Effect of magnetic nanoparticles and silver-loaded magnetic nanoparticles on advanced wastewater treatment and disinfection

Preparation and application of composite magnetic flocculants for wastewater treatment: A review

Wastewater treatment plays a vital role in protecting natural environments. Among the various wastewater treatment methods, flocculation achieves effective wastewater treatment, owing to its high efficiency, convenience, and cost-effectiveness. Compared to traditional flocculants, Composite magnetic flocculants have attracted significant attention due to their distinctive "core-shell" structure, magnetic flocculation mechanism and high efficiency recovery. This promotes sustainable development in wastewater treatment, highlighting the significant prospects for its application and potential advancement. This review begins by discussing the raw materials and treatment methods of composite magnetic flocculants and presenting common materials and associated preparation techniques. By combining the advantages of organic and inorganic components, disparate raw materials give flocculants different properties and flocculation efficiency. Through the comprehensive analysis of the flocculation mechanism, the flocculation efficiency of various wastewater treatment targets was elucidated, and the exceptional performance in overcoming steric hindrance was introduced. Subsequently, recycling approaches were summarized to determine the advantages and disadvantages in terms of recovery efficiency, operational difficulty, and impact on particle structure. Based on the current developmental status, this review provides a prospective outlook on future exploration trends in composite magnetic flocculants, valuable references, and theoretical foundations for related research and engineering practices.

Controlled Capture of Magnetic Nanoparticles from Microfluidic Flows by Ferromagnetic Antidot and Dot Nanostructures

The capture of magnetic nanoparticles (MNPs) is essential in the separation and detection of MNPs for applications such as magnetic biosensing. The sensitivity of magnetic biosensors inherently depends upon the distribution of captured MNPs within the sensing area. We previously demonstrated that the distribution of MNPs captured from evaporating droplets by ferromagnetic antidot nanostructures can be controlled via an external magnetic field. In this paper, we demonstrate the capture of magnetic nanoparticles from a microfluidic flow by four variants of antidot array nanostructures etched into 30 nm thick Permalloy films. The nanostructures were exposed to 130 nm MNP clusters passing through microfluidic channels with square cross-sections of 400 μm × 400 μm. In the presence of a parallel magnetic field, up to 83.1% of nanoparticles were captured inside the antidot holes. Significantly higher proportions of nanoparticles were captured within the antidots from the flow than when applying the nanoparticles via droplets. In the parallel field configuration, MNPs can be focused into the regularly spaced antidot indents in the nanostructure, which may be useful when detecting or observing MNPs and their conjugates. Conversely, up to 84% of MNPs were caught outside of antidots under a perpendicular magnetic field. Antidot nanostructures under this perpendicular configuration show potential for MNP filtration applications.

Innovative grey water treatment using eco-friendly bio-photocatalyst AgCuFe2O4@chitosan in the presence of synergistic effects of persulfate activation: optimization and mechanisms

In this study, AgCuFe2O4@Chitosan bio-photocatalyst was synthesized to make the most of environmental benignity and chemical stability for advanced greywater applications. The photocatalyst was evaluated under UV irradiation by synergistic activation of persulfate. FESEM, EDS-Mapping, and BET analyses showed quasi-spherical nanoparticles with a homogeneous size distribution, homogenous elements dispersion, and 15.305 m2/g surface area. XRD analysis confirmed that Ag and Cu were effectively incorporated into the chitosan matrix, which increased its crystallinity and stability. The photocatalyst showed a good magnetic property with an Ms. value equal to 17.13 emu/g, which helped in its easy retrieval and reuse. The TGA analysis demonstrated that the bio-composite had high thermal stability up to 600 °C. The optimal treatment conditions were a pH of 3, 2 mM persulfate, and 0.8 g/L photocatalyst dosage, where COD removal efficiencies were 82.9 % and 73.7 %, for synthetic and natural greywater, correspondingly. During the degradation process, greywater followed a pseudo-first-order kinetic model, where both sulfate and hydroxyl radicals played key roles in the elimination of COD. Moreover, the bio-photocatalyst was very reusable up to more than a few runs of treatment cycles with very good performance, underpinning the possible applications in the greywater treatment process in a sustainable manner.

