Expanded Clay Aggregate, ECA, Leca, Natural Organic Matter (

Natural Organic Matter (Nom) Removal

  • Recent researches in Norway concerning coagulation-contact filtration for the removal of natural organic matter (NOM) include filter media based on Expanded Clay Aggregates  (ECA®) filters and Chitosan as a biodegradable and natural coagulant. 
  • The main benefits associated with Chitosan as a coagulant are:
    • Reduced solids production compared with other conventional coagulants
    • Treatment and disposal of biodegradable, natural sludge, which does not contain metal hydroxides from metal-based coagulants. 
  • Expanded Clay Aggregate (ECA®) can be produced with an inverse relationship between density and grain size, giving it an approximation to the perfect situation of decreasing grain size in the direction of flow.
  • Traditionally, this significant property of a filter bed is utilized in up-flow filters, or in dual or multimedia down-flow filters with combinations of two or more filter media. 
  • This research showed the pilot-scale treatment of Natural Organic Matter (NOM)-containing waters using Expanded Clay Aggregate (ECA®) as a filter media and Chitosan for coagulation. 
  • Expanded Clay Aggregate (ECA®)  is considered as the best filter media to use due to its inert (natural) nature, biological regeneration (It can be used over and over again) and lastly it is biodegradable.