Laterlite Expanded Clay is successfully used for water filtration in drinking water treatment plants and for wastewater purification, often associated with sand in dual media filtration systems or in biological filtration systems in fixed-bed biofilters.
Some of the main advantages are:
- it provides a large surface areafor filtration because of the intergranular and intragranular porosity of expanded clay
- it provides ideal conditions for development of the biofilm(consisting mainly of bacterial colonies) in which the process of biological purification actually takes place, because of the dense network of cavities within the expanded clay granules
- its durability. For all practical purposes, expanded clay is an everlasting material that does not rot, does not degrade over time, and resists acids, bases, solvents, and freeze/thaw cycles with no chemical or physical alteration.
- it is extremely easy to lay and maintainbecause of its lightness and its suitability for pumping.
- its low and controlled density means that pump filters are easy to clean (by backwashing) thereby enabling pumps of lower power to be used.
Laterlite Expanded Clay is an excellent granular medium for use in biofilters, bio-scrubbers, packed towers (air biofiltration) and many types of gas purification plants, that eliminate the airborne odours emitted by wastewater treatment plants, sewage treatment plants, industrial processes, and effluents.
Moist Laterlite Expanded Clay is used as a highly efficient filter bed allowing for the growth of the microorganisms that reduce biological odours of air flowing through the filter thanks to its dense network of cavities and its ability to retain moisture,
Because of its resistance to crushing and to acids, bases, solvents, microorganisms, insects, and freeze/thaw cycles, the excellent durability of Laterlite Expanded Clay far exceeds that of alternative odour control media based on organic materials such as wood chip, shells, or peat/heather.
Expanded Clay Laterlite is also used as substrate for constructed wetlands water treatment systems and as a floating cover for sludge storage tanks to limit gas and odours emissions.