Search

Chromium (Cr), due to its greater contamination in aquifers and distinct eco-toxic impacts, is of greater environmental concern. This study aimed to synthesize nanocomposites of almond shells biochar (BC) with zerovalent bismuth and/or copper (Bi0/BC, Cu0/BC, and Bi0–Cu0/BC) for the removal of Cr from aqueous solution. The synthesized nanocomposites were investigated using various characterization techniques such as XRD, FTIR spectroscopy, SEM, and EDX. The Cr removal potential by the nanocomposites was explored under different Cr concentrations (25–100 mg/L), adsorbent doses (0.5–2.0 g/L), solution pH (2–8), and contact time (10–160 min). The above-mentioned advanced techniques verified successful formation of Bi0/Cu0 and their composite with BC. The synthesized nanocomposites were highly effective in the removal of Cr. The Bi0–Cu0/BC nano-biocomposites showed higher Cr removal efficiency (92%) compared to Cu0/BC (85%), Bi0/BC (76%), and BC (67%). The prepared nanocomposites led to effective Cr removal at lower Cr concentrations (25 mg/L) and acidic pH (4.0). The Cr solubility changes with pH, resulting in different degrees of Cr removal by Bi0–Cu0/BC, with Cr(VI) being more soluble and easier to adsorb at low pH levels and Cr(III) being less soluble and more difficult to adsorb at high pH levels. The experimental Cr adsorption well fitted with the Freundlich adsorption isotherm model (R2 > 0.99) and pseudo-second-order kinetic model. Among the prepared nanocomposites, the Bi0–Cu0/BC showed greater stability and reusability. It was established that the as-synthesized Bi0–Cu0/BC nano-biocomposite showed excellent adsorption potential for practical Cr removal from contaminated water. [ABSTRACT FROM AUTHOR]

Hexavalent chromium Cr(VI) has emerged as a contaminant of prime concern for the environmentalists because of its improper disposal by tannery, dye, and electroplating industries. Adsorption is the most exploited method for its removal from industrial wastewater because of its high removal efficiency even at low Cr(VI) concentration, minimal sludge, and ease of regeneration. In recent years, several adsorbents of biological origin such as plants, algae, fungi, and bacteria have been explored for Cr(VI) remediation. This review comprehends the recent studies involving usage of biopolymer‐based nano‐composites with respect to its adsorption mechanisms, adsorption capacities, isotherms, and kinetics. The conventional abiotic and biotic techniques for removal of Cr(VI) are also discussed with a comparative insight of their adsorption capacity and removal efficiency. Nano‐biocomposites integrate the functional properties of both nanoparticles and biopolymers, which make them efficient biosorbents. Nano‐biocomposites offer a large surface area, reduced particle loss, minimal particle agglomeration on the surface, and high stability. Common kinetic models among the nano‐biocomposites, and various equilibrium models are also analyzed to understand the mode of adsorption and associated factors. These materials are mostly found to follow monolayer adsorption with ion exchange, electrostatic interaction, and surface complexation as major players in the process. [ABSTRACT FROM AUTHOR]

• Synthesis and characterization of CMC/PUA via sustainable approch. • CMC/PUA naobiocomposites is utilize for coatings. • It will serve as environmentally friendly material for protective coatings. • CMC/PUA bionanocomposites characterize by FTIR, SEM and XRD,. An effort has been made to synthesize sustainable polyurethane-amide (PUA) organoclay by incorporating natural materials. Polyol derived from castor oil, toluene diisocyanate (TDI), and cetyl pyridinium chloride (CPC) modified Montmorillonite (Mt) clay have been used in this purpose. The modification of Mt clay with CPC serves a dual purpose by increasing the D -spacing between clay layers and enhancing the compatibility of clay with organic polymers. The investigations included varying the percentage of TDI at three different levels to assess its impact on the physical, mechanical and corrosion resistance characteristics of bio-nanocomposite. The presence of characteristics C H bonds at 2854 cm−1 (sym. −CH 2) and 2928 cm−1 (asym. −CH 2 –) in CMC are absent in Mt, confirming formation of CPC modified Mt clay (CMC). Structural investigations of nanobiocomposites were done by Scanning electron microscopy and X-ray diffraction studies and TGA analysis. The findings suggest that the synthesized bio-nanocomposites could serve as a novel and environmentally friendly material for protective coatings. [Display omitted] [ABSTRACT FROM AUTHOR]

