Editorial

4 pages, 163 KiB

Open AccessEditorial

by Shahin Homaeigohar

Water 2020, 12(5), 1507; https://doi.org/10.3390/w12051507 - 25 May 2020

Cited by 14 | Viewed by 3169

The studies introduced in this special issue aim to provide a state-of-the-art vision for nanomaterials-based technology that could profit the water treatment industry. Given the expanding crisis of water shortages across the world, this perspective is invaluable and of paramount importance. No doubt, [...] Read more.

The studies introduced in this special issue aim to provide a state-of-the-art vision for nanomaterials-based technology that could profit the water treatment industry. Given the expanding crisis of water shortages across the world, this perspective is invaluable and of paramount importance. No doubt, as the environmental challenges are going to be more complicated and to extend to as-yet unconsidered areas, we need to upgrade our facilities and knowledge to address them properly. Nanomaterials are indeed promising building blocks for such advanced technologies that enable them to purify water streams from complex pollutants in an energy, cost and time-effective manner. The focus of the (review and original research) articles collected in this issue is on various kinds of nanomaterials made of carbon, polymer, metal, and metal oxides (magnetic and photocatalyst), that are employed for adsorption and photodegradation of heavy metals and organic pollutants, respectively. Here, I briefly review the insights given in these precious studies and suggest new directions for future research in this field. Full article

(This article belongs to the Special Issue Water Treatment with New Nanomaterials)

Research

Jump to: Editorial, Review

12 pages, 3405 KiB

Open AccessArticle

Magnetic Sorbent for the Removal of Selenium(IV) from Simulated Industrial Wastewaters: Determination of Column Kinetic Parameters

by Andrew Ying, Samuel F. Evans, Costas Tsouris and M. Parans Paranthaman

Water 2020, 12(5), 1234; https://doi.org/10.3390/w12051234 - 26 Apr 2020

Cited by 5 | Viewed by 2392

Abstract

A novel meso- and microporous tire-derived-carbon support with magnetic iron oxide nanoparticle adsorbents that selectively adsorbs Se(IV) ions from simulated contaminated water has been developed. In this work, the physicochemical characteristics of the composite adsorbent are characterized with respect to porosity and surface [...] Read more.

A novel meso- and microporous tire-derived-carbon support with magnetic iron oxide nanoparticle adsorbents that selectively adsorbs Se(IV) ions from simulated contaminated water has been developed. In this work, the physicochemical characteristics of the composite adsorbent are characterized with respect to porosity and surface area, chemical composition, and microstructure morphology. The kinetics of this composite adsorbent in a fixed-bed setting has been determined. Several column runs were conducted and analyzed by inductively coupled plasma-optical emission spectroscopy (ICP-OES) to determine the concentration gradient vs time. These results were then fit to a pseudo-second order rate law to obtain equilibrium values. Combining calculated equilibrium values with effluent concentration data, enabled the application of the Adams–Bohart model to determine reaction constants and column coefficients. Column parameters obtained from different flow rates and fittings of the Adams–Bohart model were remarkably consistent. These findings enable the application of this sorbent to fixed-bed column systems and opens up further research into mixed pollutants tests with real wastewater and scaling of selenium pollutant removal. Full article

(This article belongs to the Special Issue Water Treatment with New Nanomaterials)

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15 pages, 4258 KiB

Open AccessArticle

Au/ZnO Hybrid Nanostructures on Electrospun Polymeric Mats for Improved Photocatalytic Degradation of Organic Pollutants

by Laura Campagnolo, Simone Lauciello, Athanassia Athanassiou and Despina Fragouli

Water 2019, 11(9), 1787; https://doi.org/10.3390/w11091787 - 28 Aug 2019

Cited by 24 | Viewed by 3582

Abstract

An innovative approach for the fabrication of hybrid photocatalysts on a solid porous polymeric system for the heterogeneous photocatalytic degradation of organic pollutants is herein presented. Specifically, gold/zinc oxide (Au/ZnO)-based porous nanocomposites are formed in situ by a two-step process. In the first [...] Read more.

