A novel arsenic removal process for water using cupric oxide nanoparticles

Abstract

Recent studies suggest that the cupric oxide (CuO) nanoparticles effectively adsorb aqueous arsenic species under a wide range of water chemistries. However, to develop CuO nanotechnology to a field application level, further studies are necessary. Batch adsorption kinetic experiments were conducted to determine the time course of uptake of arsenic by CuO nanoparticles. A reactor with CuO nanoparticles was developed to conduct continuous flow-through experiments to filter arsenic from groundwater samples. Groundwater samples spiked with 100 μg/L of arsenic were passed through (1L/h) the flow-through reactor. Samples from the flow-through reactor were collected at a regular interval and analyzed for arsenic and other chemical components (e.g., pH, major and trace elements). The CuO nanoparticles adsorbed with arsenic were regenerated with a sodium hydroxide (NaOH) solution and tested again in the flow-through reactor. Three natural groundwater samples with above 10 μg/L of arsenic were also tested with the flow-through reactor. The arsenic adsorption process by CuO nanoparticles was kinetically rapid and followed the pseudo-second-order rate. The continuous flow-through reactor with CuO nanoparticles was effective in filtering arsenic from spiked or natural groundwater. The regenerated CuO nanoparticles were also effective in filtering arsenic from groundwater. Arsenic mass balance data from regeneration studies suggested that 99% of input arsenic concentration was recovered. The CuO nanoparticle treatment did not show any discernible effects on the chemical quality of groundwater samples. Results of this study suggest that CuO nanoparticles show potential for developing a simple process for field applications to remove arsenic from water.

Facile one-pot preparation of goethite/parabutlerite nanocomposites and their removal properties and mechanism toward As(V) ions

“…The S 2p 3/2 binding energy of the goethite/parabutlerite nanocomposites is 168.5 eV. This value was agree well with the ones of sulfate (SO 4 2− ) or more exactly (O SO 3 − ) [23].…”

“…The obtained adsorbent was dried at 60 • C. The method of testing the adsorption capability of the regenerated adsorbent was the same as the experiments above. To study the competitive effects of some coexisting anions (Cl − , SO 4 2− , NO 3 − , CO 3 2− , HCO 3 − , and PO 4 3− ) on As(V) removal, 10 mL of 9.89 mg L −1 As(V) solutions containing each of various components (0.1 mM, 1 mM, and 10 mM) and 10 mg adsorbent were shaken for 24 h. Then, the adsorbent was separated via centrifugation and the supernatant was collected for metal concentration measurements. The effect of pH on As (V) removal was studied by varying the initial solution pH between 3 and 11.…”

“…Metallic oxides were very important adsorbent because of their remarkable advantages such as low cost and easy preparation. So, various nanostructured metallic oxides have been synthesized for arsenic removal, such as CuO [4], Al 2 O 3 [5], CeO 2 [6], TiO 2 [7], Fe-Ti [8] and Fe-Ce hybird oxides [9]. For the removal mechanism, the ion-exchange between the surface hydroxyl groups and arsenic ions were widely reported [6][7][8][9].…”

Arsenic removal by nanoparticles: a review

“…Batch adsorption kinetic experiments were conducted in order to determine the time course of uptake of arsenic by CuO nanoparticles by Reddy et al (2013). They developed a reactor with CuO nanoparticles and conducted continuous flow-through experiments to filter arsenic from groundwater samples.…”

Adsorption of arsenic(V) from aqueous solutions by goethite/silica nanocomposite

“…The high regression coefficient value and good agreement between calculated and experimental q e values suggested that the adsorption of As(V) onto goethite/silica nanocomposite follows the pseudo-second-order kinetics. Several authors reported in the literature that the pseudosecond-order kinetic model fit the experimental data accurately on the adsorption of arsenic onto cupric oxide nanoparticles (Reddy et al 2013), hierarchically porous CeO 2 -ZrO 2 nanospheres , and ultrafine aFe 2 O 3 nanoparticles (Tang et al 2011).…”