Arsenic(V) Removal by Sulfate Modified Iron Oxide-Coated Sand (SMIOCS) in a Fixed Bed Column

Abstract

A novel granular media developed by the coating of iron, barium and sulfur on quartz sand surface has been demonstrated to be an effective sorbent for removal of arsenic(V) from a 0.01 M NaNO3-spiked distilled water system in laboratory-scale tests. The results of fixed bed studies indicate that arsenic(V) removal is dependent on pH, the size of sorbent and influent arsenic concentrations. The particle size of media has shown significant differences in reactor breakthrough times in similar experimental conditions. The removal of As(V) may be explained using the surface complexation theory. The presence of alkalinity (250–260 mg/L as CaCO3) and hardness (200 mg/L as CaCO3) slightly increases reactor breakthrough time for similar experimental conditions without alkalinity and hardness. Desorption studies using 0.2 M NaOH as elutant resulted in nearly 92% recovery of arsenic(V). A theoretical model based on two parameters has shown good correlation with observed experimental data generated during depth variation studies.

Novel Anionic Clay Adsorbents for Boiler-Blow-Down Waters Reclaim and Reuse

“…The experimental breakthrough time for the adsorbent with the smaller particle size ( br  = 36,305) is greater than the breakthrough time of that with the larger particle size ( br  = 21,812). The increased breakthrough times have also been reported by other investigators, and were explained by the faster adsorption kinetics exhibited by the smaller particles [Vaishya et al, 2006;Malkoc et al, 2006].…”

Adsorption of arsenic from aqueous solution on synthetic hydrous stannic oxide

“…The adsorbents studied so far are many and include amorphous iron hydroxide [6], hydrous ferric oxide [7], granular ferric hydroxide [8], ferrihydrite [9], red mud [10], activated alumina [11][12][13], iron oxide coated polymeric materials [14], iron oxide coated sand [15], Fe(III)-Si binary oxide [16], iron oxide impregnated activated alumina [17], blast furnace slug [18], iron-cerium bimetal oxide [19], iron-coated sponge [20], nano-scale zerovalent iron [21][22][23], sulfate modified iron oxide-coated sand [24] and hydrous ferric oxide incorporated into naturally occurring porous diatomite [25]. In our laboratory, we have used crystalline hydrous ferric oxide [26], crystalline hydrous titanium oxide [27], granular hydrous zirconium oxide [28] and iron(III)-tin(IV) binary mixed oxide [29] for arsenic removal.…”

Synthesis of Pure Micro- and Nanopyrite and Their Application for As (III) Removal from Aqueous Solution

“…It has been proposed that As (III) reacts with FeS 2 to form longer chain polysulfides such as iron tetrasulfide (FeS 4 ) [18]. The equation is shown as follows: 7FeS 2 + 2As (OH) 3 3FeS 4 + 2FeAsS + 2Fe (OH) 3 (9) The surface precipitates containing FeAsS were observed for FeS 2 after contact with As (III). FeAsS has a very high environmental stability and field evidence demonstrates that arsenopyrite does not readily decompose under water-saturated near-surface conditions [19,20].…”

“…Adsorption is considered as a low cost and reliable technique [8] and much more efficient choice for removal of inorganic compounds than the conventional treatment [9]. The various adsorbents have been applied to remove arsenic, such as natural iron containing minerals [10], titanium dioxide [11], zero-valent iron [12], red mud [13], and magnetic nanoparticles [14].…”