Ozonation experiments were carried out under continuous operation in a bubble column. The effect of several parameters (inlet dye concentration, applied ozone dose, pH and conductivity) in colour and TOC removal of an acid dye solution was investigated with the aim to optimize the operation conditions. The ozone consumption was measured in each experiment. Ozonation was found to be effective for decolourisation of an acid dye; however, it only has a slight effect on TOC removal. Increasing the inlet dye concentration leads to a decrease in the decolourisation efficiency and an increase in the ozone consumption. The decolourisation increases with the applied ozone dose. Colour removal efficiencies for different ozone doses were between 76 and 100%. In the pH range 5-9, the decolourisation efficiency decreases with pH only when buffered solutions were used. The presence of salt decreases the decolourisation efficiency. Several dyes of different classes were also studied and ozonation was found to be effective for decolourisation but considerably less efficient for TOC removal. Under the conditions tested, only the disperse and sulphur dyes presented a colour removal lower than 86%. Practical application of this process was validated by treating two industrial textile effluents collected after two different biological treatments.
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http://dx.doi.org/10.1016/j.jhazmat.2006.05.006 | DOI Listing |
J Hazard Mater
January 2025
School of Environmental Science and Engineering, Southwest Jiaotong University, Sichuan, Chengdu 611756, China. Electronic address:
The ultraviolet-activated peroxymosnofulate (UV/PMS) system, an effective advanced oxidation process for removing dissolved organic matter (DOM) from wastewater, is limited by high chloride ion (Cl) concentrations in landfill leachate. This study used Fourier transform ion cyclotron resonance mass spectrometry to explore the transformation of DOM in the UV/PMS system with a high Cl concentration. The results revealed that elevated Cl levels generate reactive chlorine species, including chlorine radicals, dichlorine radicals, and hypochlorous acid/hypochlorite, reducing the total organic carbon (TOC) removal efficiency of Suwannee River natural organic matter (SRNOM) from 78.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
School of Environmental Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan 611756, China. Electronic address:
Although hydroxyl radicals (OH) degrade organic pollutants nonselectively, their mineralization rate during the treatment of waste leachate biological treatment effluent (BTL) using Fenton or Fenton-like systems is not high, and the reason is unknown. In this study, we investigated three typical Fenton-like systems that act on dissolved organic matter (DOM) in BTL. We analyzed the molecular composition of DOM resistant to OH, using ultrahigh resolution mass spectrometry.
View Article and Find Full Text PDFAWWA Water Sci
March 2024
Department of Civil, Construction, and Environmental Engineering, North, Carolina State University, Raleigh, North, Carolina, USA.
Per- and polyfluoroalkyl substances (PFAS) occur widely in drinking water, and consumption of contaminated drinking water is an important human exposure route. Granular activated carbon (GAC) adsorption can effectively remove PFAS from water. To support the design of GAC treatment systems, a rapid bench-scale testing procedure and scale-up approach are needed to assess the effects of GAC type, background water matrix, and empty bed contact time (EBCT) on GAC use rates.
View Article and Find Full Text PDFMolecules
December 2024
School of Physics, Changchun Normal University, Changchun 130032, China.
A highly versatile Z-scheme heterostructure, HoSmSbO/YbDyBiNbO (HYO), was synthesized using an ultrasonic-assisted solvent thermal method. The HYO heterojunction, composed of dual ABO compounds, exhibits superior separation of photogenerated carriers due to its efficient Z-scheme mechanism. The synergistic properties of HoSmSbO and YbDyBiNbO, particularly the excellent visible light absorption, enable HYO to achieve exceptional photocatalytic performance in the degradation of fenitrothion (FNT).
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
January 2025
Department of Environmental Health, Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran.
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