Water Disinfection Research Articles

Magnéli Ti4O7 nanowire induces locally enhanced electric field and electrocatalytic activity for rapid and efficient water disinfection via synergistic electroporation and electrochlorination

Waterborne pathogens in drinking water remains a prominent cause of morbidity and mortality in developing rural areas. Electrochlorination offers a promising alternative for decentralized water disinfection, but its efficiency was strongly restrained by the low Cl- concentrations in natural waters. Herein, we proposed a Magnéli Ti4O7 nanowire-assisted electrochemical approach via forming locally enhanced electric field over nanowire tips for reinforcing electroporation, and via forming locally enhanced charge density for promoting Cl- enrichment and subsequent electrochlorination on anodic nanowire tips. Ti4O7 nanowires induced the enhancement of electric field by 4 orders of magnitude and Cl- concentration by ∼3 orders of magnitude at nanowire tips, and promoted ∼3 times more active chlorine generation at a voltage of 3.0 V compared with non-nanostructured one. Synergistic electroporation and electrochlorination on nanowires enabled rapid and efficient disinfection with hydraulic retention time of ∼36 s and energy consumption below ∼5 J/L/log for inactivation of various gram-positive/negative bacteria and phage MS2. Analyses of cell morphology and membrane integrity revealed that electroporation-induced cell pores provided diffusion channels of reactive chlorine species for oxidative damage of cell structures, resulting in ∼1.5–4.5 times lower energy consumption than the thin-film, nanoparticle, and nanorod ones. The excellent operation stability for tap water with significant bacterial inactivation and active chlorine generation demonstrated its great application potential for decentralized water disinfection.

Enhancement of solar water disinfection using different types of clay

This study delves into the impact of incorporating natural nanoparticles (mineral clays) into contaminated water during the Solar water disinfection (SODIS) process. The experiment involved introducing contaminated water samples into glass containers containing 1 × 10−3 gm/ml of a specific clay type. These containers were then exposed to solar radiation for varying time intervals. Subsequently, samples were extracted from each container, and the total counts of Total Coliform, P. aeruginosa aeruginosa, and E.coli were measured using the IDEXX setup. The results revealed that Zeolite, a specific type of clay, exhibited the shortest disinfection process among the mineral clay samples. The optimal concentration of Zeolite, which effectively reduced the concentration of Total Coliform, P. aeruginosa, and E.coli concentration, was 1 × 10−3 gm/ml. In conclusion, adding Zeolite to wastewater was observed to positively impact the disinfection process, accelerating the inactivation process by reducing the number of pathogenic microorganisms.

Comparative Life Cycle Assessment of Four Municipal Water Disinfection Methods

The disinfection of treated water is an important process to provide healthy water to the public. The chosen disinfection methods can vary depending on the water source, regulations, targeted microorganisms, operating conditions, capital costs and operation and maintenance costs. Another important factor for decision-makers is the environmental impacts caused by the disinfection process. This paper will reveal the life cycle assessment (LCA) of four different water disinfection scenarios at a municipal scale from the operational phase. A comparison is made between chlorination systems, two ultraviolet disinfection systems that use different types of lamps and an ozonation system. The results demonstrate that the UV disinfection system with low-pressure lamps had the lowest environmental impact across all categories, followed by chlorination. In contrast, the ozonation system and the UV disinfection system with LED lamps showed the highest impacts in all categories, primarily due to their high electricity consumption. Changes in the electricity mix had a substantial influence on the impact categories for all disinfection methods, but the gradation of the water disinfection methods was not that significant. Studies on the environmental impacts of the water disinfection process need to be carried out for larger flow rates to increase the information on this topic.

The effect of ozone water disinfection on color stability of nanoparticles reinforced maxillofacial silicones

The effect of ozone water disinfection on color stability of nanoparticles reinforced maxillofacial silicones

Neurodevelopmental toxicity of a ubiquitous disinfection by-product, bromoacetic acid, in Zebrafish (Danio rerio)

