An Investigation into the Adsorption of Ammonium by Zeolite-Magnetite Composites

Abstract

The discharging of ammonium from industrial, domestic, and livestock sewage has caused eutrophication of the water environment. The objectives of this study are to synthesize magnetic zeolite (M-Zeo) by an eco-friendly, economical, and easy procedure and to investigate its suitability as an adsorbent to remove ammonium from an aqueous solution. Based on characterization from XRD, BET, and SEM-EDS, Fe3O4 was proved to successfully load on natural zeolite. The effect of pH, temperatures, reacting times, initial ammonium concentrations, and regeneration cycles on ammonium adsorption was examined by batch experiments. The ammonium adsorption process can be best described by the Freundlich isotherm and the maximum adsorptive capacity of 172.41 mg/g was obtained. Kinetic analysis demonstrated that the pseudo-second-order kinetic model gave the best description on the adsorption. The value of pH is a key factor and the maximum adsorption capacity was obtained at pH 8. By using a rapid sodium chloride regeneration method, the regeneration ratio was up to 97.03% after five regeneration cycles, suggesting that M-Zeo can be recycled and magnetically recovered. Thus, the economic-efficient, great ammonium affinity, and excellent regeneration characteristics of M-Zeo had an extensively promising utilization on ammonium treatment from liquid.

Municipal Solid Waste Fly Ash-Derived Zeolites as Adsorbents for the Recovery of Nutrients and Heavy Metals—A Review

“…Ammonium can also be desorbed by pH adjustment, either by increasing the pH to drive the equilibrium between ammonium and ammonia towards ammonia and releasing the compound as partially dissolved and gaseous NH 3 [229,230] or by decreasing the pH to reverse the electrostatic forces. However, the desorption process is typically further accelerated by adding competing ions (i.e., salts), as this will also contribute to the regeneration of the zeolite [150,160,231]. Adsorption of phosphate is usually done using metal-doped zeolites under slightly acidic conditions (Table 8).…”

Evaluation of ammonium issues in Indonesian groundwater: Potential sources and removal methods

“…In addition, different adsorbent materials have different adsorption capabilities. Many materials have been used for the adsorption of NH4 + , such as zeolite, natural clay, biochar, activated carbon, resin, and composite materials [49][50][51][52][53][54]. However, natural-based materials are promising due to their abundance and being environmentally friendly.…”

Zinc Oxide/Iron Oxide Nanocomposites for Photodegradation and Adsorption of Pollutants in Water

“…The goal is to reach a final pH able to reduce the inorganic carbon discharges from sewage effluents, avoiding the algal blooms in the receptor water body. 60 The surface complexation between exposed Zn and Fe Lewis acid in MZ would be the preferential mechanism from which NH 4 + remained adsorbed in the NCs. In a previous work, experimental and theoretical tools support the idea that a coordination bond could take place between NH 4 + and the ZnO NPs surface.…”

“…It is worth mentioning that this working pH was selected to favor the presence of NH 4 + instead of NH 3 and also to replicate the pH registered on sewage discharges. The goal is to reach a final pH able to reduce the inorganic carbon discharges from sewage effluents, avoiding the algal blooms in the receptor water body …”