The removal of Cr(III) ions and methylene blue (MB) from aqueous solutions by xanthated corn cob (xCC) in batch conditions was investigated. The sorption capacity of xCC strongly depended of the pH, and increase when the pH rises. The kinetics was well fitted by pseudo-second-order and Chrastil's model. Sorption of Cr(III) ions and MB on xCC was rapid during the first 20 min of contact time and, thereafter, the biosorption rate decrease gradually until reaching equilibrium. The maximum sorption capacity of 17.13 and 83.89 mg g for Cr(III) ions and MB, respectively, was obtained at 40 °C, pH 5, and sorbent dose 4 g dm for removal of Cr(III) ions and 1 g dm for removal of MB. The prediction of purification process was successfully carried out, and the verification of theoretically calculated amounts of sorbent was confirmed by using packed-bed column laboratory system with recirculation of the aqueous phase. The wastewater from chrome plating industry was successfully purified, i.e., after 40 min concentration of Cr(III) ions was decreased lower than 0.1 mg dm. Also, removal of MB from the river water was successfully carried out and after 40 min, removal efficiency was about 94%.
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http://dx.doi.org/10.1007/s11356-017-9419-1 | DOI Listing |
Anal Chim Acta
February 2025
Department of Chemistry, Tamkang University, New Taipei City, 25137, Taiwan. Electronic address:
Background: Trivalent chromium (Cr(III)) and its highly soluble carboxyl complexes, often discharged into the environment by industries such as electroplating, leather tanning, and textile manufacturing, present severe risks to human health and ecosystems due to their high toxicity. These compounds are notoriously difficult to detect and remove during wastewater treatment, as they can persist in aqueous environments. Consequently, there is a pressing need for the development of simple, cost-effective, and reliable methods for their detection, which can improve monitoring, facilitate timely interventions, and enhance environmental protection efforts.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes 748, São Paulo 05508-000, Brazil. Electronic address:
In this study, kapok fiber (KF) a hollow and hydrophobic fiber, was modified with cetyltrimethylammonium bromide (CTAB) or cetylpyridinium chloride (CPC), rendering adsorbed amount of ∼0.75 × 10 mol/g. Small-angle X-ray scattering (SAXS) measurements of dry KF/CTAB and KF/CPC evidenced a periodic distance of ∼2.
View Article and Find Full Text PDFMass Spectrom (Tokyo)
December 2024
Department of Applied Chemistry for Environment, School of Science and Technology, Kwansei Gakuin University, Gakuen-Uegahara-1, Sanda, Hyogo 669-1330, Japan.
A simple and rapid analytical method was developed for the simultaneous determination of two chromium species, Cr(III) and Cr(VI), in the environmental waters by high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS). This study incorporated a chelating pretreatment with 2,6-pyridinedicarboxylic acid (PDCA) to convert Cr(III) species into a stable Cr(III)-PDCA anion complex, which was then separated from Cr(VI) oxyanion using an anion exchange column. Building on the fundamental analytical approach proposed by Shigeta .
View Article and Find Full Text PDFTalanta
April 2025
Functional Nanomaterials Laboratory, Center for Micro/Nanomaterials and Technology, and Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China. Electronic address:
The differentiation of valence states plays a crucial role in determining the toxicity of chromium (Cr) in environmental samples. In this work, two modes of colorimetric and electrochemical analytical methods based on a fungus like porous CoS (FP CoS) nanosensor were developed for rapid, specific, and portable detection trace/ultra-trace chromium species (Cr(VI) and Cr(III)). The FP CoS exhibited peroxidase activity as a nanozyme for the colorimetric detection of Cr(VI), catalyzing the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) to a blue oxidation product (oxTMB) in the presence of Cr(VI) instead of unstable HO as an oxidizer at room temperature over existing methods.
View Article and Find Full Text PDFEnviron Pollut
February 2025
School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou, 510006, China; Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, South China University of Technology, Guangzhou, 510006, China.
Cr(III) oxidation by birnessite was the dominant geologic source of Cr(VI), which increases the environmental mobility and toxicity of Cr, threatening ecological safety. Photochemically hydroxyl radical (•OH) generated by birnessite was widely accepted to be the dominant reactive oxygen species (ROS) oxidating Cr(III). However, birnessite and Cr mainly co-exist in dark subsurface soils, with contribution of nonphotochemical ROS remaining unclear.
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