A review by Mojtaba Kordrostami and Ali Akbar Ghasemi-Soloklui, published in the journal Biochar, explores the innovative and expanding role of this carbon-rich material in nuclear science and technology. Biochar, obtained from pyrolyzing biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More at temperatures typically ranging from 300 to 700^°C, possesses unique qualities like a high surface area, substantial porosity, and an abundance of functional groups. These characteristics lend it a remarkable capacity for adsorption, making it a versatile and low-cost tool for environmental cleanup. The applications of biochar span nuclear waste management, radiation shielding, and catalysis, offering sustainable alternatives to complicated and costly traditional methods.

In nuclear waste management, biochar is highly effective at adsorbing and immobilizing radionuclides. Its large surface area and porous structure provide extensive sites for radioactive contamination adsorption, which significantly reduces the mobility of radionuclides. Mechanisms like ion exchange and the creation of long-lasting complexes with functional groups (such as phenolic, carboxyl, and hydroxyl groups) facilitate the selective retention of radioactive elements. Laboratory and field studies have demonstrated biochar’s ability to treat various radionuclides. For instance, modified biochar-based materials have achieved uranium removal efficiencies of up to 99% from contaminated water. Biochar derived from eucalyptus wood was found to effectively adsorb uranium with removal efficiencies reaching up to 90%. Furthermore, low-cost biochar made from hydrothermal carbonized reed straw showed effective uranium adsorption capacities reaching 120 mg g−1. Studies have also confirmed its effectiveness in removing radioactive cesium (134Cs and 137Cs) and strontium (90Sr), demonstrating high adsorption capacities.

Beyond waste management, biochar presents a novel approach to radiation shielding. Its high carbon content and layered structure provide a barrier against ionizing radiation, including gamma rays. Unlike conventional shielding materials like lead, which is heavy and toxic, biochar is non-toxic, lightweight, and environmentally sustainable. The material is flexible, making it suitable for portable shields and protective gear. Research shows that combining biochar with other substances enhances its protective properties. Biochar-polymer composites, for example, achieved up to 30 dB shielding effectiveness at 30% biochar content in the X-band frequency (8–12 GHz), effectively attenuating 99.9% of incident radiation. Additionally, when biochar derived from agricultural waste was added to concrete mixes, the resulting biochar-reinforced concrete reduced neutron radiation by up to 20% compared to standard concrete. This enhancement in neutron attenuation is promising for safety improvements in nuclear facilities. The structural and porous qualities of biochar also enable the uniform distribution of high atomic number materials, which boosts gamma radiation shielding effectiveness. The manufacturing process can be tuned for nuclear-grade biochar by controlling pyrolysis conditionsThe conditions under which pyrolysis takes place, such as temperature, heating rate, and residence time, can significantly affect the properties of the biochar produced.   More like temperature, which is critical for optimizing surface area and porosity, thereby improving radioactive material adsorption capabilities. Advanced techniques like Microwave-Assisted PyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More and Hydrothermal Carbonization (HTC) are being used to produce high-quality, specialized biochar. In the nuclear sector, economic evaluations point to biochar’s potential for cost-effectiveness throughout the entire lifecycle compared to conventional materials. Furthermore, life cycle assessments (LCA) consistently indicate that using biochar for remediation yields net environmental benefits due to its carbon sequestration properties, with sequestered carbon being up to 4.5 times greater than the total greenhouse gases emitted over the system’s life cycle. This ecological benefit, coupled with its versatility and effectiveness, positions biochar as a major component in advancing safe and sustainable nuclear technology. Ongoing research, including the use of machine learning to predict and optimize biochar properties, is expected to accelerate its transition from laboratory research to real-world applications in the nuclear industry.

Source: Kordrostami, M., & Ghasemi-Soloklui, A. A. (2025). Innovative applications of biochar in nuclear remediation and catalysis. Biochar, 7(74).