Relationship between feed water quality and membrane performance during the filtration of real secondary effluent

Abstract

Water quality of feed stream certainly has a close relationship with membrane fouling during the microfiltration of secondary effluent. The current study tested the ceramic membrane performance using secondary effluents from two wastewater treatment plants and a pilot scale A²/O treatment equipment. Reversible and irreversible fouling were discussed using different water quality parameters. The water quality was characterized using general parameters, as well as particle size distribution (PSD) and fluorescence spectrum of different organic compositions. Higher particle concentration in feed water leads to a higher reversible fouling. Wider PSD results in lower porosity of the cake layer and higher cake layer resistance. Hydraulic pressure above 50 kPa results in the deformation of suspended particles and a more compact cake layer; thus, more dissolved or colloidal materials are retained. Based upon the humic substance content in secondary effluent from different wastewater treatment plants, higher humic substance concentration might contribute greatly to the irreversible fouling in the ceramic microfiltration of secondary effluent.

Keywords:

• Secondary effluent
• Microfiltration
• Particle matter
• Organic matter
• Membrane fouling

Acknowledgments

The study was financially supported by the Fundamental Research Funds for the Central Universities (YX2010-26) and Research Fund for the Doctoral Program of Higher Education of China (20100014120003).