Heavy Metal Pollution In Water Research Articles

Microbial remediation of heavy metal-polluted water

Heavy metal pollution in water has become a global environmental problem, threatening aquatic ecosystems and human health. Physical and chemical methods can effectively remove heavy metal pollutants, while their applications are limited due to the high costs, complex operation, and susceptibility to secondary pollution. Bioremediation is the most promising method for eliminating toxic pollutants. Microorganisms including bacteria, fungi, and algae can convert toxic heavy metals into less toxic forms, which has become an effective and environmentally friendly solution for the remediation of heavy metal pollution in water environments. This paper expounds the toxicity and mechanism of heavy metal pollution, microbial remediation mechanisms, and primary microbial remediation strategies, providing a reference for the removal or reduction of metal pollutants in water environments as well as the development of related technologies.

Role of heavy metals pollution on emergence of antibiotic co-resistance in E. coli isolates

Background: Heavy metal pollution in water is one of the most serious environmental problems. These findings have prompted the idea that metal-exposed bacteria may have altered resistance to antibiotics. This study was performed to investigate the presence of heavy metal resistance genes (HMRGs) in Escherichia coli.Methods: HMRGs and antibiotic resistance of 100 E. coli from sewage and fresh water were detected by PCR. Minimum inhibitory concentrations (MICs) of heavy metals were determined by the broth micro dilution method. Antibiotic discs used to detect multidrug resistance, was recovered and assembled using third-generation sequencing.Results: The frequency of different HMRGs in E. coli ranged from 1–67%., while prevalence of ESBL genes ranged 5-17% in freshwater isolates, and 54- 96% in swage isolates. MICs of heavy metals for E. coli ranged widely from ≤8.0-800 mg/L. Moreover, HMRGs (PbRT, cadD arsB, PcoA, czrc, and chrA) were found to be significantly associated with one or more ARGs ( tetA, blaTEM, blaSHV and blaCTX) (P < 0.05).Conclusion: In conclusion, HMRGs were widely present in E. coli isolated Dujla river and sewage water were significantly associated with DRGs . It is remarkable that the coexistence of HMRGs, DRGs and ARGs confer co-resistance to heavy metals, and antibiotics.Keywords: Heavy metals; Antibiotic resistance

Immobilization of Pb2+ and Cd2+ in water by sodium alginate magnet-biochar composite and LCA evaluation

Heavy metal pollution in water is one of the most pressing global environmental problems. In this research, two kinds of phosphorus-modified walnut shell biochar gel beads (P@WSBGB) and ferromagnetic gel beads (P@FWSBGB) were prepared by an environmentally friendly method to solve this problem. The maximum adsorption capacities for Pb2+ were 197 mg g−1 for P@WSBGB and 180 mg g−1 for P@FWSBGB, and for Cd2+, they were 125 mg g−1 and 108 mg g−1, respectively. Although Fe3O4 loading reduced adsorption capacity by approximately 10 %, life cycle assessment(LCA) showed that P@FWSBGB had a lower environmental impact than P@WSBGB when adsorbing the same amount of 1 mg of Pb2+. This indicates that a reasonable load of Fe3O4 can reduce the environmental impact. Conversely, when adsorbing Cd2+, the result was the opposite, demonstrating that unreasonable loading increased the environmental impact. To ensure that Fe3O4 loading did not lead to increased environmental impacts, we further analyzed the data to determine the optimal Fe3O4 loading level. The optimal Fe3O4 loading was determined to be 12.5 % for Pb2+ adsorption and <12.5 % for Cd2+. The main adsorption mechanism is that the -COOH and -OH groups on the surface of biochar form complexes with Pb2+ and Cd2+. Ion exchange, electrostatic attraction, co-precipitation of phosphate, and physical adsorption also contribute to the removal of Pb2+ and Cd2+. In summary, this research solved the challenge of difficult recycling of biochar powder and provides new insights for the synthesis and condition optimization of magnetic adsorbents.

Recycled Jute Non-Woven Material Coated with Polyaniline/TiO2 Nanocomposite for Removal of Heavy Metal Ions from Water.

