scholarly journals The Roles of Nanomaterials in Conventional and Emerging Technologies for Heavy Metal Removal: A State-of-the-Art Review

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 625 ◽  
Author(s):  
Mahesan Naidu Subramaniam ◽  
Pei Sean Goh ◽  
Woei Jye Lau ◽  
Ahmad Fauzi Ismail
Keyword(s):  
Heavy Metal ◽  
Active Sites ◽  
Metal Removal ◽  
High Surface ◽  
Heavy Metal Removal ◽  
High Surface Area ◽  
Water Security ◽  
Wet Chemical Synthesis ◽  
Integral Role ◽  
Living Organisms

Heavy metal (HM) pollution in waterways is a serious threat towards global water security, as high dosages of HM poisoning can significantly harm all living organisms. Researchers have developed promising methods to isolate, separate, or reduce these HMs from water bodies to overcome this. This includes techniques, such as adsorption, photocatalysis, and membrane removal. Nanomaterials play an integral role in all of these remediation techniques. Nanomaterials of different shapes have been atomically designed via various synthesis techniques, such as hydrothermal, wet chemical synthesis, and so on to develop unique nanomaterials with exceptional properties, including high surface area and porosity, modified surface charge, increment in active sites, enhanced photocatalytic efficiency, and improved HM removal selectivity. In this work, a comprehensive review on the role that nanomaterials play in removing HM from waterways. The unique characteristics of the nanomaterials, synthesis technique, and removal principles are presented. A detailed visualisation of HM removal performances and the mechanisms behind this improvement is also detailed. Finally, the future directions for the development of nanomaterials are highlighted.

scholarly journals Adsorption of Hexavalent Chromium and Divalent Lead Ions on the Nitrogen-Enriched Chitosan-Based Activated Carbon

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1907
Author(s):  
Fatma Hussain Emamy ◽  
Ali Bumajdad ◽  
Jerzy P. Lukaszewicz
Keyword(s):  
Heavy Metal ◽  
Activated Carbon ◽  
Metal Ions ◽  
Metal Removal ◽  
High Surface ◽  
Heavy Metal Removal ◽  
High Surface Area ◽  
Kinetics Of Adsorption ◽  
Removal Of Heavy Metals ◽  
Pseudo Second Order

Optimizing the physicochemical properties of the chitosan-based activated carbon (Ch-ACs) can greatly enhance its performance toward heavy metal removal from contaminated water. Herein, Ch was converted into a high surface area (1556 m2/g) and porous (0.69 cm3/g) ACs with large content of nitrogen (~16 wt%) using K2CO3 activator and urea as nitrogen-enrichment agents. The prepared Ch-ACs were tested for the removal of Cr(VI) and Pb(II) at different pH, initial metal ions concentration, time, activated carbon dosage, and temperature. For Cr(VI), the best removal was at pH = 2, while for Pb(II) the best pH for its removal was in the range of 4–6. At 25 °C, the Temkin model gives the best fit for the adsorption of Cr(VI), while the Langmuir model was found to be better for Pb(II) ions. The kinetics of adsorption of both heavy metal ions were found to be well-fitted by a pseudo-second-order model. The findings show that the efficiency and the green properties (availability, recyclability, and cost effectiveness) of the developed adsorbent made it a good candidate for wastewaters treatment. As preliminary work, the prepared sorbent was also tested regarding the removal of heavy metals and other contaminations from real wastewater and the obtained results were found to be promising.

Heavy metal removal from stormwater runoff by sorption

2019 ◽  
pp. 207-217
Author(s):  
Hulya Genr-Fuhrman ◽  
Peter S. Mikkelsen ◽  
Anna Ledin
Keyword(s):  
Heavy Metal ◽  
Metal Removal ◽  
High Surface ◽  
Heavy Metal Removal ◽  
High Surface Area ◽  
The Other ◽  
Heavy Metal Cations ◽  
Batch Tests ◽  
Coated Sand ◽  
Granulated Activated Carbon

In this study, several sorbents (i.e. alumina, activated bauxsol coated sand (ABCS), bark,bauxsol coated sand (BCS), fly ash (FA), granulated activated carbon (GAC), iron oxidecoated sand (IOCS), natural zeolite (NZ), sand, and spine!) are investigated with the longterm goal of developing a feasible technology for heavy metal removal during secondarytreatment of storm water. The sorbents are tested in batch tests for their As, Cd, Cr, Cu, Ni andZn removal efficiency from synthetic stormwater samples, where all of these metals coexisted at a starting pH of 6.5. It is found that each sorbent has different affinity to the heavymetals, with heavy metal cations (i.e. Cd, Cu, Ni and Zn) removed more effectively thanheavy metal anions (i.e. As and Cr) by all sorbents except IOCS, which has a high affinitytowards As. The results further indicated that alumina and BCS outperform the other sorbents,possibly due to high surface area of alumina and the favourable sorption sites of BCS;whereas NZ, sand and bark were the least efficient. On the other hand, although FAeffectively retained Cd, Ni and Zn, the leaching of As, Cr, and Cu is a concern.

scholarly journals Nanostructured faujasite zeolite as metal ion adsorbent: kinetics, equilibrium adsorption and metal recovery studies

2020 ◽  
Author(s):  
Mariana B. Goncalves ◽  
Djanyna V. C. Schmidt ◽  
Fabiana S. dos Santos ◽  
Daniel F. Cipriano ◽  
Gustavo R. Gonçalves ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Metal Ions ◽  
Metal Ion ◽  
Active Sites ◽  
Metal Removal ◽  
High Surface ◽  
High Surface Area ◽  
Kinetic Studies ◽  
Crystallization Time ◽  
X Ray

