Kinetic and biosorption analysis of ammonia‑nitrogen (NH3−N) by Bacillus subtilis strain ON358108, isolated from eutrophicated Dal Lake waters in Srinagar, India

Abstract

Ammonia‑nitrogen (NH3-N) is pivotal in aquatic ecosystems, yet its excess poses ecological and health risks. Through batch experiments, this study investigates Bacillus subtilis' efficacy in degrading ammonia‑nitrogen (NH3-N) Bacillus subtilis adapted to concentrations up to 150 mg/L over days, influenced by temperature, pH, initial ammonia‑nitrogen (NH3-N) concentration, and biomass abundance. In the present investigation, the biosorption of ammonia nitrogen (NH3-N) (from 100 ppm concentration of ammonia nitrogen solution) was maximum (about 89 % ± 1.5 mgg) under conditions: pH 7, adsorbent dosage 0.5 g in 50 mL of ammonia‑nitrogen solution, and temperature of 30 °C. Analytical techniques including SEM, XRD, BET, TEM, and FTIR corroborated findings. Pseudo-second-order kinetics and Langmuir model fitting indicated physical and chemical involvement in biosorption. This study underscores Bacillus subtilis' potential for ammonia‑nitrogen (NH3-N) remediation, providing insights into optimized conditions and mechanistic understanding crucial for water quality management and ecosystem preservation.