Correlations between physico-chemical properties and nickel adsorption parameters in soils used in sanitary landfill liners

Ricardo Antonio Ferreira Da Silva,Danilo Brito Da Costa,William De Paiva,Márcio Camargo De Melo,Veruschka Escarião Dessoles Monteiro

doi:10.14295/ras.v34i3.29914

Ricardo Antonio Ferreira Da Silva, Danilo Brito Da Costa + Show 3 more

Open Access

https://doi.org/10.14295/ras.v34i3.29914

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Abstract

The adsorption of heavy metals by sanitary landfill liners represents a measure of protection of surface and groundwaters against contamination by metals, mitigating risks to public health. Hence, this research aimed to identify, from correlations, the influence of physico-chemical properties of soils applied in landfill liners using nickel adsorption parameters. Batch equilibrium tests with initial nickel concentrations of 45 to 1440 mg.L-1 were performed in clayey sand and bentonite clay soil, as well as in mixtures. Nickel adsorption parameters from Freundlich and Langmuir isotherm models were obtained, exhibiting a better adjustment in the Freundlich model based on R² and RMSE criteria. Thus, the addition of bentonite clay improved the adsorption to nickel, and the cationic exchange capacity (CEC) was the property that considerably influenced the metal retention in the studied soils.

Highlights

Sanitary landfill liners are waterproofing barriers that aim to prevent the offsite migration of liquid and gaseous byproducts generated by landfills, avoiding a possible contamination of the underground, surface and groundwaters
The clayey sand is from a quarry located in the Campina Grande Sanitary Landfill (CGSL), and the bentonite clay is from a quarry in the city of Boa Vista – PB, apart 25 km from the CGSL
According to test method NBR 13896 (ABNT, 1997), this is an admissible value for waterproofing of sanitary landfill base liners

Summary

Introduction

Sanitary landfill liners are waterproofing barriers that aim to prevent the offsite migration of liquid and gaseous byproducts generated by landfills, avoiding a possible contamination of the underground, surface and groundwaters. The most used liners in landfill bases are composed by compacted layers of clayey soils or by the combination of these layers with geosynthetics, regarding minimum waterproofing requirements (LOCASTRO and DE ANGELIS, 2016). The liquid byproduct produced by landfills, known as leachate, has as main toxic component heavy metals. These metals can be transported in soil by physical processes of advection or dispersion, and can be retained as a result of chemical processes, such as adsorption (FETTER et al, 2018). The understanding of the influence of physico-chemical properties of soils in the adsorption of heavy metals is essential for the choice of materials to be used as base liners in sanitary landfills, and contributes to an effective protection of natural resources

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