Ammonia removal from an aqueous solution by the use of a natural clay

A series of batch experiments were conducted to ascertain the ability of a natural clay (smectite clay) to remove ammonia from synthetic wastewater samples composed of ammonium acetate (CH3CO2NH4). The reaction with ammonia was observed to be very rapid, with half the amount of ammonium ions being sorbed in the first minute in all instances. Estimated ammonia adsorbed was favoured by low sorbate concentration, small particle size of sorbent, and an alkaline medium. The sorption kinetics studies strongly indicated that the sorption process was largely governed by interfoliaire spaces diffusion and that ten minutes are sufficient to adsorb a maximum of ammonia. The temperature is without effect on the sorption from 20 degree to 40 degree. The equilibrium data fitted the Langmuir sorption model, a possible indication of a monolayer coverage of ammonium ions on the surface of the particle. The Langmuir correlation of the equilibrium data suggested that ion exchange might have been the dominant sorption mechanism. The smectite clay seemed to have some fairly good potential for ammonia removal with the sorption capacity being about 0,5 mmol (NH4+) per 100 mg of sorbent. However, this needs to be investigated further through flow through conditions and in the presence of other ions as in real wastewater.