Impact of Silver Nanoparticles in Wastewater on Heavy Metal Transport in Soil and Uptake by Radish Plants

This study was conducted to understand the effect of silver nanoparticles (Ag NPs) on soil mobility and plant uptake of heavy metals present in wastewater irrigation systems. Radish (Raphanus sativus) was grown in pots under controlled environment, irrigated with synthesized wastewater containing various heavy metals, with and without silver nanoparticles. Soil samples were collected at 30, 45, 51, and 56 days after seeding. Radish was harvested on day 57, and different plant parts (peel, flesh, stem, and leaf) were sampled. Presence of silver nanoparticles in wastewater led to increased (p<0.05) uptake of several heavy metals (chromium, copper, iron, lead, and zinc) by different plant parts. However, no significant differences were observed in soil metal concentrations between the two treatments. The results indicate that presence of nanoparticles in wastewater can facilitate heavy metal uptake by wastewater irrigated food crops, and thus pose a potential health risk for humans.