Growing volumes of textile waste and heavy metal pollution of water are emerging environmental challenges. In an attempt to tackle these issues, a non-woven sorbent based on jute fibers was fabricated by recycling the textile waste from the carpet industry. The influence of contact time, concentration, pH and temperature on the sorption of lead and copper ions from aqueous solutions was studied. In order to enhance the sorption capacity of the non-woven material, in situ synthesis of polyaniline (PANI) in the presence of TiO2 nanostructures was performed. The contribution of TiO2 nanoparticles and TiO2 nanotubes to the uniformity of PANI coating and overall sorption behavior was compared. Electrokinetic measurements indicated increased swelling of modified fibers. FTIR and Raman spectroscopy revealed the formation of the emeraldine base form of PANI. FESEM confirmed the creation of the uniform nanocomposite coating over jute fibers. The modification with PANI/TiO2 nanocomposite resulted in a more than 3-fold greater sorption capacity of the material for lead ions, and a 2-fold greater absorption capacity for copper ions independently of applied TiO2 nanostructure. The participation of both TiO2 nanostructures in PANI synthesis resulted in excellent cover of jute fibers, but the form of TiO2 had a negligible effect on metal ion uptake.

Pb2+ and Cd2+ ion adsorption capability of a novel hydrotalcite-like absorbent FeMnNi-LTH in water

This paper discusses the application of a layered triple hydroxide (FeMnNi-LTH) in removing Pb2+ and Cd2+ ions from aqueous solutions. The material was synthesized via co-precipitation, adhering to a molar ratio of 1:1:2 (Fe:Mn:Ni). It was characterized using FTIR, XRD, SEM and TEM. The results indicate that the synthesized material is classified as a hydrotalcite and exhibits a well-defined layered structure. Batch experiments were conducted to investigate the adsorption of Pb2+ and Cd2+ by FeMnNi-LTH, taking into account various factors such as coexisting ions, pH, temperature, adsorbent dosage, and contact time. The experimental results showed that the adsorption capacity of this material for Pb2+ and Cd2+ was 253.89 mg/g and 56.90 mg/g at 25 °C, respectively. Moreover, it exhibits a consistent high adsorption capacity across a broad pH range (pH 3–5.5). When cations coexist, they compete for adsorption sites in the following order: Zn2+ > Ca2+ > Mg2+ > Cd2+/Pb2+. Based on the calculated thermodynamic parameters, it is inferred that the adsorption process is endothermic and spontaneous. The adsorption mechanism, as analyzed by modeling and characterization, involves isomorphic substitution, surface complexation, precipitation, electrostatic attraction, and physical adsorption. The quantitative analysis of the adsorption mechanism revealed that FeMnNi-LTH primarily adsorbs Pb2+ and Cd2+ via precipitation and surface complexation. It was revealed by comparison with other adsorbents that the synthesized FeMnNi-LTH can be used for remediation of heavy metal pollution in water.

Simultaneous removal of lead(II) and cadmium(II) from acidic wastewater by Fe-modified sludge biochar

In natural environments, heavy metal water pollution often involves simultaneous presence of various heavy metal ions (HMs), posing significant challenges for their removal. In this study, Fe-modified sludge biochar was synthesized via the co-precipitation method, and the effects of various environmental factors on simultaneously removing lead(II) and cadmium(II) by Fe@SBC were investigated. Batch adsorption experiments showed that Fe@SBC has a higher removal capacities for Pb(II) than for Cd(II) in both single or binary solutions. Increasing solution pH promoted the HMs removal on Fe@SBC. Coexisting divalent cations (Mg2+ and Ca2+) exhibited stronger inhibitory effects on HMs removal by Fe@SBC than monovalent cations (K+ and Na+). The presence of humic acid (HA) did not affect Pb(II) removal on Fe@SBC in either single or binary systems. In single systems, increasing HA concentration enhanced Cd(II) removing on Fe@SBC, while in binary systems, increasing HA concentrations inhibited the Cd(II) removal on Fe@SBC. The sorption of Pb(II) and Cd(II) on Fe@SBC followed the pseudo-second-order kinetic model and the Langmuir model. The removal mechanisms involved electrostatic interactions, complexation with O-containing group, and mineral dissolution-precipitation. After three regenerations, the adsorption capacity of Fe@SBC for Pb(II) and Cd(II) decreased by approximately 5–10 %. In summary, this environmentally friendly composite material has great potential for simultaneously remediating of Pb(II) and Cd(II).

