A new technology for local treatment of leachate water from disposal sites has been developed by Geodesign AB. Two different models has been tested, towers based on light expanded clay and towers based on branches from Salix. The working principle of both tower models is as follows:

Working principle

• Evaporation of water phase.
• Sprinkle leachate water on top of Light Expanded Clay or branches of Salix.
• Addition of oxygen from air.
• Bacteria decomposition (bio-bed).
• Exposure to UV-light
• Concentration and precipitation of metals, salts and organic compounds.
• Redeposition of the concentrated sludge (metals, salts, organics.)

Benefits and advantages

• Contaminants stay on disposal area. No discharge to recipient. Minimum or zero environmental impact.
• Oxygen reduction (reduction of BOD and COD) will take place in the Evapo-Precipitation-Tower. Recipients will be protected against oxygen consumption from leachate water.
• All leachate water can be treated locally.
• Uncomplicated technology.

Technology

• The Evapo-Precipitation-Tower is base on 15-50 cassettes constructed into a tower.
• The cassettes are filled with light expanded clay (Leca) 12-20 mm diameter.
• The tower will be erected on a concrete foundation.
• Leachate water is intermittently sprinkled from top of cassettes.
• Slugde can be separated from treated leachate water in a dam.