Efficient Removal of Lead from Washing Effluent of Lead-contaminated Soil with Garlic Peel

Garlic peel as promising low-cost support for the cobalt nanocatalyst; synthesis and catalytic studies

The development of cost-effective and applied catalysts for organic pollutants degradation is the cornerstone for the future valorizations of these hazardous wastes. Garlic peel was employed as solid support for the assembly of cobalt nanoparticles and was further applied for the catalytic degradation of 4-nitrophenol, bromophenol blue, and a mixture of both. A Cobalt@garlic peel nanocomposite with the morphology of semi-spherical and randomly distributed nanoparticles was prepared without the aid of any hazardous chemicals. The functional groups facilitated the adsorption of cobalt ions onto the surface of garlic peel through van der Waals forces and/or hydrogen bonds. The catalytic experiments were carried out under different operational parameters including pollutant concentration, catalytic dosage, and pH value to identify the optimal conditions for the model solutions. The results showed that the optimal pH for 4-nitrophenol degradation was around 9 and the maximum rate constant 4.56 × 10^-3 sec^-1. The most prominent feature of the proposed catalyst is the easy/efficient recovery and recycling of the nanoparticles from the reacting medium. This work provided a simple method for designing other similar biomass-stabilized nanocatalysts which might sharply reduce the catalytic treatment costs and broaden the scope of applications.

Development of multifunctional food packaging films based on waste Garlic peel extract and Chitosan

A sustainable multifunctional food packaging composite film containing waste garlic peel extract (GPE) and Chitosan (CH) was prepared. This film exhibited antimicrobial potential towards Staphylococcus aureus and Klebsiella pneumoniae. GPE/CH films' morphological, physical, and functional properties were compared to those of CH film. Fourier transform infrared showed the interactions through hydrogen bonding between CH and GPE in the blends that improved the polymers' compatibility. Furthermore, X-ray diffraction analysis validated the compatibility between GPE and CH. GPE/CH films exhibited higher thickness and moisture content than the CH film. Remarkably, GPE/CH films showed lower water vapor barrier properties and higher ultra-violet protection and mechanical strength than CH film. Compact surfaces of the GPE infused CH films were unveiled through Scanning electron microscopy. GPE/CH film showed improved thermal stability after the addition of GPE. MTT method's cytotoxicity study manifested that the GPE/CH films are antioxidant and non-cytotoxic, implicating their biocompatibility and non-toxicity. The results suggest that GPE/CH films can find widespread commercial applications like food packaging materials, replacing the commonly used petrochemical plastics.

Biosorption of tungstate onto garlic peel loaded with Fe(III), Ce(III), and Ti(IV)

In present study, garlic peel (GP) was modified by loading with Fe(III), Ti(IV), and Ce(III) through a cation exchange process, i.e., nGP-COOH + Mn+ = (nGP-COO)-Mn+ + nH+ (M = Fe, Ce, Ti), which could adsorb tungstate effectively under the weakly acidic conditions. The optimal initial pH for maximum adsorption of W(VI) was determined at 1~3 for Ti-GP, 1~4 for Fe-GP, and 3 for Ce-GP, respectively; and at pH 2.5, the corresponding maximum adsorption capacity for Fe-GP, Ti-GP, and Ce-GP was evaluated as 91.5 mg/g, 83 mg/g, and 84 mg/g tungsten respectively. Coexisting anions like chloride, sulfate, and carbonate showed little effect on tungsten adsorption, while fluoride and phosphate inhibited the adsorption drastically. The column adsorption showed that the breakthrough point for Ce-GP, Ti-GP, and Fe-GP was 180 min, 200 min, and 270 min respectively. And 0.1 mol/L NaOH effectively eluted the adsorbed tungsten, and concentration of the eluted solution had almost 6, 19.9, and 22 factors of the initial tungstate concentration correspondingly.