Skip to main content

Treatment of municipal secondary effluent using polyolefin microfiltration membranes in vacuum-driven submerged membrane configuration to remove pathogens

Buy Article:

$17.50 plus tax (Refund Policy)

Or sign up for a free trial

Abstract:

The objective of this study was to characterize the application of HYDRAsub™ hollow fiber polyolefin (polypropylene/polyethylene) microfiltration membranes in the submerged membrane configuration in the treatment of municipal secondary effluent. Filtration was effected by applying vacuum while the membranes are immersed in the feed to be filtered. The effect of operating parameters such as filtrate flux and cleaning method (aeration and filtrate backwashing) on membrane fouling rate was studied. The feed and filtrate quality was monitored over the course of the testing by measuring the turbidity and total suspended solids.

Testing was conducted on secondary effluent feed at the La Salina wastewater treatment plant in Oceanside, California. The tests were conducted with a polyolefin hollow fiber membrane bundle (20 mm diameter) submerged in a tank containing the feed water. Outside-in filtrate flow was effected by applying suction on the lumen side of the membranes. Operating parameters were varied and their effect on membrane fouling rate was monitored. The permeability of fouled membranes was restored by chemical cleaning.

In the bench-scale test, the polyolefin membranes proved to be quite effective in providing excellent filtrate quality and maintaining a low fouling rate. Filtrate turbidity values were less than 1 NTU. No fiber clogging or breakage was observed during the course of the testing. The membranes showed complete recovery of permeability after chemical cleaning.

A second phase in the same pilot test was to test membranes in the commercial HYDRAsub™ membrane module configuration on the same feed source. The impact of scaling-up the membrane module on system parameters was studied. Some of the parameters studied were operating flux, fouling rate, backwash frequency, chemically enhanced backwash procedure, and CIP cleaning procedure.

The HYDRAsub™ commercial module prototype was operated for more than three months. It showed a lower value for stable operating flux compared to the bench-scale module. Feed conditioning with ferric chloride and chlorine addition and daily chemical backwashing were essential for stable operation. The addition of chlorine resulted in chloramine formation which was helpful in assuring disinfection in the membrane system. Membrane cleaning interval was 60 days. The filtrate quality indicated excellent turbidity reduction with filtrate turbidity <0.1 NTU and TSS removal. It was shown to be suitable for operation of a downstream reverse osmosis system at low fouling rates.

The study provided a basic understanding of the operating characteristics of polyolefin hollow fiber membranes in the treatment of municipal secondary effluent. It provided a basis for designing full-scale systems and drafting operational guidelines for them.

Document Type: Research Article

DOI: https://doi.org/10.2175/193864705783978672

Publication date: 2005-01-01

More about this publication?
  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

    A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Learn about the many other WEF member benefits and join today
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more