Recent Advances in Nanomaterials for Wastewater Treatment
01 Jan 2019-pp 21-58
TL;DR: In this paper, the use of semiconducting nanoparticles for wastewater treatment is discussed, and the role of nanomaterials in adsorption techniques (specifically, carbon-based nanoadsorbents) is discussed in detail.
Abstract: Developing an efficient wastewater treatment technique is one of the major necessities of the twenty-first century, owing to the scarcity of water resources. Besides, it is of paramount important to find appropriate methodologies to economically treat wastewater. Recent advances in nanotechnology have attracted the attention of many researchers for wastewater treatment. The major advantages of such nanomaterial-based systems are that they can be reused and have been found to be very effective. Though many research works have been reported in this regard, there is very limited collective information. Hence, the major objective of this work is to describe recent achievements in nanomaterial-based systems for wastewater treatment. This chapter critically reviews and lists the uses of nanomaterials in wastewater treatment. This comprises the utilization of semiconducting nanoparticles either alone or combined with ozonation, the Fenton process, or sonolysis for effective degradation/removal of organic pollutants. Furthermore, the effectiveness of nanotechnology in antimicrobial activity to produce pure water via an eco-friendly route is discussed. Similarly, the role of nanomaterials in adsorption techniques (specifically, carbon-based nanoadsorbents) to remove heavy metal contamination from industrial wastewater is also discussed in detail.
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TL;DR: In this article, a review emphasises advances in nanotechnology and their respective kinetics, different reaction-based models for wastewater treatment, and discusses several nano-material based approaches employed in wastewater treatment deliberated in this manuscript.
17 citations
TL;DR: In this article , a review summarizes recent advances in the synthesis, reporting techniques, and applications of functionalized nanomaterials (FNMs) in adsorptive and photocatalytic removal of pollutants from wastewater.
Abstract: Abstract Nanotechnology has emerged as an extraordinary and rapidly developing discipline of science. It has remolded the fate of the whole world by providing diverse horizons in different fields. Nanomaterials are appealing because of their incredibly small size and large surface area. Apart from the naturally occurring nanomaterials, synthetic nanomaterials are being prepared on large scales with different sizes and properties. Such nanomaterials are being utilized as an innovative and green approach in multiple fields. To expand the applications and enhance the properties of the nanomaterials, their functionalization and engineering are being performed on a massive scale. The functionalization helps to add to the existing useful properties of the nanomaterials, hence broadening the scope of their utilization. A large class of covalent and non-covalent functionalized nanomaterials (FNMs) including carbons, metal oxides, quantum dots, and composites of these materials with other organic or inorganic materials are being synthesized and used for environmental remediation applications including wastewater treatment. This review summarizes recent advances in the synthesis, reporting techniques, and applications of FNMs in adsorptive and photocatalytic removal of pollutants from wastewater. Future prospects are also examined, along with suggestions for attaining massive benefits in the areas of FNMs.
6 citations
TL;DR: In this paper , a simple hydrothermal method was used to synthesize the SrTiO3/rGO@Ag composites, followed by decorating the surface with Ag particles by using the photodeposition process.
Abstract: Understanding the graphene/semiconductor/metal interactions is crucial to design innovative photocatalytic materials with efficient photocatalytic activity for environmental cleanup applications. SrTiO3 on reduced graphene oxide (rGO) with various graphene contents was successfully synthesized in this study utilizing a simple hydrothermal method, followed by decorating the surface with Ag particles by using the photodeposition process. Under UV-visible light irradiation, the resulting composites were tested for their improved photocatalytic activity to decompose methylene blue (MB). The prepared photocatalysts were characterized by XRD, SEM, EDX, DLS, FT-IR, Raman spectroscopy, and DRS. First-principle density functional theory calculations (DFT) were also carried out by using the generalized gradient approximation (GGA) and PBE functional with the addition of on-site Coulomb correction (GGA + U). The obtained SrTiO3/rGO@Ag composites showed great improvement in the photocatalytic performances over pristine SrTiO3. For the degradation reaction of MB, SrTiO3/rGO20%@Ag4% composites yielded the best photocatalytic activity with efficacy reach 94%, which was also shown that it could be recycled up to four times with nearly unchanged photocatalytic activity.
