Removal of Nitrate from Aqueous Solution by Bio-Calcium from Iraqi Eggshells

Abstract

Nitrate contamination of drinking water is one of Iraq's environmental problems in some of its most vital lands as a result of sewage sedimentation, agricultural fertilizer waste, and remnants of war. Iraqi egg waste (bio-calcium Iraqi eggshells) was tested to remove nitrates, which is considered one of the best investments to achieve industrial sustainability on the one hand and reduce environmental problems on the other. The optimum conditions for removal were pH = 6, 120 min, 0.5 g Iraqi eggshells, and 150 rpm where 95.73% of nitrates were removed by Iraqi eggshells. The equilibrium data analysis determined that the (Langmuir isotherm) model was the best for describing adsorption, while (pseudo-second-order) adsorption kinetics were significantly appropriate for demonstrating nitrate adsorption kinetics, and a statistical model for nitrate removal percentage was developed.