A novel porous lignocellulosic standing hierarchical hydroxyapatite for enhanced aqueous copper(II) removal.

Potentially toxic metal-polluted water resources are a heavily discussed topic the pollution by potentially toxic metals can cause significant health risks. Nanomaterials are actively developed towards providing high specific surface area and creating active adsorption sites for the treatment and remediation of these polluted waters. In an effort to tackle the limitations of conventional type adsorbents, nano-hydroxyapatite (HAp) was developed in this study by in situ generation onto wood powder, resulting in the formation of uniform hybrid powder (HAp@wood composite) structure consisting of HAp nanoparticles that showed the removal efficiency up to 80 % after 10 min; the maximum adsorption capacity for Cu(II) ions (98.95 mg/g-HAp) was higher compared to agglomerated nano-HAp (72.85 mg/g-HAp). The adsorption capacity of Cu(II) remained stable (89.85-107.66 mg/g-HAp) during the four adsorption-desorption cycles in multi-component system, thereby demonstrating high selectivity for Cu(II). This approach of using nanoparticle is relatively simple yet effective in improving the adsorption of potentially toxic metals and the developed approach can be used to develop advanced nanocomposites in commercial wastewater treatment.

Advances in gum-based hydrogels and their environmental applications.

Gum-based hydrogels (GBHs) have been widely employed in diverse water purification processes due to their environmental properties, and high absorption capacity. More desired properties of GBHs such as biodegradability, biocompatibility, material cost, simplicity of manufacture, and wide range of uses have converted them into promising materials in water treatment processes. In this review, we explored the application of GBHs to remove pollutants from contaminated waters. Water resources are constantly being contaminated by a variety of harmful effluents such as heavy metals, dyes, and other dangerous substances. A practical way to remove chemical waste from water as a vital component is surface adsorption. Currently, hydrogels, three-dimensional polymeric networks, are quite popular for adsorption. They have more extensive uses in several industries, including biomedicine, water purification, agriculture, sanitary products, and biosensors. This review will help the researcher to understand the research gaps and drawbacks in this field, which will lead to further developments in the future.

Physico-chemical and biological remediation techniques for the elimination of endocrine-disrupting hazardous chemicals.

Due to their widespread occurrence and detrimental effects on human health and the environment, endocrine-disrupting hazardous chemicals (EDHCs) have become a significant concern. Therefore, numerous physicochemical and biological remediation techniques have been developed to eliminate EDHCs from various environmental matrices. This review paper aims to provide a comprehensive overview of the state-of-the-art remediation techniques for eliminating EDHCs. The physicochemical methods include adsorption, membrane filtration, photocatalysis, and advanced oxidation processes. The biological methods include biodegradation, phytoremediation, and microbial fuel cells. Each technique's effectiveness, advantages, limitations, and factors affecting their performance are discussed. The review also highlights recent developments and future perspectives in EDHCs remediation. This review provides valuable insights into selecting and optimizing remediation techniques for EDHCs in different environmental matrices.

Mixed pollutants adsorption potential of Eichhornia crassipes biochar on Manihot esculenta processing industry effluents.

The starch is one of the most essential food stuff and serves as a raw material for number of food products for the welfare of human. During the production process enormous volume of effluents are being released into the environment. In this regard, this study was performed to evaluate the physicochemical traits of Manihot esculenta processing effluent and possible sustainable approach to treat this issue using Eichhornia crassipes based biochar. The standard physicochemical properties analysis revealed that the most the parameters (EC was recorded as 4143.17 ± 67.12 mhom-1, TDS: 5825.62 ± 72.14 mg L-1, TS: 7489.21 ± 165.24 mg L-1, DO: 2.12 ± 0.21 mg L-1, BOD 2673.74 ± 153.53 mg L-1, COD: 6672.66 ± 131.21 mg L-1, and so on) were beyond the permissible limits and which can facilitate eutrophication. Notably, the DO level was considerably poor and thus can support the eutrophication. The trouble causing E. crassipes biomass was used as raw material for biochar preparation through pyrolysis process. The temperature ranging from 250 to 350 °C with residence time of 20-60 min were found as suitable temperature to provide high yield (56-33%). Furthermore, 10 g L-1 concentration of biochar showed maximum pollutant adsorption than other concentrations (5 g L-1 and 15 g L-1) from 1 L of effluent. The suitable temperature required to remediate the pollutants from the effluent by biochar was found as 45 °C and 35 °C at 10 g L-1 concentration. These results conclude that at such optimized condition, the E. crassipes effectively adsorbed most of the pollutants from the M. esculenta processing effluent. Furthermore, such pollutants adsorption pattern on biochar was confirmed by SEM analysis.

