title: Ageing decreases the phytotoxicity of zero-valent iron nanoparticles in soil cultivated with Oryza sativa.
abstract: This paper was aimed to study the impact of "ageing" (aged in non-saturated soil for 2 and 4 weeks prior to exposure) nanoscale zero-valent iron (nZVI) on the terrestrial plant. The effects of nZVI on Oryza Sativa germination, seedlings growth, chlorophyll biosynthesis, oxidative stress and the activities of antioxidant enzymes at low (250 mg/kg) and high (1000 mg/kg) concentrations were investigated in this study. The results showed that neither the freshly added nor the "ageing" nZVI to the soil had a significant effect on germination, regardless of concentration. At the low concentration, the freshly added nZVI had no visible toxic effects on the rice seedlings growth, but the rice seedlings exhibited obvious toxic symptoms at the high concentration. At the high concentration, toxicity effects of nZVI were reduced after aging with 2 and 4 weeks in soils compared to fresh nZVI, but the "ageing" nZVI continued to significantly inhibit the rice seedlings growth compared with the control, and the inhibition rates of 2 and 4-week-old nZVI were not significantly different. The mechanism of ageing decreased the phytotoxicity of nZVI was due to nZVI particles incomplete oxidation, and some of which had remained in the soil after 4 weeks aged.
authors.affiliation: School of Chemistry and Environment, South China Normal University, Guangzhou, 510006, China.|Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System, Guangzhou, 510006, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.affiliation: School of Chemistry and Environment, South China Normal University, Guangzhou, 510006, China. zhqfang@scnu.edu.cn.|Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System, Guangzhou, 510006, China. zhqfang@scnu.edu.cn.
authors.forename: Zhanqiang
authors.initials: Z
authors.lastname: Fang
authors.affiliation: School of Chemistry and Environment, South China Normal University, Guangzhou, 510006, China. pengyh@scnu.edu.cn.|Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System, Guangzhou, 510006, China. pengyh@scnu.edu.cn.
authors.forename: Wen
authors.initials: W
authors.lastname: Cheng
authors.affiliation: Department of Science and Environmental Studies, The Hong Kong Institute of Education, Hong Kong, 00852, China.
authors.forename: Pokeung Eric
authors.initials: PE
authors.lastname: Tsang
authors.affiliation: Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL, 36849, USA.
authors.forename: Dongye
authors.initials: D
authors.lastname: Zhao
mesh_terms: D052918:Environmental Restoration and Remediation; D018525:Germination; D007501:Iron / Q000737:chemistry / Q000633:toxicity*; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D012275:Oryza / Q000187:drug effects*; D010084:Oxidation-Reduction; D036226:Seedlings; D012987:Soil; D012989:Soil Pollutants / Q000737:chemistry / Q000633:toxicity*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D007501:Iron
keywords: Ageing; Phytotoxicology; Rice; Soil; nZVI