Lentil Hydrothermal Carbonization: A Dual Solution for Water Purification and Growth Enhancement

Amid growing concerns regarding water quality and food security, our study pioneers a dual-purpose approach utilizing the lentil hydrothermal carbonization (HTC) approach. We present activated carbon derived from lentils, showcasing exceptional efficiency with a remarkable > 99% removal of Methylene Blue (MB), starting with an initial concentration of 4.4 µg/ml. Optimization of activation parameters revealed a straightforward and environmentally friendly process, eliminating the need for an inert atmosphere. The kinetic study emphasized a close alignment with a first-order reaction model, with a rate constant of 0.127 $$\:{s}^{-1}$$ . The activated carbon’s performance was further evaluated for its ability to remove food dyes, achieving removal efficiencies of 32% for red dye and 65% for green dye. Finally, the lentil-derived supernatant, a byproduct of HTC, proved instrumental in promoting hydroponic maize growth, manifesting significant improvements in shoot and root parameters, increasing their weight by 94% and 200%, respectively. This study presents an innovative and sustainable solution at the confluence of water purification and agricultural enrichment, contributing to the global discourse on resource efficiency and waste minimization.