Preparation of Micro-Nano Material Composed of Oyster Shell/Fe3O4 Nanoparticles/Humic Acid and Its Application in Selective Removal of Hg(II)

Abstract

Micro-nano composite material was prepared to adsorb Hg(II) ions via the co-precipitation method. Oyster shell (OS), Fe3O4 nanoparticles, and humic acid (HA) were used as the raw materials. The adhesion of nanoparticles to OS displayed by scanning electron microscopy (SEM), the appearance of the (311) plane of standard Fe3O4 derived from X-ray diffraction (XRD), and the transformation of pore sizes to 50 nm and 20 μm by mercury intrusion porosimetry (MIP) jointly revealed the successful grafting of HA-functionalized Fe3O4 onto the oyster shell surface. The vibrating sample magnetometer (VSM) results showed superparamagnetic properties of the novel adsorbent. The adsorption mechanism was investigated based on X-ray photoelectron spectroscopy (XPS) techniques, which showed the process of physicochemical adsorption while mercury was adsorbed as Hg(II). The effects of pH (3–7), initial solution concentration (2.5–30 mg·L−1), and contact time (0–5 h) on the adsorption of Hg(II) ions were studied in detail. The experimental data were well fitted to the Langmuir isotherm equation (R2 = 0.991) and were shown to follow a pseudo-second-order reaction model (R2 = 0.998). The maximum adsorption capacity of Hg(II) was shown to be 141.57 mg·g−1. In addition, this new adsorbent exhibited excellent selectivity.

Review of shell waste reutilization to promote sustainable shellfish aquaculture

“…A nanocomposite prepared using oyster shells, Fe 3 O 4 nanoparticles, and humic acid as raw materials exhibits remarkably selectivity in the co‐precipitation method with an excellent capacity for mercury removal (91.2 mg/g). The maximum adsorption capacities for Pb 2+ and Cd 2+ are 24.9 and 9.5 mg/g respectively 22 . Oyster shell powder can immobilize multiple metals in contaminated soils.…”

“…He et al 22 prepared SiO 2 /Fe 3 O 4 /hydroxyapatite with oyster shell. The composite powder had a large specific surface area, excellent stability, paramagnetism and unique selectivity.…”

“…and Cd 2+ are 24.9 and 9.5 mg/g respectively. 22 Oyster shell powder can immobilize multiple metals in contaminated soils. The heavy metal ion immobilization efficiency follows the order of:…”

“…The maximum adsorption capacity of Pb 2+ increased with the pyrolysis temperature, and the removal of exchangeable Pb was accomplished by means of ion exchange, complexation, precipitation, and Cπ interaction. 59 He et al 22…”

Adsorption Processing for the Removal of Toxic Hg(II) from Liquid Effluents: Advances in the 2019 Year

“…A 0.5 M HCl solution was used to remove Hg(II) loaded onto the adsorbent with yields exceeding 97% in the 1st cycle, though there was a 8% and 6% loss in adsorption and desorption capacities, respectively, after 5 cycles. A micro-nano composite material was prepared via the co-precipitation method [34]. Oyster shell (OS), Fe 3 O 4 nanoparticles, and humic acid (HA) were used as the raw materials.…”