Degradation of tetracycline in water by biochar supported nanosized iron activated persulfate

Chemosphere. 2020 Dec:261:127844. doi: 10.1016/j.chemosphere.2020.127844. Epub 2020 Aug 26.

Abstract

Biochar supported nanosized iron (nFe(0)/BC) was synthesized and used as a persulfate (PS) activator to degradation tetracycline (TC). The influence of the initial pH values, PS and nFe(0)/BC dosage, initial TC concentration, and coexist anions were investigated. In the nFe(0)/BC-PS system, TC could be effectively removed at various pH values (3.0-9.0). The degradation efficiency of TC (100 mg/L) was 97.68% using nFe(0)/BC (0.4 g/L) and persulfate (1 mM) at pH 5.0. Coexisting ions (HCO3- and NO3-) had an inhibitory effect on TC degradation. The removal of TC could be fitted by a pseudo-second-order model. Electron-Spin Resonance (ESR) analysis and scavenging tests suggested that sulfate radicals (SO4·-) and hydroxyl radicals (HO·) were responsible for TC degradation. Details of the advanced oxidation process (AOP)-induced degradation pathways of TC were determined based on liquid chromatography mass-spectrometry (LC-MS) analysis. The nFe(0)/BC could still maintain 86.38% of its original removal capacity after five cycles. The findings of this study proved that nFe(0)/BC can be applied to activate PS for the treatment of pollution caused by TC.

Keywords: Activation; Degradation; Persulfate; Tetracycline; nFe(0)/BC.

MeSH terms

  • Charcoal / chemistry*
  • Hydroxyl Radical / chemistry
  • Iron / chemistry*
  • Models, Theoretical
  • Nanoparticles / chemistry*
  • Oxidation-Reduction
  • Sodium Compounds / chemistry*
  • Sulfates / chemistry*
  • Tetracycline / analysis*
  • Wastewater / chemistry
  • Water Pollutants, Chemical / analysis*
  • Water Purification / methods*

Substances

  • Sodium Compounds
  • Sulfates
  • Waste Water
  • Water Pollutants, Chemical
  • biochar
  • sulfate radical
  • Charcoal
  • Hydroxyl Radical
  • Iron
  • Tetracycline
  • sodium persulfate