Adsorption of ibuprofen using waste coffee derived carbon architecture: Experimental, kinetic modeling, statistical and bio-inspired optimization.

Pharmaceuticals in water are a growing environmental concern, as they can harm aquatic life and human health. To address this issue, an adsorbent made from coffee waste that effectively removes ibuprofen (a common pharmaceutical pollutant) from wastewater was developed. The experimental adsorption phase was planned using a Design of Experiments approach with Box-Behnken strategy. The relation between the ibuprofen removal efficiency and various independent variables, including adsorbent weight (0.01-0.1 g) and pH (3-9), was evaluated via a regression model with 3-level and 4-factors using the Response surface methodology (RSM) . The optimal ibuprofen removal was achieved after 15 min using 0.1 g adsorbent at 32.4 °C and pH = 6.9. Moreover, the process was optimized using two powerful bio-inspired metaheuristics (Bacterial Foraging Optimization and Virus Optimization Algorithm). The adsorption kinetics, equilibrium, and thermodynamics of ibuprofen onto waste coffee-derived activated carbon were modeled at the identified optimal conditions. The Langmuir and Freundlich adsorption isotherms were implemented to investigate adsorption equilibrium, and thermodynamic parameters were also calculated. According to the Langmuir isotherm model, the adsorbent's maximum adsorption capacity was 350.00 mg g-1 at 35 °C. The findings revealed that the ibuprofen adsorption was well-matched with the Freundlich isotherm model, indicating multilayer adsorption on heterogeneous sites. The computed positive enthalpy value showed the endothermic nature of ibuprofen adsorption at the adsorbate interface.

Organic gelatin-coated ZnNPs for the production of biodegradable biopolymer films.

Petroleum-based polymers have raised significant environmental concerns. It is critical to create compostable, good biocompatibility, and nontoxic polymers to replace petroleum-based polymers. Thus, this research was performed to extract the gelatin from fish waste cartilage and coated it over the surface of spherical shaped pre-synthesized ZnNPs along with a suitable plasticizer to produce the biodegradable film. The presence of gelatin on the surface of ZnNPs was first confirmed using UV-visible spectrophotometers, as well as the characteristic functional groups involved in the coating were investigated using Fourier-Transform Infrared Spectroscopy (FTIR). The morphological appearance of gelatin coated ZnNPs was ranged from 41.43 to 52.31 nm, the shape was found as platonic to pentagonal shape, and the fabricated film was observed through Scanning Electron Microscope (SEM). The thickness, density, and tensile strength of fabricated film were found to be 0.04-0.10 mm, 0.10-0.27 g/cm3, and 31.7 kPa. These results imply that the fish waste cartilage gelatin coated ZnNPs-based nanocomposite can be used for film preparation as well as a wrapper for food and pharmaceutical packaging.

Latest advances in layered covalent organic frameworks for water and wastewater treatment.

