Oak, mulberry and cherry leaf extract used as reducing agent to produce green nZVI.
SEM and TEM results confirmed the formation nZVIs with size within 10–30 nm.
A green nZVIs was used for As(III) and Cr(VI) removal.
OL-nZVI and ML-nZVI adsorption capacities are higher for As(III) than for Cr(VI).
CH-nZVI adsorption capacity is higher for Cr(VI) than for As(III).