Batch-Mode Denitrifying Woodchip Bioreactors for Expanded Treatment Flexibility

Carolina Díaz-García, Laura E. Christianson

Research output: Contribution to journalArticlepeer-review


Denitrifying woodchip bioreactors successfully remove nitrates from reverse osmosis desalinization brine. On-farm desalination plants only operate for several hours per day in batch mode, meaning bioreactors should also operate in batch cycles, although this type of bioreactor operation is relatively unstudied. This study compared two tests of three cycles of 24 h per week with two treatments each (Test 1 8 vs. 24 h, and Test 2 8 vs. 12 h). Cylindrical pilot-scale bioreactors were filled with 130 kg of citrus woodchips and an average of 322 L of brine. The results show that the treatments with longer saturation periods of 24 and 12 h exhibited higher removal rates under operational conditions (i.e., 8 h flooding based on a 24 h cycle) than the 8 h treatment. However, the nitrate removal rates of the 8 h treatment were higher under fill cycle conditions (i.e., 8 h flooding based on an 8 h cycle). Dissolved organic carbon liberated from the woodchips was greater in treatments with longer drying periods (i.e., treatments with shorter saturation periods). Batch bioreactors should be considered under applicable conditions to increase nitrate removal rates.

Original languageEnglish (US)
Article number206
JournalWater (Switzerland)
Issue number2
StatePublished - Jan 2024


  • brine
  • desalination
  • hydraulic retention time
  • Mar Menor
  • nitrate
  • nutrient removal
  • organic carbon

ASJC Scopus subject areas

  • Biochemistry
  • Geography, Planning and Development
  • Aquatic Science
  • Water Science and Technology


Dive into the research topics of 'Batch-Mode Denitrifying Woodchip Bioreactors for Expanded Treatment Flexibility'. Together they form a unique fingerprint.

Cite this