Fossil oil derived materials exhibit non‐degradable properties with a limited availability. To overcome these limitations, a biodegradable starch/poly(ε‐caprolactone) based Coloisite‐20A nanocomposites are developed in this research study. The overall performance of these newly developed nanocomposite materials is deeply investigated. First, the morphological analysis of the nanocomposites is examined using X‐ray diffraction, transmission electron microscopy, and atomic force microscopy. Thereafter, mechanical performance of the nanocomposites is analyzed through tensile and flexural tests. The water‐based contact angle and sorption testing are conducted to confirm the hydrophobic or hydrophilic nature of the nanocomposite. Finally, the degradation behavior of this nanocomposite is estimated by the soil‐burial tests followed by Fourier transform infrared analysis, field emission electron microscopy, and transmission electron microscopy. All the experiments are performed for the control and the test samples. The developed nanocomposites exhibit maximum tensile strength of 6.30 MPa with a water sorption of 6.08% for a 24 h of water immersion tests. On the other hand, the soil‐burial degradation reflects a maximum weight loss of 45.4% after 56 days of degradation period. Hence, moderately hydrophobic, low strength, biodegradable hybrid nanocomposites are developed to counter the use of non‐degradable plastic composites. [ABSTRACT FROM AUTHOR]

Water quality is deteriorating continuously as increasing levels of toxic inorganic and organic contaminants mostly discharging into the aquatic environment. Removal of such pollutants from the water system is an emerging research area. During the past few years use of biodegradable and biocompatible natural additives has attracted considerable attention to alleviate pollutants from wastewater. The chitosan and its composites emerged as a promising adsorbents due to their low price, abundance, amino, and hydroxyl groups, as well as their potential to remove various toxins from wastewater. However, a few challenges associated with its practical use include lack of selectivity, low mechanical strength, and solubility in acidic medium. Therefore, several approaches for modification have been explored to improve the physicochemical properties of chitosan for wastewater treatment. Chitosan nanocomposites found effective for the removal of metals, pharmaceuticals, pesticides, microplastics from the wastewaters. Nanoparticle doped with chitosan in the form of nano-biocomposites has recently gained much attention and proven a successful tool for water purification. Hence, applying chitosan-based adsorbents with numerous modifications is a cutting-edge approach to eliminating toxic pollutants from aquatic systems with the global aim of making potable water available worldwide. This review presents an overview of distinct materials and methods for developing novel chitosan-based nanocomposites for wastewater treatment. • Chitosan a bio-sorbent play an important role in wastewater treatment. • Nanocomposites reduce wastewater pollutants with wider applications. • Nanocomposites affect the metal sorption properties during wastewater treatment. • Chitosan showed potential adsorption in the removal of toxic chemicals. [ABSTRACT FROM AUTHOR]

Population growth and industrialization is associated with the elevation of hazardous pollutants, including heavy metals, biomedical wastes, personal-care products, endocrine-disrupters, pharmaceutically active compounds, and colorants in the environment. The scientific focus has been devoted to developing novel adsorbents to mitigate hazardous pollutants by constructing hybrids of different polymers and nano-structured materials for improved workability and physicochemical attributes. Recently, much attention has been devoted to nanomaterials in environmental remediation, owning to their exceptional characteristics including novel electrical/chemical features, quantum size effects, tunable functionalization, high scalability, and surface-area-to-volume ratio. Target-specific designing of nanocomposites impart high functionality. The cost-effective and eco-friendly synthesis of bioadsorbent materials is increasing for the removal of hazardous pollutants. Due to biocompatible, biodegradable, and eco-friendly nature, sodium alginate has been widely reported for the preparation of bioadsorbent materials to remove different inorganic/organic pollutants. In this review, the potentialities of alginate-based nanocomposites have been described for environmental remediation purposes. Different nanomaterials, including silica, metallic oxide, graphene oxide, hybrid inorganic-organic, non-magnetic-magnetic, carbon nanorods, nanotubes, polymeric nanocarriers, and several other materials have been described in combination with alginate biopolymer for environmental remediation. [Display omitted] • Alginate-based nano-adsorbent materials to remediate pollutants are reviewed. • Recalcitrant pollutants present a serious threat to environmental sustainability. • Various nanohybrids-assisted remediation approaches are given for pollutants. [ABSTRACT FROM AUTHOR]