Impacts of molybdenum-, nickel-, and lithium- oxide nanomaterials on soil activity and microbial community structure.

The nano forms of the metals molybdenum oxide (MoO3 ), nickel oxide (NiO) and lithium oxide (Li2 O) are finding wide application in advanced technologies including batteries and fuel cells. We evaluated soil responses to nanoMoO3 , nanoNiO, and nanoLi2 O as some environmental release of the materials, either directly or following the land application of biosolids, is expected. Using Drummer soil (Fine-silty, mixed, superactive, mesic Typic Endoaquolls), we evaluated the impacts of the three nanometals on soil gas (N2 O, CH4 , and CO2 ) emissions, enzyme activities (β-glucosidase and urease), and microbial community structure (bacterial, archaeal, and eukaryal) in a 60 day microcosms incubation. Soil treated with nanoLi2 O at 474 μg Li/g soil, released 3.45 times more CO2 with respect to the control. Additionally, β-glucosidase activity was decreased while urease activity increased following nanoLi2 O treatment. While no clear patterns were observed for gas emissions in soils exposed to nanoMoO3 and nanoNiO, we observed a temporary suppression of β-glucosidase activity in soil treated with either metal. All three domains of microbial community were affected by increasing metal concentrations. This is the first evaluation of soil responses to nanoMoO3 , nanoNiO, or nanoLi2 O.