4 citations
01 Jan 2021
TL;DR: In this paper, the authors discuss the latest technologies which are available right now using the chalcogenides nanomaterials, as catalysts, remediation of various environmental contaminants, and their role in treating contaminated water including organic contaminants degradation alongside bacterial disinfection.
Abstract: Nowadays pollution is a major concern for human mankind. As the generations are passing by, the more the worse it is getting to protect the environment. Every part of the environment is being contaminated due and in reverse, the humans and the other living being getting affected due to the consequences done by humans. Even though there are several technologies available to protect the environment still we find some voids to fill in and in this process, new technology evolves in. Water pollution is also considered to be one of the most ghastly situations, where economic development, rapid industrialization and even the population overgrowth is playing a key role. Due to rapid growth the release of several organic as well as inorganic substances into the environment, this is further leading to environmental pollution as well as the contamination of water. Because of this, combining nanotechnology in wastewater treatment will improve the quality of water. The major advantage of using the nanoparticles is they possess unique characteristics and have a high surface area where the unwanted particles get absorbed in these nanoparticles and get removed from them because of their high surface area. It can also be used for removing toxic substances. In this chapter, we discuss the latest technologies, which are available right now using the chalcogenides nanomaterials. Like, to disinfect the bacterial communities in wastewater, aspects of chalcogenide nanomaterials, as catalysts, remediation of various environmental contaminants, and their role in treating the contaminated water including organic contaminants degradation alongside bacterial disinfection.
3 citations
References
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TL;DR: From the strong reductive properties it is obvious that AgNPs can be used in water sanitization and converting some organic compounds in to non-hazardous materials, and showed potential applications in the field of electro chemistry, sensor, catalyst, nano- devices and medical.
Abstract: In the present research work a novel, nontoxic and ecofriendly procedure was developed for the green synthesis of silver nano particle (AgNPs) using Caruluma edulis (C. edulis) extract act as reductant as well as stabilizer agents. The formation of AgNPs was confirmed by UV/Vis spectroscopy. The small and spherical sizes of AgNPs were conformed from high resolution transmission electron microscopy (HRTEM) analysis and were found in the range of 2-10nm, which were highly dispersion without any aggregation. The crystalline structure of AgNPs was conformed from X-ray diffraction (XRD) analysis. For the elemental composition EDX was used and FTIR helped to determine the type of organic compounds in the extract. The potential electrochemical property of modified silver electrode was also studied. The AgNPs showed prominent antibacterial motion with MIC values of 125 μg/mL against Bacillus subtilis and Staphylococcus aureus while 250 μg/mL against Escherichia coli. High cell constituents' release was exhibited by B. subtilis with 2 × MIC value of silver nanoparticles. Silver nanoparticles also showed significant DPPH free radical scavenging activity. This research would have an important implication for the synthesis of more efficient antimicrobial and antioxidant agent. The AgNP modified electrode (GC/AgNPs) exhibited an excellent electro-catalytic activity toward the redox reaction of phenolic compounds. The AgNPs were evaluated for electrochemical degradation of bromothymol blue (BTB) dyes which showed a significant activity. From the strong reductive properties it is obvious that AgNPs can be used in water sanitization and converting some organic perilous in to non-hazardous materials. The AgNPs showed potential applications in the field of electro chemistry, sensor, catalyst, nano-devices and medical.
39 citations
TL;DR: In this article, the effect of preparation conditions on the morphology, crystallite size and catalytic efficiency of nanoferrites was analyzed using X-ray diffraction and scanning electron microscopy.