Disinfection of public drinking water and swimming pools is crucial for preventing waterborne diseases, but it can produce harmful disinfection by-products (DBPs), increasing the risk of various diseases for those frequently exposed to such environments. Bromoacetic acid (BAA) is a ubiquitous DBP, with toxicity studies primarily focused on its in vitro cytotoxicity, and insufficient research on its neurodevelopmental toxicity. Utilizing zebrafish as a model organism, this study comprehensively explored BAA’s toxic effects and uncovered the molecular mechanisms through neurobehavioral analysis, in vivo two-photon imaging, transcriptomic sequencing, pharmacological intervention and molecular biological detection. Results demonstrated BAA induced significant changes on various indicators in the early development of zebrafish. Furthermore, BAA disrupted behavioral patterns in zebrafish larvae across locomotion activity, light-dark stimulation, and vibration stimulation paradigms. Subsequent investigation focused on larvae revealed BAA inhibited neuronal development, activated neuroinflammatory responses, and altered vascular morphology. Transcriptomic analysis revealed BAA-stressed zebrafish exhibited downregulation of visual transduction-related genes and activation of ferroptosis and cellular apoptosis. Neurobehavioral disorders were recovered by inhibiting ferroptosis and apoptosis. This study elucidates the neurodevelopmental toxicity associated with BAA, which is crucial for understanding health risks of DBPs and for the development of more effective detection methods and regulatory strategies.

Viruses in Wastewater-A Concern for Public Health and the Environment.

Wastewater monitoring provides essential information about water quality and the degree of contamination. Monitoring these waters helps identify and manage risks to public health, prevent the spread of disease, and protect the environment. Standardizing the appropriate and most accurate methods for the isolation and identification of viruses in wastewater is necessary. This review aims to present the major classes of viruses in wastewater, as well as the methods of concentration, isolation, and identification of viruses in wastewater to assess public health risks and implement corrective measures to prevent and control viral infections. Last but not least, we propose to evaluate the current strategies in wastewater treatment as well as new alternative methods of water disinfection.

Factors influencing the inactivation of Bacillus subtilis by epigallocatechin gallate (EGCG)

ABSTRACT Epigallocatechin gallate (EGCG) is an exceptional plant polyphenol for drinking water disinfection, due to its lasting antibacterial capabilities and broad spectrum of health benefits. Nevertheless, its effectiveness and the underlying mechanisms against chlorine-resistant bacteria, such as Bacillus subtilis, have not been thoroughly explored under various water conditions. The study at hand probed the inactivation rates of EGCG on B. subtilis was subjected to different concentrations, contact times, acidic or basic environments, and temperatures; biological mechanisms were examined by analyzing alkaline phosphatase, proteins, glucose, ATP, and redox biomolecules. Results indicated a positive correlation between EGCG concentration and the inactivation rate of B. subtilis, with the rate notably rising at EGCG levels below 800 mg/l and under acidic pH. The inactivation efficiency increased with temperature increments from 25 to 45 °C. Moreover, EGCG exerted a detrimental impact on the structural integrity, energy metabolism, and the antioxidant defense system of B. subtilis showed a dose-dependent antimicrobial activity against Escherichia coli. Consequently, this study provides a strong foundation for evaluating EGCG's efficacy against chlorine-resistant bacteria, promoting its theoretical application for drinking water treatment and guiding methodological advancements for broader applications.

Formation of halonitromethanes from different nitrophenol compounds during UV/post-chlorination: Impact factors, DFT calculation, reaction mechanisms, and toxicity

As ubiquitous chemical substances in water bodies, nitrophenol compounds (NCs) can form chlorinated halonitromethanes (Cl-HNMs) in the chlorination process. This work chose six typical NCs to explore Cl-HNMs produced during the UV/post-chlorination process, and Cl-HNMs yields from these NCs followed the increasing order of 4-, 2-, 2-amino-3-, 2-methyl-3-, 3-, and 2-chloro-3-nitrophenol. The Cl-HNMs yields increased continually or increased firstly and declined with post-chlorination time. Increasing chlorine dosage favored Cl-HNMs formation, while excessive chlorine dosage decreased Cl-HNMs produced from 2- and 4-nitrophenol. Besides, appropriate UV radiation, acidic pH, and higher precursor concentrations facilitated Cl-HNMs formation. Then, the reaction mechanisms of Cl-HNMs generated from these different NCs were explored according to density functional theory calculation and identified transformation products (TPs), and the main reactions included chlorine substitution, benzoquinone compound formation, ring opening, and bond cleavage. Moreover, the Cl-HNMs generated from 2-chloro-3-nitrophenol were of the highest toxicity, and the six NCs and their TPs also presented ecotoxicity. Finally, two kinds of real waters were used to explore Cl-HNMs formation and toxicity, and they were significantly distinguishable compared to the phenomena observed in simulated waters. This work will give new insights into Cl-HNMs formation from different NCs in water disinfection processes and help better apply the UV/post-chlorination process to water treatments.