An innovative approach for the fabrication of hybrid photocatalysts on a solid porous polymeric system for the heterogeneous photocatalytic degradation of organic pollutants is herein presented. Specifically, gold/zinc oxide (Au/ZnO)-based porous nanocomposites are formed in situ by a two-step process. In the first step, branched ZnO nanostructures fixed on poly(methyl methacrylate) (PMMA) fibers are obtained upon the thermal conversion of zinc acetate-loaded PMMA electrospun mats. Subsequently, Au nanoparticles (NPs) are directly formed on the surface of the ZnO through an adsorption dipping process and thermal treatment. The effect of different concentrations of the Au ion solutions to the formation of Au/ZnO hybrids is investigated, proving that for 1 wt % of Au NPs with respect to the composite there is an effective metal–semiconductor interfacial interaction. As a result, a significant improvement of the photocatalytic performance of the ZnO/PMMA electrospun nanocomposite for the degradation of methylene blue (MB) and bisphenol A (BPA) under UV light is observed. Therefore, the proposed method can be used to prepare flexible fibrous composites characterized by a high surface area, flexibility, and light weight. These can be used for heterogeneous photocatalytic applications in water treatment, without the need of post treatment steps for their removal from the treated water which may restrict their wide applicability and cause secondary pollution. Full article

(This article belongs to the Special Issue Water Treatment with New Nanomaterials)

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11 pages, 3336 KiB

Open AccessArticle

Preparation of Biomass Activated Carbon Supported Nanoscale Zero-Valent Iron (Nzvi) and Its Application in Decolorization of Methyl Orange from Aqueous Solution

by Bo Zhang and Daping Wang

Water 2019, 11(8), 1671; https://doi.org/10.3390/w11081671 - 12 Aug 2019

Cited by 18 | Viewed by 5030

Abstract

The nanoscale zero-valent iron (nZVI) has great potential to degrade organic polluted wastewater. In this study, the nZVI particles were obtained by the pulse electrodeposition and were loaded on the biomass activated carbon (BC) for synthesizing the composite material of BC-nZVI. The composite [...] Read more.

The nanoscale zero-valent iron (nZVI) has great potential to degrade organic polluted wastewater. In this study, the nZVI particles were obtained by the pulse electrodeposition and were loaded on the biomass activated carbon (BC) for synthesizing the composite material of BC-nZVI. The composite material was characterized by SEM-EDS and XRD and was also used for the decolorization of methyl orange (MO) test. The results showed that the 97.94% removal percentage demonstrated its promise in the remediation of dye wastewater for 60 min. The rate of MO matched well with the pseudo-second-order model, and the rate-limiting step may be a chemical sorption between the MO and BC-nZVI. The removal percentage of MO can be effectively improved with higher temperature, larger BC-nZVI dosage, and lower initial concentration of MO at the pH of 7 condition. Full article

(This article belongs to the Special Issue Water Treatment with New Nanomaterials)

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16 pages, 2257 KiB

Open AccessArticle

Comparative Study of Four TiO₂-Based Photocatalysts to Degrade 2,4-D in a Semi-Passive System

by Gisoo Heydari, Jordan Hollman, Gopal Achari and Cooper H. Langford

Water 2019, 11(3), 621; https://doi.org/10.3390/w11030621 - 26 Mar 2019

Cited by 7 | Viewed by 3571

Abstract

In this study, the relative efficiency of four forms of supported titanium dioxide (TiO₂) as a photocatalyst to degrade 2,4-dichlorophenoxyacetic acid (2,4-D) in Killex^®, a commercially available herbicide was studied. Coated glass spheres, anodized plate, anodized mesh, and electro-photocatalysis [...] Read more.

In this study, the relative efficiency of four forms of supported titanium dioxide (TiO₂) as a photocatalyst to degrade 2,4-dichlorophenoxyacetic acid (2,4-D) in Killex^®, a commercially available herbicide was studied. Coated glass spheres, anodized plate, anodized mesh, and electro-photocatalysis using the anodized mesh were evaluated under an ultraviolet – light-emitting diode (UV-LED) light source at λ = 365 nm in a semi-passive mode. Energy consumption of the system was used to compare the efficiency of the photocatalysts. The results showed both photospheres and mesh consumed approximately 80 J/cm³ energy followed by electro-photocatalysis (112.2 J/cm³), and the anodized plate (114.5 J/cm³). Although electro-photocatalysis showed the fastest degradation rate (K = 5.04 mg L⁻¹ h⁻¹), its energy consumption was at the same level as the anodized plate with a lower degradation rate constant of 3.07 mg L⁻¹ h⁻¹. The results demonstrated that three-dimensional nanotubes of TiO₂ surrounding the mesh provide superior degradation compared to one-dimensional arrays on the planar surface of the anodized plate. With limited broad-scale comparative studies between varieties of different TiO₂ supports, this study provides a comparative analysis of relative degradation efficiencies between the four photocatalytic configurations. Full article

(This article belongs to the Special Issue Water Treatment with New Nanomaterials)

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9 pages, 1464 KiB

Open AccessFeature PaperArticle

An Amphiphilic, Graphitic Buckypaper Capturing Enzyme Biomolecules from Water

by Shahin Homaeigohar and Mady Elbahri

Water 2019, 11(1), 2; https://doi.org/10.3390/w11010002 - 20 Dec 2018

Cited by 17 | Viewed by 3003

Abstract

The development of carbon nanomaterials for adsorption based removal of organic pollutants from water is a progressive research subject. In this regard, carbon nanomaterials with bifunctionality towards polar and non-polar or even amphiphilic undesired materials are indeed attractive for further study and implementation. [...] Read more.