Scenedesmus acuminatus as a potential phycoremediator: Enrichment and detoxification of cadmium/lead

Heavy metal pollution in water can cause severe environmental problems, harm the ecosystem, and ultimately threaten human health. The traditional methods used to remove heavy metals from water are expensive, inefficient, and can cause secondary pollution. However, microalgae have potential applications in the removal of toxic heavy metal pollutants from water. In this study, six green algae were screened in terms of their ability to adsorb cadmium (Cd) and lead (Pb) from a liquid medium. Ion content analyses confirmed that Scenedesmus acuminatus had the strongest Cd- and Pb-absorption ability. S. acuminatus was subjected to Cd and Pb treatments, and then transcriptome sequencing analysis was conducted. The results of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses indicated that the “proteasome” pathway was enriched with differentially expressed genes (DEGs) under Cd treatment, and the “photosynthesis” pathway was enriched with DEGs under Pb treatment. These results imply that the proteasome pathway maintained protein homeostasis and cellular activity by degrading damaged proteins under Cd toxicity, and that photosynthesis was affected by Pb toxicity in S. acuminatus. In conclusion, S. acuminatus showed a strong ability to accumulate Cd/Pb and might alleviate heavy metal toxicity and reduce heavy metal efflux using the ubiquitin-proteasome system. The results of this study identify a novel microalgal strain with potential applications in phytoextraction and phytoremediation, and provide information about the molecular mechanisms of Cd/Pb accumulation in this alga. These data provide a theoretical basis for reducing Cd/Pb toxicity and will be useful for devising strategies to protect aquatic animals and plants.

Study of the Factors Influencing the Adsorption of Heavy Metal Pollutants in Water by Activated Carbon Gel Particles

Study of the Factors Influencing the Adsorption of Heavy Metal Pollutants in Water by Activated Carbon Gel Particles

Groundwater Quality Assessment with Respect to Heavy Metal Content by using Heavy Metal Pollution Index (HPI) of Moradabad District, Uttar Pradesh, India

Heavy metal pollution index (HPI), is a rating method to assess the water quality and to categorize the groundwater pollution with respect to heavy metals content. The aims of the present study are to look over the current status of heavy metals pollution in and around Moradabad city. Heavy metal pollution in water has gained universal consciousness due to its tenacity, accumulation in the food chain and negative effects on ecological as well as human health. Its variation in concentration can cause deterioration of water. The study focuses on examining the content of heavy metal (Zn, Fe, Cd, Mn, Pb, Ni, Cu, and Cr) in the 30 water samples from the surrounding areas of Moradabad city. The concentrations of Cd, Mn, Fe, Cu, Pb, Zn, Ni, and Cr in water samples were recorded in the pre- and post-monsoon season of 2017. The examined samples reveal that the contamination level of heavy metal is in the following sequence Ni&gt;Fe&gt;Pb&gt;Cd&gt;Cr&gt;Cu&gt;Zn&gt;Mn in premonsoon 2017, whereas in postmonsoon season, heavy metals values are shown as Fe&gt;Pb&gt;Ni&gt;Mn&gt;Cr&gt; Cu&gt;Zn&gt;Cd. The HPI average value in pre-monsoon 2017 is 13.07, which recommended that the groundwater quality is good. While in post-monsoon season HPI average values has been 159.26 suggesting that the water quality is poor to inferior. The correlation matrix has been evaluated and shows a positive correlation with the elements. The immense production of industrial solid waste in Moradabad city and its improper disposal in the form of heap piled outside the city area generates leachate. Heavy metal leaching from these disposal points may contaminate the groundwater as well as surface water resources. The study shows that heavy metal concentration has a noticeable rise in water due to different anthropogenic and various natural sources of contamination.

Metal-Organic Frameworks for Dual Photo-Oxidation and Capture of Arsenic from Water.

Despite rapid technological progress, heavy metal water pollution, and particularly arsenic contamination, remains a significant global challenge. In addition, the stabilization of trivalent arsenic as neutral arsenite (AsIII) species hinders its removal by conventional sorbents. While adsorption of anionic arsenate (AsV) species is in principle more feasible, there are only few adsorbents capable of adsorbing both forms of arsenic. In this work, we explore the potential of two well-known families of Metal-Organic Frameworks (MOFs), UiO-66 and MIL-125, to simultaneously adsorb and photo-oxidize arsenic species from water. Our results demonstrate that the formation of AsV ions upon light irradiation promotes the subsequent adsorption of AsIII species. Thus, we propose the combined utilization of photocatalysis and adsorption with Metal-Organic Framework photocatalysts for water remediation purposes.

Application and mechanism of carbonate material in the treatment of heavy metal pollution: a review.