Advancement in nanomaterials for environmental pollutants remediation: a systematic review on bibliometrics analysis, material types, synthesis pathways, and related mechanisms

Environmental pollution is a major issue that requires effective solutions. Nanomaterials (NMs) have emerged as promising candidates for pollution remediation due to their unique properties. This review paper provides a systematic analysis of the potential of NMs for environmental pollution remediation compared to conventional techniques. It elaborates on several aspects, including conventional and advanced techniques for removing pollutants, classification of NMs (organic, inorganic, and composite base). The efficiency of NMs in remediation of pollutants depends on their dispersion and retention, with each type of NM having different advantages and disadvantages. Various synthesis pathways for NMs, including traditional synthesis (chemical and physical) and biological synthesis pathways, mechanisms of reaction for pollutants removal using NMs, such as adsorption, filtration, disinfection, photocatalysis, and oxidation, also are evaluated. Additionally, this review presents suggestions for future investigation strategies to improve the efficacy of NMs in environmental remediation. The research so far provides strong evidence that NMs could effectively remove contaminants and may be valuable assets for various industrial purposes. However, further research and development are necessary to fully realize this potential, such as exploring new synthesis pathways and improving the dispersion and retention of NMs in the environment. Furthermore, there is a need to compare the efficacy of different types of NMs for remediating specific pollutants. Overall, this review highlights the immense potential of NMs for mitigating environmental pollutants and calls for more research in this direction.

Efficacy of iron-silver bimetallic nanoparticles to enhance radiotherapy

Radiotherapy (RT) is one of the primary cancer treatment methods. Radiosensitizers are used to enhance RT and protect healthy tissue. Heavy metals have been studied as radiosensitizers. Thus, iron oxide and iron oxide/silver nanoparticles have been the main subjects of this investigation. A simple honey-based synthesis of iron (IONPs) and iron-silver bimetallic nanoparticles (IO@AgNPs) were prepared followed by characterization with transmission electron microscope (TEM), absorption spectra, vibrating sample magnetometer (VSM), and X-ray diffraction (XRD). Additionally, Ehrlich carcinoma was induced in 30 adult BALB/c mice and divided into 6 groups. Mice of group G1 were not treated with nanoparticles or exposed to irradiation (control group), and group G2 and G3 were treated with IONPs and IO@AgNPs respectively. Mice of group G4 were exposed to a high dose of gamma radiation (HRD) (12 Gy). Groups G5 and G6 were treated with IONPs and IO@AgNPs followed by exposure to a low dose of gamma radiation (LRD) (6 Gy) respectively. The impact of NP on the treatment protocol was evaluated by checking tumor growth, DNA damage, and level of oxidative stress in addition to investigating tumor histopathology. Additional research on the toxicity of this protocol was also evaluated by looking at the liver's cytotoxicity. When compared to HRD therapy, combination therapy (bimetallic NPs and LRD) significantly increased DNA damage by about 75% while having a stronger efficacy in slowing Ehrlich tumor growth (at the end of treatment protocol) by about 45%. Regarding the biosafety concern, mice treated with combination therapy showed lower alanine aminotransferase (ALT) levels in their liver tissues by about half the value of HRD. IO@AgNPs enhanced the therapeutic effect of low-dose radiation and increased the efficacy of treating Ehrlich tumors with the least amount of harm to normal tissues as compared to high radiation dosage therapy.

