Nanomaterials For Water Treatment Research Articles

A COMPREHENSIVE REVIEW ON CHARACTERIZATION, SYNTHESIS, OF NANOMATERIALS AND ITS APPLICATION IN WATER TREATMENT

Nanomaterials offer unique properties that make them highly suitable for addressing water quality challenges. Understanding their characterization and synthesis is pivotal for optimizing their performance in water treatment applications. Various analytical techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and surface area analysis are discussed for nanomaterial characterization. Additionally, synthesis methods including physical, chemical, and biological approaches are explored in detail, highlighting their advantages and limitations. The review also delves into the diverse applications of nanomaterials in water treatment, including pollutant removal, disinfection, and membrane filtration. Moreover, recent advancements and emerging trends in the field are examined to provide insights into future research directions. This review provides a comprehensive overview of the characterization techniques, synthesis methods, and applications of nanomaterials in water treatment. Overall, this review serves as a valuable resource for researchers, engineers, and policymakers involved in the development and implementation of nanomaterial-based water treatment technologies. Keywords: Nanomaterial, Characterization, Water treatment, Synthesis

The Use of Magnetic Porous Carbon Nanocomposites for the Elimination of Organic Pollutants from Wastewater

One of the most significant challenges the world is currently facing is wastewater treatment. A substantial volume of effluents from diverse sources releases numerous pollutants into the water. Among these contaminants, organic pollutants are particularly concerning due to the associated risk of being released into the environment, garnering significant attention. Rapid advancements in agriculture and industry on a global scale generate vast volumes of hazardous organic compounds, which eventually find their way into natural systems. Recently, the release of industrial wastewater has been increasing, due to the progress of numerous businesses. This poses a danger to humans and the environment, leading to environmental contamination. The application of carbon nanocomposites in applied nanotechnology has recently expanded due to their large surface area, substantial pore volume, low preparation cost, and environmental resilience. Expanding the use of nanomaterials in water treatment is essential, as magnetic carbon nanocomposites consistently demonstrate an efficient elimination of pollutants from water solutions. In the current study, we have highlighted the application of magnetic porous carbon nanocomposites in removing organic pollutants from wastewater.

Recent Advances in Nanomaterials-Based Adsorbents for Organophosphorus Contaminant Removal in Water: An Overview

The presence of organophosphorus contaminants (OPCs) in water is a major concern due to their toxicity and adverse effects on human health and the environment. Traditional water treatment methods such as coagulation, sedimentation, and filtration are not always effective in removing OPCs from water, making it necessary to explore alternative methods. Nanomaterials, due to their unique physical, chemical and biological properties, have emerged as promising adsorbents for the removal of OPCs from water. This review article focusses on the recent developments in the use of nanomaterials as adsorbents for the removal of OPCs from water. The article covers various types of nanomaterials, including carbon-based nanomaterials, metal-based nanomaterials and other hybrid nanomaterials. The mechanisms of OPC adsorption by nanomaterials, such as electrostatic interactions, hydrogen bonding, and Van der Waals forces, are also discussed. The article further highlights the factors affecting the adsorption capacity of nanomaterials, such as pH, temperature, and concentration of OPCs. Additionally, the article examines the challenges associated with the application of nanomaterials in water treatment, such as the potential release of nanomaterials into the environment and the need for cost-effective and scalable synthesis methods.

Magnetic recoverable Ag3PO4/Fe3O4/γ-Fe2O3 nanocomposite

The use of nanomaterials in water treatment is an alternative for the development of new systems to optimize the purification process. Heterogeneous photocatalysis is used for the treatment of wastewaters contaminated with recalcitrant pollutants that cannot be removed with conventional wastewater treatment techniques. Silver phosphate (Ag3PO4) can be used in visible-light driven photocatalysis. An important challenge of heterogeneous photocatalysis is to find a proper support for the photocatalysts to reduce the expense associated with the separation and reuse of these materials. However, the immobilization of the catalyst leads to lower reaction rates because the exposed surface area decreases and the material used as support can also interfere. In the last years, the use of magnetic materials to support photocatalysts has attracted special attention because it allows high surface areas to be exposed. Only few authors have reported the use of Ag3PO4/magnetic nanocomposites for photocatalysis and these need to be continued to improve their efficiency. In this work we synthesized Ag3PO4 and supported it on ferromagnetite (Fe3O4). In this study, Fe3O4 was synthesis following the Massart’s method. Ag3PO4 was synthesised over Fe3O4 from the reaction between silver nitrate (AgNO3) and disodium hydrogen phosphate (Na2HPO4). For characterization, DRS, SEM, XRD and magnetization studies were carried out. Ag3PO4 was synthesised and satisfactorily supported over magnetite (Fe3O423). The photodegradation of 10 mg·L−1 of methylene blue was achieved, although the apparent reaction rate constant was slightly lower for the magnetic composite than for bare Ag3PO4. This is explained because the composite contained 48% of the active Ag3PO4 material, as depicted form XRD studies.

