Groundwater contamination by arsenic (As) is a serious issue in many countries, particularly in middle- and low-income nations. High concentrations of As in drinking water and groundwater cause serious health problems. Numerous technologies, such as ion exchange, oxidation, coagulation–flocculation, phytoremediation, membrane filtration, and adsorption, have been applied to remove As from the water environment. Among these technologies, adsorption is the preferred method in low- and middle-income countries due to its affordability, high efficiency, and ease of design, operation, and maintenance. Along with this technology, a variety of materials have been developed and investigated for their ability to remove As from water environments, though iron-based adsorbents have been reported to be the most effective. Thus, the aim of this paper is to briefly review the sources of As and the prevalence of As species in water bodies, as well as the currently available technologies for As removal. A detailed analysis of recent studies on iron-based adsorbents used to remove As from aqueous solutions in both laboratory conditions and field conditions is presented.

This study investigated the removal capacity of arsenic (As) by natural manganese ore materials (OMN). We used scanning electron microscopy (SEM), X-Ray Fluorescence (XRF), and point-of-zero charge pHPZC to characterize the OMN. The As adsorption capacity of OMN was tested at different pHs and flow rates in the adsorption columns. The results indicated that pH affected the As removal capacity of OMN. The column adsorption was carried out continuously at a constant flow rate of 10 mL/min for 30 days. The feed solutions with As concentrations of 0.3 and 0.1 mg/L were pumped into two columns in an up-flow mode. Two column adsorptions were 7.5 cm in diameter and 17.5 cm in height and were packed with 900 g of OM. During the 30 days of the experiments, As concentrations in the effluent ranged from 0.006-0.217 mg/L and 0.003-0.051 mg/L, respectively, when As concentrations in the influent were 0.3 and 0.1 mg/L. The As concentration in the treated solution during the first 12 days, when using a solution containing As at a concentration of 0.1 mg/L, was below the WHO guidelines for drinking water quality and national technical regulation on domestic water quality (QCVN 01-1:2018/BYT) (0.01 mg/L for As).