UV-induced photocatalytic degradation of aqueous acetaminophen: the role of adsorption and reaction kinetics

Environ Sci Pollut Res Int. 2015 Feb;22(3):2219-30. doi: 10.1007/s11356-014-3411-9. Epub 2014 Aug 31.

Abstract

Nanostructured titania supported on activated carbon (AC), termed as integrated photocatalytic adsorbents (IPCAs), were prepared by ultrasonication and investigated for the photocatalytic degradation of acetaminophen (AMP), a common analgesic and antipyretic drug. The IPCAs showed high affinity towards AMP (in dark adsorption studies), with the amount adsorbed proportional to the TiO2 content; the highest adsorption was at 10 wt% TiO2. Equilibrium isotherm studies showed that the adsorption followed the Langmuir model, indicating the dependence of the reaction on an initial adsorption step, with maximum adsorption capacity of 28.4 mg/g for 10 % TiO2 IPCA. The effects of initial pH, catalyst amount and initial AMP concentration on the photocatalytic degradation rates were studied. Generally, the AMP photodegradation activity of the IPCAs was better than that of bare TiO2. Kinetic studies on the photocatalytic degradation of AMP under UV suggest that the degradation followed Langmuir-Hinshelwood (L-H) kinetics, with an adsorption rate constant (K) that was considerably higher than the photocatalytic rate constant (k r), indicating that the photocatalysis of AMP is the rate-determining step during the adsorption/photocatalysis process.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetaminophen / chemistry*
  • Acetaminophen / radiation effects
  • Adsorption
  • Catalysis
  • Kinetics
  • Photolysis*
  • Spectroscopy, Fourier Transform Infrared
  • Titanium / chemistry*
  • Water
  • Water Pollutants, Chemical / chemistry*
  • Water Pollutants, Chemical / radiation effects

Substances

  • Water Pollutants, Chemical
  • Water
  • titanium dioxide
  • Acetaminophen
  • Titanium