Search

Humans are exposed to cadmium and lead in various regions of the world daily due to industrial development and climate change. Increasing numbers of preclinical and clinical studies indicate that heavy metals, such as cadmium and lead, play a role in the pathogenesis of eye diseases. Excessive exposure to heavy metals such as cadmium and lead can increase the risk of impaired vision. Therefore, it is essential to better characterize the role of these non-essential metals in disease etiology and progression. This article discusses the potential role of cadmium and lead in the development of age-related eye diseases, including age-related macular degeneration, cataracts, and glaucoma. Furthermore, we discuss how cadmium and lead affect ocular cells and provide an overview of putative pathological mechanisms associated with their propensity to damage the eye., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier GmbH.. All rights reserved.)

In modern times, wastewater treatment is vital due to increased water contamination arising from pollutants such as nutrients, pathogens, heavy metals, and pharmaceutical residues. Polysaccharides (PSAs) are natural, renewable, and non-toxic biopolymers used in wastewater treatment in the field of gas separation, liquid filtration, adsorption processes, pervaporation, and proton exchange membranes. Since addition of nanoparticles to PSAs improves their sustainability and strength, nanocomposite PSAs has gained significant attention for wastewater treatment in the past decade. This review presents a comprehensive analysis of PSA-based nanocomposites used for efficient wastewater treatment, focusing on adsorption, photocatalysis, and membrane-based methods. It also discusses potential future applications, challenges, and opportunities in adsorption, filtration, and photocatalysis. Recently, PSAs have shown promise as adsorbents in biological-based systems, effectively removing heavy metals that could hinder microbial activity. Cellulose-mediated adsorbents have successfully removed various pollutants from wastewater, including heavy metals, dyes, oil, organic solvents, pesticides, and pharmaceutical residues. Thus, PSA nanocomposites would support biological processes in wastewater treatment plants. A major concern is the discharge of antibiotic wastes from pharmaceutical industries, posing significant environmental and health risks. PSA-mediated bio-adsorbents, like clay polymeric nanocomposite hydrogel beads, efficiently remove antibiotics from wastewater, ensuring water quality and ecosystem balance. The successful use of PSA-mediated bio-adsorbents in wastewater treatment depends on ongoing research to optimize their application and evaluate their potential environmental impacts. Implementing these eco-friendly adsorbents on a large scale holds great promise in significantly reducing water pollution, safeguarding ecosystems, and protecting human health., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Biochar can be used for soil remediation in environmentally beneficial manner, especially when combined with nanomaterials. After a decade of research, still, no comprehensive review was conducted on the effectiveness of biochar-based nanocomposites in controlling heavy metal immobilization at soil interfaces. In this paper, the recent progress in immobilizing heavy metals using biochar-based nanocomposite materials were reviewed and compared their efficacy against that of biochar alone. In details, an overview of results on the immobilization of Pb, Cd, Cu, Zn, Cr, and As was presented by different nanocomposites made by various biochars derived from kenaf bar, green tea, residual bark, cornstalk, wheat straw, sawdust, palm fiber, and bagasse. Biochar nanocomposite was found to be most effective when combined with metallic nanoparticles (Fe 3 O 4 and FeS) and carbonaceous nanomaterials (graphene oxide and chitosan). This study also devoted special consideration to different remediation mechanisms by which the nanomaterials affect the effectiveness of the immobilization process. The effects of nanocomposites on soil characteristics related to pollution migration, phytotoxicity, and soil microbial composition were assessed. A future perspective on nanocomposites' use in contaminated soils was presented., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

A novel functional cellulose carbon aerogel@Na 2 Ti 3 O 7 @Cu 2 O (CA@Na 2 Ti 3 O 7 @Cu 2 O) nanocomposite was prepared by in situ growth technique and impregnation method, and its photocatalytic and adsorption properties were explored. The cationic intercalation structure of Na 2 Ti 3 O 7 nanosheets gives CA@Na 2 Ti 3 O 7 @Cu 2 O nanocomposites excellent adsorption capacity of heavy metal ions (31.0-118.7 mg/g). The Cu 2 O nanoparticles in CA@Na 2 Ti 3 O 7 @Cu 2 O nanocomposite showed excellent photocatalytic activity, and the removal rate of methylene blue (MB) was up to 99 %. Furthermore, the CA@Na 2 Ti 3 O 7 @Cu 2 O nanocomposites could be easily regenerated and reused, providing a new way to effectively solve the problem of wastewater treatment containing heavy metal ions and organic dyes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

This study aims to investigate novel applications for chicken feather waste hydrolysate through a green, sustainable process. Accordingly, an enzymatically degraded chicken feather (EDCFs) product was used as a dual carbon and nitrogen source in the production medium of bacterial cellulose (BC). The yield maximization was attained through applying experimental designs where the optimal level of each significant variable was recorded and the yield rose 2 times. The produced BC was successfully characterized by FT-IR, XRD and SEM. On the other hand, sludge from EDCFs was used as a paper coating agent. The mechanical features of the coated papers were evaluated by bulk densities, maximum load, breaking length, tensile index, Young's modulus, work to break and coating layer. The results showed a decrease in tensile index and an increase in elongation at break. These indicate more flexibility of the coated paper. The coated paper exhibits higher resistance to water vapor permeability and remarkable oil resistance compared to the uncoated one. Furthermore, the effectiveness of sludge residue in removing heavy metals was evaluated, and the sorption capacities were ordered as Cu ++  > Fe ++  > Cr ++  > Co ++ with high affinity (3.29 mg/g) toward Cu ++ and low (0.42 mg/g) towards Co ++ in the tested metal solution., (© 2022. The Author(s).)

