Simultaneous Removal of Arsenic and Manganese from Synthetic Aqueous Solutions Using Polymer Gel Composites

Abstract

The groundwater in approximately 50% of the Bangladesh landmass contains Mn concentrations greater than the limit prescribed by the WHO drinking water guidelines. Although studies have suggested that γ-FeOOH can effectively remove Mn from water, its practicability has not been investigated, considering that the additional processes required to separate the adsorbents and precipitates are not environment-friendly. To improve the efficiency of adsorptive Mn-removal under natural conditions, we employed a cationic polymer gel composite, N,N’-Dimethylaminopropyl acrylamide, methyl chloride quaternary (DMAPAAQ) loaded with iron hydroxide (DMAPAAQ + FeOOH), and a non-ionic polymer gel composite, N,N’-Dimethylacrylamide (DMAA) loaded with iron hydroxide (DMAA + FeOOH). DMAPAAQ + FeOOH exhibited a higher As removal efficiency under natural conditions while being environment-friendly. Our results suggest that the higher efficiency of the cationic gel composite is owed to the higher γ-FeOOH content in its gel structure. The maximum adsorption of Mn by DMAPAAQ + FeOOH was 39.02 mg/g. Furthermore, the presence of As did not influence the adsorption of Mn on the DMAPAAQ + FeOOH gel composite and vice versa. DMAPAAQ adsorbed As and the γ-FeOOH particles simultaneously adsorbed Mn. Our findings can serve as a basis for the simultaneous removal of contaminants such as As, Mn, Cr, and Cd.

WITHDRAWN: Simultaneous adsorption of malachite green, methyl orange, and rhodamine B with TiO 2 /macadamia nutshells-derived activated carbon composite

“…positive value of ∆H° (4.836 kJ•mol -1 for MG, 8.1838 kJ•mol -1 for MO, and 10.624 kJ•mol -1 for RhB) suggests that the adsorption process in the system is endothermic. This means that the total energy absorbed by the system for bond-breaking is greater than the total energy released due to bond-forming [51]. The positive value of ΔS° suggests the increase in randomness in the system as the dye molecules get adsorbed onto TiO2/MAC.…”

Simultaneous adsorption of malachite green, methyl orange, and rhodamine B with TiO2/macadamia nutshells-derived activated carbon composite

“…A positive value of ΔH°(4.836 kJ•mol -1 for MG, 8.1838 kJ•mol -1 for MO, and 10.624 kJ•mol -1 for RhB) suggests that the adsorption process in the system is endothermic (table 7). This means that the total energy absorbed by the system for bond-breaking is greater than the total energy released due to bond-forming [43]. The positive value of ΔS°suggests the increase in randomness in the system as the dye molecules get adsorbed onto TiO 2 /MAC.…”

The Preparation and Characterization of N,N-Dimethyl Acrylamide-Diallyl Maleate Gel/Hydrogel in a Non-Aqueous Solution

“…If the gel can retain a large amount of water without dissolving in it, then it is called hydrogel [ 2 ]. Due to their diverse properties, gels are widely used in metal adsorption [ 3 ], agriculture [ 4 ], electronics [ 5 ], biomedical engineering [ 6 ], and drug delivery [ 7 ]. Usually, co-polymeric hydrogels are prepared in aqueous solution by applying gamma radiation.…”