Metal Ion Remediation Research Articles

In situ self-assembly of ZIF-8@sodium alginate composite hydrogels for enhanced adsorption of Cu2+ Ions

With the advancement of science and technology, the issue of wastewater pollution has escalated, necessitating urgent attention to wastewater treatment. In this study, a highly efficient adsorbent for Cu2+ was successfully synthesized through in situ self-assembly using Ca2+ as the cross-linking agent in ZIF-8@ALG composite hydrogel. The results demonstrated that the incorporation of Ca2+ as the cross-linker enhanced both adsorption capacity and swelling properties of ZIF-8@ALG composite hydrogel. Adsorption performance evaluation revealed that the hydrogel followed pseudo-second-order kinetic model for Cu2+ adsorption and Freundlich isotherm model with a theoretical maximum adsorption capacity of 309.57 m g−1. Thermodynamic analysis indicated that Cu2+ adsorption onto the hydrogel occurred spontaneously with heat absorption. Furthermore, excellent reusability was observed after five cycles of usage without significant loss in adsorption efficiency. Overall, these findings highlight the potential application of ZIF-8@ALG composite hydrogel as an effective solution for wastewater remediation and recovery of heavy metal ions.

Chemical Synthesis of Bimetallic Ag/Co Nanoparticles for Colorimetric Detection of Cr3+ and Fe3+ and Its Catalytic Performance

Precious metal nanoparticles, especially Ag-based nanoparticles due to their strong surface plasma effect and excellent catalytic performance, have been widely applied in environmental remediation and detection of heavy metal ions in aqueous solution. In this study, first, bimetallic Ag/Co nanoparticles (Ag/Co NPs) modified by sodium citrate were synthesized by chemical reduction method. Second, bimetallic Ag/Co NPs were used as colorimetric probe for detecting [Formula: see text] and [Formula: see text] in aqueous solution simultaneously for the first time. The results showed that the probe had high specificity towards [Formula: see text] and [Formula: see text] among the tested metal ions. When [Formula: see text] was mixed with Ag/Co NPs, the solution quickly changed from yellow to pink, meanwhile, the UV–Vis absorption intensity declined at 400[Formula: see text]nm and a new prominent absorption band was formed at 530[Formula: see text]nm. While [Formula: see text] was mixed with Ag/Co NPs, the solution quickly changed from yellow to nearly colorless. The linear relationship between absorbance of bimetallic Ag/Co NPs at 400[Formula: see text]nm and −log of [Formula: see text] concentration is 1[Formula: see text]nM to 10[Formula: see text][Formula: see text]M, which [Formula: see text] and [Formula: see text]. The limit of detection (LOD) for this study was 1.14[Formula: see text]nM. Similar to [Formula: see text], the LOD for [Formula: see text] was calculated 16.3[Formula: see text][Formula: see text]M. In addition, the catalytic performance of bimetallic Ag/Co NPs was evaluated by methylene blue (MB) in the presence of H2O2. The catalytic degradation efficiency of bimetallic Ag/Co NPs was about 4.8 times greater than monometallic Ag NPs, confirming Ag and Co NPs had obviously synergistic effect. Therefore, this result made bimetallic Ag/Co NPs had potential application in the field of environmental remediation.

Nanocellulose: A sustainable functional construct for the remediation of heavy metal ions from water

Heavy metals are considered to be a significant pollutant in water bodies, adversely affecting human health by causing various severe diseases after passing down the food chain. The rise in environmental problems due to the usage of non – biodegradable materials leads to the necessity of eco–friendly materials. The abundant and eco-friendly nature of the nanocellulose makes them promising substitutes for non-sustainable materials, nowadays. It is also possible to find the chemical components (cellulose, hemicellulose, and lignin) present in a source and the cellulose yield. In this context, nanocellulose has gained considerable attention among nanomaterials as a promising candidate for the adsorption of toxic heavy metal ions because of its large surface area, light weight, low cost, biocompatible nature, etc. Moreover, the numerous surface hydroxyl groups present in its surface make them suitable for the wide range of surface functionalization with different groups. They can thus be used individually or in combination with other materials for excellent adsorption towards various toxic heavy metal ions. The state of research on modified nanocellulose as an adsorbent for heavy metals is principally discussed in this review. Mainly two types of plant-based nanocelluloses; cellulose nanofibers (CNFs) and cellulose nanocrystals (CNCs), are discussed in detail in this review. The extraction of nanocellulose via a green approach was also covered. This review comprises comprehensive details on the modifications and other relevant properties of nanocellulose which would facilitate the adsorption of toxic heavy metals.