Magnetic characterization techniques and micromagnetic simulations of magnetic nanostructures: from zero to three dimensions

The investigation of the magnetic characteristics of magnetic nanostructures (MNs) in various dimensions is a crucial direction of research in nanomagnetism, with MNs belonging to various dimensions exhibiting magnetic properties related to their geometry. A better understanding of these magnetic properties is required for MN manipulation. The primary tools for researching MNs are magnetic characterisation techniques with great spatial resolution and spin sensitivity. Micromagnetic simulation is another technique that minimises experimental costs, while providing information on the magnetic structure and magnetic behaviour, and has enormous potential for predicting, validating, and extending the magnetic characterisation results. This review first looks at the progress of research into quantitatively characterising the magnetic properties of low-dimensional (including 0D, 1D, and 2D) and 3D MNs in two directions: magnetic characterisation techniques and micromagnetic simulations, with a particular emphasis on the potential for future applications of these techniques. Single magnetic characterization techniques, single micromagnetic simulations, or a mix of both are utilised in these research studies to investigate MNs in a variety of dimensions. How the magnetic characterisation techniques and micromagnetic simulations can be better applied to MNs in various dimensions is then outlined. This discussion has significant application potential for low-dimensional and 3D MNs.

Mesoporous Ag-functionalized magnetic activated carbon-based agro-waste for efficient removal of Pb(II), Cd(II), and microorganisms from wastewater

Herein, eco-friendly mesoporous magnetic activated carbon-based agro-waste nanosorbents incorporating antimicrobial silver nanoparticles (Mag@AC1-Ag and Mag@AC1-Ag) have been prepared. Various techniques (XRD, SEM/EDX, TEM, FTIR, and BET analysis) were employed to characterize the prepared nanosorbents before being utilized as novel nanosorbents to remove Pb+2 and Cd+2 ions. Mag@AC1-Ag and Mag@AC1-Ag exhibited rapid and excellent uptake of Pb+2 and Cd+2. The pseudo-second-order kinetics and the Langmuir isotherm are more suitable for the explanation of the experimental results. The thermodynamic parameters showed that the Pb+2 and Cd+2 sorption by the nanosorbents was a spontaneous and endothermic reaction. The prepared nanosorbents can be effectively regenerated using HCl and recycled up to the fifth cycle. These nanosorbents' potential uses for eliminating Pb+2 and Cd+2 from real water samples were evaluated. Moreover, the results revealed that both Mag@AC1-Ag and Mag@AC2-Ag exhibited high antimicrobial activity against fecal coliform (gram-negative) and Bacillus subtilis (gram-positive).

Adsorption and Desorption Study of Reusable Magnetic Iron Oxide Nanoparticles Modified with Justicia adhatoda Leaf Extract for the Removal of Textile Dye and Antibiotic

The release of tetracycline hydrochloride (TCH) and methylene blue (MB) dye into the aquatic system uncontrollably caused major environmental and health problems; hence, their prevention required serious attention. Adsorption process is now being researched in order to increase adsorption efficiency and reprocess to alleviate environmental issues. The use of magnetic nanoparticle as an adsorbent for wastewater treatment has a lot of prospective. A magnetic iron oxide nanoparticle surface modified by Vasaka (Justicia adhatoda) leaf extract (JA-MIONs) is used to give a fast removal approach for MB dye and TCH antibiotics. Dynamic light scattering, UV-Vis and band gap measurement, powder X-ray diffraction, Fourier-transform infrared spectroscopy, and transmission electron microscopy were operated to analyse the formation and size of these magnetic nanoparticles. The impacts of different factors such as contact time (30-150 min), adsorbate concentration (10-50 mg/L), pH (4-10), and adsorbent dose (2-10 mg) were explored. Adsorption kinetics and isotherms show that it follows the pseudo-first-order kinetic and the Freundlich isotherm, with maximum adsorption capacities of 76.92 mg/g for MB and 200 mg/g for TCH at 298 K. The reusability of the JA-MIONs eventually exhibited a decline in the adsorption percentage of MB and TCH after five and four times respectively. After the desorption-adsorption cycles, this adsorbent continued to exhibit significant adsorption capacity. This investigation furnished the significant reference data for the synthesis of JA-MIONs as a novel and auspicious adsorbent for the industrial clean-up of toxic dyes and heavily used antibiotics from water.