Nanoscience and nanotechnology for water remediation: an earnest hope toward sustainability.

Water pollution and the global freshwater crisis are the most alarming concerns of the 21st century, as they threaten the sustainability and ecological balance of the environment. The growth of global population, climate change, and expansion of industrial processes are the main causes of these issues. Therefore, effective remediation of polluted water by means of detoxification and purification is of paramount importance. To this end, nanoscience and nanotechnology have emerged as viable options that hold tremendous potential toward the advancement of wastewater treatment methods to enhance treatment efficiency along with augmenting water supply via utilization of unconventional water sources. Materials at the nano level have shown great promise toward water treatment applications owing to their unique physicochemical properties. In this focus article, we highlight the role of new fundamental properties at the nano scale and material properties that are drastically increased due to the nano dimension (e.g. volume-surface ratio) and highlight their impact and potential toward water treatment. We identify and discuss how nano-properties could improve the three main domains of water remediation: the identification of pollutants, their adsorption and catalytic degradation. After discussing all the beneficial aspects we further discuss the key challenges associated with nanomaterials for water treatment. Looking at the current state-of-the-art, the potential as well as the challenges of nanomaterials, we believe that in the future we will see a significant impact of these materials on many water remediation strategies.

Nanomaterials for Water Treatment: Breakthroughs and Potential Applications

Nanomaterials for Water Treatment: Breakthroughs and Potential Applications

Application of Nanomaterials in Water Treatment: Arsenic and Natural Organic Matter Removal.

Globally, around 150 million people are still supplied with arsenic contaminated drinking water. The groundwaters effected often contain problematic concentrations of natural organic matter (NOM), which plays an important role in releasing As into the aquifer. Thus, this review explores the recent literature relating to the application of various nanomaterials to solve these drinking water supply problems and highlights the work that still needs to be done. After an extensive initial search patent papers were selected based on their quality and relevance to the topic of this review: the use of magnetic nanomaterials based on pure magnetic materials, magnetic composites of carbon/graphene/biochars, polymeric matrices, metal-organic frameworks and mixed-oxide magnetic nanocomposites, as As adsorbents and as photocatalysts for NOM removal. 160 papers relating to the application of nanomaterials for As removal were reviewed and 38 papers covering photocatalysts for NOM removal. These papers were organised by type of nanomaterial, and their important findings summarised. Although many authors have demonstrated effective solutions in the laboratory, the following areas still need to be addressed: the challenges posed by larger pilot and full scale continuously operated processes; the treatment of complex natural water matrices; which technologies will be required to economically separate nanoparticles from the treated water; whether the nanoparticles will be more economically and environmentally sustainable than other techniques available. Despite these significant gaps in the literature, the body of work carried out thus far, as summarised in this review paper, strongly suggests that full scale treatment solutions applying (magnetic) nanomaterials may prove highly effective in the future for both arsenic and NOM removal.

Advanced Oxidation Processes Coupled with Nanomaterials for Water Treatment.

Water quality management will be a priority issue in the near future. Indeed, due to scarcity and/or contamination of the water, regulatory frameworks will be increasingly strict to reduce environmental impacts of wastewater and to allow water to be reused. Moreover, drinking water quality standards must be improved in order to account for the emerging pollutants that are being detected in tap water. These tasks can only be achieved if new improved and sustainable water treatment technologies are developed. Nanomaterials are improving the ongoing research on advanced oxidation processes (AOPs). This work reviews the most important AOPs, namely: persulfate, chlorine and NH2Cl based processes, UV/H2O2, Fenton processes, ozone, and heterogeneous photocatalytic processes. A critical review of the current coupling of nanomaterials to some of these AOPs is presented. Besides the active role of the nanomaterials in the degradation of water contaminants/pollutants in the AOPs, the relevance of their adsorbent/absorbent function in these processes is also discussed.

Nano-enhanced Dialytic Fluid Purification: CFD Modeling of Pb(II) Removal by Manganese Oxide.

