Arsenic Retention on Technosols Prepared with Nanoparticles and Ferric Soil from Mine Drainage Water

Darío R Bolaños-Guerrón,Johanna Paz,Carina Stael,María Balseiro-Romero,Viviana P Sánchez-Gómez,Andrés R Izquierdo

doi:10.1155/2018/6840856

Darío R Bolaños-Guerrón, Johanna Paz + Show 4 more

Open Access

https://doi.org/10.1155/2018/6840856

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Abstract

Mining activities generate a large amount of solid waste and acid drains that contain heavy metals in high concentrations. In wastewater of gold mines from Southern Ecuador (Portovelo), arsenic concentrations between 4.8 and 27.5 μg/L have been detected. In this context, the objective of this study is to prepare a technosol, which was used in the capture of arsenic dissolved in the acid drains. Technosol was elaborated using a clay-silty soil (iron-rich soil), collected in the mining area, and iron nanoparticles synthetized with the extract of orange peel. The technosol was experimentally characterized using adsorption isotherms and uptake kinetics. Besides, a mathematical model was developed using Vensim® to scale the process and predict the dynamic behavior of the adsorbent. Results indicate that adsorption behavior of technosol can be fitted to Langmuir isotherms (R2 > 0.9), with 95% of adsorption of As from an input of 4.5 mg/L. The model will be useful to predict the time needed to remedy contaminated water and the duration of the adsorbent (until its saturation).

Highlights

Arsenic is a trace element of high toxicity and carcinogenicity, whose natural environmental distribution presents an enormous variability and ubiquity due to a combination of climate and geology but without a significant correlation [1, 2]
Arsenic concentrations in the environment may increase due to anthropogenic activities, being agriculture, mining, and petroleum refining, the main activities contributing to the contamination of soil and water resources [3]
Many studies have been carried out by the World Health Organization (WHO), the European Union (EU), and the United States Environmental Protection Agency (US EPA), among other international organizations, in order to establish the best water decontamination techniques according to toxicity and economical studies [5]

Summary

Introduction

Arsenic is a trace element of high toxicity and carcinogenicity, whose natural environmental distribution presents an enormous variability and ubiquity due to a combination of climate and geology but without a significant correlation [1, 2]. Mine drainage water may present enormously high concentrations of heavy metals, with the consequent risks for the ecosystems and human health. Due to the development and application of novel materials with extremely high sorbent capacities, this technique can be applied with a significant efficiency. In this context, the use of nanosorbents has emerged as a promising alternative for the cleanup of As-contaminated water (zero valent and iron oxide nanoparticles), due to their distinctive and advantageous properties, such as the small size, high surface area, and high reactivity due to the large number of sorption active sites [11, 12]

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