Among the many heavy metal pollution treatment agents, carbonate materials show strong flexibility and versatility by virtue of their high adsorption capacity for heavy metals and the characteristics of multiple and simple modification methods. It shows good potential for development. This review summarizes the application of carbonate materials in the treatment of heavy metal pollution according to the research of other scholars. It mainly relates to the application of surface-modified, activated, and nano-sized carbonate materials in the treatment of heavy metal pollution in water. Natural carbonate minerals and composite carbonate minerals solidify and stabilize heavy metals in soil. Solidification of heavy metals in hazardous waste solids is by MICP. There are four aspects of calcium carbonate oligomers curing heavy metals in fly ash from waste incineration. The mechanism of treating heavy metals by carbonate in different media was discussed. However, in the complex environment where multiple types of pollutants coexist, questions on how to maintain the efficient processing capacity of carbonate materials and how to use MICP to integrate heavy metal fixation and seepage prevention in solid waste base under complex and changeable natural environment deserve our further consideration. In addition, the use of carbonate materials for the purification of trace radioactive wastewater and the safe treatment of trace radioactive solid waste are also worthy of further exploration.

APPLICATION OF BIOREMEDIATION IN MITIGATION OF HEAVY METAL STRESS ON PLANTS

Heavy metals are toxic metals which are persistent in nature due to their nondegradable nature.Due to increase in industrialization and urbanization heavy metals are being added to theenvironment and consequently causing heavy metal pollution of water and soil. These heavy metals cause significant stress on crop plants and effect various parameters such as growth and yield. Manymethods like physical, chemical and biological methods are available to degrade these heavymetals. Recently, bioremediation is being widely used because of its cost-effective andenvironment friendly approach. Bioremediation is a biological process which makes use ofmicroorganisms to remove hazardous substances or environmental pollutants from air, water,soil, industrial effluents etc. Bacteria and fungi are mostly employed for bioremediation.These organisms are genetically engineered for effective use in bioremediation. This not onlydiscussed about the importance of bacteria for bioremediation of heavy metals but alsodiscussed about the challenges and limitations of bacteria for bioremediation. In this chapter, a variety of mechanisms responsible for adaptation of microorganisms to high heavy metal concentrations, e.g. metal sorption, uptake and accumulation, extracellular precipitation and enzymatic oxidation or reduction, will be reported. Moreover, molecular mechanisms responsible for their metal tolerance will be described.

Decoration of dandelion-like manganese-doped iron oxide microflowers on plasma-treated biochar for alleviation of heavy metal pollution in water

Carbon-based biowaste incorporated with inorganic oxides as a composite is an enticing option to mitigate heavy metal pollution in water resources due to its more economical and efficient performance. With this in mind, we constructed manganese-doped iron oxide microflowers resembling the dandelion-like structure on the surface of cold plasma-treated carbonized rice husk (MnFe2O3/PCRH). The prepared composite exhibited 45% and 19% higher removal rates for Cu2+ and Cd2+, respectively than the pristine CRH. The MnFe2O3/PCRH composite was characterized using XRD, FTIR, FESEM, EDX, HR-TEM, XPS, BET, TGA, and zeta potential, while the adsorption capacities were investigated as a function of pH, time, and initial concentration in batch trials. As for the kinetics, the pseudo-second-order was the rate-limiting over the pseudo-first-order and Elovich model, demonstrating that the chemisorption process governed the adsorption of Cu2+ and Cd2+. Additionally, the maximum adsorption capacities of the MnFe2O3/PCRH were found to be 122.8 and 102.5 mg/g for Cu2+ and Cd2+, respectively. Based on thorough examinations by FESEM-EDS, FTIR, and XPS, the possible mechanisms for the adsorption can be ascribed to surface complexation by oxygen-containing groups, a dissolution-precipitation of the ions with –OH groups, electrostatic attraction between metal ions and the adsorbent's partially charged surface, coordination of Cu2+ and Cd2+ with π electrons by aromatic/graphitic carbon in the MnFe2O3/PCRH, and pore filling and diffusion. Lastly, the adsorption efficiencies were maintained at about 70% of its initial adsorption even after five adsorption-desorption cycles, displaying its remarkable stability and reusability.

