Ammonium adsorption, desorption and recovery by acid and alkaline treated zeolite

In this study, the suitability of zeolite as a possible medium for ammonium adsorption, desorption and recovery from wastewater was investigated. Specifically, batch adsorption and desorption studies with solutions enriched in NH4+ were conducted employing zeolite to evaluate how the chemical treatment and contact time affect adsorption and desorption. Several experimental tests were carried out considering both untreated and treated zeolite. Untreated and HCl-Na treated zeolite adsorbed up to 11.8 mg NH4+ g−1 and showed the highest efficiency in recovering NH4+ from aqueous solution. Regardless of pre-treatment, treatments with NaCl resulted in higher and faster adsorption of NH4+ than treatments with CaCl2 and MgCl2.