Chlorine dioxide may be an alternative to acidification and chlorination for drinking water chemical disinfection in dairy beef bulls

Alternative water disinfectants to chlorination need to be identified because its effectiveness is limited by water pH and potentially carcinogen by−products resulted from chlorination and organic compound reaction. The first study aimed to evaluate the effect of different drinking water chemical disinfection treatments on water quality, its potential hazard effects on animal health, water and feed consumption, and apparent total tract digestibility in dairy beef bulls fed high-concentrate diets. For 224 days, 24 Holstein bulls (176 ± 16.3 kg BW, and 149 ± 5.8 days of age) were individually assigned to one of four treatments with different drinking water chemical disinfectants: without disinfection (CTR); acidification and chlorination (ACCHL; 0.65 mL/L H3PO4 and 0.14 mL/L NaClO 15%); hydrogen peroxide (PER; 0.15 mL/L); and chlorine dioxide (DIO; 2.50 mL/L). Data were analysed with a mixed-effects model. Treatments affected the chemical characteristics of the water: in ACCHL, pH was 6.60 and free residual chlorine was 0.75 mg/L; in PER, H2O2 was 10.6 mg/L; and in DIO, ClO2 was 0.52 mg/L. Water physicochemical quality parameters in all treatments were below maximal thresholds established for safe water consumption by the Water Safety Royal Decree (RD 140/2003). In addition, the total coliform count of treated waters was reduced (P = 0.01) compared with CTR; moreover, ACCHL and DIO treatments were more effective in reducing total coliform count than PER. Dry matter intake tended (P = 0.07) to increase in DIO compared with CTR. Treatments did not affect blood parameters nor apparent total tract digestibility. The second study aimed to evaluate the potential benefit on animal performance of two drinking water disinfectants under commercial conditions in dairy beef crossbred Holstein bulls fed high-concentrate diets. Ninety-six animals (307 ± 4.4 kg BW, and 224 ± 1.8 days of age) were allocated to six pens for 140 days and assigned to one of two treatments: ACCHL, most common water disinfectant, and DIO. Data were analysed with a mixed-effects model. Water total coliform count and water consumption were similar between treatments. Concentrate intake was greater (P = 0.02) in ACCHL for the last 14 study days. Growth performance and carcass quality were similar between treatments. In summary, acidification and chlorination, H2O2, and ClO2 as drinking water disinfectants in dairy beef bulls had good disinfecting activity without detrimental effects on health and nutrient digestibility, and performance.

The efficacy of current treatment processes to remove, inactivate, or reduce environmental bloom-forming Escherichia coli.

Escherichia coli is excreted in high numbers from the intestinal tract of humans, other mammals, and birds. Traditionally, it had been thought that E. coli could grow only within human or animal hosts and would perish in the environment. Therefore, the presence of E. coli in water has become universally accepted as a key water quality indicator of fecal pollution. However, recent research challenges the assumption that the presence of E. coli in water is always an indicator of fecal contamination, with some types of E. coli having evolved to survive and grow in aquatic environments. These strains can form blooms in water storages, resulting in high E. coli counts even without fecal contamination. Although these bloom-forming strains lack virulence genes and pose little threat to public health, their presence in treated water triggers the same response as fecal-derived E. coli. Yet, little is known about the effectiveness of treatment processes in removing or inactivating them. This study evaluated the effectiveness of current treatment processes to remove bloom-forming strains, in comparison to fecal-derived strains, with conventional coagulation-flocculation-sedimentation and filtration investigated. Second, the effectiveness of current disinfection processes-chlorination, chloramination, and ultraviolet (UV) light to disinfect bloom-forming strains in comparison to fecal-derived strains-was assessed. These experiments showed that the responses of bloom isolates were not significantly different from those of fecal E. coli strains. Therefore, commonly used water treatment and disinfection processes are effective to remove bloom-forming E. coli strains from water.IMPORTANCEThe presence of Escherichia coli in water has long been used globally as a key indicator of fecal pollution and for quantifying water safety. Traditionally, it was believed that E. coli could only thrive within hosts and would perish outside, making its presence in water indicative of fecal contamination. However, recent research has unveiled strains of E. coli capable of surviving and proliferating in aquatic environments, forming blooms even in the absence of fecal contamination. While these bloom-forming strains lack the genes to be pathogenic, their detection in source or drinking water triggers the same response as fecal-derived E. coli. Yet, little is known about the efficacy of treatment processes in removing them. This study evaluated the effectiveness of conventional treatment and disinfection processes in removing bloom-forming strains compared to fecal-derived strains. Results indicate that these commonly used processes are equally effective against both types of E. coli, reassuring that bloom-forming E. coli strains can be eliminated from water.

