Green sol-gel synthesis of novel nanoporous copper aluminosilicate for the eradication of pathogenic microbes in drinking water and wastewater treatment

A Review on Bioflocculant-Synthesized Copper Nanoparticles: Characterization and Application in Wastewater Treatment

Copper nanoparticles (CuNPs) are tiny materials with special features such as high electric conductivity, catalytic activity, antimicrobial activity, and optical activity. Published reports demonstrate their utilization in various fields, including biomedical, agricultural, environmental, wastewater treatment, and sensor fields. CuNPs can be produced utilizing traditional procedures; nevertheless, such procedures have restrictions like excessive consumption of energy, low production yields, and the utilization of detrimental substances. Thus, the adoption of environmentally approachable "green" approaches for copper nanoparticle synthesis is gaining popularity. These approaches involve employing plants, bacteria, and fungi. Nonetheless, there is a scarcity of data regarding the application of microbial bioflocculants in the synthesis of copper NPs. Therefore, this review emphasizes copper NP production using microbial flocculants, which offer economic benefits and are sustainable and harmless. The review also provides a characterization of the synthesized copper nanoparticles, employing numerous analytical tools to determine their compositional, morphological, and topographical features. It focuses on scientific advances from January 2015 to December 2023 and emphasizes the use of synthesized copper NPs in wastewater treatment.

Exploring nanoarchitectonics and optical properties of PAA-ZnO@BCP wide-band-gap organic semiconductors

This work reports the formation of polyacrylic acid (PAA)-zinc oxide (ZnO)-bromocresol purple (BCP), (PAA-ZnO@ (0.00-0.01) BCP wide-bandgap organic semiconductors deposited onto glass substrates via a sol-gel polymerization process. These semiconductor films were deposited on glass substrates using a spin coating and then dried at 60 °C. The PAA-ZnO film appeared to be of amorphous phase, and films loaded with BCP revealed semicrystalline behavior. The surface of the films exhibited adherence and extended grains. The hydrogen bonds formed between PAA-ZnO and the BCP dye within the PAA-ZnO@BCP films was performed using FTIR-spectroscopy. The prepared nanocomposites demonstrate an indirect band transition which is affected slightly by adding ZnO and BCP dye. Optical parameters such as the absorption coefficient, the refractive index, the dielectric constant, optical conductivity, optical depth, and optical electronegativity of the prepared nanocomposites were studied as functions of incident light energy (wavelength). The PAA carbonyl group n-π* transition and BCP aromatic ring π-π* transitions were detected at about 285 (for all samples) and 432 nm (for BCP loaded samples), respectively. The superior photoluminescence characteristics observed in the BCP/PAA-Zn films excited with a wavelength of 250 nm indicated the successful loading of the BCP dye during the self-aggregation of the PAA-Zn film.

Silver decorated on cobalt ferrite nanoparticles as a reusable multifunctional catalyst for water treatment applications in non-radiation conditions

In this investigation, cobalt ferrite nanoparticles (CFO NPs) were synthesized using a hydrothermal method. Then, silver nanoparticles (Ag NPs) were decorated on CFO NPs to form Ag/CFO NPs using jasmine extract as a reducing agent of Ag+ ions. The properties of Ag/CFO NPs were characterized by X-ray powder diffraction, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, vibrating sample magnetometry, and catalytic tests in non-radiation conditions. The catalytic results indicated that the Ag/CFO NPs could activate peroxymonosulfate to generate sulfate radicals for the decomposition of different dyes such as methylene blue, methyl orange, and rhodamine B. For the Ag/CFO sample, Ag NPs validated the roles in dye adsorption, reduction of 4-nitrophenol, and improvement of antibacterial behavior. The growth inhibition activity of Ag/CFO NPs was observed against Pseudomonas aeruginosa (18.18 ± 2.48 mm) and Staphylococcus aureus (10.14 ± 0.72 mm). Furthermore, Ag/CFO NPs displayed good reusability after three consecutive runs. Therefore, Ag/CFO material is shown to be a potential multifunctional catalyst in wastewater treatment.

