Biogeochemical processes in northern peatland ecosystems are influenced by seasonal temperature fluctuations that are changing with the climate. Methylmercury (MeHg), commonly produced in peatlands, affects downstream waters; therefore, it is important to understand how temperature transitions affect mercury (Hg) dynamics. We investigated how the freeze-thaw cycle influences belowground peat pore water total Hg (THg), MeHg, and dissolved organic carbon (DOC). Four large, intact peat columns were removed from an ombrotrophic peat bog and experimentally frozen and thawed. Pore water was sampled across seven depths in the peat columns during the freeze-thaw cycle and analyzed for THg, MeHg, and DOC concentrations. Freezing results showed increased concentrations of THg below the ice layers and limited change in MeHg concentrations. During thawing, THg concentrations significantly increased, whereas MeHg concentrations decreased. Limited bromide movement and depth decreases in THg and DOC concentrations were associated with increased bulk density and degree of humification in the peat. The experiment demonstrates the effects of the freeze-thaw cycle on Hg concentrations in northern peatlands. Changes to freeze-thaw cycles with climate change may exacerbate Hg cycling and transport processes in peatland environments.
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Nanomaterials (Basel)
December 2024
Unidad Departamental de Química Analítica, Departamento de Química, Facultad de Ciencias, Universidad de La Laguna, Avda. Astrofísico Fco. Sánchez, s/n, 38206 La Laguna, Spain.
Arsenic contamination of water endangers the health of millions of people worldwide, affecting certain countries and regions with especial severity. Interest in the use of Fe-based metal organic frameworks (MOFs) to remove inorganic arsenic species has increased due to their stability and adsorptive properties. In this study, the performance of a synthesized Nano-{Fe-BTC} MOF, containing iron oxide octahedral chains connected by trimesic acid linkers, in adsorbing As(III) and As(V) species was investigated and compared with commercial BasoliteF300 MOF.
View Article and Find Full Text PDFBiopolymers
January 2025
School of Pharmacy and Bioengineering, Keele University, Keele, UK.
Cryogels were fabricated by combining polyvinyl alcohol (PVA) and chitosan of varying molecular weights (Mw). In this study, the effects of chitosan Mw, types of boron-containing molecules on network formation, and boron release rate in resulted cryogels were investigated. The PVA/chitosan blend maintained a constant 4.
View Article and Find Full Text PDFEnviron Res
January 2025
College of Chemistry, Liaoning University, Shenyang 110036, P. R. China; Liaoning Key Laboratory of Chemical Additive Synthesis and Separation, Yingkou Institute of Technology, Yingkou 115014, P. R. China. Electronic address:
Basic dyes are highly toxic and have adverse effects on humans such as accelerated heart rate, shock, cyanosis, and tissue necrosis upon ingestion or skin contact. Efficient removal of basic dye pollutants from wastewater is therefore essential for the protection of the environment and human health. Biomolecules exhibit excellent dye removal performance in terms of removal capacity, selectivity, and rate.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Department of Food Engineering and Technology, Tezpur University, Napaam, Sonitpur, Tezpur, Assam, India. Electronic address:
Microwave-assisted extraction of pectin from Dillenia indica (DI) fruit was optimized using Box-Behnken design to maximize yield and quality. Parameters such as solid:solvent (1:10-1:30), microwave power (200-600 W), and extraction time (4-10 min) were varied to determine the optimal conditions. Through experimentation, the optimized extraction parameters were identified as 1:23.
View Article and Find Full Text PDFFood Chem
January 2025
College of Food Science, Northeast Agricultural University, Harbin, Heilongjiang 150030, China. Electronic address:
In this study, the effect of freeze-thaw (F-T) processes on the mechanical and water absorption performance of citrate cross-linked chitosan/poly(vinyl alcohol) hydrogel pads was evaluated. An excellent cross-linking of 4 % (w/w) citrate was indicated by enhanced peak strength in Fourier-transform infrared spectroscopy and X-ray diffraction patterns, which was applied to the subsequent F-T process. The results in the deswelling rate, water contact angle, and relaxation time of samples exhibited a tendency to decrease and then increase with increasing F-T cycles, reaching a minimum of 0.
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