Utilization of water treatment plant sludge for creating green bricks and examining its gamma radiation shielding potential

Abstract

This study presents the utilization of water treatment plant sludge (WTPS) as a feasible substitute in brick manufacturing, offering a sustainable solution with significant environmental benefits. The research presents a novel approach for handling low- to moderate-level radioactive wastes, using WTPS bricks as a shielding material for gamma rays. WTPS was geotechnically, physically, and morphologically characterized. Fired bricks were developed with various clay weight fractions combined with WTPS and assessed for mechanical properties. These bricks were analyzed using scanning electron microscopy, X-ray fluorescence, and X-ray diffraction. Bricks with 20% clay content exhibited the highest dry compressive strength of 27.26 MPa at 1,100°C, with a 127.15% increase in wet compressive strength when the firing temperature increased from 1,000°C to 1,100°C. Bricks with higher clay content demonstrated the lowest water absorption rates. Additionally, these bricks showed lower porosity and higher bulk density with increased firing temperature. Monte Carlo simulations showed that bricks with 20% and 10% clay content (FB203 and FB103) exhibited the highest linear attenuation coefficient values, effectively reducing gamma-ray leakage by factors of 3.43 and 3, respectively. This research offers sustainable construction materials and innovative radioactive waste handling solutions, promoting cleaner and safer energy in nuclear industries.