Impact of pathogenic bacterial communities present in wastewater on aquatic organisms: Application of nanomaterials for the removal of these pathogens

Contaminated wastewater (WW) can cause severe hazards to numerous delicate ecosystems and associated life forms. In addition, human health is negatively impacted by the presence of microorganisms in water. Multiple pathogenic microorganisms in contaminated water, including bacteria, fungi, yeast, and viruses, are vectors for several contagious diseases. To avoid the negative impact of these pathogens, WW must be free from pathogens before being released into stream water or used for other reasons. In this review article, we have focused on pathogenic bacteria in WW and summarized the impact of the different types of pathogenic bacteria on marine organisms. Moreover, we presented a variety of physical and chemical techniques that have been developed to provide a pathogen-free aquatic environment. Among the techniques, membrane-based techniques for trapping hazardous biological contaminants are gaining popularity around the world. Besides, novel and recent advancements in nanotechnological science and engineering suggest that many waterborne pathogens could be inactivated using nano catalysts, bioactive nanoparticles, nanostructured catalytic membranes, nanosized photocatalytic structures, and electrospun nanofibers and processes have been thoroughly examined.

Integrating thermodynamics towards bulk level synthesis of nano Ni catalysts: a green mediated sol–gel auto combustion method

Novel strategy for the environmentally benign bulk level synthesis of nickel nanoparticles.

A dual-functional sulfone biscompound containing 1,2,3-triazole moiety for decolorization and disinfection of contaminated water

Water decontamination from toxic dyes and pathogenic microorganisms is critical for life on Earth. Herein, we report the synthesis of sulfone biscompound containing 1,2,3-triazole moiety and evaluation of its dye decolorization and biocidal and disinfection efficiencies. The decolorization efficiency was tested under different experimental conditions, while the biocidal action was examined against various types of waterborne pathogens, and the disinfection of some pathogenic microbes was executed in artificially contaminated water. The findindgs illustrated that the solution initial pH (pHi) affected the decolorization efficiency significantly. About complete removal of 10 mg/L malachite green (MG) dye was achieved after 10 min using 3 g/L of the sulfone biscompound at pHi 6. The pseudo-second-order equation suited the adsorption kinetics accurately, while the equilibrium data was suited by Langmuir isotherm model. Electrostatic, n-π, and π-π interactions brought about the adsorption of MG onto the sulfone biscompound. The biocidal results indicated that the sulfone biscompound had a powerful antibacterial potential against the tested bacterial species. Likewise, the distinction trail revealed that after 70-90 min of direct contact with an effective dose, the tested pathogens could be completely eliminated (6-log reduction). Overall, the newly synthesized sulfone biscompound can efficiently remove cationic dyes and disinfect contaminated water.

Ecofriendly synthesis and characterization of Ni2+ codoped silica magnesium zirconium copper nanoceramics for wastewater treatment applications

This article investigates the effect of Ni²⁺ content on structural (XRD, XPS), morphological (TEM), and magnetic behaviors of silica magnesium zirconium copper nanoceramics calcined at 800 °C. The sol–gel route is followed for the silica magnesium zirconium copper/(0.0–0.7) Ni²⁺ samples preparation. X-ray photoelectron spectroscopy is employed to analyze the chemical states of elements for the samples. The three representative binding energy magnitudes for O, Ni, and Cu reside at 534, 857, and 979 eV, consecutively. The saturation magnetization constricts with the elevation of Ni²⁺ content, while the magnetic hysteresis loop resembles the superparamagnetic attitude. The optical spectra present the possibility of direct and indirect transitions in the prepared nanoceramics. Energy gap (value and type), refractive index, and real and imaginary dielectric constant were extracted. The energy gap approaches 3.75 eV and 3.71 eV for direct and indirect transitions correspondingly with (0.7) Ni²⁺. The antimicrobial and the toxicity performance of all inspected nanocomposites were conducted against pathogenic microbes. The attained results evidenced that SMZC-0.7Ni possesses energetic antimicrobial potential against all targeted microbes. The investigated SMZC-0.7Ni nanocomposite functioned to eradicate frequent waterborne pathogens in wastewater at an appropriate dose (100 mg/L), demonstrating that SMZC can be utilized as a competent disinfectant in the municipal wastewater decontamination process. Inherently, SMZC-0.7Ni can be employed as an excellent nano-weapon against multiple dangerous microorganisms.