Fiber welded EDTA-modified cellulose for remediation of heavy metal ions

Ethylenediaminetetraacetic acid (EDTA) is a well-known metal chelator and an attractive ligand for covalently modifying adsorbents for bioremediation. Cellulose, a naturally occurring biopolymer, has immense potential as an inexpensive, earth abundant, biocompatible scaffold for EDTA-facilitated environmental remediation; however, pretreatment of the material is required to achieve sufficient degrees of chemical modification. In this study, Natural Fiber Welding (NFW) is used to prepare commercial cotton Aida cloth for EDTA functionalization. Following NFW, the cotton scaffold was covalently modified with up to 0.56 mmol of EDTA per gram of adsorbent, a nearly 2.5-fold increase over native material. The welded EDTA-modified substrates were tested qualitatively against cobalt and quantitatively against nickel, reaching equilibrium binding capacities (qe) of up to 46 mg metal per g of adsorbent, on par with capacities reported from past work on EDTA-modified cellulose. In addition, adsorbent material could be regenerated using mild acid treatment with no significant loss in qe. Unlike the controls, the fiber-welded EDTA-Aida did not fray even after 3 chelation cycles, indicating enhanced textile robustness afforded through NFW treatment. Overall, NFW offers a new approach to converting commercially available, sustainable biomaterials into robust adsorbents for environmental remediation.

Remediation of multifarious metal ions and molecular docking assessment for pathogenic microbe disinfection in aqueous solution by waste-derived Ca-MOF.

The present study demonstrates an eco-friendly and cost-effective synthesis of calcium terephthalate metal-organic frameworks (Ca-MOF). The Ca-MOF were composed of metal ions (Ca2+) and organic ligands (terephthalic acid; TPA); the former was obtained from egg shells, and the latter was obtained from processing waste plastic bottles. Detailed characterization using standard techniques confirmed the synthesis of Ca-MOF with an average particle size of 461.9 ± 15nm. The synthesized Ca-MOF was screened for its ability to remove multiple metal ions from an aqueous solution. Based on the maximum sorption capacity, Pb2+, Cd2+, and Cu2+ ions were selected for individual parametric batch studies. The obtained results were interpreted using standard isotherms and kinetic models. The maximum sorption capacity (qm) obtained from the Langmuir model was found to be 644.07 ± 47, 391.4 ± 26, and 260.5 ± 14mgg-1 for Pb2+, Cd2+, and Cu2+, respectively. Moreover, Ca-MOF also showed an excellent ability to remove all three metal ions simultaneously from a mixed solution. The metal nodes and bonded TPA from Ca-MOF were dissociated by the acid dissolution method, which protonated and isolated TPA for reuse. Further, the crystal structure of Ca-MOF was prepared and docked with protein targets of selected pathogenic water-borne microbes, which showed its disinfection potential. Overall, multiple metal sorption capability, regeneration studies, and broad-spectrum antimicrobial activity confirmed the versatility of synthesized Ca-MOF for industrial wastewater treatment.

Polyrhodanine-Functionalized Magnetic-Activated Carbon for Efficient Removal of Lead Ions and Malachite Green From Wastewater

The development of wastewater treatment agents with high treatment capacity and efficient separation is crucial for the remediation of heavy metal ions and organic dye wastewater. In this study, a polyrhodanine functional magnetic-activated carbon composite (PR-mAC) was synthesized via a one-step co-precipitation method combined with chemical oxidation polymerization. As an innovative water treatment agent, PR-mAC possesses not only environmentally friendly and easily obtainable raw materials but also magnetic properties that facilitate its reusability. Notably, PR-mAC exhibited remarkable removal efficiency towards lead ion (Pb(II)) and malachite green (MG). Experimental results demonstrated that the adsorption of Pb(II) and MG followed quasi-second-order kinetic model, while the Hill isothermal adsorption model and Redlich–Peterson isothermal adsorption model were suitable for Pb(II) and MG removal, respectively. All adsorption processes were spontaneous endothermic reactions. The maximum adsorption capacities reached 223.71 mg/g and 315.46mg/g, respectively. Even after undergoing 5 cycles, the material maintained satisfactory removal performance for Pb(II) and MG pollutants. Therefore, the prepared PR-mAC represents an optimal agent for wastewater treatment due to its effective capability in removing both metal ions and dyes.

