Synthesis and characterization of α-Fe2O3/γ-Fe2O3-nanoparticles from recyclable electro-coagulated sludge: insights and predictions for different application

Abstract

This research work reports on the synthesis and characterization of iron oxide nanoparticles from sludge. Precipitates generated from the electro-coagulation process were collected, size reduced, beneficiated, and thermally treated in an inert atmosphere to form iron oxide nanoparticles. Structural, surface, and optical properties of raw and thermally treated sludge were examined using XRD, SEM, FTIR, UV/Vis, TGA/DTA, and Zeta Potential. The X-ray diffraction pattern confirmed that as the sludge is annealed at a temperature of 100, 300, 500, and 800 °C, the phase transformed to goethite, magnetite, maghemite, and hematite respectively. Pure hematite weere formed at the highest temperature. The crystallite size of hematite nanoparticle was calculated using the two most intense diffraction peaks and found to be about 30.4 nm at 800 °C and 28.3 nm at 500 °C. The SEM micrograph for heat-treated powered has an irregular shape with rough and porous surfaces leading to the best adsorptive feature. The optical band gap was found to be 2.06, 1.98, and 2.00 eV for 300 °C, 500 °C, and 800 °C heat-treated samples respectively. These findings can be an input to the industrialists and environmentalists that controlled sludge recycling mechanisms during wastewater treatment is beneficial in terms of cost and sustainability. Furthermore, an integrated wastewater treatment system with resource recycling technology at the initial stage of the installation could be made.

Recycling electro-coagulated sludge from textile wastewater treatment plants as an adsorbent for the adsorptions of fluoride in an aqueous solution

“…This can make the adsorbent surfaces more adsorptive morphology. This is also further confirmed by X-ray diffraction as shown in Figure 2 in that the produced powder is dominantly the maghemite (γ-Fe 2 O 3 ) and hematite (α-Fe 2 O 3 ) type of iron oxides [29]. Thus, it can be deduced that the goethite and magnetite materials underwent an oxidative transformation of those nanoparticle iron species.…”

“…Adsorbents were prepared through thermal treatment at a temperature of 500 C from size reduced and wet treated EC sludge according to previous works [28]. The water content of the studied EC sludge was reported as 5.2% and the loss was recorded up to 99.7 C in the thermogravimetric analysis [29]. The thermal treatment was conducted using a muffled furnace (Nabertherm LT 3/11/P330) with a constant nitrogen flow rate at 10 ml/min for 3 h to produce maghemite and/or hematite iron nanoparticle.…”

Synergistic effect of oxide nanoparticles and inorganic inhibitor on anti-corrosion performance of epoxy coating

“…The band at 880 cm −1 is because of the stretching vibration of Fe–O–Fe bond (Du et al , 2013). The peaks at 1,632 cm −1 can be attributed to the water of hydration (Aragaw and Aragaw, 2020). The absorption peak at 1,384 cm −1 also only is observed in the Fe 2 O 3 @Ce 3+ powder, it can be assigned to the absorption of cerium(III) nitrate on the surface of Fe 2 O 3 nanoparticles.…”