SELANGOR, Malaysia — Sept. 1, 2015 — While wastewater can be reused for drinking water and other uses, researchers have studied the possibility of using another part of the process — sewage sludge — in the making of concrete, according to a press release.
Predictions expect sludge volume from sewage water treatment to rise, but disposal options in Malaysia are limited because of environmental concerns, noted the release. Wastewater plants cannot bury the sludge because of its high heavy metal content.
Concrete in the country is in high demand, so a recent study by researchers at the Universiti Teknologi MARA investigated the possibility of using the sludge as an alternative cement material, stated the release.
The researchers produced domestic waste sludge powder (DWSP), then mixed it with cement to create different types of concrete (Grades 30, 40 and 50), shared the release. Then they compared it with normal concrete in terms of compressive strength, water absorption and permeability, and permeability to salt.
Results showed potential for using DWSP in concrete, but more detailed research is needed to produce a quality product, reported the release. Except in Grade 40, the compressive strengths of DWSP concrete decreased as DWSP increased in the concrete mix.
"Water absorption and water permeability increased as the percentage of DWSP increased," explained the release. "However, normal concrete was more permeable than DWSP concrete of Grade 40, suggesting that DWSP enhanced the durability of this concrete. Additionally, the resistance to chloride permeability increased for concretes with up to 15 [percent] DWSP."
You can find the entire release here.