摘要
采用自主构建的平面光极技术(PO),以凹凸棒石黏土钝化土壤-根系微界面为研究对象,精细刻画土壤-根系微界面pH值和O_(2)的同步变化特征.研究结果首次直观和定量证实,不同钝化土壤剖面pH值和O_(2)在毫米尺度呈高度的空间异质性并具有显著的差异(P<0.01).添加凹凸棒石黏土使土壤pH值升高但对O_(2)微环境影响不显著,钝化土壤-根系2~5mm范围内pH值降低0.31~0.87个单位,而O_(2)含量增加至58.56~82.01μmol/L,靠近根基部位为根系分泌有机酸和O_(2)的热点区域,与CK相比,中、高Cd污染钝化土壤-根系微界面酸化和释氧能力较强,在一定程度上会促进钝化Cd的再活化和水稻根系的吸收.
Herein two self-established planar optode methods(PO)were successfully deployed to in situ,high-resolution investigate the fine-scale and simultaneous variations of micro-environmental conditions e.g.pH and O_(2) across the passivated soil-root interfaces.For the first time,our results quantitatively and directly revealed the high degrees of spatiotemporal heterogeneity of pH and O_(2) throughout the rhizosphere at the sub-mm scale.Significant differences(P<0.01)among three Cd treatments were observed.The addition of the attapulgite clays significant elevated the pH micro-environemnts,but had slight effects on the micro-distributions of O_(2) within the soil profiles.There was a visible and distinct range of 2~5mm surrounding the rice roots where pH values were generally decreased by 0.31~0.87 and O_(2) concentrations were increased to 58.56~82.01μmol/L.Notably higher rhizosphere acidification and O_(2) leakage always occurred locally around the basal roots.The higher abilities of rhizosphere acidification and O_(2) leakage within the passivated soil-root micro interfaces would potentially promote the reactivation and root uptake of passivated Cd.
作者
任静华
范健
孙宇
廖启林
许伟伟
刘玲
韩超
顾雪元
REN Jing-hua;FAN Jian;SUN Yu;LIAO Qi-lin;XU Wei-wei;LIU Ling;HAN Chao;GU Xue-yuan(Technology Innovation Center for Ecological Monitoring&Restoration Project on Land(arable),Ministry of Natural Resources,Geological Survey of Jiangsu Province,Nanjing 210018,China;State Key Laboratory of Science and Environment,Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,Nanjing 210008,China;State Key Laboratory of Pollution Control and Resource Reuse,School of the Environment,Nanjing University,Nanjing 210023,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2023年第4期1782-1790,共9页
China Environmental Science
基金
国家自然科学基金资助项目(41907141)
江苏省自然科学基金资助项目(BK20171075)
污染控制与资源化研究国家重点实验室开放基金资助项目(PCRRF20034)。