Nano-enhanced dialytic fluid purification is an evolution of biomedical dialysis that has been proposed as a novel method for applying nanomaterials in water treatment. Using nanosized hexagonal birnessite (δ-MnO2) in a simplified dialytic system, we demonstrate herein an almost complete removal (98%) of Pb(II) within 3 h of treatment while monitoring environmental variables pH and Eh (redox potential). A mathematical model of the purification process is constructed in COMSOL Multiphysics to demonstrate how nanoadsorption using free-flowing nanoparticles in a dialytic system can be studied theoretically using computational fluid dynamics (CFD). The CFD model closely agrees with experimental results, estimating a 95% removal over 3 h of treatment and suggesting an 18% consumption of available adsorbent capacity. Additional insights into the progress and mechanisms of the adsorption process are also revealed. Finally, the nanoenhanced model is compared against standard dialysis absent of nanomaterials using COMSOL, and key differences in removal efficiency are highlighted. Results indicate that nanoenhanced dialysis can attain almost complete removal in 3 h of treatment or reach the same removal goal as standard dialysis in less than two-third of the treatment time.

Nanoconfinement-Mediated Water Treatment: From Fundamental to Application.

Safe and clean water is of pivotal importance to all living species and the ecosystem on earth. However, the accelerating economy and industrialization of mankind generate water pollutants with much larger quantity and higher complexity than ever before, challenging the efficacy of traditional water treatment technologies. The flourishing researches on nanomaterials and nanotechnologies in the past decade have generated new understandings on many fundamental processes and brought revolutionary upgrades to various traditional technologies in almost all areas, including water treatment. An indispensable step toward the real application of nanomaterials in water treatment is to confine them in large processable substrate to address various inherent issues, such as spontaneous aggregation, difficult operation and potential environmental risks. Strikingly, when the size of the spatial restriction provided by the substrate is on the order of only one or several nanometers, referred to as nanoconfinement, the phase behavior of matter and the energy diagram of a chemical reaction could be utterly changed. Nevertheless, the relationship between such changes under nanoconfinement and their implications for water treatment is rarely elucidated systematically. In this Critical Review, we will briefly summarize the current state-of-the-art of the nanomaterials, as well as the nanoconfined analogues (i.e., nanocomposites) developed for water treatment. Afterward, we will put emphasis on the effects of nanoconfinement from three aspects, that is, on the structure and behavior of water molecules, on the formation (e.g., crystallization) of confined nanomaterials, and on the nanoenabled chemical reactions. For each aspect, we will build the correlation between the nanoconfinement effects and the current studies for water treatment. More importantly, we will make proposals for future studies based on the missing links between some of the nanoconfinement effects and the water treatment technologies. Through this Critical Review, we aim to raise the research attention on using nanoconfinement as a fundamental guide or even tool to advance water treatment technologies.

Use of nanohybrid nanomaterials in water treatment: highly efficient removal of ranitidine.

Entire elimination of pharmaceutical drugs from waste- and domestic-waters has attracted great attention due to their potent adverse effects on human health, particularly the human immune system. Many risks have been related to the presence of different types of drugs at different concentrations in wastewater. These risks include antimicrobial resistance (AMR), endocrine action, hormonal activation of cancers, and photodegradation of drugs. In this study, new nanohybrid materials consisting of graphene oxide (GO) and oxidized carbon nanotubes (OCNTs) were developed to remove a well-known drug, namely, ranitidine that treats stomach ulcers and gastrointestinal (GI) reflux disease from aqueous solutions. The characterization of synthesized nanohybrid GO-OCNTs was performed using spectroscopic (FTIR, and XRD), thermogravimetric (TGA) and microscopic (SEM) techniques. Batch adsorption experiments were used to investigate the technical feasibility of using synthesized GO-OCNTs for the removal of ranitidine from aqueous solutions. The effects of different operating conditions such as contact time, nanohybrid mass, solution temperature, solution pH, % crosslinking agent, and GO-to-OCNT ratio on the entire elimination of ranitidine were investigated. The experimental results indicated that the removal of ranitidine was very efficient, where 98.3% removal of the drug from aqueous solutions was achieved with a drug uptake of 97.8 mg g−1. Moreover, the results indicated the optimum conditions for the removal of ranitidine, which are as follows: contact time = 140 minutes, nanohybrid GO-OCNT mass = 10 mg, solution temperature = 290 K, solution pH = 6.4, % crosslinking agent = 0.5%, and GO to O-CNT ratio = 1 : 4. The equilibrium data were fitted to different adsorption isotherms and Langmuir was found to best describe our data. Dynamic studies demonstrated that ranitidine adsorption followed pseudo-second order, and the thermodynamic parameters confirmed exothermic drug adsorption as well as the physisorption process.

Water treatment by new-generation graphene materials: hope for bright future.