This review provides an overview of recent progress in the development of layered covalent organic frameworks (LCOFs) for the adsorption and degradation of pollutants in water and wastewater treatment. LCOFs have unique properties such as high surface area, porosity, and tunability, which make them attractive adsorbents and catalysts for water and wastewater treatment. The review covers the different synthesis methods for LCOFs, including self-assembly, co-crystallization, template-directed synthesis, covalent organic polymerization (COP), and solvothermal synthesis. It also covers the structural and chemical characteristics of LCOFs, their adsorption and degradation capacity for different pollutants, and their comparison with other adsorbents and catalysts. Additionally, it discussed the mechanism of adsorption and degradation by LCOFs, the potential applications of LCOFs in water and wastewater treatment, case studies and pilot-scale experiments, challenges, and limitations of using LCOFs, and future research directions. The current state of research on LCOFs for water and wastewater treatment is promising, however, more research is needed to improve their performance and practicality. The review highlights that LCOFs have the potential to significantly improve the efficiency and effectiveness of current water and wastewater treatment methods and can also have implications for policy and practice.

A comprehensive review of lignocellulosic biomass derived materials for water/oil separation.

With rapid socioeconomic development, oil is widely used in all aspects of modern society. However, the extraction, transport, and processing of oil inevitably lead to the production of large quantities of oily wastewater. Traditional oil/water separation strategies are often inefficient, costly, and cumbersome to operate. Therefore, new green, low-cost, and high-efficiency materials must be developed for oil/water separation. As widely sourced and renewable natural biocomposites, wood-based materials have become a hot field recently. This review will focus on the application of several wood-based materials in oil/water separation. The state of research on wood sponges, cotton fibers, cellulose aerogels, cellulose membranes, and some other wood-based materials for oil/water separation over the last few years and provide an outlook on their future development are summarized and investigated. It is expected to provide some direction for future research on the use of wood-based materials in oil/water separation.

Chitosan-supported metal nanocatalysts for the reduction of nitroaromatics.

The second most abundant natural polymer in the earth's crust is chitosan (CS). The unique physical, chemical, structural, and mechanical features of this natural polymer have led to its increased application in a variety of fields such as medicine, catalysis, removal of pollutants, etc. To eliminate various pollutants, it is preferable to employ natural compounds as their use aids the removal of contaminants from the environment. Consequently, employing CS to eliminate contaminants is a viable choice. For this aim, CS can be applied as a template and support for metal nanoparticles (MNPs) and prevent the accumulation of MNPs as well as a reducing and stabilizing agent for the synthesis of MNPs. Among the pollutants present in nature, nitro compounds are an important and wide category of biological pollutants. 4-Nitrophenol (4-NP) is one of the nitro pollutants. There are different ways for the removal of 4-NP, but the best and most effective method for this purpose is the application of a metallic catalyst and a reducing agent. In this review, we report the recent developments regarding CS-supported metallic (nano)catalysts for the reduction of nitroaromatics such as nitrophenols, nitroaniline compounds, nitrobenzene, etc. in the presence of reducing agents. The metals investigated in this study include Ag, Au, Ni, Cu, Ru, Pt, Pd, etc.

Spotlighting of the role of catalysis for biomass conversion to green fuels towards a sustainable environment: Latest innovation avenues, insights, challenges, and future perspectives.

Recently, extensive resources were dedicated to studying how to use catalysis to convert biomass into environmentally friendly fuels. Problems with this technology include the processing of lignocellulosic sources and the development/optimization of novel porous materials as efficient monofunctional and bifunctional catalysts for biomass fuel production. This paper reviews recent advancements in catalysts procedures. Besides, it offers assessments of the methods used in catalytic biomass pyrolysis. Understanding the catalytic conversion process of lignocellulosic biomass into bio-oil remains a key research challenge in biomass catalytic pyrolysis.

A review on pollutants remediation competence of nanocomposites on contaminated water.

Clean freshwater has been required for drinking, sanitation, agricultural activities, and industry, as well as for the development and maintenance of the eco - systems on which all livelihoods rely. Water contamination is currently a significant concern for researchers all over the world; hence it is essential that somehow this issue is resolved as soon as possible. It is now recognised as one of the most important research areas in the world. Current wastewater treatment techniques degrade a wide range of wastewaters efficiently; however, such methods have some limitations. Recently, nanotechnology has emerged as a wonderful solution, and researchers are conducting research in this water remediation field with a variety of potential applications. The pollutants remediation capability of nanocomposites as adsorbents, photocatalysts, magnetic separation, and so on for contaminant removal from contaminated water has been examined in this study. This study has spotlighted the most significant nanocomposites invention reported to date for contaminated and effluent remediation, as well as a research gap as well as possible future perspectives.

