For thousands of years, bricks have been made from clay. The water treatment plant sludge is extremely close to brick clay in chemical composition, suggesting that it could be a potential substitute for brick clay.
HEGAZY, BADR EL-DIN E. ; FOUAD, H.A. ; HASSANAIN, A.M. (2012): Brick Manufacturing From Water Treatment Sludge And Rice Husk Ash. In: Australian Journal of Basic and Applied Sciences: Volume 6 , 453-461. URL [Accessed: 24.07.2019]