Biogas sparging to control fouling and enhance resource recovery from anaerobically digested sludge centrate by forward osmosis

Minh T. Vu, Luong N. Nguyen, Md Abu Hasan Johir, Xiwang Zhang, Long D. Nghiem, Menachem Elimelech

Research output: Contribution to journalArticleResearchpeer-review

22 Citations (Scopus)


This study demonstrates the proof-of-concept of biogas sparging to control membrane fouling during sludge centrate pre-concentration by forward osmosis (FO). Sludge centrate sparging by biogas reduced membrane fouling (measured by water flux decline) and filtration time by two and eight times, respectively, compared to FO operation without biogas sparging at the same water recovery of 60%. In addition, the water flux was almost fully recovered by physical flushing when biogas sparging was applied. Biogas sparging also resulted in a significant improvement in the enrichment of organic, ammonia, and phosphate to close to the theoretical value based on mass balance calculation. In other words, organic matter and nutrients were retained in the bulk solution for subsequent recovery. Fouling mitigation and nutrient enrichment improvement by biogas sparging could be attributed to carbonate buffering to maintain a near neutral pH for preventing calcium phosphate precipitation on the membrane surface and ammonia volatilisation.

Original languageEnglish
Article number119176
Number of pages8
JournalJournal of Membrane Science
Publication statusPublished - 1 May 2021


  • Anaerobic co-digestion
  • Biogas sparging
  • Forward osmosis
  • Membrane fouling
  • Nutrient recovery

Cite this