in natural waters and wastewaters. Biological limitation to degrade such compounds is another cause for inefficient removal.Physical barriers like membranes possessing pore sizes smaller than the compounds to be removed emerged as a good solution. Nanofiltration and reverse osmosis proved to be quite effective for xenobiotics removal in potable water production in the Paris purification plant of Méry-sur-Oise. However, even these very narrow pore membrane processes may result in incomplete removal: xenobiotics retention is high but factors such as adsorption, size exclusion and charge repulsion affect unpredictably their retention. The water solutions complexity to be treated renders xenobiotics removal predictions even more difficult due to interactions between xenobiotics and compounds in water.Removal of xenobiotics by microfiltration and ultrafiltration is very low because adsorption on the membrane is the main retention mechanism. Combining those with other processes (e.g. activated carbon) can considerably improve xenobiotics removal.The least studied processes in xenobiotics removal are electrodialysis, membrane distillation and pervaporation. Electrodialysis removal of organic xenobiotics shows a breakthrough through the membrane possibly due to adsorption followed by diffusion. Membrane distillation presents high removal rates of xenobiotics due to the compounds low vapour pressure. For volatile organic xenobiotics or solutions of trace amounts both membrane distillation and pervaporation can be used, xenobiotics interaction with the membrane being the key factor.In this book chapter a thorough synopsis of current knowledge on xenobiotics removal is presented and balanced with recent fundamental studies of underlying mechanisms, informing both the practitioner regarding membrane capabilities for xenobiotics removal and the researcher with the current state-of-art.

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Particle interactions and removal of trace contaminants from water and wastewaters

Cited by 65 publications

References 11 publications

Fate of Steroid Estrogens in Australian Inland and Coastal Wastewater Treatment Plants

Fate of Steroid Estrogens in Australian Inland and Coastal Wastewater Treatment Plants

Mechanistic evaluation of the sorption properties of endocrine disrupting chemicals in sewage sludge biomass

Xenobiotics Removal by Membrane Technology: An Overview

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