Assessing the Relative Sustainability of Point-of-Use Water Disinfection Technologies for Off-Grid Communities.

Point-of-use (POU) water disinfection technologies can be adopted to provide access to safe drinking water by treating water at the household level; however, navigating various POU disinfection technologies can be difficult. While numerous conventional POU devices exist, emerging technologies using novel materials or advanced processes have been under development and claim to be of lower cost with higher treatment capacity. However, it is unclear if these claims are substantiated and how novel technologies compare to conventional ones in terms of cost and environmental impacts when providing the same service (i.e., achieving a necessary level of disinfection for safe drinking water). This research assessed the sustainability of four different POU technologies (chlorination using sodium hypochlorite, a silver-nanoparticle-enabled ceramic water filter, ultraviolet mercury lamps, and ultraviolet light-emitting diodes). Leveraging open-source Python packages (QSDsan and EXPOsan), the cost and environmental impacts of these POU technologies were assessed using techno-economic analysis and life cycle assessment as per capita cost (USD·cap-1·yr-1) and global warming potential (kg CO2 eq·cap-1·yr-1). Impacts of water quality parameters (e.g., turbidity, hardness) were quantified for both surface water and groundwater, and uncertainty and sensitivity analyses were used to identify which assumptions influence outcomes. All technologies were further evaluated across ranges of adoption times, and contextual analysis was performed to evaluate the implications of technology deployment across the world. Results of this study can potentially provide valuable insights for decision-makers, nonprofit organizations, and future researchers in developing sustainable approaches for ensuring access to safe drinking water through POU technologies.

Overview of the low-cost technologies for household water treatment in developing countries

ABSTRACT This study explored various low-cost water treatment technologies that are used to minimize levels of pathogens and contaminants in raw water. The paper focused on techniques such as cloth filtration, boiling, chlorination, and solar water disinfection. In the communities, cloth filtration is applied as the initial step of treating raw water with the proper choice of cloth fabrics followed by either boiling, chlorination or solar water disinfection. In low-income communities with unclean burning fuel sources, boiling was found to be the preferred method. Chlorination was also a popular technique associated with the challenges of low or high levels of free chlorine at the point of use and disinfection by-products. Solar water disinfection required optimal residence time and detection sensors for microorganism inactivation. Overall, the paper provided valuable insights into the different low-cost water treatment techniques that are commonly used for household applications, particularly in developing countries.

Combined extraction of manganese during water purification of technogenic solutions

A method for demanganization of technogenic aqueous solutions is presented. This method involves electrocoagulation purification of aqueous systems from high metal contents and extraction of manganese (II) ions by carbon sorbent adsorption. A coagulation technology based on electrogenerated aluminum hydroxide was used. According to diffraction analysis, such a hydroxide exhibits an amorphous porous hydrogel structure with a developed sorbing surface. The micellar structure of the as-generated aluminum hydroxide, which was attributed to a modification of gibbsite, is represented by the following colloidal particle: {[m Al(OH)3] nAl(OH)2+ (n-x) OH-}x+ xOH-. The associative process of sorption on gibbsite occurs by dispersion interaction, which is governed by the force of electrostatic attraction of instantaneous and induced dipoles of electrically neutral sorbent molecules and the [Mn (OH2)2(OH)2]0 manganese hydroxo-aquo complex. The adsorption limiting value of manganese ions amounted to 4.9 mmol/g at 298 K and pH 5.8, with the adsorption equilibrium constant reaching 1.36 . 104. The electricity consumption corresponded to 12.0 А.h at an optimal electrocoagulation duration of 15 min and a current density of 1.6 мА/сm2. The final purification of aqueous solutions using carbon sorbents was conducted in a slightly alkaline medium at pH 7.5. The manganese sorption value reached 1.68 mmol/g. Therefore, the resource-saving effect of processing of technogenic hydro-mineral solution is manifested in a significant reduction of heavy metal salts and in obtaining of demanded mixed coagulants of aluminum and iron sulfates from water purification wastes. Another positive effect of electrochemical water purification consist in water disinfection and its improved ogranoleptic parameters.

