In this study, the removal of acidic functional groups and introduction of basic groups/sites on activated carbons (ACs) by outgassing and ammonia gas treatment were respectively carried out to enhance the nitrate ion adsorption in aqueous solution. Then, the relationships between nitrate ion adsorption and solution pH as well as surface charge of AC were investigated to understand the basic mechanisms of nitrate ion adsorption by AC. The result showed that the nitrate ion adsorption depended on the equilibrium solution pH (pHe) and the adsorption amount was promoted with decreasing pHe. The ACs treated by outgassing and ammonia gas treatment showed larger amount of nitrate ion adsorption than that by untreated AC. These results indicated that, since basic groups/sites could adsorb protons in the solution, the AC surface would be charged positively, and that the nitrate ion would be electrically interacted with positively charged carbon surface. Accordingly, it was concluded that basic groups/sites on the surface of AC could promote nitrate ion adsorption.
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http://dx.doi.org/10.1248/cpb.c13-00422 | DOI Listing |
JACS Au
December 2024
Laboratory of Energy Science and Engineering, Department of Mechanical and Process Engineering, Eidgenössische Technische Hochschule (ETH) Zürich, 8092 Zürich, Switzerland.
There is an urgent need for inexpensive, functional materials that can capture and release CO under industrial conditions. In this context, MgO is a highly promising, earth-abundant CO sorbent. However, despite its favorable carbonation thermodynamics and potential for high gravimetric CO uptakes, MgO-based CO sorbents feature slow carbonation kinetics, limiting their CO uptake during typical industrial contact times.
View Article and Find Full Text PDFEnviron Res
December 2024
Integrated Science and Technology Research Center, Faculty of Technology and Environment, Prince of Songkla University, Phuket Campus, Kathu, Phuket 83120 Thailand. Electronic address:
Nitrate is a crucial nutrient in the natural nitrogen cycle. However, human activities have elevated nitrate levels in aquatic ecosystems beyond natural thresholds, posing risks to human health and the environment. In this work, ZnCl-doped mesoporous silica nanoparticles (ZnCl@MSN) were synthesized using a one-pot preparation method, leading to a streamlined process with reduced time and energy consumption.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Earth and Planetary Sciences, University of California, Riverside, CA, 92521, USA.
The Salton Sea (SS), California's largest inland lake at 816 square kilometers, formed in 1905 from a levee breach in an area historically characterized by natural wet-dry cycles as Lake Cahuilla. Despite more than a century of untreated agricultural drainage inputs, there has not been a systematic assessment of nutrient loading, cycling, and associated ecological impacts at this iconic waterbody. The lake is now experiencing unprecedented degradation, particularly following the 2003 Quantification Settlement Agreement-the largest agricultural-to-urban water transfer in the United States.
View Article and Find Full Text PDFGels
December 2024
Department of Biotechnology, Chemistry and Standardization, Tver State Technical University, A. Nikitina Str., Building 22, Tver 170026, Russia.
In this study, novel anion photo-responsive supramolecular hydrogels based on cysteine-silver sol (CSS) and iodate anions (IO) were prepared. The peculiarities of the self-assembly process of gel formation in the dark and under visible-light exposure were studied using a complex of modern physico-chemical methods of analysis, including viscosimetry, UV spectroscopy, dynamic light scattering, electrophoretic light scattering, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. In the dark phase, the formation of weak snot-like gels takes place in a quite narrow IO ion concentration range.
View Article and Find Full Text PDFEnviron Monit Assess
December 2024
Department of Water Engineering, University of Guilan, Rasht, Iran.
The examination of wastewater and effluents flowing into receiving water bodies is crucial for identifying pollutant sources and implementing scenarios to reduce them. In this study, QUAL2kw was used to identify, assess, and predict the pollutant load of a drainage canal located 6 km away from Anzali Wetland. Initially, the model was calibrated and validated with data collected in 2017.
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