Effective Removal of Carcinogenic Azo Dye from Water Using Zea mays-Derived Mesoporous Activated Carbon.

Addressing industrial wastewater treatment challenges and removing hazardous organic pollutants, such as carcinogenic methyl orange (MO) and azo dyes, is a pressing concern. This study explores the use of the Zea mays envelope, an agricultural waste product, to produce Z. mays activated carbon (ZMAC) through the chemical activation of maize envelopes with phosphoric acid. Various analytical techniques, including FTIR, XRD, TGA, DSC, and SEM, characterize ZMAC. Results show that ZMAC exhibits an impressive monolayer adsorption capacity of 66.2 mg/g for MO. The Langmuir isotherm model fits the experimental data well, indicating monolayer coverage of the MO on the ZMAC surface. The pH-sensitive adsorption process demonstrates an optimal removal efficiency at pH 4. ZMAC follows the pseudo-second-order kinetic model, and diffusion rate constant analysis identifies three consecutive stages in the adsorption process. Moreover, the uptake of MO ions by ZMAC is identified as an exothermic and spontaneous process. Reusability tests demonstrate efficient regeneration of ZMAC up to five times with 1 mL of 2 M HNO3 in each cycle, without sorbent mass loss. Thermodynamic analysis shows an increase in the uptake capacity from 66.2 to 73.2 mg/g with temperature elevation. This study offers practical solutions for industrial wastewater treatment challenges, providing an environmentally sustainable and effective approach to mitigate the risks associated with hazardous organic pollutants.

Silver nanoparticles synthesized by probiotic bacteria and antibacterial role in resistant bacteria.

Many dangerous bacteria have become highly resistant to traditional antibiotics, which is a huge public health concern. This study investigated the use of silver nanoparticles biosynthesized in a culture filtrate of Lactobacillus acidophilus as antimicrobials. UV-visual spectrophotometry, Fourier-transform-infrared spectroscopy, X-ray power diffraction, and scanning electron microscopy have all validated the findings. The biosynthesized nanoparticles ranged in size from 33 to 90 nm. The cytotoxicity of the nanosilver generated was then investigated using nine 200 g BW rats separated into three groups. When compared to the control group, the treated rats showed little signs of toxicity; parameters of physiological function, including alanine transaminase, aspartate aminotransferase, albumin, creatinine, and urea were significantly different in treated and non-treated animals. Moreover, the antibacterial role of the generated silver nanoparticles was examined in multi-drug resistant (MDR) pathogenic bacteria, Proteus vulgaris, Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae, revealing high antibacterial activity against the examined bacteria. For more demonstration of the effect of the nanosilver on transcription and gene regulation of treated and non-treated bacteria differential display droplet digital-PCR was used, and the results revealed that several genes were up- and down-regulated. Some genes were selected for DNA sequencing and according to the sequence analysis, these genes were mecA, beta-lactam, and unidentified protein genes, and these have been deposited in the GenBank Database with the following accession numbers: Staphylococcus MZ748472 and Klebsiella MZ748473. We conclude that silver nanoparticles biosynthesized by L. acidophilus are environmentally friendly and have antibacterial activities against MDR pathogenic bacteria.