生态与农村环境学报 ›› 2016, Vol. 32 ›› Issue (4): 675-681.doi: 10.11934/j.issn.1673-4831.2016.04.025

• 污染控制与修复 • 上一篇    下一篇

水稻秸秆腐解液对水稻根部吸收纳米银(AgNP)速率的影响

李敏1,2, 宋吟玲1, 党菲2, 王玉军2, 周东美2   

  1. 1. 苏州科技大学环境科学与工程学院, 江苏 苏州 215009;
    2. 中国科学院南京土壤研究所土壤环境与污染修复重点实验室, 江苏 南京 210008
  • 收稿日期:2015-10-21 出版日期:2016-07-25 发布日期:2016-07-26
  • 通讯作者: 宋吟玲 E-mail:yinling-song@hotmail.com;党菲 E-mail:fdang@issas.ac.cn E-mail:yinling-song@hotmail.com;fdang@issas.ac.cn
  • 作者简介:李敏(1989-),女,山东莱芜人,硕士生,主要从事重金属对植物的生物有效性研究。E-mail:molulimin@163.com
  • 基金资助:

    国家自然科学基金重点项目(41430752)

Effect of Decomposed Rice Straw Solution on AgNP Uptake by Rice Roots

LI Min1,2, SONG Yin-ling1, DANG Fei2, WANG Yu-jun2, ZHOU Dong-mei2   

  1. 1. College of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China;
    2. Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
  • Received:2015-10-21 Online:2016-07-25 Published:2016-07-26

摘要:

以水稻秸秆腐解液作为有机质加入纳米银(AgNP)体系中,考察总有机碳(TOC)浓度和分子量组分对水稻根部吸收AgNP速率的影响。结果表明,当ρ(TOC)为0~20 mg·L-1时,水稻根部对AgNP的吸收速率随TOC浓度的升高呈线性降低;当ρ(TOC)达20~80 mg·L-1时,水稻根部对AgNP的吸收速率趋于稳定。溶液中AgNP的动力学过程表明,水稻秸秆腐解液抑制了AgNP溶出的过程,不同TOC浓度处理组ρ(Ag+)比对照降低27.5%~95.5%,且ρ(TOC)越高,溶液中Ag+浓度越低。水稻秸秆腐解液能促进AgNP颗粒的团聚,增大AgNP颗粒尺度,使AgNP不易被水稻吸收。水稻秸秆腐解液的不同分子量组分也会影响水稻根部对AgNP的吸收速率,且低分子量组分(<3 kDa)和未超滤的对照组水稻秸秆腐解液对水稻根部吸收AgNP速率的影响相近,说明低分子量组分对水稻根部吸收AgNP起重要作用。

关键词: 纳米银, 水稻秸秆腐解液, 吸收速率, 溶解, 团聚

Abstract:

Decomposed rice straw solution was used as amendment of organic matter to investigate effects of natural organic matter (NOM) on AgNP phyto-availability. AgNP uptake rate decreased with increasing levels of total organic carbon (TOC, 0-20 mg·L-1) and then tended to level off when TOC rose beyond 20 mg·L-1 till 80 mg·L-1 in concentration. Analysis of the dynamic process of AgNP in the solution demonstrates that dissolution of AgNP was inhibited by NOM and decreased by 27.5%-95.5% in a dose-dependent manner as against the CK. Obviously the amendment of NOM leads to a reduction of the concentration of silver ion dissolved in the exposure medium and consequently a lower AgNP uptake rate of the crop. Meanwhile, the NOM tended to promote aggregation of AgNP, thus expanding the size of AgNP particles, and making them hard to be absorbed by rice. In addition, composition of NOM in molecular weight would also affect AgNP uptake. NOM low in molecular weight (<3 kDa) was found to have an effect on AgNP uptake comparable to that the pristine NOM did, indicating that the fraction of low molecular weight NOM plays an important role in AgNP uptake by rice roots.

Key words: nanosilver, rice straw decomposing solution (NOM), uptake rate, dissolution, aggregation

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