Removal of Pb ions using green Co3O4 nanoparticles: Simulation, modeling, adsorption, and biological studies.

Chemical co-precipitation synthesized novel and green cobalt-oxide nanoparticles (Co3O4-NPs) utilizing cobalt nitrate as cobalt precursors. FTIR, Raman, scanning electron microscopy, UV visible, X-ray powder diffraction, and BET was used to analyze the surface characteristics, composition, and morphology, of the NPs. These green Co3O4-NPs were employed to remove Pb ions from simulated wastewater solutions at various pH, adsorbate, temperature, and dose concentrations. At dose 20 mg/L, pH 6.0, 20 mg/L (Pb(II) solution, 25 °C of temperature, and 45 min for equilibrium, nearly 99.44% of Pb ions were removed. To evaluate the kinetic data, four different kinetic equations were used. The data fit the Elovich rate equation better than the other three models. Thermodynamic and isothermal studies were also evaluated, and the maximum adsorption capacity of 450.45 mg/g was observed at 298.15 K. 0.1 M HNO3, and 0.1 HCl were used to regenerate used Co3O4-NPs. Simulation results show the strong correlation of the Co atom in the Co3O4-NPs generates active delocalized surface states, which are energetically most favorable for heavy metal (Pb ions) adsorption and removal, supporting the experimental outcomes. In concluding remarks, green Co3O4-NPs can also be used as an adsorbent to remove Pb ions from wastewater bodies.

Persistence and remote sensing of agri-food wastes in the environment: Current state and perspectives.

Food demand is expected to increase globally by 60-110% from 2005 to 2050 due to diet shifts and population growth. This growth in food demand leads to the generation of enormous agri-food wastes (AFWs), which could be classified into pre-consumption and post-consumption. The AFW represents economic losses for all stakeholders along food supply chains, including consumers. It is reported that the direct financial, social, and environmental costs of food waste are 1, 0.9, and 0.7 trillion USD/year, respectively. Diverse conventional AFW management approaches are employed at the different life cycle levels (entre supply chain). The review indicates that inadequate transportation, erroneous packaging, improper storage, losses during processing, contamination, issues with handling, and expiry dates are the main reason for the generation of AFWs in the supply chain. Further, various variables such as cultural, societal, personal, and behavioral factors contribute to the AFW generation. The selection of a specific valorization technology is based on multiple physicochemical and biological parameters. Furthermore, other factors like heterogeneity of the AFWs, preferable energy carriers, by-products management, cost, end-usage applications, and environmental legislative and disposal processes also play a crucial role in adopting suitable technology. Valorization of AFW could significantly impact both economy and the environment. AFWs have been widely investigated for the development of engineered added-value biomaterials and renewable energy production. Considering this, this study has been carried out to highlight the significance of AFW cost, aggregation, quantification, and membrane-based strategies for its management. The study also explored the satellite remote sensing data for Spatio-temporal monitoring, mapping, optimization, and management of AFW management. Along with this, the study also explained the most recent strategies for AFW valorization and outlined the detailed policy recommendation along with opportunities and challenges. The review suggested that AFW should be managed using a triple-bottom-line strategy (economic, social, and environmental sustainability).