Effects of flooding and ferrhydrite on copper fractionation in paddy soil
Chemical fraction plays an influential role in solubility and potential bioavaitability of heavy metals in soils.Seasonally flooding and iron reduction are significant environmental processes of paddy soil.They may influence the fractionation of cooper (Cu) in paddy soil.In this study,an anaerobic incubation experiment was conducted to simulate the anaerobic environment of flooded paddy soil.The fractionations of native and spiked Cu in paddy soil were determined using a modified sequential extraction procedure (SEP) method.Thc effects of flooding time on Cu fractions were determined.The effects of ferrihydrite on Cu fractions were also investigated to understand the interaction between Cu contamination and iron reduction process.The results showed that the native Cu in soil were most in the residual and organic matter fractions,but the more available fractions,such as,the exchangeable and carbonates fractions occupied only a little proportion.After flooding,the native Cu in soil released from organic matter fraction and crystalloid ferric oxides fraction,and transferred to the easy extracted fractions,such as,amorphous ferric oxides,carbonates and exchangeable fractions.The spiked Cu was easily absorbed by carbonates and organic matter in soil,but after flooding,the two fractions transferred into ferric oxides fraction,especially amorphous ferric oxides fraction.Similar phenomena were observed after adding ferrihydrite in soil except for the disposal of added 400mg/kg Cu.The process of iron reduction was inhibited significantly by Cu contamination and the inhibition of Cu contamination to iron reduction decreased after adding ferrihydrite.The transformation of Cu fractions had significant relation to the process of iron anaerobic reduction in paddy soil.
Paddy soil Copper fractionation Ferrihydrite Flooding Iron reduction
Beibei Liu Dong Qu Xin Chen Qinfen Li Lixu Peng
Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haiko College of Resources and Environment, Northwest A&F University, Yangling 712100, China
国际会议
2013 International Symposium on Environmental Science and Technology(2013环境科学与技术国际会议)
大连
英文
107-112
2013-06-04（万方平台首次上网日期，不代表论文的发表时间）