文章基本信息

标题：PHYTOTOXIC EFFECTS OF TiO_2-NPs IN TWO MACROPHYTES FOR CONSTRUCTED WETLANDS
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作者：Shuangxi Wen ; Mi Xiao ; Mian Li 等
期刊名称：Fresenius Environmental Bulletin
印刷版ISSN：1018-4619
出版年度：2019
卷号：28
期号：9
页码：6733-6743
语种：English
出版社：PSP Publishing
摘要：This study aimed to investigate nanometer titania (TiO_2-NPs) toxicity in two species of plants commonly used in constructed wetlands: Cera- tophyllum demersum and Phragmites australis. The seed germination, plantlet development and physiology were evaluated by exposure experiments. Moreover, Ti distribution and accumulation were determined through TEM-EDX and ICP-MS measurement. Results showed no significant differences in germination rates among plant seeds treated with low-level (≤ 500 mg L~(-1)) TiO_2-NPs. By contrast, exposure to high-level (≥1000 mg L~(-1)) TiO_2-NPs showed different results, the germination rates and seedling masse for Ceratophyllum demersum or Phragmites australis seeds decreased obviously to 30% and 0.77 g or 31.67% and 0.36 g, respectively, when the seeds were exposed to 2000 mg L~(-1) TiO_2- NPs for 6 d. The growth of Ceratophyllum demer- sum and Phragmites australis was inhibited during the TiO_2-NPs exposure to the plants. TiO_2-NPs displayed phytotoxicity with reduced chlorophyll contents increased Superoxide Dismutase (SOD) activity, and Malondialdehyde (MDA) contents in both plant species. TiO_2-NPs could enter into the Ceratophyllum demersum and Phragmites australis, and higher concentration could result in more entrance. However, it was difficult for TiO_2-NPs to transfer from Phragmites australis roots to stems and leaves. Ti accumulation reached 866 and 829 µg g~(-1) d.wt. in Ceratophyllum demersum and Phragmites australis roots, respectively. By contrast, only 28µg g~(-1) d.wt of Ti was translocated to the Phragmites australis stems, and no Ti was detected in Phragmites australis leaves during 12 d of treatment.
关键词：TiO_2 nanoparticles;phytotoxicity;Ceratophyllum demersum;Phragmites australis;accumulation