<b>Utilization of Cow Bones as Precursor for Eco-Friendly Liquid Fertilizer Production</b>

Abstract

Cow bone serves as a sustainable source for organic phosphorus extraction and eco-friendly waste disposal. This study investigates the production of liquid fertilizer from cow bones through acidification (50%, 60%, and 70% nitric acid) and subsequent neutralization with ammonia. Quantitative analysis revealed total phosphorus concentrations of 3850 ± 120 mg/L (0.385% w/w), 4620 ± 145 mg/L (0.462% w/w), and 5280 ± 160 mg/L (0.528% w/w) for 50%, 60%, and 70% acid-treated samples, respectively. Total nitrogen content ranged from 1.85 ± 0.08% to 2.43 ± 0.11% w/w, with nitrate-nitrogen comprising 68-72% and ammonium-nitrogen 28-32%. Calcium concentrations ranged from 1,250 ± 65 to 1,840 ± 85 mg/L. Phosphorus recovery efficiency increased from 62.3 ± 2.8% to 78.1 ± 3.2% with increasing acid concentration. The fertilizers exhibited pH of 6.4-6.9 and electrical conductivity of 4.8-6.2 mS/cm. UV/Vis spectroscopy revealed shifts in absorption peaks following treatment, indicating molecular structural changes. FTIR analysis confirmed removal of organic components (disappearance of -C-H bonds at 2922.2 cm-1 and 2853.3 cm-1) while preserving essential phosphate ions (1004.5-1030.6 cm-1) and nitrogen-containing functional groups (1628.8-1638.2 cm-1). This study provides quantitative evidence supporting the potential of cow bone-derived liquid fertilizer as a sustainable alternative for addressing agricultural nutrient deficiencies while minimizing waste.