Optimistic and possible contribution of nanomaterial on biomedical applications: A review.

Nanomaterials have many advantages over bulk materials, including enhanced surface-to-volume proportion as well as magnetic traits. It has been a steady rise in research with using nanomaterials in various biomedical fields in the past few decades. Constructing nanomaterials has emerged as a leading research primary concern in order to discover specialized biomedical applications. Since, their advantageous properties including chemical stability, non-toxicity, bio - compatibility, relatively high magnetization, and strong magnetic vulnerability, nanoparticles of iron oxide had already influenced implementations in different biomedical fields. Nanomaterials can be divided up into four nanomaterials such as metallic nanomaterials, bimetallic or alloy nanomaterials, metal oxide nanomaterials, as well as magnetic nanomaterials. Hence, the purpose of this review is to conduct such in discussion on emerging advancements in nanomaterials for biomedical, with such a special emphasis upon those options of nanomaterials including metallic nanomaterials: Au and Ag, bimetallic nanomaterials: Fe-Co and Fe-Pt, and metal oxides: TiO2 and CeO2. Securing this information gap will result in a better comprehension of the contribution of nanomaterial type and subsequent huge-scale applications in aspects of both their potential and challenges.

Nanofibrous/biopolymeric membrane a sustainable approach to remove organic micropollutants: A review.

Aquifers are severely polluted with organic and inorganic pollutants, posing a serious threat to the global ecological system's balance. While various traditional methods are available, the development of innovative methods for effluent treatment and reuse is critical. Polymers have recently been widely used in a variety of industry sectors due to their unique properties. Biopolymers are a biodegradable material that is also a viable alternative to synthetic polymers. Biopolymers are preferably obtained from cellulose and carrageenan molecules from various biological sources. While compared with conventional non-biodegradable polymeric materials, the biopolymer possesses unique characteristics such as renewability, cost-effectiveness, biodegradability, and biocompatibility. The improvements towards the biopolymeric (natural) membranes have also been thoroughly discussed. The use of nanofillers to stabilise and improve the effectiveness of biopolymeric membranes in the elimination of organic pollutants is one of the most recent developments. This was discovered that the majority of biopolymeric membranes technology consolidated on organic pollutants. More research should be directed toward against emerging organic/persistent organic pollutants (POP) and micropollutants. Furthermore, processes for regenerating and reusing utilized biopolymer-based carbon - based materials are emphasized.

Low carbon footprint preparation of MXene incorporated lignocellulosic fibers for high thermal conductivity applications.

New wood-based composite materials with thermal conductivity are greatly desired in the fields of packaging materials for electronic components. In this study, a new multifunctional composite material (M@FC) is prepared by simply blending clay-like Ti3C2Tx MXene and delignified wood fibers together, and then followed by an infusing epoxy resin with environmentally friendly vacuum assisted resin transfer molding (VARTM) process. The resulting M@FC (0.92 W m-1 K-1) possesses superior thermal conductivity as compared to natural wood (0.099 W m-1 K-1) and most polymers. Furthermore, after the VARTM process, the structure of the M@FC is tighter, and thus showing excellent mechanical properties (tensile strength of 93.0 MPa and flexural strength of 172.7 MPa). In addition, good water resistance and excellent flame retardant property are observed for M@FC. The improvement of thermal conductivity provides the possibility for its application for packaging materials in electronic components. This study using waste wood as the important component provides a new idea for carbon cycling and recycling of natural resources.

Multilayered Nanocomposites Prepared through Quadruple-Layering Approach towards Enhanced Mechanical Performance.

