Congo red dye degradation using Fe-containing mineral as a reactive material derived from waste foundry dust.

This study investigated the applicability of industrial waste. The high affinity of Fe-based products is widely used for industrial effluents because of their capability to oxidize contaminants. Waste foundry dust (WFD) is an Fe oxide that has been investigated as a potential reactive material that causes the generation of reactive oxidants. We aimed to investigate the physicochemical properties of WFD and the feasibility in the Fenton oxidation process. The WFD was used as a catalyst for removing Congo red (CR), to evaluate the generation of •OH and dissolution of Fe during the oxidation process. The linkage of •OH generation by WFD with eluted Fe(II) through the Fe dissolution was found. The Fenton oxidation reaction, CR degradation was affected by H2O2 concentration, initial pH, WFD dosage, initial CR concentration, and coexisting anions. The CR degradation efficiency increased with an increase in H2O2 concentration and WFD dosage. In addition, chloride and sulfate in solution promoted CR degradation, whereas carbonate had a negative effect on the Fenton oxidation process. The elution of Fe promotes CR degradation, over three reuse cycles, the degradation performance of the CR decreased from 100 to 81.1%. For the Fenton oxidation process, •OH generation is linked to Fe redox cycling, the surface passivation and Fe complexes interrupted the release of reactive oxidants, which resulted in the degradation of the CR decreased. This study proposed that WFD can serve as catalysts for the removal of CR.

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

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.

Waste foundry dust (WFD) as a reactive material for removing As(III) and Cr(VI) from aqueous solutions.

This study evaluates the use of waste foundry dust (WFD) as a reactive material for mitigating water pollution using As(III) and Cr(VI) as model contaminants. A detailed structural characterization of WFD was performed using X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). Batch removal experiments and kinetic studies for removal of both As(III) and Cr(VI) were conducted at various initial pH values (2-10), concentrations (1-100 mg/L), and solid-to-liquid ratios (2.5-125 g/L). The results show that WFD consisted of small particles (< 30 µm) with magnetic properties, mainly composed of quartz (SiO2) and magnetite (Fe3O4). The maximum removal capacity of WFD was 12.6 mg/g for As(III) at pH 3.0 and 6.1 mg/g for Cr(VI) at pH 5.0. WFD was effective in a wide pH range, from 3.0 to 8.0, and in high concentrations, up to 100 mg/L. WFD removed As(III) and Cr(VI) from aqueous solutions through complex processes including adsorption, precipitation, and redox reactions by oxidation of Fe(II). The results of this study suggest that WFD can be used as a reactive material for removal of As(III) and Cr(VI) from aqueous solutions.

Data describing characteristics of waste foundry dust (WFD), sorbent obtained before and after batch sorption tests using As(III) and Cr(VI) aqueous solutions.

This article presents data on characteristics of waste foundry dust (WFD), sorbent obtained before and after batch sorption tests using As(III) and Cr(VI) aqueous solutions, by performing X-ray Diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) coupled with energy dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) analyses. Data are related to a research article "Waste foundry dust (WFD) as a reactive material for removing As(III) and Cr(VI) from aqueous solutions" [1]. The data provide information obtained from various analytical methods to investigate mechanisms of As(III) and Cr(VI) removal from aqueous solutions by WFD, an industrial by-product. These data can be of interest to researchers studying contaminant removal mechanisms by reactive materials, in particular industrial by-products.