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.