Nanoparticles and nanomaterials have gained a huge amount of attention in the last decade due to their unique and remarkable properties. Metallic nanoparticles like zinc oxide nanoparticles (ZnONPs) have been used very widely as plant nutrients and in wastewater treatment. Here, ZnONPs were synthesized by using onion peel and characterized by various sophisticated instruments like Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), and field emission scanning electron microscopes (FESEM). FTIR confirmed ZnONPs synthesis due to the formation of the band in the region of 400–800 cm⁻¹, while FESEM confirmed the spherical shape of the particles whose size varies in the range of 20–80 nm. FTIR revealed several bands from 1000–1800 cm⁻¹ which indicates the capping by the organic molecules on the ZnONPs, which came from onion peel. It also has carbonyl and hydroxyl groups, due to the organic molecules present in the Allium cepa peel waste. The average hydrodynamic size of ZnONPs was 500 nm as confirmed by DLS. The synthesized ZnONPs were then used as a plant nutrient where their effect was evaluated on the growth of Vigna radiate (mung bean) and Triticum aestivum (wheat seeds). The results revealed that the germination and seedling of mung and wheat seeds with ZnONPs were grown better than the control seed. However, seeds of mung and wheat with ZnONPs at median concentration exposure showed an enhancement in percent germination, root, and shoot length in comparison to control. Thus, the effect of ZnONPs has been proved as a nano-based nutrient source for agricultural purposes.

The growing global need for uncontaminated water in the face of escalating pollution levels has emphasized the urgent requirement for efficient wastewater treatment. This comprehensive review explores advanced techniques in wastewater treatment, addressing the necessity for effective wastewater management due to increasing water scarcity and pollution from various sources such as households, industries, and agriculture. Despite their widespread use, conventional wastewater treatment methods frequently fail to adequately address complex and emergent contaminants. This review covers innovative approaches such as membrane filtration processes, advanced oxidation processes (AOPs), electrochemical treatments, and adsorption using novel materials such as carbon nanotubes. These advanced techniques demonstrate superior capabilities in removing complex contaminants including metals, organic and inorganic chemicals, and pathogens. It also highlights the environmental benefits and potential for resource recovery and conservation offered by these advanced methods. Furthermore it underscores the potential of these advanced techniques to improve treatment efficiency, reduce operational costs, and achieve higher water quality standards, thereby contributing to sustainable water management practices.

A bacterial strain AST2.2 with chlorpyrifos degrading ability was isolated by enrichment technique from apple orchard soil with previous history of chlorpyrifos use. Based on the morphological, biochemical tests and 16S rRNA sequence analysis, AST2.2 strain was identified as Pseudomonas resinovarans. The strain AST2.2 utilized chlorpyrifos as the sole source of carbon and energy. This strain exhibited growth upto 400mg/l concentration of chlorpyrifos and exhibited high extracellular organophosphorus hydrolase (OPH) activity. Gas chromatography-flame ionization detector (GC-FID) studies revealed that Pseudomonas resinovarans AST2.2 degraded 43.90 % of chlorpyrifos (400 mg/l) within 96 hrs. Intermediates of chlorpyrifos degradation were identified using GC-MS. This strain have potential to degrade chlorpyrifos and thus can be used for bioremediation and ecological restoration of sites contaminated with chlorpyrifos

Anish Kumar Sharma and Jyotsana Pandit. Microbiol. Biotechnol. Lett. 2023;51:374-89. https://doi.org/10.48022/mbl.2308.08011