The complex suite of organic materials in carbonaceous chondrite meteorites probably originally formed in the interstellar medium and/or the solar protoplanetary disk, but was subsequently modified in the meteorites' asteroidal parent bodies. The mechanisms of formation and modification are still very poorly understood. We carried out a systematic study of variations in the mineralogy, petrology, and soluble and insoluble organic matter in distinct fragments of the Tagish Lake meteorite. The variations correlate with indicators of parent body aqueous alteration. At least some molecules of prebiotic importance formed during the alteration.
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http://dx.doi.org/10.1126/science.1203290 | DOI Listing |
Heliyon
January 2025
Department of Earth Sciences, Carleton University, 1125 Colonel By Dr, Ottawa, ON, K1S 5B6, Canada.
Metal mining operations can release toxic metals to surrounding environments where site-specific conditions control the movement of contaminants. Colloid-facilitated transport, the transport of contaminants with small, mobile particles, has been recognized as a potential contaminant transport vector in groundwater, but it remains unclear under what conditions it is important and whether neutral, metal-rich mine drainage from legacy mining impacts this transport vector. This work presents a set of laboratory column experiments that study the effect of colloids on metal mobility in saturated, wetland sediment that has been receiving neutral mine drainage for nearly a century, using mixed and single metal input solutions at neutral pH.
View Article and Find Full Text PDFJ Environ Qual
January 2025
Institute for the Environment, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Population growth in coastal areas increases nitrogen inputs to receiving waterways and degrades water quality. Wetland habitats, including floodplain forests and marshes, can be effective nitrogen sinks; however, little is known about the effects of chronic point source nutrient enrichment on sediment nitrogen removal in tidally influenced coastal systems. This study characterizes enrichment patterns in two tidal systems affected by wastewater treatment facility (WWTF) effluent and assesses the impact on habitat nitrogen removal via denitrification.
View Article and Find Full Text PDFAnal Chim Acta
February 2025
Instituto de Química, Universidade Federal de Goiás, 74690-900, Goiânia, GO, Brazil; Instituto Nacional de Ciência e Tecnologia de Bioanalítica, Campinas, 13084-971, SP, Brazil. Electronic address:
Background: Distinct classes of environmental contaminants - such as microplastics, volatile organic compounds, inorganic gases, hormones, pesticides/herbicides, and heavy metals - have been continuously released into the environment from different sources. Anthropogenic activities with unprecedented consequences have impacted soil, surface waters, and the atmosphere. In this scenario, developing sensing materials and analytical platforms for monitoring water and air quality is essential to supporting worldwide environmental control agencies.
View Article and Find Full Text PDFEnviron Res
January 2025
College of Forestry & Landscape Architecture, South China Agricultural University, Guangzhou 510642, China. Electronic address:
Promoting soil structure is considered an essential prerequisite for abandoned mine land restoration. Sewage sludge (SS) has the potential to improve soil structure. However, traditional SS application to improve soil structure requires a lot of SS, potentially exacerbating heavy metal (HM) contamination.
View Article and Find Full Text PDFWater Res
January 2025
School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China; Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China. Electronic address:
The influence of algal organic matter (AOM) on the settling performance of algal flocs remains poorly understood. To address this, we employed fractionation techniques based on molecular weight to isolate different AOM fractions and analyzed their effects on floc structure and settling performance. This involved comparing the concentrations, compositions, potentials, and functional groups of organic matter before and after coagulation-sedimentation.
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