Photocatalytic degradation of 2,4-DNT in simulated wastewater by magnetic CoFe2O4/SiO2/TiO2 nanoparticles

Environ Sci Pollut Res Int. 2022 Jan;29(5):6479-6490. doi: 10.1007/s11356-021-13690-3. Epub 2021 Aug 28.

Abstract

Discharge of 2,4-dinitrotoluene (2,4-DNT) into the environment leads to a serious soil and water sources pollution problem, due to toxicity and possible carcinogenicity of this toxic substance. In this work, the photocatalytic degradation of 2,4-DNT was investigated using CoFe2O4/SiO2/TiO2 nanoparticles. The catalyst features were characterized by using XRD, TEM, EDX, UV-vis DRS, FTIR, and VSM techniques. The influence of different experimental factors on degradation efficiency including pH value, catalyst dosages, and initiate concentration of 2,4-DNT were investigated. Mineralization of the model pollutant was determined using TOC analysis under optimum conditions. A possible mechanism, process kinetic and reusability of magnetic photocatalyst were also performed. In optimum experimental conditions (pH=3, photocatalyst dosage=0.75 g/L, 2,4-DNT=0.025 g/L), degradation efficiency achieved 88.5% within 180-min reaction time with TOC removal of 55.6%. Dominate oxidizing radicals during the degradation of 2,4-DNT by CoFe2O4/SiO2/TiO2 were hydroxyl radicals. The photocatalytic degradation of 2,4-DNT followed first-order rate kinetics. After three successive use cycles, the degradation efficiency was reduced by 64%. Our results revealed that the synthesized CoFe2O4/SiO2/TiO2 photocatalyst was a good choice for degradation of 2,4-DNT, due to proper potential reusability and catalytic activity.

Keywords: 2,4-DNT; CoFe2O4/SiO2/TiO2; Magnetic; Nanoparticles; Photocatalysis; Treatment; Wastewater.

MeSH terms

  • Catalysis
  • Dinitrobenzenes
  • Magnetic Phenomena
  • Nanoparticles*
  • Silicon Dioxide
  • Titanium
  • Wastewater*

Substances

  • Dinitrobenzenes
  • Waste Water
  • titanium dioxide
  • Silicon Dioxide
  • Titanium
  • 2,6-dinitrotoluene