Bioactive tri-component nanofibers from cellulose acetate/lignin//N-vanillidene-phenylthiazole copper-(II) complex for potential diaper dermatitis control

Current research targets innovative medical textiles of nanofibrous nature and antibacterial activity to prevent diaper dermatitis. The work is based on electrospun nanofibers from cellulose acetate (CA) and lignin (Lig) polymers. A series of new copper complexes were synthesized and loaded to the CA/Lig solution mix then subjected to electrospinning, giving rise to the tricomponent bioactive mats CA/Lig/Cu-complex. The surface morphology of electrospun nanofiber mats was smooth and homogenous as the concentration of lignin increased in the mixture. The incorporation of lignin improved the electrospinnability of the cellulose acetate; however, it increased the fiber diameter. The water contact angle, absorption underload were significantly improved as lignin content increased. The incorporation of Cu-complex in electrospun CA and CA/Lig fiber mats occurred without any substantial change in the surface morphology, indicating well encapsulation of the complex. The electrospun mats were active against Pseudomonas aeruginosa, Acinetobacter baumannii, Staphylococcus epidermidis, and Streptococcus faecalis. The cytotoxicity, protein leakage, and biological results, together with the above studies, would advocate copper complex loaded CA/Lig nanofibers as a potential candidate for hygienic applications.

Polyphenol stabilized copper nanoparticle formulations for rapid disinfection of bacteria and virus on diverse surfaces

Rapid and sustained disinfection of surfaces is necessary to check the spread of pathogenic microbes. The current study proposes a method of synthesis and use of copper nanoparticles (CuNPs) for contact disinfection of pathogenic microorganisms. Polyphenol stabilized CuNPs were synthesized by successive reductive disassembly and reassembly of copper phenolic complexes. Morphological and compositional characterization by transmission electron microscope (TEM), selected area diffraction and electron energy loss spectroscopy revealed monodispersed spherical (ϕ5-8 nm) CuNPs with coexisting Cu, Cu(I) and Cu (II) phases. Various commercial grade porous and non-porous substrates, such as, glass, stainless steel, cloth, plastic and silk were coated with the nanoparticles. Complete disinfection of 10⁷copies of surrogate enveloped and non-enveloped viruses: bacteriophage MS2, SUSP2, phi6; and gram negative as well as gram positive bacteria:Escherichia coliandStaphylococcus aureuswas achieved on most substrates within minutes. Structural cell damage was further analytically confirmed by TEM. The formulation was well retained on woven cloth surfaces even after repeated washing, thereby revealing its promising potential for use in biosafe clothing. In the face of the current pandemic, the nanomaterials developed are also of commercial utility as an eco-friendly, mass producible alternative to bleach and alcohol based public space sanitizers used today.

Antibacterial Activities and Molecular Docking of Novel Sulfone Biscompound Containing Bioactive 1,2,3-Triazole Moiety

In this study, a new synthetic 1,2,3-triazole-containing disulfone compound was derived from dapsone. Its chemical structure was confirmed using microchemical and analytical data, and it was tested for its in vitro antibacterial potential. Six different pathogenic bacteria were selected. MICs values and ATP levels were determined. Further, toxicity performance was measured using MicroTox Analyzer. In addition, a molecular docking study was performed against two vital enzymes: DNA gyrase and Dihydropteroate synthase. The results of antibacterial abilities showed that the studied synthetic compound had a strong bactericidal effect against all tested bacterial strains, as Gram-negative species were more susceptible to the compound than Gram-positive species. Toxicity results showed that the compound is biocompatible and safe without toxic impact. The molecular docking of the compound showed interactions within the pocket of two enzymes, which are able to stabilize the compound and reveal its antimicrobial activity. Hence, from these results, this study recommends that the established compound could be an outstanding candidate for fighting a broad spectrum of pathogenic bacterial strains, and it might therefore be used for biomedical and pharmaceutical applications.

Inactivation of waterborne fungal spores by 1-bromo-3-chloro-5,5-dimethylhydantoin: Kinetics, influencing factors and mechanisms

