Green Silver Nanoparticles for Enhancing the Phytoremediation of Soil and Water Contaminated by Fipronil and Degradation Products

Abstract

Fipronil has been associated with neurotoxicity, carcinogenicity, endocrine disruption, persistence in soil, and low uptake by plants and is a potential groundwater contaminant. Fipronil degradation by silver nanoparticles (AgNPs) from medicinal plant extracts was investigated in spiked water. Also, remediation capacity of soil contaminated by fipronil under the combined application of green AgNPs and phytoremediation was investigated. Brassica-AgNps, Ipomoea-AgNps, Camellia-AgNps, and Plantago-AgNps in water solution significantly reduced fipronil residues by 95.45, 90.15, 63.65, and 63.48%) during 2 days of treatment as compared with 18.42% in untreated water without AgNps. Fipronil amide and fipronil-desulfenyl metabolites were detected in water under the influence of AgNps. The contribution of Brassica-AgNps, Plantago-AgNps, Ipomoea-AgNps, and Camellia-AgNps to the dissipation of fipronil in the soil were 68.8, 54.64, 43.75, and 30.99%, respectively, compared with 10.14% by Plantago major alone through 6 days. Low uptake and translocation of fipronil by P. major roots and leaves were seen in flooded soil alone or under the influence of AgNps within 6 days of treatment. However, the resulting fipronil amide product accumulates in large quantities in P. major roots and leaves. These results show that AgNps and P. major play a major role for the remediation of fipronil contaminated water and in flooded soil, while P. major played an important role for remediation the polar break product, fipronil-amide as phytoremediation.