Four low-cost iron-bearing geo-adsorbents were tested for As(V) removal without pretreatment: Montanit300® (M), diatomite (D), pumice (P) and black sand (BS). The solids were carefully characterized by different analytical techniques (SEM-EDX, TPD-pyridine, N₂ Physisorption, XRD and point of zero charge). The adsorption of As(V) was evaluated through isotherms and kinetic studies (bottled water matrix, pH${}_0=8,25$ g/L of solids), and experiments addressing pH effect (pH${}_0=3.6,7.5,11$) and the presence of interfering anions (Cl${}^{-}$, SO${}_4^{2-}$, NO${}_3^{-}$, PO${}_4^{3-}$). Experimental results were fitted to the Freundlich and Langmuir sorption isotherms. Under the employed conditions, P showed negligible adsorption, M and D presented adsorption capacities around 0.02 mg/g and, in spite its lower surface area, BS displayed the highest value (0.045 mg/g), which relates to a higher density of Fe species, M and D samples were easily regenerated (80%–100% desorption) through a basic treatment (0.01 M NaOH) and presented fast adsorption kinetics (1 h for D and seconds for M). BS showed a slow adsorption kinetic (24 h) and poor regeneration (only 50% desorption). Sample M (natural zeolite) resulted a promising option due to its remarkably fast adsorption kinetic, easy regeneration and adsorption capacity suitable for systems with relatively low As concentrations.

在不进行预处理的情况下，测试了四种低成本的含铁地质吸附剂的As（V）去除：Montanit300®（M），硅藻土（D），浮石（P）和黑砂（BS）。通过不同的分析技术（SEM-EDX，TPD-吡啶，N ₂物理吸附，XRD和零电荷点）仔细表征了固体。通过等温线和动力学研究（瓶装水基质，pH值）评估As（V）的吸附${}_0=8，25$ 克/升固体）和解决pH效应（pH${}_0=3。6，7。5，11$）和干扰阴离子（Cl${}^{-}$，所以${}_4^{2-}$，否${}_3^{-}$，PO${}_4^{3-}$）。实验结果适用于Freundlich和Langmuir吸附等温线。在使用条件下，P的吸附量可忽略不计，M和D的吸附量约为0.02 mg / g，尽管表面积较低，但BS的最大值（0.045 mg / g），与较高的Fe密度有关。物种，M和D样品通过碱性处理（0.01 M NaOH）易于再生（80％–100％解吸），并具有快速的吸附动力学（D 1 h，M 2s）。BS显示出缓慢的吸附动力学（24小时）和不良的再生（仅50％的解吸）。样品M（天然沸石）因其极快的吸附动力学，易于再生和适用于As浓度相对较低的系统的吸附能力而成为一种有前途的选择。