Application of Unmodified Brachystegia spiciformis Leaf Biomass in the Adsorption of Nitrate Ions

The application of Brachystegia spiciformis leaf powder in the adsorption of nitrate ions was conducted on both synthetic and real water samples. Optimum adsorption conditions for nitrate adsorption were pH of 4, equilibration time of 45 min, and biosorbent dose of 1.5 g. Batch adsorption was used in this study and nitrate ions were analyzed using the salicylic acid method. Non-linear adsorption isotherm fitting indicated that the experimental data was described well by the Langmuir model with a monolayer adsorption capacity of 5.97 mg/g. The Langmuir's separation factor, R-L, values were in the range, 0 < R-L < 1, indicating favorable interactions between nitrate ions and Brachystegia spiciformis leaf powder adsorbent. The pseudo first order model provided the best fit to the experimental kinetics data with an R-2 value of 0.9880 and a rate constant of (7.3 +/- 0.1) x 10(-2) min(-1). The Brachystegia spiciformis leaf powder adsorbent achieved 100% and 78% nitrate ions removal from dam water and industrial effluent water respectively. We have shown that a cheap biomass adsorbent that has high activity towards nitrate ions adsorption can be produced and applied in the adsorption of nitrates from water.

Automated summary

The study demonstrated the use of Brachystegia spiciformis leaf powder as an effective adsorbent for removing nitrate ions from water, achieving high removal rates from both dam water and industrial effluent. The experimental data fit well with the Langmuir model, indicating favorable interactions between nitrate ions and the adsorbent. The pseudo first order model provided the best fit to the kinetics data, with a rate constant of (7.3 +/- 0.1) x 10(-2) min(-1).