Removal of Cr6+ ions and mordant violet 40 dye from liquid media using Pterocladia capillacea red algae derived activated carbon-iron oxides

Abstract

In recent years, water pollution has become one of the most dangerous problems facing the world. Pollution of water with heavy metals and different dyes has caused many harmful effects on human health, living organisms and our environment. In this study, iron oxide nanomagnetic composite from Pterocladia Capillacea red algae-derived activated carbon (PCAC-IO) was synthesized by co-precipitation method using different iron salts and different base solutions. The synthesized nanocomposite was investigated with various characterization techniques such as FTIR, BET, SEM-EDX, TEM, XRD, and VSM. The obtained PCAC-IO adsorbent was used for Cr6+ ions and Mordant Violet 40 (MV40) dye removal. The adsorption mechanism of Cr6+ ions and MV40 dye on PCAC-IO was examined using several adsorption and kinetic isotherm models. Langmuir and Freundlich models were investigated using experimental data. Pseudo-first-order (PFO), Pseudo-second-order (PSO) and intraparticle diffusion models (IPDM) were applied to identify the adsorption mechanism. It has shown that the PSO kinetic model fits better with the experimental data obtained from PCAC-IO. This result can be interpreted as the adsorption of the adsorbate on the nanocomposite as chemical adsorption. The optimum conditions for maximum Cr6+ ions removal (96.88%) with PCAC-IO adsorbent occur at room temperature, 5 g L−1 adsorbent concentration, 100 mg L−1 initial pollutant concentration, pH 1 and at the end of 180 min, while maximum MV40 dye removal (99.76%), other conditions being the same, unlikely it occurred at pH 2.06 and after 45 min. The most suitable model for Cr6+ ions removal under the conditions of 1 L−1 g adsorbent concentration and 400 mg L−1 adsorbate concentration was Langmuir (Qmax = 151.52 mg g−1), while for MV40 removal it was Freundlich (Qmax = 303.03 mg g−1). We propose the use of activated carbon-supported iron oxide prepared from bio-waste material, especially from Pterocladia Capillacea red algae, as a promising adsorbent with high efficiency in the removal of Cr6+ ions and MV40 dye from aqueous media.

Highly Porous Carbon Materials Prepared Through KOH‐Assisted CO2‐Activation of Carbonized Waste Tires for Removal of Cr(VI) and Cd(II) from Water

“…The thermodynamics revealed the spontaneous, endothermic character, and the feasibility of the Cr(VI) adsorption process. In a study by Mohamed and their coworker, [54] an iron oxide‐commercial AC nanocomposite (CAC‐IO) prepared through the co‐precipitation method was employed with a reasonable removal of 98.6 % of Cr(VI). This was achieved with a dosage of 2 g/L, an initial Cr(VI) concentration of 100 mg/L, a pH of 1.6, a contact time of 3 h, and an ambient temperature.…”

Fabrication of date palm kernel biochar-sulfur (DPKB-S) for super adsorption of methylene blue dye from water

“…as the adsorption sites were filled. PFO, PSO, IPD, and FD models were utilized to simulate the uptake effects to quantitatively investigate the binding process of MB dye on DPKB-S [78][79][80] .…”