Chromium species (Cr(III), Cr(VI), and Cr(III)-organic) in groundwater of a tannery contaminated area were monitored during pre- and post-monsoon seasons for a period of 3 years (May 2004 to January 2007). The objectives of the study were (1) to investigate the temporal variation of chromium species and other matrix constituents and (2) to study the redox processes associated with the temporal variation of chromium species. Samples were collected from 15 dug wells and analyzed for chromium species and other constituents. The results showed that the groundwater was relatively more oxidizing during post-monsoon periods than the pre-monsoon periods. Except one sample, the concentration of chromium species were found in the order of Cr(VI)>Cr(III)>Cr(III)-organic complexes during all the pre- and post-monsoon periods. In most of the wells, the concentrations of Cr(III), Cr(VI), and Cr(III)-organic decreased during post-monsoon periods compared to their pre-monsoon concentrations. However, the Cr(VI)/Cr(Total) ratio still increased and the Cr(III)/Cr(Total) ratio decreased during post-monsoon periods in most of the samples. The possible mechanisms for the temporal variation of chromium species were (1) Fe(II) reduction of Cr(VI) vs oxidation of Fe(II) by dissolved oxygen and (2) oxidation of Cr(III) by Mn(IV).
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http://dx.doi.org/10.1007/s10661-010-1610-5 | DOI Listing |
Environ Pollut
January 2025
Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
Migration characteristics and occurrence forms of redox-sensitive metal(loid)s such as arsenic (As), chromium (Cr), and vanadium (V) remained unclear in dynamic estuarine waters. In this work, size fractionation and chemical speciation of As, Cr, and V in the Jiaomen Waterway (JMW), a tidal river of the Pearl River estuary, were explored based on (ultra)filtration, the diffusive gradients in thin films (DGT) techniques and a thermodynamic chemical equilibrium model. The results showed that As was present mainly in soluble forms in the river water, and the suspended particulate matter (SPM) was identified the major carrier for Cr.
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January 2025
Department of Seafood Processing Technology, Faculty of Fisheries, Cukurova University, Adana 01330, Balcali, Türkiye.
This study investigates the seasonal variations in the elemental composition of five economically valuable fish species from Bozcaada, North Aegean: red seabream (), gilthead seabream (), saddled seabream (), white seabream (), and common dentex (), with a focus on both essential minerals and toxic metals. Fish samples ( = 10 per species per season) were collected across four seasons, and their weights and lengths were recorded. The concentrations of elements such as calcium, potassium, magnesium, phosphorus, copper, iron, manganese, zinc, chromium, nickel, selenium, cadmium, and mercury were analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS).
View Article and Find Full Text PDFToxics
December 2024
Biofuels Institute, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China.
There is concern over potential toxic elements (PTEs) impacting river ecosystems due to human and industrial activities. The river's water, sediment, and aquatic life are all severely affected by the release of chemical and urban waste. PTE concentrations in sediment, water, and aquatic species from river ecosystems are reported in this review.
View Article and Find Full Text PDFOrg Lett
January 2025
Department of Chemistry and Materials Science, College of Science, Nanjing Forestry University, Nanjing 210037, China.
The Nozaki-Hiyama-Kishi reaction offers effective and reliable strategies for the preparation of alcohols via carbon-carbon bond formation. Typical methods usually require stoichiometric amounts of chromium salts, co-transition metals, and auxiliary reagents, which limits their practical application in industrial chemistry. To mitigate these limitations, substantial efforts have been made to develop chromium-catalytic approaches.
View Article and Find Full Text PDFRSC Adv
January 2025
Department of Physical Sciences, School of Arts and Sciences, Lebanese American University Beirut 1102-2801 Lebanon +961 1 786456, ext. 3950.
The Mediterranean Sea is an intercontinental marine environment renowned for its biodiversity and ecological significance. However, it is also one of the most polluted seas globally with significant levels of microplastics and heavy metals among other emerging contaminants. In Lebanon, inadequate waste management infrastructure and unregulated industrial discharges have exacerbated water quality deterioration by introducing these complex contaminants into surface and seawater.
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