Due to the toxicity and mobility of chromium, the disposal of chromium-containing waste is a pressing issue. Co-processing of chromium-containing waste in a cement kiln is currently one of the most effective methods. However, the presence of water-soluble hexavalent chromium (Cr(VI)) in cement limits the use of this method. In this study, NaCO was used to simulate alkali in industrial raw materials to investigate the pattern of influence of alkali content on water-soluble hexavalent chromium. The mechanisms associated with the oxidation and dissolution of chromium were investigated using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma emission spectrometry (ICP-OES). The proportion of Cr(VI) in the clinker detected by XPS increased rapidly with increasing alkali content. In the cement slurry system, alkali promotes more hexavalent chromium leaching by influencing pH and other ion concentrations (Ca, SO). Therefore, the addition of alkali to either the raw meal or to the cement slurry system will favour an increase in the water-soluble Cr(VI) content. This study may provide theoretical guidance for the preparation and use of clinkers containing chromium.
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http://dx.doi.org/10.3390/ijerph19084811 | DOI Listing |
Environ Technol
January 2025
Guangxi Key Laboratory of Theory and Technology for Environmental Pollution Control, Guilin University of Technology, Guilin, People's Republic of China.
P-chlorophenol (4-CP) and hexavalent chromium (Cr (VI)) are predominant contaminants in industrial effluents, eliciting substantial environmental and human health concerns. As a strong oxidant, Cr (Ⅵ) has the potential to facilitate the removal of 4-CP. However, the specific removal effect remains unclear.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China. Electronic address:
J Hazard Mater
December 2024
School of Environment and Resource, Southwest University of Science and Technology, Mianyang, Sichuan 621010, China; Key Laboratory of Solid Waste Treatment and Resource Recycle, Southwest University of Science and Technology, Mianyang, Sichuan 621010, China. Electronic address:
Chromium [Cr(VI)]-induced soil pollution is a serious environmental threat. Bioremediation utilizes specific microbes capable of transforming Cr(VI) into the less toxic Cr(III), however, microbial efficacy can be inhibited by elevated pollutant concentrations and competition from indigenous microbial communities. Thus, this study explored the potential of single and multi-domain microbial consortia encapsulated in alginate to overcome these shortcomings.
View Article and Find Full Text PDFPLoS One
December 2024
School of Design, Informatics and Business, Abertay University, Dundee, United Kingdom.
The reuse of electro-coagulated sludge as an adsorbent for Cr(VI) ion reduction was investigated in this study. Electro-coagulated sludge was obtained during the removal of citric acid wastewater by the electrocoagulation process. The following parameters were optimized for Cr(VI) reduction: pH (5-7), initial Cr(VI) concentration (10-50 mg/L), contact time (10-45 min), and adsorbent dosage (0.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
December 2024
Laboratory of Interface Materials Environment, Faculty of Sciences Ain Chock, Hassan II University, Casablanca, Morocco.
This study explores the use of functionalized manganese oxide (K-MnO-NH) for the removal of hexavalent chromium (Cr(VI)) ions, a highly toxic heavy metal contaminant, from wastewater. The synthesis of K-MnO-NH was achieved through a two-step process, followed by comprehensive characterization using various analytical techniques, which confirmed the material's formation as a pure phase. The K-MnO-NH exhibited exceptional chromium removal efficiency, achieving up to 90% (4.
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