Hydroxyapatite@cellulose@nZVI composite: Fabrication and adsorptive removal of doxycycline, Cr(VI) and As(III) from wastewater

In this study, a biogenic nanocomposite (HAP@CL@nZVI) was successfully developed using hydroxyapatite derived from eggshell waste, cellulose, and green-synthesized nano zero-valent iron for the removal of doxycycline (DOX), Cr(VI), and As(III) from aqueous solutions. Under optimized conditions, HAP@CL@nZVI demonstrated high adsorption capacity, with pH playing a critical role in the process with peak adsorption occurring at pH 8 for DOX, pH 2 for Cr(VI), and pH 7 for As(III). Mechanisms involved electrostatic attraction, hydrogen bonding, and π-π interactions for DOX, while electrostatic interactions and surface complexation governed Cr(VI) and As(III) adsorption. The Langmuir isotherm model indicated monolayer adsorption processes, with maximum adsorption capacities of 74.07, 111.11 and 79.37 mg/g for DOX, Cr(VI), and As(III) respectively. Kinetic studies unveiled pseudo-first-order kinetics for DOX and pseudo-second-order kinetics for Cr(VI) and As(III). The study highlights strong regeneration potential of HAP@CL@nZVI, rendering it a sustainable, eco-friendly adsorbent for pharmaceutical wastewater treatment and toxic metal ion remediation.

Schiff Bases, Syntheses, Characterisation and their Application to Heavy Metal Removal: A Review

Schiff bases are compounds resulting from the condensation reaction between an aldehyde or ketone with primary amines. The confirmation of the formation of these compounds involves the use of characterisation techniques which encompasses spectroscopic and thermoanalytical techniques. Recently, Schiff bases have garnered attention because of their wide applications which range from industrial uses to use in remediation of metal ions. Their use in extraction of heavy metal is of particular interest due to rising levels of metal pollution globally. The ability of Schiff bases to form coordination complexes with metal ions makes them suitable for these purposes. This review article outlines the synthesis, characterisation and application of Schiff bases to metal extraction.

Novel Carbon Nanomaterial Synthesized from Banana Leaf Decorated with Metal Nanoparticles for Remediation of Toxic Metal Ions

Abstract: In the present work, a novel carbon nanomaterial decorated with metal nanoparticles was prepared from banana leaf. An eco-friendly, carbon neutral with a high-cost efficiency quotient substance. The precursor, banana leaf was pyrolyzed in an inert atmosphere and activated by using alkali solution. It was then decorated with copper nanoparticles to obtain the final product. BET analysis revealed its significant specific surface area. The synergic effect of high surface area and nanometal decoration makes this carbon nanomaterial suitable for removal of Pb, Co and Cr toxic metal ions. It is very effective even when the concentration of metal ions is very low. Characterization of nanomaterials was carried out by SEM, HRTEM and XRD. The effect of pH on removal of toxic metal ions was also studied.

Engineered Bacillus subtilis Biofilm@Biochar living materials for in-situ sensing and bioremediation of heavy metal ions pollution

The simultaneous sensing and remediation of multiple heavy metal ions in wastewater or soil with microorganisms is currently a significant challenge. In this study, the microorganism Bacillus subtilis was used as a chassis organism to construct two genetic circuits for sensing and adsorbing heavy-metal ions. The engineered biosensor can sense three heavy metal ions (0.1–75 μM of Pb2+ and Cu2+, 0.01–3.5 μM of Hg2+) in situ real-time with high sensitivity. The engineered B. subtilis TasA-metallothionein (TasA-MT) biofilm can specifically adsorb metal ions from the environment, exhibiting remarkable removal efficiencies of 99.5% for Pb2+, 99.9% for Hg2+and 99.5% for Cu2+ in water. Furthermore, this engineered strain (as a biosensor and absorber of Pb2+, Cu2+, and Hg2+) was incubated with biochar to form a hybrid biofilm@biochar (BBC) material that could be applied in the bioremediation of heavy metal ions. The results showed that BBC material not only significantly reduced exchangeable Pb2+ in the soil but also reduced Pb2+ accumulation in maize plants. In addition, it enhanced maize growth and biomass. In conclusion, this study examined the potential applications of biosensors and hybrid living materials constructed using sensing and adsorption circuits in B. subtilis, providing rapid and cost-effective tools for sensing and remediating multiple heavy metal ions (Pb2+, Hg2+, and Cu2+).

