Scientists from South Ural State University, Russia, have improved the sustainability of building materials by combining sludge from water treatment plants with clay to create durable ceramics.
Sludge is formed at drinking water treatment stations when natural water is treated with coagulants. Large amounts of this sludge is pumped into sewage treatment plants, where it causes additional strain on municipal services. Water treatment sludge, if obtained in the right way, can be used to improve the properties of building materials. The team at South Ural State University (SUSU) have developed a new freeze-thaw method which combines clay and water treatment sludge, the details of which were published in the journal Materials.
A research group led by SUSU’s Aleksandr Orlov has determined that 4% of the precipitate obtained by the team’s freeze-thaw method allows for a reduction in the firing temperature of the moulded material, and also reduces the sensitivity to drying and accelerates its process.
Orlov said: “We have comprehensively considered the process of obtaining sludge and its use for modifying building materials. The papers that we have analysed for our research reflect the results of only one part of the process. Of course, the practice of modifying ceramics with building materials exists; in America, expanded clay is obtained this way. However, in Russia, such experiments have almost never been carried out, and work has not been done on the example of Chelyabinsk at all.”
The team tested the material using a hydraulic press, a furnace, and a derivatograph. The data on the improvement of the properties of ceramics have been reviewed in the laboratory of the Chelyabinsk plant specialising in the production of ceramic blocks and bricks.
The introduction of such a method of waste treatment and sludge use may be of interest to enterprises producing building materials. In this case, the results of the research by the SUSU scientists will be useful in the field of resource saving, ecology, and construction.