Effect of Pyrolysis Temperature on Phosphorus Release From Fish Scale Biochar in Wheat Crop

ABSTRACT The conversion of agroindustrial waste into functional materials supports sustainable process engineering by enabling controlled phosphorus (P) release to improve nutrient use efficiency and reduce environmental impacts. This study assesses biochar from fish scales as a sustainable P source. Biochars produced at temperatures between 300°C and 600°C were characterized by yield, PZC, TGA, FTIR, SEM, elemental analysis, and total/available P by ICP‐OES. Phosphorus release kinetics were fitted to mathematical models. Increased pyrolysis temperature enhanced available P. The Korsmeyer–Peppas model best described release, indicating diffusion‐controlled slow release. Carbon content decreased with higher pyrolysis temperature. Wheat greenhouse trials confirmed fertilizer efficacy. Fish scale biochar is a promising sustainable phosphate source for process‐oriented agricultural technologies.