Amine-functionalized UiO-66 incorporated electrospun cellulose/chitosan porous nanofibrous membranes for removing copper ions

Cellulose (CE)/chitosan (CS)/amine-functionalized zirconium 1, 4-dicarboxybenzene metal–organic framework (UiO-66-NH2) porous nanofiber membranes were prepared by direct electrospinning and surface in-situ growth and then used to remove copper ions (Cu2+) from polluted water. The micro-morphology, porosity, thermal stability, chemical groups, crystallographic structure, and adsorption performance of CE/CS/UiO-66-NH2 nanofibrous membranes were characterized. The hydrophilicity, thermal stability, and adsorption capacity of the membranes were greatly improved by incorporating UiO-66-NH2. The direct electrospinning CE/CS/UiO-66-NH2 nanofibers displayed the irregular, bumpy shapes and large fiber diameters (768.99–1039.74 nm). They also increased the chemical active sites due to the effective and uniform combination of UiO-66-NH2 with nanofibers. This resulted in a superior adsorption performance than the one with in-situ preparation. The CE/CS/UiO-66-NH2-5 showed the highest adsorption capacity of 121.16 mg g−1 and a removal rate of 90.69 %. The optimal Cu2+ adsorption conditions were obtained at an initial Cu2+ concentration of 100 mg L-1 and in weakly acidic media (pH = 5). The Langmuir model was optimal to describe Cu2+ adsorption of the nanofibrous membranes. The adsorption process involved both physical adsorption with chemical adsorption. This provides a novel strategy to combine metal–organic frameworks with the natural biomasses via electrospinning, which shows a promising application for efficient remediation of heavy metal ions in wastewater.

Biosorptive removal of selected metal ions from simulated wastewater using highly metal-resistant bacteria

Abstract In the current scenario of the need for cost-effective remediation, our study aimed to assess the remedial potential of bacteria obtained from metal-rich wastewater. To simulate the conditions, we prepared wastewater containing five toxic metals (Cu, Cr, Ni, Fe, and Pb). Two types of metal-resistant bacteria were isolated from a prominent wastewater drain in Lahore, Pakistan. These isolated bacteria were thoroughly characterized, both phenotypically and genotypically. Subsequently, the isolated bacteria were exposed to the wastewater solution containing each of the aforementioned metals at a concentration of 250 ppm. The exposed isolates were then incubated for a duration of 15 days. After 5 days, we measured the uptake of metals by the bacterial isolates. Following the 15-day incubation period, we observed that the bacterial isolates demonstrated the maximum efficiency in removing metals, with approximately 47.5% of Fe, 77% of Ni, 75.75% of Cu, 64% of Cr, and 82.5% of Pb being removed. These findings have significant implications for the development of environmentally friendly and cost-effective strategies for metal ion remediation.

Agricultural Solid Wastes Based Adsorbent Materials in the Remediation of Heavy Metal Ions from Water and Wastewater by Adsorption: A Review.

Adsorption has become the most popular and effective separation technique that is used across the water and wastewater treatment industries. However, the present research direction is focused on the development of various solid waste-based adsorbents as an alternative to costly commercial activated carbon adsorbents, which make the adsorptive separation process more effective, and on popularising the sustainable options for the remediation of pollutants. Therefore, there are a large number of reported results available on the application of raw or treated agricultural biomass-based alternatives as effective adsorbents for aqueous-phase heavy metal ion removal in batch adsorption studies. The goal of this review article was to provide a comprehensive compilation of scattered literature information and an up-to-date overview of the development of the current state of knowledge, based on various batch adsorption research papers that utilised a wide range of raw, modified, and treated agricultural solid waste biomass-based adsorbents for the adsorptive removal of aqueous-phase heavy metal ions. Metal ion pollution and its source, toxicity effects, and treatment technologies, mainly via adsorption, have been reviewed here in detail. Emphasis has been placed on the removal of heavy metal ions using a wide range of agricultural by-product-based adsorbents under various physicochemical process conditions. Information available in the literature on various important influential physicochemical process parameters, such as the metal concentration, agricultural solid waste adsorbent dose, solution pH, and solution temperature, and importantly, the adsorbent characteristics of metal ion removal, have been reviewed and critically analysed here. Finally, from the literature reviewed, future perspectives and conclusions were presented, and a few future research directions have been proposed.