Abstract The hydrothermal synthesis of nano-faujasite has been successfully performed and the effects of some crystallization parameters were investigated, along with the use of this material as a heavy-metal ion adsorbent. X-ray diffraction patterns have shown that the structure of the nano-faujasite is strongly dependent on both the crystallization time and the alkalinity of the synthesis medium. According to N2 physisorption, X-ray fluorescence, SEM/EDS, and solid state 29Si and 27Al NMR data, the produced nano-faujasite consists of a solid with low molar Si/Al ratio (1.7), with high availability of ion exchange sites and high surface area/small particle size, allowing easy diffusion of metal ions to adsorbent active sites. As a consequence, an excellent performance on removal of Cd2+, Zn2+ and Cu2+ ions was found for this solid. The adsorption capacity followed the order Cd2+ (133 mg·g−1) > Zn2+ (115 mg·g−1) > Cu2+ (99 mg·g−1), which agrees with the order of increasing absolute values of the hydration energy of the metal ions. Kinetic studies and adsorption isotherms showed that the metal ion removal takes place by ion exchange on the monolayer surface of the nano-faujasite. The electrochemical recovery of copper in metallic form exhibited an efficiency of 80.2% after 120 min, which suggests that this process can be adequately implemented for full-scale metal removal.

Photocatalytic Treatment of Environmental Pollutants using Multilevel- Structure TiO2-based Organic and Inorganic Nanocomposites

2020 ◽  
Vol 7 (3) ◽  
pp. 161-178
Author(s):  
Jiabai Cai ◽  
Shunxing Li
Keyword(s):  
Organic Semiconductor ◽  
Metal Removal ◽  
High Surface ◽  
Heavy Metal Removal ◽  
Hollow Spheres ◽  
High Surface Area ◽  
Chemical Properties ◽  
Volume Ratio ◽  
Diverse Range ◽  
Inorganic And Organic

Nanostructured materials often exhibit unique physical properties, such as fast carrier transport, subwavelength optical waveguiding, and a high surface-area-to-volume ratio. When the size of a material is reduced to nanoscale dimensions, its physical and chemical properties can change dramatically. In addition, nanostructures offer exciting new opportunities for environmental applications. In this review, we aim to provide an up-to-date summary of recent research related to multifunctional TiO2-based inorganic and organic semiconductor nanomaterials, covering both their synthesis and applications. After a brief introduction of the definition and classification of TiO2-based inorganic and organic semiconductor nanomaterial structures, we discuss various application strategies, such as sewage treatment, heavy metal removal, and the oxidation of alcohols to the corresponding aldehydes. In our previous work, we fabricated a variety of TiO2-based hollow spheres using a diverse range of materials from inorganic semiconductors to organic semiconductors and applied these structures as photocatalysts. Further, the development of these nanostructures may enable numerous applications in the field of environmental technology.

Metal-Organic Frameworks for Heavy Metal Removal From Water

2021 ◽  
pp. 92-111
Author(s):  
Mintu Maan Dutta ◽  
Paran Jyoti Borpatra
Keyword(s):  
Heavy Metal ◽  
Metal Removal ◽  
Anthropogenic Activities ◽  
Heavy Metal Removal ◽  
Metal Species ◽  
Essential Components ◽  
Novel Material ◽  
Metal Organic ◽  
Living Organisms ◽  
Adsorption Capability

Clean and safe drinking water is one of the most important and essential components on earth for human survival. However, due to the various anthropogenic activities, the surface and groundwater have been contaminated with heavy metals and radionuclides, and it has become a serious problem of concern globally. These non-biodegradable heavy metal ions from water tends to accumulate in the soil and living organisms and causes serious health hazards in humans. Thus, the finding of recyclable, water-stable MOFs, and multi-functional MOFs (hybrid MOFs) with superior adsorption capability have emerged as a novel material for the removal of heavy metal species (such as Cr(III)/Cr(VI), Cu(II), Hg(II), Cd(II), As(III)/As(V), Pb(II), radionuclides U(VI), Se(IV)/(VI), Cs(I) from aqueous solution. This chapter deals with the recent development of MOFs and their application in heavy metal removal from water.

Metal-organic-framework derived hollow manganese nickel selenide spheres confined with nanosheets on nickel foam for hybrid supercapacitors

2021 ◽  
Author(s):  
Bahareh ameri ◽  
Akbar Mohammadi Zardkhoshoui ◽  
Saied Saeed Hosseiny Davarani
Keyword(s):  
Active Sites ◽  
Nickel Foam ◽  
Metal Organic Framework ◽  
High Surface ◽  
Metal Organic Frameworks ◽  
High Surface Area ◽  
Supercapacitive Performance ◽  
Hybrid Supercapacitors ◽  
Porous Networks ◽  
Metal Organic

Metal-organic frameworks (MOFs) derived nanoarchitectures have special features, such as high surface area (SA), abundant active sites, exclusive porous networks, and remarkable supercapacitive performance when compared to traditional nanoarchitectures. Herein,...

Research trends of heavy metal removal from aqueous environments

2021 ◽  
Vol 287 ◽  
pp. 112322
Author(s):  
Morteza Nazaripour ◽  
Mir Amir Mohammad Reshadi ◽  
Seyed Ahmad Mirbagheri ◽  
Mehdi Nazaripour ◽  
Alireza Bazargan
Keyword(s):  
Heavy Metal ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Research Trends ◽  
Aqueous Environments
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