Graphical abstract

Leveraging the potential of silver nanoparticles-based materials towards sustainable water treatment

Increasing demand of pure and accessible water and improper disposal of waste into the existing water resources are the major challenges for sustainable development. Nanoscale technology is an effective approach that is increasingly being applied to water remediation. Compared to conventional water treatment processes, silver nanotechnology has been demonstrated to have advantages due to its anti-microbial and oligodynamic (biocidal) properties. This review is focused on environmentally friendly green syntheses of silver nanoparticles (AgNPs) and their applications for the disinfection and microbial control of wastewater. A bibliometric keyword analysis is conducted to unveil important keywords and topics in the utilisation of AgNPs for water treatment applications. The effectiveness of AgNPs, as both free nanoparticles (NPs) or as supported NPs (nanocomposites), to deal with noxious pollutants like complex dyes, heavy metals as well as emerging pollutants of concern is also discussed. This knowledge dataset will be helpful for researchers to identify and utilise the distinctive features of AgNPs and will hopefully stimulate the development of novel solutions to improve wastewater treatment. This review will also help researchers to prepare effective water management strategies using nano silver-based systems manufactured using green chemistry.

A Review of the Techno-Economic Feasibility of Nanoparticle Application for Wastewater Treatment

The increase in heavy metal contamination has led to an increase in studies investigating alternative sustainable ways to treat heavy metals. Nanotechnology has been shown to be an environmentally friendly technology for treating heavy metals and other contaminants from contaminated water. However, this technology is not widely used in wastewater treatment plants (WWTPs) due to high operational costs. The increasing interest in reducing costs by applying nanotechnology in wastewater treatment has resulted in an increase in studies investigating sustainable ways of producing nanoparticles. Certain researchers have suggested that sustainable and cheap raw materials must be used for the production of cheaper nanoparticles. This has led to an increase in studies investigating the production of nanoparticles from plant materials. Additionally, production of nanoparticles through biological methods has also been recognized as a promising, cost-effective method of producing nanoparticles. Some studies have shown that the recycling of nanoparticles can potentially reduce the costs of using freshly produced nanoparticles. This review evaluates the economic impact of these new developments on nanotechnology in wastewater treatment. An in-depth market assessment of nanoparticle application and the economic feasibility of nanoparticle applications in WWTPs is presented. Moreover, the challenges and opportunities of using nanoparticles for heavy metal removal are also discussed.

Wastewater Treatment Using Novel Magnetic Nanosponges

Modern agricultural activities and concentrated animal feeding operations (CAFOs) are two of the major sources of groundwater contamination that affect the quality of drinking water. Conventional water quality improvement methods include direct filtration, coagulation/settling treatment techniques, membrane-based systems, and absorption-based systems. However, to date, there are no efficient and cost-effective processes available for water treatment. This study developed an innovative nanotechnology-based technique to improve groundwater quality. Magnetic nanosponges (MNSs) were synthesized and characterized using two different magnetic nanoparticles along with polymeric coagulants. The efficiency of MNSs in removing pollutants in wastewater collected from local diary and swine CAFO lagoons was investigated. Standard water quality evaluation parameters, such as the total organic content (TOC), turbidity, total suspended solids (TSS), and biological oxygen demand (BOD), were measured prior to and after treatment with MNSs. The results demonstrate the potential of MNSs to improve the quality of groundwater and support the development of a cost-effective best management practice (BMP) that also employs traditional coagulants at CAFOs and other wastewater treatment plants.

Sustainable nanotechnology based wastewater treatment strategies: achievements, challenges and future perspectives

Nanotechnology is being an emerging science for wastewater treatment requires more research emphasis and depth knowledge. For wastewater treatment, different forms of nanomaterials are used based on the type of contaminants and treatment efficiency desired. With the development in the field of nanomaterials, novel and emerging nanomaterials are coming into existence. The nanomaterials used for wastewater treatment can be carbon, single-walled carbon nanotubes, multiple walled carbon nanotubes, covalent organic frameworks, metal and metal oxide- based nanoparticles. Graphene based nanoparticles, their oxides (GO) and reduced graphene oxide (rGO) find tremendous applicability to be used in wastewater treatment purposes. Due to the introduction of graphene oxide nanoparticles in the adsorbent materials, their adsorption capacities have get enhanced and such materials have also improved the mechanical stability of the adsorbent. Ferric oxide shows greater adsorption capacities for organic pollutants. Furthermore, magnetic nano-powder confers a low adsorption capacity for phenols. Pyrrolidone reduced graphene oxide (PVP-RGO) nanoparticles have been used as adsorbents for the elimination of inorganic target contaminant copper, with great adsorption (1698 mg/g). The present study comprehensively reviews nanotechnology as a wastewater treatment strategy besides enlightening its safety issues and efficiency. The novelty of this article is that it highlights the overview of recent applications of various types of nanomaterials and research works releated to it. Such an approach will be helpful to get insights into technological advances, applications and future challenges of nanotechnology implementation for wastewater treatment.