Silk based adsorbents for remediation of heavy metal ions from wastewater

Silk, a natural biopolymer possessing superior adsorbent properties, is excessively utilized in water remediation. This study illustrates degumming of silk fibroin using microwave radiations and batch adsorption of nickel ions from aqueous (aq.) solution. The removal of sericin from silk was confirmed through surface, functional group and thermal analysis. The water contact angle of degummed silk was observed to be 163°, exhibiting superhydrophobicity. The degummed silk fibroin demonstrated superior adsorption capacity of 27 mg/g in contrast with raw silk of 17 mg/g at constant adsorbent dose and contact time, and the former exhibited lowered adsorption time by 2 h compared to the latter.

Microwave assisted synthesized graphene oxide nanocomposites for remediation of toxic metal ions

Here we report the eco-friendly synthesis of graphene magnetic and non-nonmagnetic nanocomposites, namely GO/Fe3O4 and GO-Ni(OH)2, by employing microwave energy. The nanocomposites were explored for the adsorption of toxic Pb2+ and Cd2+ ions. The characterization techniques of XRD, Raman, FESEM and HRTEM confirmed the structure quality and morphology of both nanocomposites. The adsorption studies were conducted using ICP-OES characterization data. The adsorption of Pb2+ and Cd2+ ions on the surface of the nanocomposites were described well by the Freundlich model. The results of the adsorption studies show that the GO/Fe3O4 nanocomposite shows a high adsorption of Cd2+ ions relative to Pb2+ ions due to the formation of a cadmium complex (CdOH +) in the solution which has a higher stability constant value as compared to the lead complex PbOH +. However, the nonmagnetic GO-Ni(OH)2 nanocomposite shows a higher adsorption of Pb2+ ions due to its high electronegativity relative to Cd2+ ions. It was found that the adsorption varies with the concentration of the metal ions.

Facile Strategy for Fabricating an Organosilica-Modified Fe3O4 (OS/Fe3O4) Hetero-nanocore and OS/Fe3O4@SiO2 Core-Shell Structure for Wastewater Treatment with Promising Recyclable Efficiency.

The development of a sustainable process for heavy metal ion remediation has become a point of interest in various fields of research, including wastewater treatment, industrial development, and health and environmental safety. In the present study, a promising sustainable adsorbent was fabricated through continuous controlled adsorption/desorption processes for heavy metal uptake. The fabrication strategy is based on a simple modification of Fe3O4 magnetic nanoparticles with organosilica in a one-pot solvothermal process, carried out in order to insert the organosilica moieties into the Fe3O4 nanocore during their formation. The developed organosilica-modified Fe3O4 hetero-nanocores had hydrophilic citrate moieties, together with hydrophobic organosilica ones, on their surfaces, which facilitated the further surface coating procedures. To prevent the formed nanoparticles from leaching into the acidic medium, a dense silica layer was coated on the fabricated organosilica/Fe3O4 (OS/Fe3O4). In addition, the prepared OS/Fe3O4@SiO2 was utilized for the adsorption of cobalt(II), lead(II), and manganese(II) from the solutions. The data for the adsorption processes of cobalt(II), lead(II), and manganese(II) on OS/(Fe3O4)@SiO2 were found to follow the pseudo-second-order kinetic model, indicating the fast uptake of heavy metals. The Freundlich isotherm was found to be more suitable for describing the uptake of heavy metals by OS/Fe3O4@SiO2 nanoparticles. The negative values of the ΔG° showed a spontaneous adsorption process of a physical nature. The super-regeneration and recycling capacities of the OS/Fe3O4@SiO2 were achieved, comparing the results to those of previous adsorbents, with a recyclable efficiency of 91% up to the seventh cycle, which is promising for environmental sustainability.

Highly efficient novel nanostructured dendritic macromolecules for remediation of aquatic heavy metal ions

Highly efficient novel nanostructured dendritic macromolecules for remediation of aquatic heavy metal ions

Regulating energy band structures of triazine covalent organic frameworks with electron-donating/withdrawing substituents for visible-light-responsive photocatalytic tetracycline degradation and Cr(VI) reduction

