Microalgae, such as Chlorella vulgaris and Scenedesmus obliquus, are highly efficient at capturing carbon dioxide through photosynthesis, converting it into valuable biomass. This biomass can be further processed into carbon materials with applications in various fields, including water treatment. The reinforcement learning (RL) method was used to dynamically optimize environmental conditions for microalgae growth, improving the efficiency of biodiesel production. The contributions of this study include demonstrating the effectiveness of RL in optimizing biological systems, highlighting the potential of microalgae-derived materials in various industrial applications, and showcasing the integration of renewable energy technologies to enhance sustainability. The study demonstrated that Chlorella vulgaris and Scenedesmus obliquus, cultivated under controlled conditions, significantly improved absorption rates by 50% and 80%, respectively, showcasing their potential in residential heating systems. Post-cultivation, the extracted lipids were effectively utilized for biodiesel production. The RL models achieved high predictive accuracy, with R2 values of 0.98 for temperature and 0.95 for oxygen levels, confirming their effectiveness in system regulation. The development of activated carbon from microalgae biomass also highlighted its utility in removing heavy metals and dyes from water, proving its efficacy and stability, thus enhancing the sustainability of environmental management. This study underscores the successful integration of advanced machine learning with biological processes to optimize microalgae cultivation and develop practical byproducts for ecological applications.

Enhanced concrete construction through carbon incorporation in nanotechnology-enabled cementitious materials can be achieved using biochar. Biochar is a carbon additive, improving concrete’s mechanical strength and durability while reducing porosity and enhancing sustainability. The objective is to leverage the unique properties of biochar, derived from carbon nanotechnology, to improve mechanical strength durability, and reduce porosity in concrete. By integrating biochar, this research aims to develop a more resilient and environmentally friendly construction material, addressing performance and sustainability challenges in modern concrete construction. However, a significant research gap exists in understanding biochar's long-term effects and optimal concentrations in cementitious matrices. This study seeks to fill this gap by systematically investigating the performance enhancements and material properties imparted by biochar in various concrete formulations. The study demonstrated that incorporating carbon-rich biochar into concrete significantly enhances its structural performance and sustainability. The life-cycle assessment (LCA) of biochar-incorporated concrete reveals significant environmental benefits, highlighting its potential for sustainable construction practices. Integrating biochar into concrete enhances the material’s durability and longevity, reducing the need for frequent repairs and replacements, thus conserving resources. The use of biochar supports sustainable waste management by utilizing agricultural and forestry residues, thereby reducing waste and conserving natural resources. Nanotechnology in concrete, through the use of biochar, improves the material’s mechanical properties, creating a denser and more durable matrix that requires less maintenance. These findings underscore the dual benefits of enhancing concrete performance while promoting environmental sustainability, making biochar-incorporated concrete a promising solution for eco-friendly construction. Optimal biochar concentration at 7% by weight improved compressive strength by 20%, reduced freeze–thaw damage by 80%, and decreased chemical degradation by up to 85%. Additionally, biochar reduced concrete porosity and water absorption, creating a denser and more durable matrix. These results highlight the dual benefits of using biochar for carbon sequestration and improving concrete's mechanical properties, supporting its use in sustainable construction practices.