Metallic nanoparticles photodegraded antibiotics and co-application improved wheat growth and nutritional quality...

Antibiotics are now considered as emerging environmental pollutants due to their persistent nature and continuous exposure through irrigation with wastewater contaminated with antibiotics. The aim of present study was to assess the potential of nanoparticles for the photodegradation of antibiotics and subsequent stress alleviation via Titania oxide (TiO₂) application for improvement in crop productivity and quality in terms of the nutritional composition. In the first phase, different nanoparticles, TiO₂, Zinc oxide (ZnO), and Iron oxide (Fe₂O₃) with varying concentrations (40-60 mg L^-1) and time-periods (1-9 days) were tested to degrade amoxicillin (Amx) and levofloxacin (Lev) @ 5 mg L^-1 under the visible light. Results indicated that TiO₂ nanoparticles (50 mg L^-1) were the most effective nanoparticles for the removal of both antibiotics with maximum degradation of 65% and 56% for Amx and Lev, respectively, on the 7th day. In the second phase, a pot experiment was conducted in which TiO₂ (50 mg L^-1) was applied individually and along with antibiotics (5 mg L^-1) in order to evaluate the effect of nanoparticles on stress alleviation for growth promotion of wheat exposed to antibiotics. Plant biomass was reduced by Amx (58.7%) and Lev (68.4%) significantly (p < 0.05) when compared to the control. However, co-application of TiO₂ and antibiotics improved the total iron (34.9% and 42%), carbohydrate (33% and 31%), and protein content (36% and 33%) in grains under Amx and Lev stress, respectively. The highest plant length, grain weight, and nutrient uptake were observed upon application of TiO₂ nanoparticles alone. Total iron, carbohydrates, and proteins in grains were significantly increased by 52%, 38.5%, and 40%, respectively compared to the control (with antibiotics). The findings highlight the potential of TiO₂ nanoparticles for stress alleviation, growth, and nutritional improvement under antibiotic stress upon irrigation with contaminated wastewater.