Removal of Methyl Red from Aqueous Solution Using Polyethyleneimine Crosslinked Alginate Beads with Waste Foundry Dust as a Magnetic Material

Abstract

In this study, a cost-effective adsorbent based on sodium alginate (SA) with waste foundry dust (WFD) was fabricated for the removal of methyl red (MR) from aqueous media. However, the utilization of WFD/SA beads to remove anionic dyes (such as MR) from effluents has limitations associated with their functional groups. To improve the adsorption performance, WFD/SA-polyethyleneimine (PEI) beads were formed via PEI crosslinking onto WFD/SA beads, which could be attributed to the formation of amide bonds from the carboxyl and amino groups due to the change of N-H bonds in the reaction. The Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) results indicated that PEI was crosslinked on the WFD/SA via a chemical reaction. In the FTIR spectra of WFD/SA-PEI, peaks of the –COO (asymmetric) stretching vibration shifted to 1598 and 1395 cm−1, which could be attributed to the hydrogen-bonding effect of the N–H groups in PEI. In the N1s spectrum, three deconvoluted peaks were assigned to N in –N= (398.2 eV), –NH/–NH2 (399.6 eV), and NO2 (405.2 eV). WFD/SA-PEI beads were assessed and optimized for aqueous MR adsorption. The WFD/SA-PEI beads showed a high removal efficiency for MR (89.1%) at an initial concentration of 1000 mg/L, and presented a maximum MR adsorption capacity of 672.7 mg/g MR. The adsorption process showed a good fit with the pseudo-second-order kinetic model and the Langmuir adsorption isotherm model. The amino and hydroxyl groups in the WFD/SA-PEI beads facilitate strong hydrogen bonding and electrostatic interactions. Moreover, these WFD/SA-PEI beads were easily recovered after the adsorption process.

Nanomaterials Based on Collaboration with Multiple Partners: Zn3Nb2O8 Doped with Eu3+ and/or Amino Substituted Porphyrin Incorporated in Silica Matrices for the Discoloration of Methyl Red

“…Table 1 presents some of the most recent adsorbent materials for the elimination of methyl red from wastewater. As can be seen in Table 1, the adsorption capacity varies largely from 2.15 mg/g to 672.7 mg/g [43][44][45][46][47][48][49]. When the pseudo-binary oxide Zn3Nb2O8 nanomaterials were doped with Eu 3+ ions, a shift to the smaller 2Ɵ values for the entire XRD spectrum was observed.…”

“…Table 1 presents some of the most recent adsorbent materials for the elimination of methyl red from wastewater. As can be seen in Table 1, the adsorption capacity varies largely from 2.15 mg/g to 672.7 mg/g [43][44][45][46][47][48][49]. Since then, the degradation of MR in 98.20% percentage has been performed using Fe 3 O 4 -Fe 2 O 2 @SiO 2 obtained from natural sources and H 2 O 2 as oxidizers [40].…”