Residual As(V) in Aqueous Solutions After Its Removal by Synthetic Minerals

Arsenic (As) is a carcinogenic element and the As-contamination in drinking water is considered a major health problem. Thus, we assessed the As-removing ability of the aqueous solution of six synthetic minerals: 2-line ferrihydrite (2ℓFh), goethite (Gt), hematite (Hm), layered double hydroxide (LDH), calcined layered double hydroxide (cLDH), and poorly crystallized aluminum hydroxide (pAlHyd). Our findings showed that the cLDH and LDH exhibited the highest arsenic adsorption capacity (MAC-As), in the order of 30.68 mg g and 15.40 mg g, respectively, in comparison to the other mineral matrices. However, the use LDH and cLDH as adsorbent materials should be evaluated cautiously because these minerals were not able to maintain the value of As-Residual (RC-As) in solution within the safe limit of drinking water in all of the utilized initial concentrations of As (As(V)). On the other hand, the 2ℓFh presented the highest efficiency to maintain residual concentrations of arsenic within limit of drinking water, when the As(V) was smaller than 30.0 mg L. The pAlHyd and Gt were also efficient adsorbents, maintaining RC-As concentration within the safe limit of drinking water, when the initial concentration was equal or smaller than 11.25 mg L.