Environmental contaminations have raised soaring concerns about human health worldwide. Developing metal-free photocatalysts as green agents to solve these problems is urgent. Covalent organic frameworks (COFs) are considered a promising platform for the molecule-level design of visible-light-responsive photocatalysts due to their tailored coordination/electronic structures and excellent charge carrier mobility. However, COFs without substituents (e.g., COFs-H) still suffer from broad bandgaps and low electron-hole separation efficiency. In this work, we introduced electron-donating/withdrawing substituents on COFs-H to fine-tune the bandgap and photocatalytic performance of COFs. Theoretical and experimental studies revealed that all substituents narrowed the bandgap of COFs and enhanced the electron-hole separation efficiency. Electron-withdrawing/donating substituents significantly alter the energy level of COFs-R, improving the redox capacities of photo-generated holes and electrons for tetracycline (TC) degradation and Cr(VI) reduction. The large difference in electrostatic potential between the two monomers in COFs-R enhances the charge carrier generation and intramolecular electron transfer intrinsically. This work unravels how substituents with different electronic effects regulate the energy band structures and photo-redox capacities of COFs. It further provides new insight into the precise regulation of COFs toward highly efficient visible-light-driven photocatalytic remediation of organic contaminants and heavy metal ions.

Nanovesicle and extracellular polymeric substance synthesis from the remediation of heavy metal ions from soil

Heavy metal toxicity affects aquatic plants and animals, disturbing biodiversity and ecological balance causing bioaccumulation of heavy metals. Industrialization and urbanization are inevitable in modern-day life, and control and detoxification methods need to be accorded to meet the hazardous environment. Microorganisms and plants have been widely used in the bioremediation of heavy metals. Sporosarcina pasteurii, a gram-positive bacterium that is widely known for its calcite precipitation property in bio-cementing applications has been explored in the study for its metal tolerance ability for the first time. S. pasteurii SRMNP1 (KF214757) can tolerate silver stress to form nanoparticles and can remediate multiple heavy metals to promote the growth of various plants. This astounding property of the isolate warranted extensive examinations to comprehend the physiological changes during an external heavy metal stress condition. The present study aimed to understand various physiological responses occurring in S. pasteuriiSRMNP1 during the metal tolerance phenomenon using electron microscopy. The isolate was subjected to heavy metal stress, and a transmission electron microscope examination was used to analyze the physiological changes in bacteria to evade the metal stress. S. pasteurii SRMNP1 was tolerant against a wide range of heavy metal ions and can withstand a broad pH range (5–9). Transmission Electron Microscopy (TEM) examination of S. pasteurii SRMNP1 followed by 5 mM nickel sulfate treatment revealed the presence of nanovesicles encapsulating nanosized particles in intra and extracellular spaces. This suggests that the bacteria evade the metal stress by converting the metal ions into nanosized particles and encapsulating them within nanovesicles to efflux them through the vesicle budding mechanism. Moreover, the TEM images revealed an excessive secretion of extracellular polymeric substances by the strain to discharge the metal particles outside the bacterial system. S. pasteurii can be foreseen as an effective bioremediation agent with the potential to produce nanosized particles, nanovesicles, and extracellular polymeric substances. This study provides physiological evidence that, besides calcium precipitation applications, S. pasteurii can further be explored for its multidimensional roles in the fields of drug delivery and environmental engineering.

Silver-chitosan (Ag-CH) nanocomposite hydrogel for remediation of aqueous medium

In this work, a low cost, in situ synthesized silver-chitosan (Ag-CH) nanocomposite hydrogel has been proposed for the detection and rapid removal of hexavalent chromium from water. Silver nanoparticles are enmeshed in a network of highly porous chitosan-based hydrogel matrix for the effective detection and removal hexavalent chromium. The in situ reduction of silver nitrate to silver nanoparticles within the chitosan blended polymer matrix ensures the high stability of AgNPs and the resulting Ag-CH nanocomposite acts as a colorimetric sensor for hexavalent chromium [Cr (VI)] with enhanced lower detection limit (LoD) of upto 0.1 ppb. Physico-chemical properties of the prepared Ag-CH nanocomposite hydrogel are studied using UV–Visible spectroscopy, FESEM and FTIR analysis. The Ag-CH nanocomposite shows high porosity and cross-linking, which makes it ideal as a biocompatible, low-cost and sustainable biosorbent material. The hydrogel has a high removal efficiency of 83 % for Cr (VI). The effortless regeneration of the nanocomposite hydrogel aids in its easy reusability. The biocompatibility, sustainability and reusability of the Ag-CH hydrogel confirms its effectiveness as a nanobiosorbent material and provides a potential solution for simultaneous sensing and remediation of heavy metal ions from aqueous matrices.