Ni2+ removal by ion exchange resins and activated carbon: a benchtop NMR study

Heavy metal pollution in water is a critical environmental concern, demanding effective remediation techniques. Traditional methods, including ion exchange and adsorption, often rely on inductively coupled plasma (ICP) atomic emission spectroscopy/mass spectrometry (AES/MS) for the indirect and time-consuming measurement of residual metal concentrations. In contrast, this study employs innovative direct monitoring of nickel removal by benchtop NMR relaxometry using the paramagnetic properties of Ni2+. To prove the feasibility of the NMR follow-up of Ni2+ uptake, batch experiments were performed with Amberlite IR120, Amberlite IRC748, Dowex Marathon MSC, and activated carbon (AC), which were previously characterized by various techniques. The effect of contact time, pH, and Ni2+ concentration on removal efficiency were studied. Pseudo-first and pseudo-second order kinetic models were used. The Langmuir model effectively described the equilibrium isotherms. The longitudinal and transverse relaxation curves of the loaded resins were biexponential. For sulfonic resins, a strong correlation was observed between the relaxation rates of the fast-relaxing fraction and the Ni2+ content determined by ICP-AES/MS. For IRC748, the effect of Ni2+ loading on the relaxation rates was weaker because of Ni2+ complexation. The relaxation curves of loaded AC revealed multiple fractions. Centrifugation was employed to eliminate the contribution of intergranular water. The remaining intragranular water contribution was biexponential. For high Ni2+ loadings, the relaxation rates of the slow relaxing fraction increased with the AC Ni2+ content. These results mark the initial stage in developing a column experiment to monitor, in real-time, adsorbent loading by NMR relaxometry.

Polyamidoamine dendrimers modified MXene and its high-performance adsorption behavior for Cr(VI)

Heavy metal pollution of water is a worldwide problem. The enticing characteristics exhibited by transition metal carbides (MXene) render it a good choiceas an adsorbent for removal of water pollutants. However, the limited functional group diversity and number, as well as the inadequate stability of MXene, impose limitations on its suitability for the adsorption of specific target metal ions (e.g., Hexavalent Cr(VI)). Herein, polyamidoamine (PAMAM) dendrimers, namely hyperbranched surfactant polymers, are employed to modify MXene, enhancing its surface functional group diversity and number. The presence of abundant –NH2 groups on the surface of PAMAM-modified MXene greatly enhances the adsorption capacity for Cr(VI). The pseudo-second order kinetic model and Langmuir isotherm model are suitable for describing the adsorption process. According to the Langmuir isotherm model, the maximum adsorption capacity (qm) can reach approximately 318 mg·g−1. Additionally, this adsorbent also has an excellent adsorption selectability for Cr(VI) from coexistent cations solution. Through the mechanisms of electrostatic attraction, reduction, covalent bonds, and chelation interaction, the high-performance adsorption for Cr(VI) can be achieved. Notably, the presence of PAMAM polymer as a protector ensures good stability of the composite adsorbent throughout adsorption/desorption cycle. This work provides deep insights into the advancement of highly efficient MXene-based adsorbents for water purification applications.

Using neutron activation to assess heavy metal pollution in water and sediment along Savannah River.

A comprehensive study was conducted to assess heavy elemental pollution in the Savannah River, which flows through diverse landscapes encompassing agricultural, industrial, and commercial zones in South Carolina and Georgia. The investigation focused on the impacts of various anthropogenic activities on the river, potentially harming human health and aquatic ecosystems. Thirty samples, collected from the beginning of the Savannah River at Lake Hartwell to the Savannah River estuary near the Atlantic Ocean, were analyzed using Instrumental Neutron Activation Analysis. In regions of intense industrial activities, water samples exhibited elevated concentrations of elements such as Al (0.04-1.99 mg/L), Mg (0.4-5.5 mg/L), Ba (0.08-2.8 mg/L), Zn (0.017-0.9 mg/L), Cr (0.005-1.5 mg/L), and Fe (2.8-110.13 mg/L). Similarly, sediment samples near industrial areas also exhibited enhanced concentrations of heavy elements like Cr, Zr, Rb, Co, Zn, Mg, Mn, and Al. The outcome of this study has identified a spatial trend along the Savannah River, revealing major elements responsible for pollution that could disrupt the ecological environment and potentially impact human health.

Seasonal Monitoring of Heavy Metal Pollution in Water and Zebra Mussels Dreissena polymorpha as a Potential Bioindicator Species from Lake Habitat.

In aquatic ecosystem, metal pollution is an important environmental hazard. Mussels as a bioindicator species are often used for assessment the presence of potentially toxic metals. Hence, the present study aimed to assess the effect of seasonal variations on some heavy metals (Cd, Cr, Pb, As, Zn and Cu) accumulation in water and Dreissena polymorpha from lake habitat. Our result indicated that Zn accumulated at a very high level in the zebra mussels while As accumulated at a high level in water samples. Seasonal variations significantly affected Cu concentration in the water samples (P < 0.05) while Cr concentration in the mussel samples was significantly affected by seasonal variations (P < 0.05). According to the water analysis, mean concentrations of metals are below the maximum limits established by the World Health Organization and USEPA, except As. Overall, our data emphasize anthropogenic pollution in the Turkish aquatic environment and confirm the use of D. polymorpha as a prospective biomonitor for metal polluted sites'.