Abstract: Catalytic wet peroxide oxidation of 4-chlorophenol solution was studied over nickel and zinc ferrite nanoparticles at mild conditions. The catalysts were prepared by sol–gel auto combustion method using ethylene glycol and citric acid as gelling agents at different calcination temperatures. Complete removal of 4-chlorophenol (25 ml of 1 g/l 4-chlorophenol solution) was achieved within 60 min at ambient conditions. Studies on the effect of reaction variables revealed that only a small amount of the oxidant (1 ml) is required for the complete degradation of 4-chlorophenol. 100 % of the target pollutant was removed at catalyst concentrations of 300 mg. The catalysts were reusable and the activity as well as the single phasic nature of the ferrite catalysts remained the same after five successive runs. Leaching of iron from ferrite nanoparticles was not observed after five consecutive cycles indicating the mechanism to be heterogeneous. The samples were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The results underline the effect of preparation conditions on the morphology, crystallite size and catalytic efficiency of nanoferrites.
32 citations
TL;DR: In this paper, a simple approach for the fabrication of novel sulphur decorated MoO3 nanorods (S@MoO3 nmorods) by using simple solution process method for the very first time was reported.
Abstract: In the present study, we report a simple approach for the fabrication of novel sulphur decorated MoO3 nanorods (S@MoO3 nanorods) by using simple solution process method for the very first time. The phase structural, morphology and optical properties of the as-prepared nanomaterials were comparatively characterized. The sulphur (S) nanosheets were well decorated on the surface of MoO3 rods which was clearly observed from TEM images. The applicability of the as synthesized S@MoO3 nanocomposite was demonstrated as superior photocatalyst for the photocatalytic reduction of toxic hexavalent chromium Cr(VI) to nontoxic trivalent chromium Cr(III) under visible light illumination. The photocatalytic reduction results suggested that the 1% of S@MoO3 nanorods was exhibited excellent visible light photocatalytic activity efficiency compared to pure MoO3, S and other S@MoO3 nanocomposites. The enhancement in the photocatalytic performance of 1% S@MoO3 nanorods was mainly attributed to the strong absorption in visible region and low recombination or high separation efficiency for photogenerated electrons and holes. The trapping experiments reveals that O2 ¯ radical species was strongly supported for the photocatalytic reduction of Cr(VI). The present protocols reported open up an S decorated photocatalyst might be a potential candidate for Cr(VI) removal in environmental.
30 citations
TL;DR: In this paper, a corn protein was modified to be a biocompatible adsorbent for the removal of As(V) from water, which was prepared by the incorporation of iron(III) chloride into 50% (w/v) of zein in ethanol and water.
29 citations
01 Jun 1999-Journal of Environmental Science and Health Part A-toxic\/hazardous Substances & Environmental Engineering
TL;DR: In this paper, the authors compared several Fenton-related oxidative processes, including photo-fenton reaction, Fenton reaction type, photo-type, and Photo-Fenton type, to isolate the one that can effectively remove 2,4-dinitrophenol (DNP).
Abstract: Several Fenton‐related oxidative processes, UV/H2O2, Fenton reaction, Photo‐Fenton‐type, and Photo‐Fenton have been compared to isolate the one that can effectively remove 2,4‐dinitrophenol (DNP). The following criteria were adopted to screen the best oxidative process in terms of removal of DNP: residual percentage of DNP, residual percentage of ADMI color value and residual percentage of dissolved organic carbon (DOC). Results show that the Photo‐Fenton process outranks among others based on above‐mentioned criteria. Initially, the Photo‐Fenton process gives the same oxidative capability as the Fenton reaction. As reaction progresses, the Photo‐Fenton process outperforms others because the irradiation energy from UV light stimulates the regeneration of ferrous ion, resulting in more hydroxyl radicals released from H2O2, and further enhances the removal of DNP. In addition, The analysis of pseudo first‐order rate constants indicates that the removal rate of DOC is the limiting step in the Photo‐...
29 citations