Multilayered materials are widely studied due to their special structures and great properties, such as their mechanical ones. In this paper a novel and effective technique, a quadruple-layering approach, was used to fabricate multilayered materials. This approach increases the number of layers rapidly via simple operations. Materials with 4, 16, and 64 layers with alternating layers of polypropylene and nanocomposites were fabricated using this approach, and their film morphology and mechanical properties were studied. The influence of the number of layers on the mechanical properties of the materials and the relationship between the mechanical properties of each material were investigated. The results illustrated that the tensile modulus and strength were enhanced and elongation at the break increased when the layer numbers of the multilayered materials increased. However, this approach has a defect in that as the layer number increases, the layer thickness was not uniform, thus restricting the improvement of properties. This may need to be further studied in future work.

Volatile organic compounds in water matrices: Recent progress, challenges, and perspective.

Volatile organic compounds (VOCs) are a group of organic compounds that have a molecular structure containing carbon and their chemical properties allow them to be easily converted to steam and gas and remain for a long period of time and have diverse effects on the environment. The purpose of this study is determination of the concentration of VOCs such as alachlor, anthracene, benzene, bromoform, chloroform, heptachlor, isophorone, tetrachloroethylene, γ -chlordane, toluene, etc. in water matrices. The results showed that among studies conducted on VOCs, the concentration of tetrachloroethylene, m,p-xylene, and toluene were at the top in water matrices, and the lowest average concentrations were found in chloroform, anthracene, and butyl benzyl phthalate. In terms of VOC concentrations in water matrices, China was the most polluted country. Moreover, the data analysis indicated that China was the only country with carcinogenic risk. A Monte-Carlo simulation showed that although the averages obtained were comparable to the acceptable limits, for heptachlor, the maximum carcinogenic risk is achieved at a level that is slightly over the limit, only 25% from the population being exposed.

In vitro analysis of green synthesized copper nanoparticles using Chloroxylon swietenia leaves for dye degradation and antimicrobial application.

Green fabrication of copper nanoparticles (CuNPs) is an environmentally friendly and cost-effective method of synthesis for biomedical and bioremediation applications. In recent times, bacterial pathogens contaminating or affecting food and food crops pose the greatest threat to the food industry. In addition to this issue, synthetic dyes released from the textile and dyeing industries are polluting aquatic ecosystems and agricultural lands. The combined impact of these two factors is considered a major threat to life. Therefore, the use of CuNPs will provide an effective and long-term solution as an antibacterial and dye removing agent. The current study focuses on the synthesis of CuNPs using the leaf extract of Chloroxylon swietenia (C-CuNPs). The formation of a peak at 390 nm and a change in color from yellow to dark brown confirmed the synthesis of C-CuNPs. Subsequent synthesis at pH 9 was suitable for preparing C-CuNPs. Structural and chemical characterization of C-CuNPs was performed using Fourier Transfer Infra-Red (FTIR), X-ray diffraction (XRD), Dynamic Light scattering (DLS), and Scanning Electron Microscopy (SEM) analysis. The synthesized C-CuNPs possess a crystalline nature, a functional group that resembles C. swietenia, and are negatively charged and spherical in shape. C-CuNPs were tested against Congo red, Coomassie blue, and crystal violet and they showed complete degradation within 24 h under optimum conditions. Disk diffusion and broth dilution assay were used to test the antibacterial activity of C-CuNPs against Staphylococcus nepalensis, Staphylococcus gallinarum, Pseudomonasstutzeri,Bacillus subtilis, and Enterococcus faecalis. Therefore, the present study represents the first report on C-CuNPs' ability to degrade synthetic dyes and kill foodborne bacterial pathogens. Thus, the study has shed light on the potential of green synthesized CuNPs as bioremediation and packaging material in the future.

Supercritical water gasification of hyperaccumulators for hydrogen production and heavy metal immobilization with alkali metal catalysts.

