Magnetic iron oxide/clay nanocomposites for adsorption and catalytic oxidation in water treatment applications

Abstract

Physical and chemical methods have been developed for water and wastewater treatments. Adsorption is an attractive method due to its simplicity and low cost, and it has been widely employed in industrial treatment. In advanced schemes, chemical oxidation and photocatalytic oxidation have been recognized as effective methods for wastewater-containing organic compounds. The use of magnetic iron oxide in these methods has received much attention. Magnetic iron oxide nanocomposite adsorbents have been recognized as favorable materials due to their stability, high adsorption capacities, and recoverability, compared to conventional sorbents. Magnetic iron oxide nanocomposites have also been reported to be effective in photocatalytic and chemical oxidation processes. The current review has presented recent developments in techniques using magnetic iron oxide nanocomposites for water treatment applications. The review highlights the synthesis method and compares modifications for adsorbent, photocatalytic oxidation, and chemical oxidation processes. Future prospects for the use of nanocomposites have been presented.

Magnetic Adsorbents for Wastewater Treatment: Advancements in Their Synthesis Methods

“…Since then, the synthesis of magnetic adsorbents has drawn considerable attention, as indicated by the growing number of publications. Diverse effective adsorbents have been reported to incorporate magnetic particles, such as metal oxides [ 26 , 27 ], silica-based materials [ 28 , 29 , 30 , 31 , 32 ], carbon-based materials [ 33 , 34 , 35 ], graphene oxide [ 36 ], biopolymers, such as lignin [ 37 ], cellulose [ 38 ], chitosan [ 39 ], synthetic polymers [ 40 , 41 , 42 ], molecularly imprinted polymers [ 43 ], metal organic frameworks [ 44 ], and biowaste [ 45 , 46 ]. Magnetic adsorbents can be prepared using physical methods, such as mechanical agitation (stirring, vibration, milling, and ultrasonication) at room or elevated temperatures in some cases, along with the addition of adhesives.…”

Montmorillonite-anchored magnetite nanocomposite for recovery of ammonium from stormwater and its reuse in adsorption of Sc3+

“…Additionally, an ammonium-pillared MT/Fe 3 O 4 nanocomposite was synthesised for caesium (Cs + ) removal from water and soil [20]. Moreover, the semiconductor properties of magnetite provide possible photocatalytic reactions-such as the degradation of organic pollutants-as an extra merit [21][22][23][24].…”

Influencing Factors in the Synthesis of Photoactive Nanocomposites of ZnO/SiO2-Porous Heterostructures from Montmorillonite and the Study for Methyl Violet Photodegradation

“…In addition, the enhancement of photocatalytic activity, mainly related to their chemical and environmental stability, can be achieved by using solid catalysts to support metal and metal oxide nanoparticles homogeneously [7]. Various solid supports have been reported to enhance the performance of metal and metal oxide catalysts for AOPs, and undoubtedly, the utilization of clay as a support material has received intensive interest [8][9][10][11]. Previous works reported the enhanced performance of clay-supported metal oxides in AOPs, which was mainly related to their stability in hostile environments and their recyclability and reusability.…”

“…Previous works reported the enhanced performance of clay-supported metal oxides in AOPs, which was mainly related to their stability in hostile environments and their recyclability and reusability. Such clay-supported metal oxides of ZnO, ZrO 2 , SnO 2 , and TiO 2 -pillared clays were characterized and noted to have distinctive photocatalytic activities, with the supportive adsorptive capability being attributed to the porosity of the material [9,[12][13][14]. Based on some considerations, such as the range of band gap energy, chemical stability, and cost effectiveness, ZnO was chosen as a good alternative to TiO 2 as a photocatalyst.…”