Immobilized algae-based treatment of herbicide-contaminated groundwater

Water Environ Res. 2021 Feb;93(2):263-273. doi: 10.1002/wer.1405. Epub 2020 Aug 4.


Scenedesmus species, immobilized on alginate gel, was found effective in removing nitrate, atrazine, magnesium, phosphorus, zinc, oxadiazon, and triallate from groundwater in a continuous flow reactor. The laboratory-scale experiments with synthetic groundwater, made of 8.8 mg/L NO3 -N and 90 µg/L atrazine, were performed at a hydraulic retention time of 7 days and the temperatures of 20 and 35°C. The highest uptake of nitrate and atrazine was observed at 20°C (97% and 70%, respectively). When tested in actual groundwater, 92% of nitrate, 100% of magnesium, 99.9% of phosphorus, and 92% of zinc were successfully removed at the end of 29 days' treatment operations. The algal beads removed 100% of oxadiazon and triallate in the first 10 days, but some of the herbicides diffused back into the solution toward the end of the treatment process. PRACTITIONER POINTS: Immobilized algae-alginate beads can remove nitrate, atrazine, oxadiazon, and triallate from groundwater in continuous flow reactor. The uptake rate of nitrate and atrazine is higher in room temperature (20°C). Same algae beads could be reused for herbicide uptake for the average of 10 days. The immobilized system is a natural sustainable alternative that can be used in groundwater pump and treat.

Keywords: Scenedesmus sp.; biological treatment; groundwater; herbicides removal; immobilized algae; nitrate removal; oxadiazon; triallate.

MeSH terms

  • Atrazine*
  • Groundwater*
  • Herbicides*
  • Nitrates
  • Scenedesmus*
  • Water Pollutants, Chemical*


  • Herbicides
  • Nitrates
  • Water Pollutants, Chemical
  • Atrazine