Water is the most important and essential component of earth's ecosystem playing a vital role in the proper functioning of flora and fauna. But, our water resources are contaminating continuously. The whole world may be in great water scarcity after few decades. Graphene, a single-atom thick carbon nanosheet, and graphene nanomaterials have bright future in water treatment technologies due to their extraordinary properties. Only few papers describe the use of these materials in water treatment by adsorption, filtration, and photodegradation methods. This article presents a critical evaluation of the contribution of graphene nanomaterials in water treatment. Attempts have been made to discuss the future perspectives of these materials in water treatment. Besides, the efforts are made to discuss the nanotoxicity and hazards of graphene-based materials. The suggestions are given to explore the full potential of these materials along with precautions of nanotoxicity and its hazards. It was concluded that the future of graphene-based materials is quite bright.

Design of Iron-Based Nanomaterials As Catalysts for Efficient Water Treatment and Electrochemical Energy Conversion

Materials design for iron-based nanomaterials in water treatment and electrochemical energy conversion has largely remained two distinct fields of research and engineering. Yet, the overall goals are the same; materials must be highly active for the target reaction, chemically stable with relevant lifetimes, and tunable for broad applicability and optimization in engineering systems. Further, the detailed characterization performed on catalysts in the electrochemistry arena could benefit efforts to develop catalysts and reactive materials in the water treatment community. Our research focuses on the development of iron-based catalysts and reactive nanomaterials for water contaminant degradation and alkaline electrochemical energy conversion applications, where we synthesize and tune nanoparticle properties, such as phase, composition, and morphology, to target specific reactions. In this talk, I will discuss key examples of how we synthesize our nanomaterials, our work on understanding the roles of nanoparticle structure and composition in reactivity, and opportunities for the synergistic blending of materials design and knowledge of how to design iron-based nanocatalysts for water and energy applications. In particular, an understanding of nanoparticle composition and phase in bimetallic iron-nickel hydroxide nanoparticles for alkaline water electrolysis supports our efforts to design similar catalysts for reductive degradation of the contaminant trichloroethylene, and we are also investigating the role of conductivity in carbon support materials used for water treatment applications. Our work on understanding how nanoparticle synthesis parameters affect nanoparticle performance has led to identification of specific parameters that may be tuned to optimize our catalysts for both arenas, and we have identified specific ligands used during solution-phase synthesis that are important to our catalytic reactions of interest. Overall, there remain many opportunities to draw from experimental progress made in both the water treatment and electrochemistry research communities, and I will touch on several key opportunities that we see in our work.

TiO2 nanosheet-graphene oxide based photocatalytic hierarchical membrane for water purification

There is a rising concern over the toxicity of nanomaterials which emphasizes the need for reforms in application of nanomaterials in water treatment. A hierarchical membrane with a thin layer of photocatalyst coated on top of the membrane surface has emerged as a better alternate for immobilization of photocatalyst. Studies have revealed that nanoparticles are not pliable for synthesis of hierarchical membranes due to their smaller size and low stability after deposition. TiO2 nanosheets serve as better alternate due their thin structure which enables stable layer formation. Integrating the nanosheets with modifiers like graphene oxide can further enhance the photocatalytic activity. The sheet structure of graphene oxide enhances stable film formation and also acts as support for interconnecting TiO2 nanosheets. In the present work, TiO2 nanosheets are modified with graphene oxide and used to develop a hierarchical membrane by depositing a catalyst coating on a support membrane. The hierarchical membrane performance was studied using Congo red dye as model pollutant and the effect of catalyst loading on the permeate flux and dye removal were analyzed.

Antibacterial properties of Ag and Ag/AgCl nanoparticles from radish and tea extracts for water treatment applications

Silver nanoparticles (AgNPs) have antibacterial properties and are widely used for water disinfection. This technology is commercially applied in point-of-use water treatment as a post-treatment for filtrate water. However, the current process of synthesizing AgNPs has several disadvantages including the use of hazardous chemicals, consumption of a large amount of energy and the formation of hazardous byproducts. Here, we report an alternative and green synthesis using plant extracts. In this work, the plant extracts came from radish (R) and tea (T), and the AgNPs were derived from a microwave irradiation method. The AgNPs synthesized by chemical-based microwave irradiation (Ag-C) were also used as a control material. The novel method produced a smaller size of nanostructures with good dispersion ability and less agglomeration than those from chemical synthesis. The antibacterial properties of AgNPs on Gram-negative bacteria Escherichia coli (E. coli) and Gram-positive bacteria Staphylococcus aureus (S. aureus) were investigated. The results revealed that AgNPs from both green synthesis and chemical-based methods inactivated both types of bacteria. The green-synthesized AgNPs from radish juice provided a higher percentage of inhibition of E. coli than that of S. aureus. The inactivation rates of the AgNPs increased with increasing concentration of AgNPs. As the concentration of the Ag/AgCl-R and Ag-R increased from 150 μg/mL to 300 μg/mL, complete inactivation required a reduced time for the reaction from 300 minutes to only 30 minutes. Finally, the Ag/AgCl-R and Ag-R offered high antibacterial activity while the Ag-T provided the lowest antibacterial activity. This work provides an alternative method for the eco-synthesis of antibacterial nanomaterials for water treatment.