The development of carbon nanomaterials for adsorption based removal of organic pollutants from water is a progressive research subject. In this regard, carbon nanomaterials with bifunctionality towards polar and non-polar or even amphiphilic undesired materials are indeed attractive for further study and implementation. Here, we created carbon buckypaper adsorbents comprising amphiphilic (oxygenated amorphous carbon (a-CO_x)/graphite (G)) nanofilaments that can dynamically adsorb organic biomolecules (i.e., urease enzyme) and thus purify the wastewaters of relevant industries. Given the dynamic conditions of the test, the adsorbent was highly efficient in adsorption of the enzyme (88%) while being permeable to water (4750 L·h⁻¹m⁻²bar⁻¹); thus, it holds great promise for further development and upscaling. A subsequent citric acid functionalization declined selectivity of the membrane to urease, implying that the biomolecules adsorb mostly via graphitic domains rather than oxidized, polar amorphous carbon ones. Full article

(This article belongs to the Special Issue Water Treatment with New Nanomaterials)

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Review

Jump to: Editorial, Research

23 pages, 6226 KiB

Open AccessReview

An Overview of the Water Remediation Potential of Nanomaterials and Their Ecotoxicological Impacts

by Mehrnoosh Ghadimi, Sasan Zangenehtabar and Shahin Homaeigohar

Water 2020, 12(4), 1150; https://doi.org/10.3390/w12041150 - 17 Apr 2020

Cited by 53 | Viewed by 4246

Abstract

Nanomaterials, i.e., those materials which have at least one dimension in the 1–100 nm size range, have produced a new generation of technologies for water purification. This includes nanosized adsorbents, nanomembranes, photocatalysts, etc. On the other hand, their uncontrolled release can potentially endanger [...] Read more.

Nanomaterials, i.e., those materials which have at least one dimension in the 1–100 nm size range, have produced a new generation of technologies for water purification. This includes nanosized adsorbents, nanomembranes, photocatalysts, etc. On the other hand, their uncontrolled release can potentially endanger biota in various environmental domains such as soil and water systems. In this review, we point out the opportunities created by the use of nanomaterials for water remediation and also the adverse effects of such small potential pollutants on the environment. While there is still a large need to further identify the potential hazards of nanomaterials through extensive lab or even field studies, an overview on the current knowledge about the pros and cons of such systems should be helpful for their better implementation. Full article

(This article belongs to the Special Issue Water Treatment with New Nanomaterials)

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30 pages, 1778 KiB

Open AccessEditor’s ChoiceReview

Role of Nanomaterials in the Treatment of Wastewater: A Review

by Asim Ali Yaqoob, Tabassum Parveen, Khalid Umar and Mohamad Nasir Mohamad Ibrahim

Water 2020, 12(2), 495; https://doi.org/10.3390/w12020495 - 12 Feb 2020

Cited by 431 | Viewed by 40270

Abstract

Water is an essential part of life and its availability is important for all living creatures. On the other side, the world is suffering from a major problem of drinking water. There are several gases, microorganisms and other toxins (chemicals and heavy metals) [...] Read more.

Water is an essential part of life and its availability is important for all living creatures. On the other side, the world is suffering from a major problem of drinking water. There are several gases, microorganisms and other toxins (chemicals and heavy metals) added into water during rain, flowing water, etc. which is responsible for water pollution. This review article describes various applications of nanomaterial in removing different types of impurities from polluted water. There are various kinds of nanomaterials, which carried huge potential to treat polluted water (containing metal toxin substance, different organic and inorganic impurities) very effectively due to their unique properties like greater surface area, able to work at low concentration, etc. The nanostructured catalytic membranes, nanosorbents and nanophotocatalyst based approaches to remove pollutants from wastewater are eco-friendly and efficient, but they require more energy, more investment in order to purify the wastewater. There are many challenges and issues of wastewater treatment. Some precautions are also required to keep away from ecological and health issues. New modern equipment for wastewater treatment should be flexible, low cost and efficient for the commercialization purpose. Full article

(This article belongs to the Special Issue Water Treatment with New Nanomaterials)

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