The application of iron nanoparticles biosynthesized using citrus peel extracts for immobilization of metal-contaminated river sediment

Citrus peels, as inevitable waste product of the citrus processing industry, cause major pollution problems in the environment. These waste products have the potential to produce zero-valent iron nanoparticles, which have been successful in treating different groups of pollutants. Sediment contamination with metals is very challenging in finding effective solution for reducing the contribution of toxicity to the environment. Thus, it is crucial to involve remediation technique as stabilization which includes the addition of inorganic amendments in order to immobilize metals from the sediment. The study demonstrates the issue with Begej sediment that has been contaminated with toxic metals and the possibility of its immobilization using biosynthesized zero-valent iron nanoparticles from citrus peel extracts. Leaching tests are used to demonstrate the benefits and drawbacks of applied treatment for forecasting the behavior of contaminants. The toxicity test, using Vibrio fisheri bacteria, is used to evaluate whether the sediment samples show inhibitory effects. The obtained treated mixtures of sediment and biosynthesized zero-valent iron nanoparticles are determined to be non-hazardous wastes because the concentrations of leached metals (Cu, Cr, Ni and Cd) have fallen below the established maximum values prescribed by German Standard Procedure for Water, Wastewater and Sediment Testing and Toxicity Characteristic Leaching Procedure. Additionally, toxicity test using Vibrio fisheri bacteria has shown that treated sediment is nontoxic. These findings represent promising results in application of zero-valent iron nanoparticles biosynthesized using citrus peel extracts for removal of inorganic pollutants and also create treated sediment for potential further beneficial sustainable use.

Automated summary

Citrus peels as waste from the citrus processing industry cause pollution problems. This study investigates the use of biosynthesized zero-valent iron nanoparticles from citrus peel extracts to treat sediment contaminated with toxic metals. The results show that this method effectively removes metal pollutants and the treated sediment is non-toxic, suggesting further potential for sustainable use.