Hybrid Metal Oxide/Biochar Materials for Wastewater Treatment Technology: A Review

Abstract

This paper discusses the properties of metal oxide/biochar systems for use in wastewater treatment. Titanium, zinc, and iron compounds are most often combined with biochar; therefore, combinations of their oxides with biochar are the focus of this review. The first part of this paper presents the most important information about biochar, including its advantages, disadvantages, and possible modification, emphasizing the incorporation of inorganic oxides into its structure. In the next four sections, systems of biochar combined with TiO 2 , ZnO, Fe 3 O 4 , and other metal oxides are discussed in detail. In the next to last section probable degradation mechanisms are discussed. Literature studies revealed that the dispersion of a metal oxide in a carbonaceous matrix causes the creation or enhancement of surface properties and catalytic or, in some cases, magnetic activity. Addition of metallic species into biochars increases their weight, facilitating their separation by enabling the sedimentation process and thus facilitating the recovery of the materials from the water medium after the purification process. Therefore, materials based on the combination of inorganic oxide and biochar reveal a wide range of possibilities for environmental applications in aquatic media purification.

Multifunctional Cross-Linked Shrimp Waste-Derived Chitosan/MgAl-LDH Composite for Removal of As(V) from Wastewater and Antibacterial Activity

“…To overcome this, surface modification, defects introduction, and building hybrid materials were common strategies reported in the literature . On the other hand, nanocomposites formed by incorporating layered inorganic materials like LDHs with polymers show remarkable changes in chemical and physical properties, , including high surface area, thermal and mechanical stability, and flexibility. , In the literature the use of MgAl-LDH for the removal of perchlorooctanoic acid, chromate, and phosphate ions proves that MgAl-LDH can be used as potent adsorbent for anionic species in native or hybrid form. MgAl-LDH shows selective adsorption toward arsenate ion depending on the molar ratio of aluminum and magnesium, nitrate ion orientation, and experimental conditions.…”

Effect of the Standardized ZnO/ZnO-GO Filter Element Substrate driven Advanced Oxidation Process on Textile Industry Effluent Stream: Detailed Analysis of Photocatalytic Degradation Kinetics

“…The nanomaterial composites have complementary additive surface properties, leading to better performance in dye removal systems than the constituents’ material themselves. The synthesized nanocomposite finds its usefulness through significant improvement by lowering the work function and modulation of the recombination rates of the photoexcited pairs through the process of hybridization …”

“…The synthesized nanocomposite finds its usefulness through significant improvement by lowering the work function and modulation of the recombination rates of the photoexcited pairs through the process of hybridization. 27 Metal oxide-based semiconductors having catalytic properties and their nanocomposites are well-known in the literature for dye remediation applications. 28−31 Research in our laboratory has also highlighted the use of such metal oxidebased nanocomposites in different remediation contexts showing their importance in the development of nextgeneration remediation agents.…”

Facile One-Step Pyrolysis of ZnO/Biochar Nanocomposite for Highly Efficient Removal of Methylene Blue Dye from Aqueous Solution

“…A combination of biochar and nanomaterials has been developed to improve adsorption capacity through several mechanisms, such as enhancing the porous structure and increasing the number of surface functional groups and the surface-to-volume ratio. − Techniques used to combine biochar and nanomaterials include impregnation, − chemical coprecipitation, , direct pyrolysis, − and others. , The porous carbon structure can be improved by activating the raw material with agents, such as ZnCl 2 , FeCl 3 , KOH, and H 3 PO 4 , in two different ways: aqueous state and solid state. ZnO nanoparticles are then loaded onto the biochar surface through self-reduction or precipitation mild pyrolysis.…”