Expanded Clay Aggregate, ECA, Leca, Bio filtration Pretreatm

Bio filtration Pretreatment

  • Biofouling control is known to be a major problem in operating membrane systems.
  • A laboratory-scale Reverse Osmosis (RO) system was setup at a water reclamation plant to study the effectiveness of using Expanded Clay Aggregate (ECA) as a bio-filter in the pretreatment process to control the biofouling. 
  • The biological activity in the Reverse Osmosis system such as product, feed and rejected streams was tested using the standard serial dilution technique. 
  • Parameters such as permeate flow-rate and differential pressure of the system were also discovered. Effects of bio-filter on Dissolved Organic Carbon and Assimilable Organic Carbon removals were carried out. 
  • Bio-filtration, using Expanded Clay Aggregate (ECA) as a bio-filter was discovered to be an ideal way of Dissolved organic carbon and Assimilable Organic Carbon removals.
  • It has removal efficiencies of 45 – 49% and 40 – 45% at a contact time of 25 - 30 minutes.
  • It was also discovered that using the bio-filtration as a pretreatment minimized the rate of biofouling. This study showed the suitability and the importance of the bio-filter (ECA) as a simple and economical way of biofouling control for Reverse Osmosis membrane.