Batch Adsorption of Ammonium Ions from Synthetic Wastewater using Local Cameroonian Clay and ZnCl2 Activated Carbon

Zing Zing Bertrand, Belibi Belibi Placide Desire, Ankoro Naphtali Odogu, Kouotou Daouda, Ndi Julius Nsami, Ketcha Joseph Mbadcam

Local Cameroonian clay and ZnCl₂ activated carbon were used for the adsorption of NH₄⁺ ions from synthetic wastewater. The Batch adsorption experiments were conducted and optimal conditions were established to better understand the effects of solution pH, initial ammonium ions concentration, adsorbents dose and contact time. The time-dependent experimental studies showed that, the adsorption quantity of ammonium ions increases with initial concentration and decrease with adsorbents dose. The ammonium ions uptake was very fast and reached equilibrium within 10 and 15 min with ZnCl₂ activated carbon and Soukamna Clay. Both ZnCl₂ activated carbon and Soukamna Clay gave best adsorption results at pH 2 and 6. FTIR, powder X-ray diffraction, chemical analysis, TGA and DSC analysis were used to characterize the Soukamna Clay. The adsorption equilibrium were confronted using Langmuir, Freundlich, Temkin and D–K–R isotherm models and their applicability were judged by comparing the correlation coefficients and the experimental calculated quantities. The D–K–R, Temkin and Freundlich isotherms models best fitted to the experimental data for Soukamna Clay while the D–K–R isotherm model fitted well with ZnCl₂ ̵ AC. The adsorption mechanism was analyzed using the pseudo-first order, pseudo-second order, the Elovich kinetic and intra-particle diffusion models. The pseudo-second order kinetic model correlates better the experimental and calculated data than the other three kinetic models which suggests that, chemisorption was more dominant with both adsorbents. Soukamna Clay and ZnCl₂ ̵ AC used successfully as a low-cost adsorbent for the removal of NH₄⁺ ions from aqueous solution can have promising application in industrial wastewater treatment.