Landfill leachate treatment by immediate one-step lime precipitation, carbonation, and phytoremediation fine-tuning

Environ Sci Pollut Res Int. 2023 Jan;30(4):8647-8656. doi: 10.1007/s11356-022-18729-7. Epub 2022 Jan 20.

Abstract

The high pollutant load of sanitary landfill leachates poses a huge challenge in the search for efficient and environment friendly solutions for their treatment. The objective of this work was to study an integrated solution of environmentally friendly technologies - immediate one-step lime precipitation (IOSLP), carbonation (CB), and phytoremediation (Phyt) - to treat a sanitary landfill leachate. In the leachate sample treatment by IOSLP, the influence of CaO concentration (18.2-33.3 gCaO L-1) and stirring time (2-60 min) on the sludge sedimentability and pollutant removal was studied. Organic load and ammonia nitrogen (AN) removal increases with CaO added, as well as sludge volume. Stirring time has a small influence on organic load and AN removal, presenting a minimum for sludge volume. Thus, the best operational conditions were chosen as 27.6 gCaO L-1, and 40-min stirring time, with 64% chemical oxygen demand (COD) removal. Sludge humidity was 2.1%, making dewatering needless. IOSLP supernatant was submitted to CB by atmospheric CO2, and 100% removals in AN and hardness were attained. Effluents from IOSLP and IOSLP + CB were utilized in Phyt tests, with Vetiver (Chrysopogon zizanioides (L.) Roberty). The best COD removal (37%) during Phyt was attained for the samples treated by IOSLP + CB.

Keywords: Carbonation; Landfill leachate; Lime; Phytoremediation; Precipitation; Vetiver (Chrysopogon zizanioides (L.) Roberty).

MeSH terms

  • Biodegradation, Environmental
  • Nitrogen
  • Oxides
  • Sewage
  • Water Pollutants, Chemical* / analysis

Substances

  • Water Pollutants, Chemical
  • lime
  • Sewage
  • Oxides
  • Nitrogen