Recovering ammonium from real treated wastewater by zeolite packed columns: The effect of flow rate and particle diameter
Sofia Maria Muscarella, Vito Armando Laudicina, Daniele Di Trapani, Giorgio Mannina
Abstract
Nitrogen (N) recovery from wastewater is a desirable way to create a (N) neutral society in view of a circular economy approach. Nitrogen recovery from wastewater by employing adsorption columns filled with zeolite can be a very attractive solution. This study assessed the effect of influent flow rates (namely, 1.6 and 2.3 L h −1 ) and particle diameters (namely, 0.5–1.0 and 2.0–5.0 mm) of zeolite packed in columns on recovering NH 4 + from real domestic treated wastewater (RDTWW). Findings revealed that maximum NH 4 + recovery can be achieved by using zeolite with the smallest particle diameter (0.5–1.0 mm) and the highest influent flow rate (2.3 L h -1 ). The maximum NH 4 + adsorption rate was 1.2, 21 and 9.8 mg NH 4 + kg -1 h -1 after 205, 32 and 35 h of operation. NH 4 + adsorption data were analysed by fitting them to both pseudo-first and pseudo-second order kinetic models. The former model best approximated NH 4 + adsorption data. Such a result suggested that the amount of NH 4 + adsorbed depended solely on the amount of NH 4 + in contact with the zeolite surface. Results successfully established the application of zeolite-packed columns in removing NH 4 + from real domestic treated wastewater and the effects of process parameters. • Zeolite packed column for NH 4 + recovery from treated wastewater was studied. • NH 4 + initial concentration, flow rate and particle diameter effect were investigated. • NH 4 + adsorption is highly governed by particle size and flow rate. • The lower the particle diameter, the higher zeolite efficiency in NH 4 + removal. • Up to 56% of NH 4 + was removed by zeolite packed column.