Membrane for water reuse: Effect of pre-coagulation on fouling and selectivity

Y. Soffer*, R. Ben Aim, A. Adin

*Corresponding author for this work

Research output: Contribution to journalConference articlepeer-review

30 Scopus citations

Abstract

Membrane filtration is adequate for producing disinfected clear water suitable for various kinds of applications. However, fouling of membranes is the main limitation. This study has focused on the ability of flocculation to remove from wastewater the organic colloids which play an important role in the fouling phenomena. First, flocculation was optimized for high-efficiency removal of suspended solids and organic material, and then, at a selected ferric chloride dose and pH, was used as a first step before filtration on membranes ranging from UF (50 KDa) to NF. This resulted in an improvement of the filtration flux. Fouling increased when high molecular weight cut-off (MWCO) membranes were used. The fouling mechanism seems to be blocking, by internal clogging and cake formation becoming preponderant with time. pH 5.5 (charge neutralization zone) provided better removal and lower fouling intensity than pH 7.8 (sweep coagulation zone). Ultrafiltration of 4 KDa at acidic pH 5.5 and 150 mg/L ferric chloride could reduce DOC by 70% and UV-254 nm by 60%. The quality of the filtrate was better than that obtained with nanofiltration at basic pH 7.8 with the same dose of flocculant and the fouling was lower with a 4 KDa membrane. Thus coupling of flocculation with a UF membrane might be the best compromise for producing, in very compact units, very clear water for possible reuse in industrial areas.

Original languageEnglish
Pages (from-to)367-372
Number of pages6
JournalWater Science and Technology
Volume42
Issue number1-2
DOIs
StatePublished - 2000
EventProceedings of the 7th International Conference of the Israel Society for Ecology and Environmental Quality Sciences - Jerusalem, Isr
Duration: 13 Jun 199918 Jun 1999

Keywords

  • Advanced wastewater treatment
  • Flocculation
  • Fouling
  • Iron coagulation
  • Membrane filtration
  • Physical-chemical treatment
  • Selectivity
  • Ultrafiltration
  • Water reuse

Fingerprint

Dive into the research topics of 'Membrane for water reuse: Effect of pre-coagulation on fouling and selectivity'. Together they form a unique fingerprint.

Cite this