Effective photochemical treatment of a municipal solid waste landfill leachate

PLoS One. 2020 Sep 22;15(9):e0239433. doi: 10.1371/journal.pone.0239433. eCollection 2020.

Abstract

This work aimed at studying the photochemical treatment of a landfill leachate using ultraviolet light, hydrogen peroxide, and ferrous or ferric ions, in a batch recycle photoreactor. The effect of inorganic carbon presence, pH, initial H2O2 amount (0-9990 mg L-1) as well as Fe(II) (200-600 ppm) and Fe(III) (300-700 ppm) concentrations on the total carbon removal and color change was studied. Prior to the photochemical treatment, a pretreatment process was applied; inorganic nitrogen and inorganic carbon were removed by means of air stripping and initial pH regulation, respectively. The leachate sent subsequently for photochemical treatment was free of inorganic carbon and contained only organic carbon with concentration 1200±100 mg L-1 at pH 5.1-5.3. The most favorable concentrations of H2O2 and ferric ions for carbon removal were 6660 mg L-1 and 400 ppm, respectively. Adjusting the initial pH value in the range of 2.2-5.3 had a significant effect on the organic carbon removal. The photo-Fenton-like process was more advantageous than the photo-Fenton one for leachate treatment. By applying the most favorable operating conditions, 88.7% removal of total organic carbon, 100% removal of total inorganic carbon, 96.5% removal of total nitrogen, and 98.2% color removal were achieved.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbon / chemistry
  • Color
  • Ferric Compounds / chemistry
  • Ferrous Compounds / chemistry
  • Hydrogen Peroxide / chemistry*
  • Hydrogen-Ion Concentration
  • Ions / chemistry
  • Iron / chemistry
  • Methylene Blue / chemistry
  • Nitrogen / chemistry
  • Oxidation-Reduction
  • Solid Waste / analysis*
  • Ultraviolet Rays*
  • Waste Disposal, Fluid / methods*

Substances

  • Fenton's reagent
  • Ferric Compounds
  • Ferrous Compounds
  • Ions
  • Solid Waste
  • Carbon
  • Hydrogen Peroxide
  • Iron
  • Nitrogen
  • Methylene Blue

Grants and funding

This research was funded by the Nazarbayev University project “Cost-Effective Photocatalysts for the Treatment of Wastewaters containing Emerging Pollutants”, Faculty-development competitive research grants program for 2020-2022, Grant Number 240919FD3932 awarded to Dr. S.G. Poulopoulos. Dr. K. Meiramkulova acknowledges the financial support by the grant “Reducing the technogenic impact on water resources with using water recycling technology” № BR05236844/215 for 2018- 2020, from the Ministry of Education and Science, Republic of Kazakhstan. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.