Robust optimization of a novel ultraviolet (UV) photoreactor for water disinfection: A neural network approach

To optimize the ultraviolet (UV) water disinfection process, it is crucial to determine the ideal geometric dimensions of a corresponding model that enhance performance while minimizing the impact of uncertain photoreactor inputs. As water treatment directly affects people's lives, it is crucial to eliminate the risks associated with the non-ideal performance of disinfection photoreactors. Input uncertainties greatly affect photoreactor performance, making it essential to develop a robust optimization algorithm in advance to mitigate these effects and minimize the physical and financial resources required for constructing the photoreactors. In the suggested algorithm, a two-objective genetic algorithm is integrated with a non-intrusive polynomial chaos expansion (PCE) technique. Additionally, the Sobol sampling method is employed to select the necessary samples for understanding the system's behavior. An artificial neural network surrogate model is trained using sufficient data points derived from computational fluid dynamics (CFD) simulations. A novel type of UV photoreactors working based on exterior reflectors is chosen to optimize the process with three uncertain input parameters, including UV lamp power, UV transmittance of water, and diffusive fraction of the reflective surface. In addition, four geometrical design variables are considered to find the optimal configuration of the photoreactor. The standard deviation (SD) and the reciprocal of log reduction value (LRV) are set as the objective functions, calculated using PCE. The optimal design provides a LRV of 3.95 with SD of 0.2. The coefficient of variation (CoV) of the model significantly declines up to 7%, indicating the decreased sensitivity of the photoreactor to the input uncertainties. Additionally, it is discovered that the robust model exhibits minimal sensitivity to changes in reflectivity in various flow rates, and its output variability aligns with the SD obtained through robust optimization.

Synergistic ferrate(VI) and chlorine for reclaimed water disinfection: Microbial control and chlorine decay mitigation

Chlorination is the most widely used disinfection technology due to its simplicity and continuous disinfection ability. However, the drawbacks of disinfection by-products and chlorine-resistant bacteria have gained increasing attention. Nowadays, ferrate (Fe(VI)) is a multifunctional and environmentally friendly agent which has great potential in wastewater reclamation and reuse. This study investigated synergistic Fe(VI) and chlorine technology for reclaimed water disinfection in terms of microbial control and chlorine decay mitigation. Specifically, synergistic disinfection significantly improved the inactivation efficiency on total coliform, Escherichia coli and heterotrophic bacteria compared to sole chlorination. Synergistic disinfection also exhibited superior performance on controlling the relative abundance of chlorine-resistant bacteria and pathogenic bacteria. In addition, the decay rate of residual chlorine was relatively lower after Fe(VI) pretreatment, which was beneficial for microbial control during the reclaimed water distribution process. Technical and economic analyses revealed that synergistic Fe(VI) and chlorine disinfection was suitable and feasible. Results of this study are believed to provide useful information and alternative options on the optimization of reclaimed water disinfection.

ДИНАМИКА ЗАГРЯЗНЕНИЯ ПОВЕРХНОСТНЫХ ВОД РЕКИ ВОЛГИ ФЕНОЛОМ

Phenols are priority pollutants of the natural environment and enter water sources through wastewater treatment plants of industrial enterprises. They pose a certain threat to the human body, since many of them are highly toxic and belong to the first class of danger. Organochlorine derivatives of phenol exhibit particularly high toxicity; under conditions of water disinfection with chlorine-containing preparations, they can form polychlorinated dibenzo-n-dioxins, which are classified as super-ecotoxicants and have a negative effect on the genetic code of the human body. As a result of the studies, the surface waters of the Volga river basin of the Kuibyshev reservoir in the water area of the city of Kazan were analyzed for the content of phenol and its derivatives using gas-liquid chromatography. When analyzing phenols in the aquatic environment, it was established that the maximum permissible concentrations norms for ortho-, meta-, para- chlorophenols, which are characterized by high toxicity to the human body and wildlife, were exceeded. The dynamics of seasonal changes in the concentration of phenol and its derivatives in the surface waters of the Volga river has been established, which are associated with the intensification of redox processes in the summer, occurring under the influence of temperature factors involving dissolved oxygen.

