The Application of Carbon Nanotube/Graphene‐Based Nanomaterials in Wastewater Treatment

Abstract

The treatment of organic wastewater is of great significance. Carbon nanotube (CNT)/graphene‐based nanomaterials have great potential as absorbent materials for organic wastewater treatment owing to their high specific surface area, mesoporous structure, tunable surface properties, and high chemical stability; these attributes allow them to endure harsh wastewater conditions, such as acidic, basic, and salty conditions at high concentrations or at high temperatures. Although a substantial amount of work has been reported on the performance of CNT/graphene‐based nanomaterials in organic wastewater systems, engineering challenges still exist for their practical application. Herein, the adsorption mechanism of CNT‐ and graphene‐based nanomaterials is summarized, including the adsorption mechanism of CNTs and graphene at the atomic and molecular levels, their hydrophilic and hydrophobic surface properties, and the structure–property relationship required for adsorption to occur. Second, the structural modification and recombination methods of CNT‐ and graphene‐based adsorbents for various organic wastewater systems are introduced. Third, the engineering challenges, including the molding of macroscopically stable adsorbents, adsorption isotherm models and adsorption kinetic behaviors, and reversible adsorption performance compared to that of activated carbon (AC) are discussed. Finally, cost issues are discussed in light of scalable and practical application of these materials.

Graphene‐Based Sorbents for Multipollutants Removal in Water: A Review of Recent Progress

“…[ 11a,47 ] In particular, trapping of nonpolar organic contaminants such as oils and organic solvents is mainly governed by pore‐filling mechanism. [ 16 ] This feature can be demonstrated by engineering highly porous 3D structures with large pore volume, low density, and high specific surface area. [ 11a,43 ] Sorption of oil and organic solvents is also dictated by surface wettability of sorbents with numerous surface modifiers including silanes, hydrophobic polymers (polyfluorowax, pyrrole, spiropyran, and etc), TiO 2 nanoparticles, kaolinite, carbon nanotubes (CNT), and graphene have been adopted to tailor the surface wettability of the sorbent materials.…”

“…As accentuated by several critical reviews, an enormous knowledge gap still exists to link the surface chemistry and physicochemical properties of advanced graphene sorbents with sorption performance for multiple pollutant control in water purification. [ 11a,c,16 ] Therefore, in this review, we primarily focus on the multipollutant remediation in water using advanced graphene sorbents, which has not been discussed previously. We highlight the rational design of these advanced graphene sorbents based on their functional groups to capture multipollutants in water, followed by establishing the fundamental structure–function–performance relationships with broad classes of pollutants (heavy metals, dyes, organic solvents, and oils).…”

Constructing Carbon-Coated Fe3O4 Hierarchical Microstructures with a Porous Structure and their Excellent Cr(VI) Ion Removal Properties

“…Compared with other treatment technologies, adsorption separation technology has been widely used in waste water treatment because of its rich adsorbent resources, simple process and low cost. Therefore, the adsorption separation method is the most active research and application in recent years to remove toxic pollutants in sewage treatment methods [27][28][29][30][31] . It is well known that the adsorbent material is very important in the adsorption separation technology, but the existing adsorbent material still needs to be further improved, especially how to realize the fast separation and improve the adsorption performance of the material.…”

Multi-Walled Carbon Nanotubes Can Promote Brassica napus L. and Arabidopsis thaliana L. Root Hair Development through Nitric Oxide and Ethylene Pathways

“…Their radial and axial dimensions are both on the order of micrometers, and both ends of the tubes are open. Due to their special structures and unique physical, chemical, biological properties, and huge application potential, they have received considerable attention [3][4][5]. Because of their excellent transmembrane and adsorption capacity [6], the research on CNTs' impact on agriculture is also emerging.…”