Fungal contamination in drinking water source has become a problem worth studying, as waterborne fungi may cause deterioration of water quality and outbreak of diseases. Various disinfection methods have been explored to control fungal spores in drinking water, such as chlor(am)ination, ozonation, chlorine dioxide treatment, but these methods are not appropriate for remote areas, owing to the difficulties in preparation, carriage and storage. In this study, a powdery disinfectant of 1-bromo-3-chloro-5,5-dimethylhydantoin (BCDMH), which facilitated transportation and preservation, was firstly chosen to inactivate opportunistic pathogens of Aspergillus niger (A. niger) and Penicillium polonicum (P. polonicum). The results revealed that the inactivation kinetics of fungal spores by BCDMH fitted to Chick-Watson model well, with the inactivation rate constant of 0.011 and 0.034 L mg^-1 min^-1 for A. niger and P. polonicum, respectively. Acidic condition and high temperature promoted the inactivation by BCDMH. Compared with chlorine, BCDMH showed relative weaker ability on inactivation of fungal spores. However, it was demonstrated that the inactivation efficiency of BCDMH was obviously enhanced by adding halide ions, with 11 or 36 folds for A. niger and 4 or 15 folds for P. polonicum by adding 40 μM Br^- or I^-. The inactivation mechanisms were detected by flow cytometry and scanning electron microscope. Fungal spores lost their culturability firstly, then membrane integrity was damaged. Meanwhile, the esterase activity and intracellular reactive oxygen species level changed, and finally intracellular adenosine triphosphate released.

The role of biofilm in the development and dissemination of ubiquitous pathogens in drinking water distribution systems: an overview of surveillance, outbreaks, and prevention

A variety of pathogenic microorganisms can survive in the drinking water distribution systems (DWDS) by forming stable biofilms and, thus, continually disseminating their population through the system's dynamic water bodies. The ingestion of the pathogen-contaminated water could trigger a broad spectrum of illnesses and well-being-related obstacles. These waterborne diseases are a significant concern for babies, pregnant women, and significantly low-immune individuals. This review highlights the recent advances in understanding the microbiological aspects of drinking water quality, biofilm formation and its dynamics, health issues caused by the emerging microbes in biofilm, and approaches for biofilm investigation its prevention and suppression in DWDS.

Facile synthesis and potential application of Ni0.6Zn0.4Fe2O4 and Ni0.6Zn0.2Ce0.2Fe2O4 magnetic nanocubes as a new strategy in sewage treatment

Disinfection using chlorine has paramount importance in the treatment of either drinking water or sewage since it can kill and inhibit all waterborne pathogens, but it may result in carcinogenic substances when interacting with organic matter. An eco-friendly sol-gel process with citrate was used to prepare the nano-cubic activated nickel-zinc ferrite magnetic nanostructures (Ni_0.6Zn_0.4Fe₂O₄ and Ni_0.6Zn_0.2Ce_0.2Fe₂O₄). The activated nanomagnetic samples were characterized using XRD, HR-TEM, HR-SEM, FTIR, and VSM techniques. The structural and magnetic results showed that the nano-cubes magnetic-structures exhibited higher crystalline degrees and an increase in the total magnetization, enabling spinel nano-ferrite to possess potentials for excellent industry various applications. Likewise, the VSM results reveal that Ce₂O₃ had a significant influence on the magnetic behavior such as the coercivity (Hc; 69.226-133.15) saturation and magnetization (Ms; 24.562-52.174). The results revealed that all Magnetic nanoparticles (MNPs) had an outstanding inhibitory effect on microbes tested. The manufactured particles showed a remarkable ability to eliminate pathogenic bacteria in real sewage samples. The results obtained endorsed that the manufactured magnetic nanoparticles (MNPs) are powerful nano-weapons with an excellent anticipated output for the deactivation of pathogenic microbes during sewage treatment, with, nickel-zinc-cerium ferrite being more effective in inhibiting microbial growth than nickel-zinc-cerium ferrite.

Nanoceramics and novel functionalized silicate-based magnetic nanocomposites as substitutional disinfectants for water and wastewater purification

Herein, we successfully synthesized nano-porous Co₂O₃/Cu₂O₃: Al₂O₃: SiO₂ ((0, 5, 7, 9) Co-CAS) using the acidic sol-gel approach and calcined at 800 °C for 4 h. The crystallization behavior and spectroscopic properties were investigated using X-ray diffraction, field emission-scanning electron microscopy, and Fourier-transform infrared absorption spectra analysis. The antibiotic properties of the nano-porous CAS, 5Co-CAS, and 9Co-CAS magnetic nanocomposites was studied against some potentially pathogenic bacteria in water and wastewater samples. The bacteria tested included Escherichia coli, Salmonella enterica, Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus, Enterococcus faecalis, and Bacillus subtilis. Incorporating Co₂O₃ resulted in the identification of three peaks at 2θ = 10.2°, 13.4°, and 15°. The introduction of cobalt nanoparticles created a ferromagnetic behavior in the CAS nanoceramic, with the magnetic moment and saturation values increasing with increased Co₂O₃ doping. 9Co-CAS was most potent against all the tested pathogens with minimum inhibitory concentrations of 25 mg/L within 40 min for E. coli and P. aeruginosa and 50 mg/L within 10 min for S. enterica; the lowest antibacterial activity was observed with the unmodified CAS. The findings revealed that the manufactured nanocomposite materials were potent disinfectants with a promising application for water and wastewater treatment.

