Just hearing the term gamma radiation might make you think of The Incredible Hulk, the giant green comic antihero transformed due to exposure to gamma rays. And you’d be forgiven if the title of a new study, “Utilization of Water Treatment Plant Sludge for Creating Green Bricks and Examining Its Gamma Radiation Shielding Potential,” would make you ask if water treatment plant sludge could have protected Bruce Banner (the Hulk’s normal-human alter ego). Despite its science fiction sound, gamma radiation, also known as ionizing radiation, exists with a wide range of uses in the medical, agricultural, nuclear, and industrial sectors. While traditional materials like lead and concrete are effective at minimizing exposure to harmful radiation, they are becoming unsustainable. One promising concept at nuclear power plants is to expand the use of fired bricks beyond load bearing to shielding materials. What other earthly material might work?
Authors Rohitash Saran, Sanchit Saxena, Hritaban Acharya, Prathmesh Bhadane, and Kaling Taki That explore using water treatment plant sludge as a sustainable and efficient alternative construction material. The benefits of using WTPS in this fashion are not only using a recycled product for radiation shielding, but minimizing the environmental impact of sludge disposal, which is usually dumped in water bodies, landfills, or incinerators. This novel research addresses a knowledge gap about the feasibility of 100% WTPS bricks by using synthesized bricks as nuclear radiation shielding material in nuclear power plants and radioactive waste disposal sites. Learn more about how this sustainability research will help the construction industry, as well as shielding applications for the nuclear industry in the Journal of Hazardous, Toxic, and Radioactive Waste at https://doi.org/10.1061/JHTRBP.HZENG-1406. The abstract is below.
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.
Explore the potential of a second life for sludge as a radiation shield, benefitting both water and nuclear energy engineering, in the ASCE Library: https://doi.org/10.1061/JHTRBP.HZENG-1406.
