Novel iron-based nanocomposites for arsenic removal in groundwater: Insights from their synthesis to implementation for real groundwater remediation

Abstract

The presence of arsenic in water samples of different nature represents a serious problem with severe consequences all around the world, but mainly in India, China, Central Africa, and Latin America. In this regard, the groundwater of the Bahía Blanca region (Bs. As. Province, Argentina in Latin America) clearly represents this problem, containing As levels higher than 200 µg L−1. On many occasions, this resource is almost the unique source of water for human consumption and other uses. The available technology is not suitable and efficient enough to provide solutions in this context. This work proposes the preparation of low-cost, easy handle and efficient material to mitigate the As contamination problem. The aim is to provide useful materials that may be implemented in the real environment; in particular, to remediate groundwater from critical rural zone. Nanocomposites with different nominal ratios of zeolite and magnetite nanoparticles were synthesized. These materials were entirely characterized by FTIR, XRD, TEM, capillary microelectrophoresis, and dynamic light scattering. Adsorption assays were performed in batches using groundwater samples collected in the rural region of Bahía Blanca (southern Chaco-Pampean plain, Argentina). The stability and reuse capability of these adsorbents were evaluated. The possibility of designing a continuous flow system was also explored by comparing the As removal data achieved in this condition with the percentage of removal corresponding to the performed batch assays. The findings collected within this work appear very promising in view of the design of a household system to remove As from groundwater.