Removal of Arsenic from Groundwater Using Lamdong Laterite as a Natural Adsorbent

Abstract

2 ), depending on the types of sediment or minerals in the water source areas or the pH value of the water [3]. While As (V) species are less toxic and strongly adsorbed to different types of mineral surfaces, especially iron hydroxides/oxides [4], As (III) species are not only more toxic than arsenate but also more difficult to eliminate from water [5].Both arsenic forms had been detected in Vietnam. Winkel et al. [6] has stated that the arsenic

Dynamic Study and Modelling of Arsenic Removal from Groundwater Using Ferromagnetic Carbon as Fixed Bed Adsorbent in Column

“…The value of pH of groundwater sample between 5.5 and 9 indicates that likely arsenic species could be H3AsO3, H2AsO4and HAsO4 2according to the equilibrium diagram of arsenic speciation [10]. These results are in agreement with conclusions of previous works in this region [14,17,31] indicating that the main forms of arsenic are probably As (III), As (V) and particulate form coated in total suspended solids from sediments. Arsenic speciation studies which are more mobile [4].…”

“…The decrease of total arsenic and As(V) removal with pH increasing can be attributed to the decreasing of electrostatic interactions between the surface charge of adsorbents and multipotent anionic species such as HAsO4 2and H2AsO4 - [18]. According to the literature, the removal efficiency of As (V) should decrease with pH increasing [11,17,23,24,25] . While when the pH was increased, As(III) removal increased from 40% to 69% according to two steps: first step (slow) between…”

“…Arsenic speciation studies were conducted using the protocol described by Edwards et al [3], modified by [28] and used by [17]. In the process of speciation, total As,…”

“…Those parameters have been calculated following the concepts of Michaels [15], reported by Kundu and Gupta [9] and used by Nugyen [17]. In From Table 2, it was observed that adsorption was occurred on 4cm of bed depth in the column at 82% of saturation.…”

“…Arsenic concentration in ground waters was ranged from 0.5 to 977.7 µg/L in Dong Thap Province [14]. In Dong Thap Province, it has been demonstrated that As(V) form is predominant in dissolved arsenic and 49.9% particulate arsenic from groundwater containing 427µg/L of total As [17].…”