Characterization of low-pressure gaseous plasma radiation and its usage for inactivation of waterborne viruses

Water disinfection is a critical treatment step for removing harmful organisms from contaminated water sources. Vacuum ultra-violet (V-UV) radiation, generated by a low-pressure gaseous plasma discharge, consists of photons with high enough energy to break molecular bonds. In this work, we constructed and characterized a low-pressure capacitively coupled gaseous plasma and used it as a V-UV radiation source to inactivate MS2 bacteriophage, a surrogate for human enteric viruses. The treatment system allows for variation of gas composition inside the sample chamber and the modulation of V-UV radiation intensity. Both were used to separate the actual germicidal contribution of V-UV radiation from producing germicidal species by using virus inactivation to determine efficiency. OH* radical production was determined through the terephthalic acid chemical probe, which showed that when air was present in the sample chamber, it resulted in the highest OH* production and the best inactivation of MS2. Furthermore, we showcase that the OH* production rate was wavelength dependent and that ozone, generated by plasma treatment in the gas phase, leads to hydroxy terephthalic acid degradation, allowing us to determine better the actual OH* production rate with different treatment regimes. Lastly, by adding an OH* scavenger to the liquid, we were able to elucidate it as the primary inactivation agent in this setup while also providing evidence of its production in the bulk liquid by the transport and subsequent decomposition of the longer-lasting ozone molecule. This study demonstrates, for the first time, the applicability of low-pressure plasma radiation as a water treatment method.

Metal–Organic Frameworks (MOFs) for Sustainable Water Disinfection: Synthesis, Characterization, and Antimicrobial Properties

Waterborne biological pollution poses a significant threat to both the environment and human health, leading to the transmission of various waterborne diseases. Ensuring the safety of drinking water is essential for safeguarding public health and reducing the prevalence of waterborne illnesses caused by microbial pollutants. Recently, there has been a notable increase in the utilization of nanoparticles for water treatment purposes. Metal-Organic Frameworks (MOFs) are emerging as promising candidates for enhancing water treatment processes due to their structural and functional adjustability and makes them stand out for environmental remediation. Notable properties include porous structures with customizable sizes, large surface areas, and internal characteristics that are variable. In this study, zeolitic-imidazolate frameworks (ZIF-8) and Ag@zeolitic-imidazolate frameworks (Ag@ZIF-8) were synthesized using 2-methylimidazole (2-MIM) as an organic linker via a facile green synthesis method and used for water disinfection. These MOFs were characterized using a range of techniques including UV-vis spectroscopy, FTIR, and X-ray diffraction, SEM/EDS. The antibacterial activity of ZIF-8 and Ag@ZIF-8 were evaluated using the disc diffusion method against Gram-negative and Gram-positive bacteria, i.e., E. coli and S. aureus, respectively. These MOFs demonstrated strong antimicrobial activity against both Gram-positive S. aureus and Gram-negative bacteria E. coli, where the Ag-ZIF-8 MOF exhibited improved antibacterial activities over ZIF-8 alone. Finally, the suggested material shows promise for reusable water filtration and disinfection against a variety of pollutants, providing a practical option to reduce environmental and public health threats.

Graphene-based Sm-doped Co-ferrite for environmental applications

A graphene-based Sm-doped Co-ferrite CoSmFe-G nanosample was created using the citrate auto-combustion method. It acts as an antibacterial agent and heavy metal remover. The sample’s physical properties were analyzed using various techniques including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, scanning electron microscopy (FE-SEM), zeta potential, and vibrating sample magnetometer (VSM) measurements. The XRD results confirmed the presence of a single-phase cubic spinel structure. The experimental results indicated that doping with graphene and samarium significantly altered the magnetic properties of CoSmFe-G nanoparticles, reducing the saturation magnetization (MS) values to 35.759 emu/g. The sample showed antibacterial properties against both gram-positive and gram-negative bacteria, with inhibition zones measuring 12–14.5 mm in diameter. Additionally, the sample exhibited efficient (Pb2+) adsorption, with a maximum removal capacity of 99.8% and a multilayer adsorption mechanism indicated by the pseudo-second-order isotherm and Freundlich model matching. The study explores the binding interactions for lead removal and highlights the potential of using graphene-based Sm-doped Co-ferrite (CoSmFe-G) nano samples as a bio-adsorbent and antibacterial agent. This could lead to practical and efficient solutions for water disinfection.

Solar water disinfection: A probabilistic methodology for predicting exposure period from time series of insolation data

Solar water disinfection: A probabilistic methodology for predicting exposure period from time series of insolation data