Environmental effects of using clay bricks produced with sewage sludge: Leachability and toxicity studies

Use of sewage sludge from wastewater treatment plants as a raw material for making clay bricks has been analyzed to be an option to dumping sludges into landfills. This alternative has been shown feasible and interesting due to the high rate of use of ceramic materials in the building sector. However, it meets with some environmental issues and some prejudices on the part of users.This work shows some leachability and toxicity tests (outgassing and offgassing) which demonstrate the environmental compatibility of these ceramic products to be used as building materials and even in deconstruction of the building once its useful life is ended.

► Analysis of leachability and toxicity from ceramic products made with different types of sewage sludges.
► The tests show the harmlessness of these materials during their life cycle.
► Application of the Netherlands Tank Leaching Test.
► Outgassing and offgassing tests for toxicity evaluation.
► Leaching balances of ceramic pieces made with different kinds of sludge, clay and eventually forestry waste.