Jun Yao, Qingna Kong, Huayue Zhu, Yuyang Long, Dongsheng Shen. Adsorption characteristics of nitrite on Friedel’s salt under the landfill circumstance. Chemical Engineering Journal. DOI: 10.1016/j.cej.2014.06.007.

Abstract

Landfill sites contain abundance of Friedel’s salt. In this study, Friedel’s salt was prepared by a coprecipitation method and characterized by the X-ray diffraction (XRD) pattern and Fourier transform infrared (FTIR) spectroscopy. The adsorption characteristics of nitrite on Friedel’s salt were investigated to reveal the effect of Friedel’s salt on the migration of nitrite in the landfill. The adsorption was an exothermic process and could be well described by Lagergren-first-order kinetics and Langmuir-Freundlich model, with a maximum adsorption capacity of 3.817 mg g^-1. Low pH was beneficial to the adsorption process. However, the Cl^-, SO₄^2-, PO₄^3- and organic matter in the leachate could restrict the adsorption to a low level. The results suggested that Friedel’s salt could affect the migration of nitrite in the landfill, which was related with the variation of the landfill circumstance.