Synthesis and characterization of magnetic biochar adsorbents for the removal of Cr(VI) and Acid orange 7 dye from aqueous solution

Abstract

In this study, different types of magnetic biochar nanocomposites were synthesized using the co-precipitation method. Two biochar materials, namely, sewage sludge biochar and woodchips biochar, were prepared at two different temperatures, viz., 450 and 700 °C. These biochars were further modified with magnetic nanoparticles (Fe 3 O 4 ). The modified biochar nanocomposites were characterized using field emission–scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET), SQUID analysis, X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR). The potential of prepared adsorbents was examined for the removal of hexavalent chromium (Cr(VI)) and Acid orange 7 (AO7) dye from water as a function of various parameters, namely, contact time, pH of solution, amount of adsorbents, and initial concentrations of adsorbates. Various kinetic and isotherm models were tested to discuss and interpret the adsorption mechanisms. The maximum adsorption capacities of modified biochars were found as 80.96 and 110.27 mg g -1 for Cr(VI) and AO7, respectively. Magnetic biochars showed high pollutant removal efficiency after 5 cycles of adsorption/desorption. The results of this study revealed that the prepared adsorbents can be successfully used for multiple cycles to remove Cr(VI) and AO7 from water. Graphical Abstract Electronic supplementary material The online version of this article (10.1007/s11356-020-09275-1) contains supplementary material, which is available to authorized users.

Experimental and DFT Computational Insights on the Adsorption of Selected Pharmaceuticals of Emerging Concern from Water Systems onto Magnetically Modified Biochar

“…This was attributed to the presence of iron oxides particles on the biochar surface. The Fe3O4/γ-Fe2O3 particles loaded on the adsorbent surface exhibit magnetic properties, which in turn render the biochar magnetically active (24). Moreover, the magnetization curve suggested that the adsorbent was ferromagnetic, attesting the potential for easy retrievability and reusability through magnetic recovery.…”

Sustainable synthesis of rose flower-like magnetic biochar from tea waste for environmental applications

“…The highest pH was obtained for TF and SS samples. Increased pH may imply the presence of inorganic alkaline components in the biochars [59] .…”

Study on Adsorbent Characteristics of Coconut Coir as a Bio Sorbent for Removal of Methylene Blue Dye

“…As shown in FT-IR, spectra a peak at 3294 cm -1 shows stretch vibration of bonded hydroxyl groups, and peak at 1643 cm -1 shows the presence of carbonyl group and confirms the carbonaceous nature of the coir. [19,20] found to be increased in 400-450 nm wavelength range with increased pH and decreases within 500-800 nm range with pH attributes the adsorption of MB increases with negative charge of surface of adsorbent. Generally, the net positive charge of adsorbate decreases with increasing pH value, leading to decrease in the repulsion between the adsorbent surface and dye.…”