Current Trends in the Application of Nanomaterials for the Removal of Emerging Micropollutants and Pathogens from Water

Water resources contamination has a worldwide impact and is a cause of global concern. The need for provision of clean water is becoming more and more demanding. Nanotechnology may support effective strategies for the treatment, use and reuse of water and the development of next-generation water supply systems. The excellent properties and effectiveness of nanomaterials make them particularly suitable for water/wastewater treatment. This review provides a comprehensive overview of the main categories of nanomaterials used in catalytic processes (carbon nanotubes/graphitic carbon nitride (CNT/g-C₃N₄) composites/graphene-based composites, metal oxides and composites, metal–organic framework and commercially available nanomaterials). These materials have found application in the removal of different categories of pollutants, including pharmaceutically active compounds, personal care products, organic micropollutants, as well as for the disinfection of bacterial, viral and protozoa microbial targets, in water and wastewater matrices. Apart from reviewing the characteristics and efficacy of the aforementioned nanoengineered materials for the removal of different pollutants, we have also recorded performance limitations issues (e.g., toxicity, operating conditions and reuse) for their practical application in water and wastewater treatment on large scale. Research efforts and continuous production are expected to support the development of eco-friendly, economic and efficient nanomaterials for real life applications in the near future.

Detection of 3,4-diaminotoluene based on Sr0.3Pb0.7TiO3/CoFe2O4 core/shell nanocomposite via an electrochemical approach

We reported a scalable sol–gel method for the preparation of Sr_0.3Pb_0.7TiO₃/CoFe₂O₄ core–shell magnetic nanocomposite with a finely controlled shell and evaluated its efficiency as an electrochemical sensor for the selective detection of 3,4-diaminotoluene.

Decontamination of ubiquitous harmful microbial lineages in water using an innovative Zn2Ti0.8Fe0.2O4 nanostructure: dielectric and terahertz properties

Many ubiquitous dangerous microbial lines could originate in different sources of polluted water and be distributed to tap water, which could cause multiple types of illnesses to humans and livestock. Despite enormous attempts to guarantee safety of potable water, these species are still regarded to be threated prevalent health issues and concerns. However, these species need a powerful disinfectant to be removed from contaminated water for receiving clean and healthy water. This study was therefore conducted to produce magnificent magnetic iron titanate zinc nano-particles (Zn₂Ti_0.8Fe_0.2O₄ MNPs) as a sophisticated approach for drinking water (DW) and wastewater purification. The identification of crystalline phase, dielectric and terahertz spectroscopy of iron zinc titanate nanostructure prepared via acidic sol-gel process and calcined at 800 °C. Results show that the formation of cubic structure for Zn₂TiO₄ phase, and the dielectric constant (ε') decreased with the higher frequency, tan (δ) has higher values at lower frequency and the conductivity increases relatively with frequency that attributes to the high resistive grain boundaries. Absorption coefficient, refractive index and dielectric properties of iron zinc titanate nano-particles was estimated via time domain-terahertz spectrometer and adjusted via the applied electric field. In particular, the Gram-negative bacteria were more prone than other microbes tested to the Magnetic Nano-Particles (MNPs). Results also was ascertained that the minimum inhibitory concentration (MIC) was 25 ppm at 30 min for E. coli and Salmonella enterica, 45 min for Listeria monocyteogens, Staphylococcus aureus, and Candida albicans and 60 min for Aspergillus niger with a noticeable bactericidal impact. Results exhibit that the MNPs explored are non-toxic and protected for individuals and the environment. MNPs can, therefore, be proposed as an expedient and impressive nano-scale applicant for inactivation during the drinking water and wastewater conservation of the prevailing dangerous microbes.