Water is a valuable natural resource, which plays a crucial role in ecological survival as well as economic progress. However, the water quality has deteriorated in recent years as a result of urbanization, industrialization and human activities due to the uncontrolled release of industrial wastes, which can be extremely carcinogenic and non-degradable, in air, water and soil bodies. Such wastes showed the presence of organic and inorganic pollutants in high dosages. Heavy metals are the most obstinate contaminants, and they can be harmful because of having a variety of detrimental consequences to the ecosystem. The existing water treatment methods in many situations may not be sustainable or effective because of their high energy requirements and ecological impacts. In this review, state-of-the-art water treatment methods for the elimination of heavy metals with the help of protein nanofibrils are covered featuring a discussion on the strategies and possibilities of developing protein nanofibrils for the active elimination of heavy metals using kitchen waste as well as residues from the cattle, agriculture, and dairy industries. Further, the emphasis has been given to their environmental sustainability and economical aspects are also discussed., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Responsive photonic crystals have attracted extensive attention due to their features of transforming external stimuli into a variation of optical signals or structural colors. In recent years, the accumulation of heavy metal ions has become a serious threat to human health and the environment. Thus, a simple and rapid method for the accurate detection of metal ions is of great importance. Herein, an imidazole-based-silica inverse opal photonic crystal (IOPC) sensor is prepared. Three different particle sizes of SiO 2 photonic crystals were used as templates for the preparation of an IOPC. The results show that the template presents a high specific surface area and interconnected nanopores. When the nanopores adsorb copper ions, the functional monomer imidazole will chelate with copper ions to form a flat quadrilateral structure. Then the nanopores of the IOPC shrink, which will result in the red shifting of the diffraction peak to complete the visual response sensing. When immersed in different concentrations of metal ions, the structural color of the IOPC changes, making it a visual sensor. In addition, it is proved that the imidazole-modified IOPC is specifically responsive to Cu 2+ , and the structural color of the sensor will shift from green to yellow after sensing. The detection limit is as low as 1 × 10 -6 mol L -1 , and the maximum offset of the diffraction peak can reach 50 nm. Therefore, the IOPC prepared here provides an ideal platform for the fast and high selective detection of Cu 2+ , and it has potential applications in the rapid detection of other heavy metal ions.

The rapid and efficient treatment of complex wastewater remains challenging. Herein, green paper-based materials with high wet strength, good oil-water separation property and high heavy metal ion adsorption capacity were prepared via a facile, cost-effective process. The introduction of amphoteric functional groups not only met the requirements for heavy metal ion adsorption, but also maintained the stable underwater superoleophobic properties of materials a wide pH range. The covalent crosslinking between cellulose fibers induced by polyethyleneimine and citric acid significantly improved the wet strength (up to 26.0 Nm/g) and the porosity. The membrane flux was increased up to 3515 L/(m 2 ·h) and the separation efficiencies were higher than 98%. Moreover, the theoretical maximum adsorption capacities for Cd(II) and Pb(II) reached 73.29 and 93.75 mg/g, respectively. Combined with filtration technology, the materials can realize the continuous and efficient purification of complex wastewater., (Copyright © 2022. Published by Elsevier B.V.)

Heavy metal ions (HMI) have attracted worldwide concern due to their serious environmental pollution which led to the risk of health conditions. From Red Malus floribunda fruits, nitrogen-doped carbon dots (N-CDs) were prepared, followed by hybrid-spherical shaped hydrogel particles (CGCDs) were prepared. The prepared CGCDs were utilized as adsorbents for HMI-(Hg(II), Cd(II), Pb(II), and Cr(III)) from water. N-CDs with about 4.0 nm in diameter were characterized by various techniques such as field emission-scanning electron microscopy (FE-SEM) and attenuated total reflection-fourier transform infrared spectroscopy (ATR-FTIR) that confirm the presence of nitrogen, oxygen, and carbon functionalities. The prepared spherical CGCDs were characterized very well before it was used as HMI adsorbents. The sizes of the CGCDs were ranges between 20 and 300 μm and the degree of swelling was calculated as 1320 %. ATR-FTIR and X-ray diffraction analyses reveal the presence of N-CDs in CGCDs. Further, FE-SEM confirms the spherical shape morphology of CGCDs. Three different concentrations of HMI solutions were 500 mg/L, 1000 mg/L, and 1500 mg/L. Hg(II) adsorbed proficiently by CGCDs in single metal ion systems with ~72 % and almost complete removal of Hg(II) ions (99 %) in multiple metal ion systems was observed. Moreover, all metal ions Hg(II), Cd(II), Pb(II), and Cr(III) were efficiently (>70 %) removed in multiple systems by CGCDs. After HMI adsorption experiments, the elemental mapping from FE-SEM and X-ray photoelectron spectroscopy studies conveys the presence of HMI on CGCDs. This suggests that CGCDs would be a suitable adsorbent for the simultaneous removal of multiple HMI from wastewater., (Copyright © 2021 Elsevier Ltd. All rights reserved.)