Enhanced Removal of Malachite Green Using Calcium-Functionalized Magnetic Biochar

Abstract

To efficiently remove malachite green (MG), a novel calcium-functionalized magnetic biochar (Ca/MBC) was fabricated via a two-step pyrolysis method. Iron-containing oxides endowed the target complexes with magnetic properties, especially the chemotactic binding ability with MG, and the addition of calcium significantly changed the morphology of the material and improved its adsorption performance, especially the chemotactic binding ability with MG, which could be confirmed through FTIR, XPS, and adsorption experiments. Electrostatic adsorption, ligand exchange, and hydrogen bonding acted as essential drivers for an enhanced adsorption process, and the maximum theoretical adsorption capacity was up to 12,187.57 mg/g. Ca/MBC maintained a higher adsorption capacity at pH = 4–12, and after five adsorption–desorption cycles, the adsorption capacity and adsorption rate of MG remained at 1424.2 mg/g and 71.21%, highlighting the advantages of Ca/MBC on adsorbing MG. This study suggests that biochar can be modified by a green synthesis approach to produce calcium-functionalized magnetic biochar with excellent MG removal capacity. The synthetic material can not only remove pollutants from water but also provide an efficient way for soil remediation.

Bench-Scale Fixed-Bed Column Study for the Removal of Dye-Contaminated Effluent Using Sewage-Sludge-Based Biochar

“…The N 2 adsorption-desorption isotherms of SSB displayed a type IV curve (Figure 1). The absence of the H3-type hysteresis loop isotherm is due to the irregular structure of SSB, as illustrated with SEM [38]. Figures 2 and 3 show the SEM images of the raw material and SSB at different magnifications.…”

“…Sustainability 2022, 14, x FOR PEER REVIEW 5 of 16 SSB, as illustrated with SEM [38]. Figures 2 and 3 show the SEM images of the raw material and SSB at different magnifications.…”

“…For instance, agricultural wastes contain lignin and lignocelluloses, which introduce a large surface area to the adsorbents [46]. Despite the excellent comparative benefits of utilizing sewage sludge, in terms of waste management and disposal, the surface SSB, as illustrated with SEM [38]. Figures 2 and 3 show the SEM images of the raw material and SSB at different magnifications.…”

Study on Preparation of Calcium-Based Modified Coal Gangue and Its Adsorption Dye Characteristics

“…Estevan D. Cruz [22] fixed Ca/double hydroxide on biochar by co-precipitation method, and the material had a good adsorption effect on congo red. Pengjie W. [23] reported that calcium doping can significantly change the morphology of the adsorbent material and improve the adsorption performance. In particular, the synthesized calcium-based magnetic biochar can efficiently adsorb malachite green dye.…”

In situ growth of ZIF-67 onto bamboo pulp black liquor porous carbons as an efficient adsorbent for malachite green removal

“…Nowadays, a variety of adsorbents such as graphene oxide [12], biochar [13], metal organic framework materials (MOFs) [14], porous carbon [15] and their derivatives have been used for removal of MG. Among these materials, MOFs are a type of metal ion-polydentate organic ligand complexes nanomaterials, which are widely used in gas storage [16], adsorption [17], catalysis [18] and sensing [19] and other elds due to their rich metal active sites, large surface area and orderly pore structure.…”