Immobilization of Arsenic and Manganese in Contaminated Groundwater by Permeable Reactive Barriers Using Zero Valent Iron and Sheep Manure

Abstract

A permeable reactive barriers (PRBs) column test was carried out to remove arsenic (As) and manganese (Mn) from groundwater using zero valent iron (ZVI), sheep manure, compost and woodchips as reactive materials. Arsenic was mainly immobilized through sorption and co-precipitation with iron-bearing minerals, and also possibly precipitation as FeAsO 4 . The presence of sulfate-reducing bacteria (SRB) in the inoculated column was suggested by decrease of sulfate concentrations and increase of 34 S in the effluent. Arsenic was more effective to immobilize in the inoculated than in the sterilized column due to co-precipitation with sulfides formed by reduction of sulfate in addition sorption and/or co-precipitation with carbonates. The Mn was mainly immobilized through adsorption onto compost and ZVI, and partly by precipitation as carbonates. Manganese was more effectively immobilized in the sterilized than in the inoculated column. Since compost is biodegraded, the capability of compost to immobilize Mn 2þ decreased in the inoculated column. The result demonstrates that As is more effective to immobilize using mixture of sheep manure with ZVI than only ZVI as reactive materials in PRBs.

Stabilization of As-, Pb-, and Cu-contaminated soil using calcined oyster shells and steel slag

“…It has been reported that various Ca-As precipitates were found to be the main compounds responsible for As immobilization by numerous researchers upon lime treatment (Dutré and Vandecasteele 1996;Dutré and Vandecasteele 1998;Moon et al 2004;Moon et al 2011b). Moreover, Fe-As precipitates which could be responsible for effective As immobilization have been widely reported (Chung et al 2001;Kim et al 2003;Lee 2006;Kumpiene et al 2008;Wilopo et al 2008;Drahota and Filippi 2009). In the case of the Pb immobilization mechanism, Pb immobilization was most probably associated with Ca, Al, Si, and O (Fig. 4b).…”

Aqueous removal of diclofenac by plated elemental iron: Bimetallic systems

“…Four main mechanisms are reported for the removal process are: (1) contaminant adsorption on Fe 0 surface or at the surface of their corrosion products [24][25][26][27][28][29]; (2) contaminant co-precipitation with metal corrosion products (MCPs) [20,30,31,32], (3) contaminant oxidation within the oxide layer [33,34], and (4) contaminant reduction including catalytic hydrodehalogenation [35][36][37]. The hart fact that oxidation of some contaminants and reduction others were reported challenges the prevailing view considering Fe 0 as a reducing agent as discussed below.…”

Removal of mercury (Hg) from contaminated water at traditional gold mining area in Central Kalimantan

“…Where Q is the sorbed Hg per unit amount of sorbents (mmol kg −1 ) at the equilibrium, C e is equilibrium concentration of mercury (mmol dm −3 ), and K f and n are constants representing the adsorption capacity and adsorption intensity of the adsorbent, respectively (Wilopo, et al, 2008). The data plotted according to the Freundlich model ( Figure 3) showed good correlation coefficients (Table 1).…”