Removal of linear and branched alkylphenols with different alkyl chain lengths or different branchings (normal, secondary, and tertiary), some of which are suspected as endocrine disrupting chemicals, from an aqueous medium were investigated through quinone oxidation by polyphenol oxidase (PPO) and subsequent quinone adsorption on chitosan beads or powders at pH 7.0 and 40 °C. PPO-catalyzed quinone oxidation increased with an increase in alkyl chain length of the alkylphenols used. Although a higher PPO dose was required for quinone oxidation of branched alkylphenols, they were completely or mostly removed by quinone adsorption on chitosan beads or powders. The apparent activity of PPO increased by a decrease in quinone concentration. On the other hand, in the homogeneous systems with solutions of chitosan and PPO at pH 6.0, longer reaction times were required to generate insoluble aggregates, and a small amount of quinone derivatives were left in the solution even under optimum conditions. These results support that the two-step reaction, that is, PPO-catalyzed quinone oxidation and subsequent quinone adsorption on chitosan beads or powders, in the heterogeneous system is a good procedure for removing linear and branched alkylphenols from aqueous medium.
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http://dx.doi.org/10.3390/polym11060931 | DOI Listing |
PLoS One
November 2024
Department of Biology, Faculty of Education, Albaydha University, Al-Baydha, Yemen.
This work demonstrates the first time synthesis of selenium nanoparticles (Se NPs) stabilized with neonol. The synthesis method was optimized using a multifactorial experiment with three input parameters. The most stable sample had a radius of 15 nm and a ζ-potential of -36.
View Article and Find Full Text PDFToxicol Lett
December 2024
Department of Pharmacology and Toxicology, University of Würzburg, Versbacherstr. 9, Würzburg 97078, Germany. Electronic address:
Arch Environ Contam Toxicol
May 2024
Water Quality Monitoring and Surveillance Division, Science and Technology Branch, Environment and Climate Change Canada, 45 Alderney Dr, Dartmouth, NS, B2Y2N6, Canada.
Alkylphenol ethoxylates comprise of many anthropogenic chemicals such as nonylphenol (NP), octylphenol (OP) and nonylphenol ethoxylates (NPEOs). The objectives of this study were to assess the frequency and magnitude of detections of 4-NP, OP and NPEOs in Canadian sediment downstream of textile associated municipal wastewater treatment plants (MWWTPs) to determine if regulatory actions have had a beneficial impact on the receiving environment. Surficial sediments were obtained in four locations in the province of Québec (Canada) and were analyzed for nonylphenol, nonylphenol monoethoxylates (NPEO), nonylphenol diethoxylates (NPEO) and octylphenol from 2015 to 2018.
View Article and Find Full Text PDFEnviron Int
January 2024
Japan Environment and Children's Study Office, Health and Environmental Risk Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-0086, Japan. Electronic address:
Humans are exposed to various bisphenols, alkylphenols and nitrophenols through dietary intake, food packaging and container materials, indoor and outdoor air/dust. This study aimed to evaluate exposure of Japanese pregnant women to environmental phenols by measuring target compounds in urine samples. From a cohort of the Japan Environment and Children's Study, 4577 pregnant women were selected.
View Article and Find Full Text PDFToxics
September 2023
Department of Environmental and Occupational Medicine, National Taiwan University Hospital, Taipei 100, Taiwan.
As one of the most common alkylphenols, 4-tertiary-octylphenol (4-tOP) is commonly used in many consumer products. Our previous epidemiological study revealed a negative correlation between serum 4-tOP levels and carotid intima-media thickness (CIMT), which serves as a biomarker of arteriosclerosis. We aimed to explore the role of apoptotic microparticles, markers of vascular endothelial cell function, in the 4-tOP and CIMT connection.
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