A review on disinfection technologies for controlling the antibiotic resistance spread

The occurrence of antibiotic-resistant bacteria (ARB) in water bodies poses a sanitary and environmental risk. These ARB and other mobile genetic elements can be easily spread from hospital facilities, the point in which, for sure, they are more concentrated. For this reason, novel clean and efficient technologies are being developed for allowing to remove these ARB and other mobile genetic elements before their uncontrolled spread. In this paper, a review on the recent knowledge about the state of the art of the main disinfection technologies to control the antibiotic resistance spread from natural water, wastewater, and hospital wastewater (including urine matrices) is reported. These technologies involve not only conventional processes, but also the recent advances on advanced oxidation processes (AOPs), including electrochemical advanced oxidation processes (EAOPs). This review summarizes the state of the art on the applicability of these technologies and also focuses on the description of the disinfection mechanisms by each technology, highlighting the promising impact of EAOPs on the remediation of this important environmental and health problem.

Templated Mesoporous Silica Outer Shell for Controlled Silver Release of a Magnetically Recoverable and Reusable Nanocomposite for Water Disinfection

In this work, we encapsulated Fe₃O₄@SiO₂@Ag (MS-Ag), a bifunctional magnetic silver core-shell structure, with an outer mesoporous silica (mS) shell to form an Fe₃O₄@SiO₂@Ag@mSiO₂ (MS-Ag-mS) nanocomposite using a cationic CTAB (cetyltrimethylammonium bromide) micelle templating strategy. The mS shell acts as protection to slow down the oxidation and detachment of the AgNPs and incorporates channels to control the release of antimicrobial Ag⁺ ions. Results of TEM, STEM, HRSEM, EDS, BET, and FTIR showed the successful formation of the mS shells on MS-Ag aggregates 50-400 nm in size with highly uniform pores ∼4 nm in diameter that were separated by silica walls ∼2 nm thick. Additionally, the mS shell thickness was tuned to demonstrate controlled Ag⁺ release; an increase in shell thickness resulted in an increased path length required for Ag⁺ ions to travel out of the shell, reducing MS-Ag-mS' ability to inhibit E. coli growth as illustrated by the inhibition zone results. Through a shaking test, the MS-Ag-mS nanocomposite was shown to eradicate 99.99+% of a suspension of E. coli at 1 × 10⁶ CFU/mL with a silver release of less than 0.1 ppb, well under the EPA recommendation of 0.1 ppm. This high biocidal efficiency with minimal silver leach is ascribed to the nanocomposite's mS shell surface characteristics, including having hydroxyl groups and possessing a high degree of structural periodicity at the nanoscale or "smoothness" that encourages association with bacteria and retains high Ag⁺ concentration on its surface and in its close proximity. Furthermore, the nanocomposite demonstrated consistent antimicrobial performance and silver release levels over multiple repeated uses (after being recovered magnetically because of the oxidation-resistant silica-coated magnetic Fe₃O₄ core). It also proved effective at killing all microbes from Long Island Sound surface water. The described MS-Ag-mS nanocomposite is highly synergistic, easy to prepare, and readily recoverable and reusable and offers structural tunability affecting the bioavailability of Ag⁺, making it excellent for water disinfection that will find wide applications.

