Redox-Ligand Complexation Controlled Chemical Fate of Ceria Nanoparticles in an Agricultural Soil

Abstract

Ceria (CeO) has received much attention in the global nanotechnology market due to its useful industrial applications. Because of its release to the environment, the chemical fate of ceria nanoparticles (NPs) becomes important in protecting the agricultural and food systems. Using experimental biogeochemistry and synchrotron-based X-ray techniques, the fate of ceria NPs (30 and 78 nm) in an agricultural soil (mildly acidic Taccoa entisols) was investigated as a function of exchangeable Ce(III) concentration (0.3 and 1.56 mM/kg in small and large NPs, respectively) under anoxic and oxic conditions. Both ceria NPs strongly adsorbed (>98%) in soils. Under the anoxic condition, the reduction of Ce(IV) was more pronounced in small NPs, whereas the greater concentration of exchangeable Ce(III) in large NPs facilitated the formation of Ce(III) phosphate/oxalate surface precipitates that suppressed the electron transfer reaction. The study shows the importance of redox-ligand complexation controlled chemical fate of ceria NPs in an agricultural soil.

Exposure to nanoceria impacts larval survival, life history traits and fecundity of Aedes aegypti

“…However, some studies have noted the modification of plant nutrient compositions and suggest additional studies into the long-term effects of these particles on the biological environment. Several studies have noted, however, the dissolution of CNPs in soils by organic ligands (redox-active species and moderate acids) [52][53][54][55][56][57] Based on the XPS data, the total amount of silver in AgCNPs is calculated to be 0.22ppb, which is dramatically lower than the required concentration of 4.2ppm in the AgNO 3 positive control (i.e., 2.7ppm free Ag + ) for comparable activity. These data indicate an approximate four orders of magnitude increase in bioactivity for AgCNP over the Ag + positive control.…”

“…However, some studies have noted the modification of plant nutrient compositions and suggest additional studies into the long-term effects of these particles on the biological environment. Several studies have noted, however, the dissolution of CNPs in soils by organic ligands (redox-active species and moderate acids) [ 52 – 57 ]…”

Fuel modification based on some metals compounds and their environmental impact

“…It is of paramount importance for the industry to examine the use of functional fuel additive components that are also compatible with environmental issues. In particular, substances that are persistent in the environment [11], bioaccumulative [12], and toxic may be banned from use (e.g. Stockholm Convention), but they are generated during combustion with additives.…”

Cerium(iv) oxide nanoparticles induce sublethal changes in honeybees after chronic exposure

“…2,4 There are multiple possible routes of nCeO 2 release to the terrestrial environment due to the atmospheric deposition of diesel automobile exhausts, 5 fly ash, 6 and coal fly ash, 7 application of biosolids and sewage sludge to landfills and farmlands, and waste disposal. 2,6,8,9 At the moment there is no information on the realistic background concentrations of nCeO 2 in the environment due to the limitations in separation and analytical methodologies, so modelling predicted environmental concentrations (PECs) is used instead. 1,6 Gottschalk et al modelled 9 NMs in the Danish environment, and the PEC for nCeO 2 in the environmental compartment was 24-1500 ng kg −1 in natural soil, 10-530 ng kg −1 in agricultural soil, and 94-5100 ng kg −1 in sludge-treated soil, while the PEC in the technical compartment was 44-2300 μg kg −1 in sewage treatment sludge and 240-12 000 μg kg −1 in fly ash.…”

“…8 nCeO 2 is considered to persist in soil due to its structural properties and association with soil particles, thus possibly entering the physical and biological cycles. 1,9,10 Once in the soil, nCeO 2 has been shown to be accumulated and translocated to edible tissues of various crops with minimal biotransformation. [11][12][13][14] Due to the high atmospheric deposition of nCeO 2 it is very likely that honeybees may come in contact with nCeO 2 through surface exposure, 1,15 inhalation, 1,15 foraging on contaminated plant resources and water droplets.…”