不同施肥处理对水稻根表铁和砷形态的影响  

CHARACTERISTICS OF Fe AND As IN THE RICE RHIZOSPHERE WITH DIFFERENT FERTILIZER AMENDMENTS

作　　者：陈学萍[1] 朱永官[1] 洪米娜[2] 王新军[1] Gault A G Charnock J M Polya D A 

机构地区：[1]中国科学院生态环境研究中心区域与城市生态国家重点实验室土壤环境实验室,北京100080 [2]华南农业大学资源环境学院植物营养系,广州510642 [3]School of Earth,Atmospheric and Environmental Sciencesand Williamson Research Cemrefor Molecular Environmental Science,University of Manchester,Oxford Road,Manchester,M139PL,UK [4]CCLRC Daresbury Laboratory,Daresbuu,Warringon,WA44AD,UK

出　　处：《环境化学》2008年第2期231-234,共4页Environmental Chemistry

摘　　要：采用XAFS研究盆栽试验砷污染土壤中添加不同肥料后,苗期水稻根表铁膜和砷的矿物学特征.Fe的K边EXAFS谱表明,铁膜主要由2-line水铁矿组成,还有少部分针铁矿和赤铁矿等晶体矿;As的EX-AFS谱显示,除了KNO3和K2SO4处理外,其余处理的铁膜中砷以三价砷为主.KNO3处理显著减少了水稻根表铁膜的形成,而且抑制了水稻对砷的吸收.不同的肥料可以影响铁膜中砷的存在形态.A pot experiment was carried out to investigate the mineral charactensucs of iron plaque ann accumulation and speciation of arsenic in rice （Oryza sativa L）, which were cultivated in the arsenic polluted soil with different treatments of fertilizers, via X-ray absorption near-edge structure （XANES）spectra and extended X-ray absorption fine structure（EXAFS） . The Fe K-edge EXAFS spectra indicated that the iron plaque was dominated by（oxyhydr） oxides, which were composed of 2-line ferrihydrite, with small proportion of goethite and hematite on the root surface. The EXAFS spectra of As showed that the speciation of arsenic in iron plaque was sequestered mainly with amorphous and crystalline iron （ oxyhydr ） oxides, and that arsenite was the predominant speciation except for the treatments of KNO3 and K2 SO4 amendments, in which As （ V ） was dominating speciation. Furthermore, we found that KNO3 addition significantly decreased iron plaque formation on the root surface, and inhibited As uptaken by rice.

关 键 词：X-射线吸收近边结构(XANES) X-射线吸收精细结构(XAFS) 水稻 铁膜 砷 肥料 

分 类 号：X173[环境科学与工程—环境科学]