A Comparative Study on Responses of Soil under Three Typical Nanoparticles Exposure: Enzyme Activities and Microbial Community Structure

Increasing consumption of nanoparticles (NPs) led to their accumulation in environment like soil, causing public anxiety to their hazards. In this study, dynamic impacts of three NPs (silver (Ag), zinc oxide (ZnO), and fullerene (C 60 )), and their derivatives on soil were evaluated along time. Different influences caused by category and concentration were also compared. As results demonstrated, Ag NPs and Ag + brought more evident toxicity on soil enzymes than others, in which dehydrogenase exerted the most sensitivity. Such stress to enzymes was dose-dependent in groups of Ag NPs, Ag + , and C 60 OH. Two-way ANOVA reveled the interaction of concentration and category on enzymes between different groups. More significant reduction of bacterial density and alterations of bacteria community were observed with Ag NPs treatment. Nitrogen transformation was suppressed by various NPs, via inhibition on related bacteria including Flavobacterium and Nitrospira . Existence of time effect on bacteria was also confirmed. In brief, metal NPs and their dissolved ions could pose stronger threats to soil microenvironment compared to metal oxide and carbon-based NPs, and their derivatives. These results provide comprehensive evidence for effects of NPs on soil, which could generate new leads on secure application of them.