The high moisture content and heavy metal concentration of hyperaccumulator are the main bottlenecks of resource utilization. Supercritical water gasification technology was used to convert Sedum plumbizincicola (a hyperaccumulator of Zn and Cd) into hydrogen gas and to immobilize HMs into biochar. Homogeneous alkali metal catalysts such as NaOH, Na2CO3 and Ca(OH)2 were added to optimize the experimental conditions. The results showed that NaOH was effective in capturing CO2in-situ, thereby shifting the water-gas shift reaction equilibrium in the forward direction. And the increase of NaOH concentration had a significant promotion effect on hydrogen production. In the non-catalytic gasification of Sedum plumbizincicola, the highest hydrogen (1.5 mol/kg) and H2 selectivity (22.9%) with greater carbon gasification efficiency (19.3%) and lower H2 gasification efficiency (8.7%) of the gas products were obtained at 400 °C with 6 wt% material concentration for 20 min. However, NaOH at 5% mass fraction maximized hydrogen and H2 selectivity up to 7.5 and 98.2%, respectively. Alkali catalyst not only promoted the generation of hydrogen-rich bio-gas but also enhanced the immobilization efficiency of heavy metals. Compared to non-catalytic, when the addition amount of NaOH was 1 wt%, the Zn、Mn、Cd、Pb、Cr accumulated in biochar increased significantly for 76.8, 42.5, 80.8, 75.6 and 80.0%, respectively. This study highlights the remarkable ability of SCWG with alkali catalyst for hydrogen production and heavy metal stabilization.

Biosynthesis of zirconium nanoparticles (ZrO2 NPs) by Phyllanthus niruri extract: Characterization and its photocatalytic dye degradation activity.

The present study focused on microwave assisted synthesis of zirconium nanoparticles (ZrO2NPs) using leaf extract of Phyllanthus niruri as ecofriendly approach and assessed its antimicrobial and bioremediation efficiency. Visual color transition from yellow to brown indicates the formation of ZrO2NPs which was further substantiated by UV-Visible absorption peak at 300 nm. Dynamic Light Scattering (DLS) analysis revealed that the average particle size of ZrO2NPs as 121.5 nm with negative zeta potential of -22.6 mv. Scanning electron microscopic analysis showed spherical shaped nanoparticles with an average size of 125.4 nm. Results of photocatalytic studies revealed that ZrO2NPs exhibited 74%, 62% and 57%, dye degradation for methyl red, methyl orange, and methyl blue respectively. Antimicrobial studies depicted that ZrO2NPs exhibited bactericidal activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Aspergillus niger at dose of 200 µg/mL. Overall results of the present study revealed biogenic synthesis of ZrO2 NPs with potent bioremediation and antimicrobial properties.

Eco-friendly, green synthesized copper oxide nanoparticle (CuNPs) from an important medicinal plant Turnera subulata Sm. and its biological evaluation.

In this report, the green fabrication of copper oxide nanoparticles (CuNPs) using Turnera subulata leaf extract and assessed for the antibacterial and photocatalytic activities. The synthesis of CuNPs was performed using the leaves of T. subulata (TS-CuNPs) and characterized using UV-visible spectrophotometry, Fourier transforms infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), and Energy-dispersive X-ray spectroscopy (EDX). Produced TS-CuNPs showing transmittance peaks approximately 707-878 cm-1, with a spherical shape particle with an average size of 58.5 nm. As synthesized TS-CuNPs were used as a coating material in cotton fabrics and tested the efficacy against Gram-negative and Gram-positive bacterial pathogens. TS-CuNPs inhibited the growth of Escherichia coli and Staphylococcus aureus on cotton fabrics. Antibiofilm activity of TS-CuNPs showed a 4-fold reduction in the biofilm formation of E. coli and S. aureus. Structural morphology of TS-CuNPs coated on cotton fabric analysis using SEM-EDX confirmed the attachment of TS-CuNPs and reduction in the bacterial attachment to the cotton fabrics. Thus, this study provides a potential strategy to improve the antibacterial property of cotton fabrics in textile production for medical, sportswear, and casual wear applications. Further, the photocatalytic activity against the tested dyes evident the potential in dye industry wastewater treatment. Hence, this work represents a simple, greener, and cost-effective route for in situ synthesis of CuNPs with the potential antibacterial and as a dye degradation agent for water remediation.