Magnetic nanoadsorbents for micropollutant removal in real water treatment: a review

Pure water will become a golden resource in the context of the rising pollution, climate change and the recycling economy, calling for advanced purification methods such as the use of nanostructured adsorbents. However, coming up with an ideal nanoadsorbent for micropollutant removal is a real challenge because nanoadsorbents, which demonstrate very good performances at laboratory scale, do not necessarily have suitable properties in in full-scale water purification and wastewater treatment systems. Here, magnetic nanoadsorbents appear promising because they can be easily separated from the slurry phase into a denser sludge phase by applying a magnetic field. Yet, there are only few examples of large-scale use of magnetic adsorbents for water purification and wastewater treatment. Here, we review magnetic nanoadsorbents for the removal of micropollutants, and we explain the integration of magnetic separation in the existing treatment plants. We found that the use of magnetic nanoadsorbents is an effective option in water treatment, but lacks maturity in full-scale water treatment facilities. The concentrations of magnetic nanoadsorbents in final effluents can be controlled by using magnetic separation, thus minimizing the ecotoxicicological impact. Academia and the water industry should better collaborate to integrate magnetic separation in full-scale water purification and wastewater treatment plants.

Enhanced removal of Co(II) and Ni(II) from high-salinity aqueous solution using reductive self-assembly of three-dimensional magnetic fungal hyphal/graphene oxide nanofibers

Layer-structured graphene oxide excellent carrier for modifications; however, its poor recoverability and stability preclude its application in wastewater treatment fields. Herein, three-dimensional magnetic fungal hyphal/graphene oxide nanofibers (MFHGs) were assembled by a reductive self-assembly (RSA) strategy for the efficient capture of Co(II) and Ni(II) from high-salinity aqueous solution. The RSA strategy is inexpensive, eco-friendly and easy to scale up. The obtained MFHGs enhanced the dispersity and stability of graphene oxide and exhibited excellent magnetization and large coercivity, leading to satisfactory solid-liquid separation performance and denser sediment. The results of batch removal experiments showed that the maximum removal capacity of MFHGs for Ni(II) and Co(II) was 97.44 and 104.34 mg/g, respectively, in 2 g/L Na₂SO₄ aqueous solution with a pH of 6.0 at 323 K, and the effects of initial pH and ionic strength on Co(II) and Ni(II) removal were explored. Yield residue analysis indicated that the high porosity and oxygen-containing functional groups of MFHGs remarkably improved their Co(II)- and Ni(II)-removal capacities. According to the analysis, hydroxyl groups and amine groups participated in the chemical reaction of Co(II) and Ni(II) removal, and cation-exchange chemical adsorption was dominant during the Co(II)- and Ni(II)-removal process. Based on the attributes of MFHGs, a continuous-flow recycle reactor (CFRR) was proposed for emergency aqueous solution treatment and exhibited satisfactory removal efficiency and regeneration performance. The combination of MFHGs and the proposed CFRR is a promising water treatment strategy for rapid treatment applications.

Emerging nano-structured innovative materials as adsorbents in wastewater treatment

Water supply around the globe is struggling to meet the rapidly increasing demand by the population, drastic changes in climate and degrading water quality. Even though, many large-scale methods are employed for wastewater treatment they display several negative impacts owing to the presence of pollutants. Technological innovation is required for integrated water management with different groups of nanomaterials for the removal of toxic metal ions, microbial disease, organic and inorganic solutes. The method of manipulating atoms on a nanoscale is nanotechnology. Nanomembranes are used in nanotechnology to soften water and eliminate physical, chemical and biological pollutants. The present review concentrates on various nanotechnological approaches in wastewater remedy, mechanisms involved to promote implementation, benefits and limitations in comparison with current processes, properties, barriers and commercialization research needs. Also the review identifies opportunities for further exploiting the exclusive features for green water management by following the advances in nanotechnology.

Microbial Nanotechnology for Bioremediation of Industrial Wastewater

Pollutant removal from industrial effluents is a big challenge for industries. These pollutants pose a great risk to the environment. Nanotechnology can reduce the expenditure made by industries to mitigate these pollutants through the production of eco-friendly nanomaterials. Nanomaterials are gaining attention due to their enhanced physical, chemical, and mechanical properties. Using microorganisms in the production of nanoparticles provides an even greater boost to green biotechnology as an emerging field of nanotechnology for sustainable production and cost reduction. In this mini review, efforts are made to discuss the various aspects of industrial effluent bioremediation through microbial nanotechnology integration. The use of enzymes with nanotechnology has produced higher activity and reusability of enzymes. This mini review also provides an insight into the advantages of the use of nanotechnology as compared to conventional practices in these areas.