Environmental applications of lignin-based hydrogels for Cu remediation in water and soil: adsorption mechanisms and passivation effects

Heavy metal pollution, particularly the excessive release of copper (Cu), is an urgent environmental concern. In this study, sodium lignosulfonate/carboxymethyl sa-son seed gum (SL-Cg-g-PAA) designed for remediation of Cu-contaminated water and soil was successfully synthesized through a free radical polymerization method using lignin as a raw material. This hydrogel exhibits remarkable Cu adsorption capability when applied to water, with a maximum adsorption capacity reaching 172.41 mg/g. Important adsorption mechanisms include surface complexation and electrostatic attraction between Cu(Ⅱ) and oxygen-containing functional groups (–OH, –COOH), as well as cation exchange involving –COONa and –SO3Na. Furthermore, SL/Cg-g-PAA effectively mitigated the bioavailability of heavy metals within soil matrices, as evidenced by a notable 14.1% reduction in DTPA extracted state Cu (DTPA-Cu) content in the S4 treatment (0.7% SL/Cg-g-PAA) compared to the control group. Concurrently, the Cu content in both the leaves and roots of pakchoi exhibited substantial decreases of 55.19% and 36.49%, respectively. These effects can be attributed to the precipitation and complexation reactions facilitated by the hydrogel. In summary, this composite hydrogel is highly promising for effective remediation of heavy metal pollution in water and soil, with a particular capability for the immobilization of Cu(Ⅱ) and reduction of its adverse effects on ecosystems.

Adsorption and Kinetics Modelling for Chromium (Cr6+) Uptake from Contaminated Water by Quaternized Date Palm Waste

The pervasive challenge of heavy metal pollution in water necessitates urgent interventions to mitigate chromium contamination. It poses significant threats to human health, aquatic ecosystems, and the environment. This research delves into the potential of date palm waste as a precursor of adsorbent for extraction of chromium from contaminated water, underscoring its potential in heavy metal remediation. Date palm waste, traditionally regarded as agricultural waste, underwent modification employing N-(3-chloro-2-hydroxypropyl) trimethylammonium chloride resulting in quaternized date palm waste (QDPW) as a prospective adsorbent for chromium extraction. The characterization techniques, including FTIR, SEM/EDX, BET, XRD, TGA/DTA, and element analysis, were employed to examine the structural and surface properties of both DPW and QDPW fibers. Optimal chromium uptake was achieved at a solution pH 6.5 over two hours, with a peak removal efficiency of 88% and an adsorption capacity of 22.26 mg/g. The equilibrium isotherms studies are consistent with Langmuir, Redlich-Peterson, and Sips isotherms, presenting a coefficient of determination (R2) of 0.989, 0.981, and 0.983, respectively. Moreover, the pseudo-second-order model was mostly aligned with the kinetics data with R2 value of 0.999. These findings showed that the quaternized date palm waste can be considered a good option to recycle the date palm waste and reduce the environmental threats in aqueous solution.

Zn-MOF@rGO nanocomposite: a versatile tool for highly selective and sensitive detection of Pb2+ and Cu2+ ions in water.

In this work, a hybrid nanocomposite material (PUC2@rGO) was prepared by integrating our previously developed Zn-MOF (PUC2) with reduced graphene oxide (rGO) through the wet impregnation method. The characterization of PUC2@rGO was performed using various analytical techniques, including FTIR, PXRD, FE-SEM, HR-TEM, XPS, zeta potential, and time-resolved FL spectroscopy. Our investigation primarily focused on assessing the composite's capability to detect water pollutants. Notably, PUC2@rGO demonstrated remarkable selectivity and sensitivity towards Pb2+ and Cu2+ ions via fluorescence quenching, exhibiting low detection limits and high quenching constant values. Spectroscopic analysis revealed that electron transfer from PUC2@rGO (donor) to the metal ions (acceptor) resulted in the observed quenching effect induced by Pb2+ and Cu2+ ions. Time-resolved fluorescence studies of PUC2@rGO before and after adding Pb2+ and Cu2+ ions confirmed dynamic quenching, further affirming strong interactions between PUC2@rGO and the targeted metal ions. These findings highlight PUC2@rGO's potential for efficiently detecting heavy metal pollutants in water.