In Response: Applications of carbon-based nanomaterials for water treatment--A business perspective.

In Response: Applications of carbon-based nanomaterials for water treatment--A business perspective.

Preparation and Toxicological Assessment of Functionalized Carbon Nanotube-Polymer Hybrids

Novel Carbon Nanotube-Polymer Hybrids were synthesized as potential materials for the development of membranes for water treatment applications in the field of Membrane Bioreactors (MBRs). Due to the toxicological concerns regarding the use of nanomaterials in water treatment as well as the rising demand for safe drinking water to protect public health, we studied the functionalization of MWCNTs and Thin-MWCNTs as to control their properties and increase their ability of embedment into porous anisotropic polymeric membranes. Following the growth of the hydrophilic monomer on the surface of the properly functionalized CNTs, that act as initiator for the controlled radical polymerization (ATRP) of sodium styrene sulfonate (SSNa), the antimicrobial quaternized phosphonium and ammonium salts were attached on CNTs-g-PSSNa through non-covalent bonding. In another approach the covalent attachment of quaternized ammonium polymeric moieties of acrylic acid-vinyl benzyl chloride copolymers with N,N-dimethylhexadecylamine (P(AA12-co-VBCHAM)) on functionalized CNTs has also been attempted. Finally, the toxicological assessment in terms of cell viability and cell morphological changes revealed that surface characteristics play a major role in the biological response of functionalized CNTs.

Applications of nanomaterials in water treatment and environmental remediation

Nanotechnology has revolutionized plethora of scientific and technological fields; environmental safety is no exception. One of the most promising and well-developed environmental applications of nanotechnology has been in water remediation and treatment where different nanomaterials can help purify water through different mechanisms including adsorption of heavy metals and other pollutants, removal and inactivation of pathogens and transformation of toxic materials into less toxic compounds. For this purpose, nanomaterials have been produced in different shapes, integrated into various composites and functionalized with active components. Nanomaterials have also been incorporated in nanostructured catalytic membranes which can in turn help enhance water treatment. In this article, we have provided a succinct review of the most common and popular nanomaterials (titania, carbon nanotubes (CNTs), zero-valent iron, dendrimers and silver nanomaterials) which are currently used in environmental remediation and particularly in water purification. The catalytic properties and functionalities of the mentioned materials have also been discussed.

Environmental implications and applications of carbon nanomaterials in water treatment

Carbon nanomaterials have been proposed as a basis for developing new technologies for photocatalytic oxidation and disinfection, improved membrane processes, adsorbents, and biofilm-resistant surfaces. This study details recent progress towards the development of these proposed applications. We explored the use of carbon nanomaterials such as fullerene C60, single-wall carbon nanotubes (SWCNTs), and multi-wall carbon nanotubes (MWCNTs) for a range of new technologies including, degradation of a probe organic compound by in situ generation of reactive oxygen species (ROS), new strategies for microbial disinfection, and the inhibition of biofilm development on membrane surfaces. The results show that the degradation of 2-chlorophenol by ROS produced microbial inactivation, and the mobility of the nanoparticle aggregates of the carbon nanomaterials all increased as suspensions were fractionated to enrich with smaller aggregates with sonication followed by successive membrane filtration.

Die intensive tierhaltung und die gesundheit von tier und mensch

The presence of emerging contaminants such as pharmaceutical and personal care products in water has caused serious problem not only to environment but also to human health. Today, the use of nanomaterials has been identified as a potential approach to address this problem because of the unique properties of nanomaterials. This chapter considers the properties of nanomaterials for water treatment with a brief touch on challenges and prospects. Current approaches of nanomaterials in water treatment include photocatalysis, adsorption, membrane technique, and disinfection. Although there are a few challenges with the use of nanomaterials, these challenges are surmountable. However, nanomaterials are promising new generation means of water treatment with excellent and superb potentials for water treatment.