Simultaneous removal of ammonium nitrogen, dissolved chemical oxygen demand and color from sanitary landfill leachate using natural zeolite

C Genethliou; I E Triantaphyllidou; D Giannakis; M Papayianni; L Sygellou; A G Tekerlekopoulou; P Koutsoukos; D V Vayenas

doi:10.1016/j.jhazmat.2020.124679

Simultaneous removal of ammonium nitrogen, dissolved chemical oxygen demand and color from sanitary landfill leachate using natural zeolite

J Hazard Mater. 2021 Mar 15:406:124679. doi: 10.1016/j.jhazmat.2020.124679. Epub 2020 Dec 3.

Authors

C Genethliou¹, I E Triantaphyllidou², D Giannakis¹, M Papayianni¹, L Sygellou³, A G Tekerlekopoulou⁴, P Koutsoukos⁵, D V Vayenas⁵

Affiliations

¹ Department of Chemical Engineering, University of Patras, GR 26504, Rion, Patras, Greece.
² Department of Chemical Engineering, University of Patras, GR 26504, Rion, Patras, Greece. Electronic address: teva@upatras.gr.
³ Institute of Chemical Engineering Sciences, Foundation for Research and Technology Hellas (FORTH/ICE-HT), 26504 Patras, Greece.
⁴ Department of Environmental Engineering, University of Patras, 2 G. Seferi Str, 30100 Agrinio, Greece.
⁵ Department of Chemical Engineering, University of Patras, GR 26504, Rion, Patras, Greece; Institute of Chemical Engineering Sciences, Foundation for Research and Technology Hellas (FORTH/ICE-HT), 26504 Patras, Greece.

PMID: 33316665
DOI: 10.1016/j.jhazmat.2020.124679

Abstract

In this study, natural zeolite with maximum adsorption capacity of 3.59 mg g^-1 was used for the simultaneous removal of ammonium nitrogen (NH₄⁺-N), dissolved chemical oxygen demand (d-COD) and color from raw sanitary landfill leachate (SLL). Saturation, desorption and regeneration tests of zeolite were performed. Optimum adsorption conditions were found for particle size 0.930 µm, stirring rate of 1.18 m s^-1, zeolite dosage of 133 g L^-1 and pH 8. NH₄⁺-N removal efficiency reached 51.63 ± 0.80% within 2.5 min of contact. NH₄⁺-N adsorption follows mostly the linear pseudo-second order model, with intra-particle diffusion. NH₄⁺-N desorption follows the linear pseudo-second order model. Adsorption data fitted to the Temkin Isotherm in linear and nonlinear forms. Saturation tests showed that zeolite can be efficiently used in three successive adsorption cycles. NH₄⁺-N release from the saturated zeolite was not completely reversible, suggesting that the zeolite may be used as slow ΝΗ₄⁺-Ν releasing fertilizer and an attractive low cost material for the treatment of SLL. NH₄⁺-N removal with the regenerated zeolite exceeded 40% of the initial concentration in the fluid within 2.5 min. SEM analysis showed significant changes through saturation and regeneration. XPS revealed that adsorption of ΝΗ₄⁺-Ν to the zeolite was accompanied by ion exchange.

Keywords: Adsorption-desorption; Color; Kinetic models; NH(4)(+)-N; d-COD.