The management of black water depends primarily on the knowledge of the dynamics of organic matter (OM), iron (Fe), sulfide (S), and manganese (Mn), at the water-sediment boundary (WSB). However, the mechanistic path of these substances leading to black water remains unsettled. In this study, a 35-day field study was conducted using the thin-film diffusion gradient technology (DGT) and the planar optrode to address the unknown combined effects of Fe, Mn, OM, S, and tannins from Eucalyptus species on Tianbao reservoir.Our results indicated that the hypolimnion was hypoxic due to thermal stratification, which caused the reduction of insoluble Fe and Mn from sediments to bottom water. Correlation analysis (Fe:S (r:0.5-0.9); Mn:S (r:0.2-0.8)) and elevated fluxes (Fe, Mn, S) connoted that these parameters interacted chemically to give black matter. The content of OM, Fe, and tannic acid in the benthic region diminished remarkably (p < 0.05) from day 1 (strong stratification) to day 35 (weak stratification), connoting that these parameters also interacted chemically to give black matter. The turbidity (clarity of the water) increased from day 1 to 35 with a significant difference (p < 0.05) recorded on day 14 confirming that black water was formed on this day when the thermal structure of the reservoir was annihilated. Correlation analysis supported the assertion that the variability in oxygen and redox conditions caused changes in Fe, Mn, and OM content at the WSB.The finding from the field research provides useful information to stakeholders on how to improve the quality of freshwater management designs.
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Sci Rep
January 2025
Hydrobiology Lab, Water Pollution Research Department, National Research Centre, Dokki, Giza, 12622, Egypt.
Carbon black (CB) as rubber reinforcement has raised environmental concerns regarding this traditional petroleum-based filler, which is less susceptible to biodegradability. Although it has great reinforcing properties, the production technique is no longer sustainable, and its cost increases regularly. For these reasons, it is wise to look for sustainable replacement materials.
View Article and Find Full Text PDFSci Total Environ
January 2025
Department of Earth Resources and Environmental Engineering, Hanyang University, Seoul 04763, Republic of Korea. Electronic address:
The CO adsorption capacity of biochar depends on the type of biomass used and its physicochemical properties; various sorption parameters including temperature, CO concentration, and humidity affect the CO adsorption capacity. Biochar derived from defatted black soldier fly larvae (BSFL) biomass was investigated for direct CO capture and exhibited a hydrophilic/mesoporous structure that contained high concentrations of alkali and alkaline metals (>10 wt%), which contribute to CO chemisorption. The CO adsorption efficiency was higher at 25 °C compared with that at 30 °C and 35 °C, probably due to reduced Brownian motion of CO molecules at lower temperatures.
View Article and Find Full Text PDFJ Racial Ethn Health Disparities
January 2025
Epidemiology and Health Economics Research (EHER), Universidad Científica del Sur, Lima, Peru.
Background: The Afro-Peruvian population is one of the ethnic minorities most affected by cultural, socioeconomic, and health barriers; however, there is little evidence on health inequalities in this ethnic group. Therefore, We aimed to determine health inequalities among the Peruvian Afro-descendant population in comparison with non-Afro-descendants.
Methods: A cross-sectional study was conducted using data from the Demographic and Family Health Survey 2022.
Alzheimers Dement
December 2024
University of California, Davis, Davis, CA, USA.
Background: Depressive symptoms are associated with reduced brain integrity. However, it is unclear if this association holds among a racially and ethnically diverse population aged ≥90 years and if there are differences by gender.
Method: The LifeAfter90 Study enrolled 212 long-term members of Kaiser Permanente Northern California who were ≥90 years old, without dementia diagnosis, and received neuroimaging via 3T MRI.
Small
January 2025
School of Material Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, 212003, P. R. China.
Multifunctional coatings have great application value in the protection of Marine equipment, ships and ship facilities, but they still suffer from the disadvantages of high preparation cost and complicated synthesis methods. Herein, employing a simple method to synthesize black carbon nitride (BCN), as the filler in polydimethylsiloxane (PDMS) to construct BCN/PDMS composite coating with a multifunctional anti-corrosion/antifouling coating capable of photothermal self-healing property. Experimental results exhibit that the BCN/PDMS coating can still possesses excellent corrosion resistance after 28 d of immersion in the simulated seawater, and the impedance modulus still manages to reach 6.
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