Smart Synthesis of Trimethyl Ethoxysilane (TMS) Functionalized Core-Shell Magnetic Nanosorbents Fe3O4@SiO2: Process Optimization and Application for Extraction of Pesticides

In the current study, a smart approach for synthesizing trimethyl ethoxysilane–decorated magnetic-core silica-nanoparticles (TMS-mcSNPs) and its effectiveness as nanosorbents have been exploited. While the magnetite core was synthesized using the modified Mössbauer method, Stöber method was employed to coat the magnetic particles. The objective of this work is to maximize the magnetic properties and to minimize both particle size (PS) and particle size distribution (PSD). Using a full factorial design (2^k-FFD), the influences of four factors on the coating process was assessed by optimizing the three responses (magnetic properties, PS, and PSD). These four factors were: (1) concentration of tetraethyl-orthosilicate (TEOS); (2) concentration of ammonia; (3) dose of magnetite (Fe₃O₄); and (4) addition mode. Magnetic properties were calculated as the attraction weight. Scanning electron microscopy (SEM) was used to determine PS, and standard deviation (±SD) was calculated to determine the PSD. Composite desirability function (D) was used to consolidate the multiple responses into a single performance characteristic. Pareto chart of standardized effects together with analysis of variance (ANOVA) at 95.0 confidence interval (CI) were used to determine statistically significant variable(s). Trimethyl ethoxysilane–functionalized mcSNPs were further applied as nanosorbents for magnetic solid phase extraction (TMS-MSPE) of organophosphorus and carbamate pesticides.

Application of oxidation-reduction potential (ORP) as a controlling parameter during the synthesis of Fe3O4@PVA nanocomposites from industrial waste (raffinate)

The objective of this study was to develop a process for the synthesis of magnetite nanocomposites from raffinate of hydrometallurgical plants containing iron ions. Towards this goal, a three-step process was developed. After the reduction of Fe(III) to Fe(II) in the first stage, Al3+ in the raffinate was precipitated as Al(OH)3 and finally magnetite NPs were synthesized by chemical co-precipitation method via controlling the oxidation-reduction potentials (ORPs). The produced nanomaterials were analyzed using XRD, TEM, VSM, TGA, and FTIR. The TG, XPS, and FTIR results affirmed the existence of PVA while TEM images illustrated the spherical nanoparticles with an average size of about 19 ± 4 nm. Evaluation of VSM data indicated the highly ferromagnetic behavior for Fe3O4 and Fe3O4@PVA products at the room temperature with a saturation magnetization of 46.98 and 35.78 emu/g, respectively.

Green Synthesis, Characterization and Application of Natural Product Coated Magnetite Nanoparticles for Wastewater Treatment

Adsorption of organic pollutants, toxic metal ions, and removal of harmful bacteria can give us clean and pure drinkable water from wastewater resources. Respective magnetite nanoparticles (MNPs) were synthesized using a cheaper and greener way in an open-air environment with the use of crude latex of Jatropha curcas (JC) and leaf extract of Cinnamomum tamala (CT). Characterization of MNPs had been performed by dynamic light scattering (DLS), Ultraviolet-visible (UV-vis) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, powdered X-ray diffraction (XRD), and field emission scanning electron microscope (FE-SEM). The size ranges of the synthesized MNPs were observed in between 20-42 nm for JC-Fe₃O₄ and within 26-35 nm for CT-Fe₃O₄ by FE-SEM images. The effect of synthesized magnetic nanoparticles in wastewater treatment (bacterial portion), dye adsorption, toxic metal removal as well as antibacterial, antioxidant, and cytotoxic activities were studied. This purification will lead to an increase in the resources of pure drinking water in the future.