Enhancing chromium removal and recovery from industrial wastewater using sustainable and efficient nanomaterial: A review.

Water contamination can be detrimental to the human health due to higher concentration of carcinogenic heavy metals such as chromium (Cr) in the wastewater. Many traditional methods are being employed in wastewater treatment plants for Cr removal to control the environmental impacts. Such methods include ion exchange, coagulation, membrane filtration, and chemical precipitation and microbial degradation. Recent advances in materials science and green chemistry have led to the development of nanomaterial that possess high specific surface areas and multiple functions, making them suitable for removing metals such as Cr from wastewater. Literature shows that the most efficient, effective, clean, and long-lasting approach for removing heavy metals from wastewater involves adsorbing heavy metals onto the surface of nanomaterial. This review assesses the removal methods of Cr from wastewater, advantages and disadvantages of using nanomaterial to remove Cr from wastewater and potential negative impacts on human health. The latest trends and developments in Cr removal strategies using nanomaterial adsorption are also explored in the present review.

Poly Lactic-Co-Glycolic Acid Nano-Carriers for Encapsulation and Controlled Release of Hydrophobic Drug to Enhance the Bioavailability and Antimicrobial Properties.

This study focusses on the fabrication of nano-carriers for delivery of ciprofloxacin through the nanoprecipitation process. This was done to examine the release of drug at the pH of stomach to find out the antibacterial action of ciprofloxacin loaded nanoparticles (NPs). Prepared NPs were characterized by Fourier Transform Infra-Red (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), and particle size analyzer (PSA) techniques. Drug yield, loading, and sustained release was studied as function of time (up to 8 h). Antibacterial activity of ciprofloxacin loaded NPs were also determined against different gram-positive and gram-negative bacteria. Results revealed that nanoprecipitation is a suitable method for encapsulation of ciprofloxacin in poly(lactic-co-glycolic acid) PLGA NPs. The drug yield and drug loading were found to be 60%. The size range of NPs observed by PSA was in the range of 5.03-6.60 nm. It can be concluded that nanoformulation of ciprofloxacin loaded PLGA NPs can be used in stomach for longer period of time to enhance the bioavailability of the drug.

A novel formulation of triethyl orthoformate mediated durable, smart and antibacterial chitosan cross-linked cellulose fabrics.

Antibacterial, durable and smart cotton fabrics was developed using chitosan-based formulation. The cellulose was covalently cross-linked with chitosan using TEOF. The antibacterial activity of prepared smart fabrics and CS was studied against S. aureus and E. coli strains. The FTIR, SEM and XRD were employed to confirm the linkage of CS molecules with cellulose in cotton fabrics. The CS of 160 KDa extracted from shrimp shell showed the optimum antibacterial activity. The prominent asymmetric, symmetric alkyl CH peaks of CS were shifted to 2930 and 2845 (cm-1), respectively. Moreover, the shifted peaks at 1590 and 1400 (cm-1) indicate the CO stretching and NH2 bending bands of CS, respectively. This confirm the existence of new imine functional group that was generated after cross-linking of NH2 groups of CS. The SEM results showed more uniform morphology of TEOF cross-linked fabrics versus CS coated fabrics, which revealed a promising microbial growth inhibition activity. The TEOF as a cross-linker has been unveiled, showcasing the effectiveness of this innovative crosslinking approach. The fabric treated with cross-linked CS exhibited remarkable antibacterial properties that endured even after undergoing 30 washing cycles. These antibacterial textiles possess substantial commercial potential across a diverse range of industries.

Enhancing growth and lipid production of marine microalgae for biodiesel production via the use of different LED wavelengths.

Wavelength of light is a crucial factor which renders microalgae as the potential biodiesel. In this study, Tetraselmis sp. and Nannochloropsis sp. as famous targets were selected. The effect of different light wavelengths on growth rate and lipid production was studied. Microalgae were cultivated for 14 days as under blue, red, red-blue LED and white fluorescent light. The growth rate of microalgae was analyzed by spectrophotometer and cell counting while oil production under improved Nile red method. Optical density result showed the microalgae exhibited better growth curve under blue wavelength. Besides, Tetraselmis sp. and Nannochloropsis sp. under blue wavelength showed the higher growth rate (1.47 and 1.64 day(-1)) and oil production (102.954 and 702.366 a.u.). Gas chromatography analysis also showed that palmitic acid and stearic acid which were compulsory components for biodiesel contribute around 49-51% of total FAME from Nannochloropsis sp. and 81-83% of total FAME from Tetraselmis sp.

Immobilized Candida antarctica lipase B: Hydration, stripping off and application in ring opening polyester synthesis.

This work reviews the stripping off, role of water molecules in activity, and flexibility of immobilized Candida antarctica lipase B (CALB). Employment of CALB in ring opening polyester synthesis emphasizing on a polylactide is discussed in detail. Execution of enzymes in place of inorganic catalysts is the most green alternative for sustainable and environment friendly synthesis of products on an industrial scale. Robust immobilization and consequently performance of enzyme is the essential objective of enzyme application in industry. Water bound to the surface of an enzyme (contact class of water molecules) is inevitable for enzyme performance; it controls enzyme dynamics via flexibility changes and has intensive influence on enzyme activity. The value of pH during immobilization of CALB plays a critical role in fixing the active conformation of an enzyme. Comprehensive selection of support and protocol can develop a robust immobilized enzyme thus enhancing its performance. Organic solvents with a log P value higher than four are more suitable for enzymatic catalysis as these solvents tend to strip away very little of the enzyme surface bound water molecules. Alternatively ionic liquid can work as a more promising reaction media. Covalent immobilization is an exclusively reliable technique to circumvent the leaching of enzymes and to enhance stability. Activated polystyrene nanoparticles can prove to be a practical and economical support for chemical immobilization of CALB. In order to reduce the E-factor for the synthesis of biodegradable polymers; enzymatic ring opening polyester synthesis (eROPS) of cyclic monomers is a more sensible route for polyester synthesis. Synergies obtained from ionic liquids and immobilized enzyme can be much effective eROPS.