Preface

Roehl, Karl Ernst; Meggyes, Tamás; Simon, Franz‐Georg; Stewart, Douglas I.

doi:10.1016/s0927-5215(05)80001-3

Cited by 2 publications

(2 citation statements)

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“…The development of innovative and effective methods for remediation of soil and water contaminated by toxic organic compounds and/or pesticides is a research area of great interest nowadays. This development involves the investigation and selection of new sorbent materials able to retain or immobilize pollutants and, if possible, at the same time able to facilitate their later degradation to prevent the transport of such compounds in soils and hence the pollution of water .…”

Section: Introductionmentioning

confidence: 99%

Effect of Different Wood Pretreatments on the Sorption−Desorption of Linuron and Metalaxyl by Woods

Rodríguez‐Cruz

Andrades

Parada

et al. 2008

J. Agric. Food Chem.

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The sorption-desorption of two different pesticides, linuron and metalaxyl, by woods was studied. Sorbent/solution ratio and sorption kinetics were also determined. Untreated wood and water, NaOH, HCl, and octadecyltrimethylammonium bromide (ODTMA) treated pine (softwood) and oak (hardwood) were used as sorbents. Linuron and metalaxyl were sorbed by untreated woods up to 80 and 40%, respectively, in a short time when the sorbent/solution ratio of 1:10 was used. Sorption of pesticides was significantly higher by pine, having higher lignin content, than by oak. Freundlich sorption constants (K(f)) were 96.2 and 74.4 (linuron) and 8.28 and 4.95 (metalaxyl) for untreated pine and oak woods and increased 1.04-2.35-fold (linuron) and 1.33-2.17-fold (metalaxyl) when woods were treated. The sorption was higher by HCl- and ODTMA-treated woods. Additionally, Freundlich desorption constants also indicated greater sorption irreversibility of both pesticides for treated woods than for untreated woods. The results revealed wood residues as a promising, low-cost, and environmentally friendly material to immobilize pesticides in soils, preventing water contamination. Wood treatments aimed at removing soluble wood extracts or at modifying wood chemical structure could increase their sorption capacity.

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Section: Introductionmentioning

confidence: 99%

Effect of Different Wood Pretreatments on the Sorption−Desorption of Linuron and Metalaxyl by Woods

Rodríguez‐Cruz

Andrades

Parada

et al. 2008

J. Agric. Food Chem.

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“…Surface complexation of uranyl and phosphate can occur through either U(VI) bonding to surface phosphate sites on hydroxyapatite or through ternary complex formation consisting of the surface calcium sites, dissolved uranyl, and dissolved phosphate, all of which utilize bidentate linkage between the phosphate tetrahedra and the uranyl equatorial shell . Precipitation occurs through formation of low-solubility uranium phosphates, namely, (UO 2 ) 3 (PO 4 ) 2 , as well as the minerals autunite Ca(UO 2 ) 2 (PO 4 ) 2 and chernikovite H 2 (UO 2 ) 2 (PO 4 ) 2 [log K sp −49.09, −47.28, and −45.48, respectively] . The increase in intensity and peak broadening in the 3600–3100 cm –1 range is attributed to the simultaneous overlapping of amide A, the hydroxyl radical of HAP, and water, either adsorbed water from the contact solution or water strongly bounded to the structure …”

Section: Resultsmentioning

confidence: 99%

Uptake and Removal of Uranium by and from Human Teeth

Younes

Ali

Duda

et al. 2021

Chem. Res. Toxicol.

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Uranium-238 ( 238 U), a long-lived radiometal, is widespread in the environment because of both naturally occurring processes and anthropogenic processes. The ingestion or inhalation of large amounts of U is a major threat to humans, and its toxicity is considered mostly chemical rather than radiological. Therefore, a way to remove uranium ingested by humans from uraniumcontaminated water or from the air is critically needed. This study investigated the uranium uptake by hydroxyapatite (HAP), a compound found in human bone and teeth. The uptake of U by teeth is a result of U transport as dissolved uranyl (UO 2 2+) in contaminated water, and U adsorption has been linked to delays in both tooth eruption and development. In this present work, the influence of pH, contact time, initial U concentration, and buffer solution on the uptake and removal of U in synthetic HAP was investigated and modeled. The influence of pH (pH of human saliva, 6.7−7.4) on the uptake of uranyl was negligible. Furthermore, the kinetics were extremely fast; in one second of exposure, 98% of uranyl was uptaken by HAP. The uptake followed pseudosecond-order kinetics and a Freundlich isotherm model. A 0.2 M sodium carbonate solution removed all the uranyl from HAP after 1 h. Another series of in vitro tests were performed with real teeth as targets. We found that, for a 50 mg/L U in PBS solution adjusted to physiological pH, ∼35% of the uranyl was uptaken by the tooth after 1 h, following pseudo-first-order kinetics. Among several washing solutions tested, a commercially available carbonate, as well as a commercially available fluoride solution, enabled removal of all the uranyl taken up by the teeth.

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Preface

Cited by 2 publications

References 0 publications

Effect of Different Wood Pretreatments on the Sorption−Desorption of Linuron and Metalaxyl by Woods

Effect of Different Wood Pretreatments on the Sorption−Desorption of Linuron and Metalaxyl by Woods

Uptake and Removal of Uranium by and from Human Teeth

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