To study the stability of NPs in thewater, 50 nmand 100 nmcitratecapped
AgNPs and 60 nm 100 nmtannic-capped AuNPs were spiked in
the filtered natural water and effluent water respectively, and the NPs
were investigated during a ten-day incubation period. The average diameters
of AgNPs and AuNPs after first day were presented in the
Table 7. Table SI-3 showed particle number concentration recoveries
of AuNPs and AgNPs spiked into filtered HuNan University effluent
and Xiangjiang River after first day.