秸秆腐解滤出液对淹水土壤镉形态变化的影响  

Effects of Straw Decomposition Filtrate on Cadmium Speciation in Soil under Flooded Condition

作　　者：赵海岚 李冰 王昌全 何姿懿 龙思帆 王棋 刘奇鑫 ZHAO Hailan;LI Bing;WANG Changquan;HE Ziyi;LONG Sifan;WANG Qi;LIU Qixin(College of Resources,Sichuan Agriculture University,Chengdu 611130,China)

机构地区：[1]四川农业大学资源学院

出　　处：《环境科学与技术》2019年第9期1-6,共6页Environmental Science & Technology

基　　金：国家重点研发计划（2018YFD080041）;四川省科技厅应用基础重大前沿项目（2018JY0002）

摘　　要：该文选取镉(Cd)污染水稻土为研究对象,通过室内培养试验,研究淹水条件下外源添加不同比例的油菜秸秆腐解滤出物对镉形态变化的影响。结果表明,随着淹水培养时间的延长(0~60 d),0.5%、1.0%、2.0%滤出液(分别相当于半量、全量和2倍量秸秆还田)添加下交换态Cd含量呈现先下降后上升的趋势;碳酸盐结合态Cd含量变化规律不明显;铁锰氧化物结合态Cd和有机结合态Cd含量先上升后降低;培养结束后,交换态Cd和碳酸盐结合态Cd分别较对照上升了126.15%~216.37%、26.37%~95.5%,铁锰氧化物结合态Cd和有机结合态Cd分别较对照下降了26.37%~95.5%与4.84%~33.89%,残渣态Cd较对照下降了23.93%~47.22%。秸秆腐解滤出液提升土壤交换态Cd含量的效果随滤液添加量增加而不断增大,但其提升作用主要体现在培养20~60 d间。有效态Cd(交换态Cd和碳酸盐结合态Cd)含量在培养结束后较对照显著上升,不可利用态Cd(残渣态Cd)含量在整个培养期内变化较小,有效态Cd与潜在有效态Cd(铁锰氧化物结合态Cd和有机结合态Cd)之间的相互转化主要体现在交换态与铁锰氧化物结合态、有机结合态之间,有机结合态Cd与交换态Cd含量呈极显著负相关关系。A soil incubation experiment was conducted to study the effects of exogenously added rape straw decomposition filtrate with different proportions on cadmium(Cd) speciation in the cadmium contaminated paddy soil under flooded condition. Results showed that the content of exchangeable Cd tends to be decreased initially and then increased with the prolonged flooding culture time(0~60 d) after adding 0.5%, 1.0% and 2.0% straw decomposition filtrate. The variation of carbonate bonded Cd content was not significant, the content of iron-manganese oxide bonded Cd and organically bonded Cd initially increased and then decreased during the whole incubation period(0~60 d). After the experiment, compared with the reference, the content of exchangeable Cd was increased by 26.37%~95.5%, the content of iron-manganese oxide bonded Cd was decreased by 26.37%~95.5%, the content of organically bonded Cd was decreased by 4.84%~33.89% and the content of residual Cd was decreased by 23.93%~47.22%. Straw decomposition filtrate significantly increased the content of soil exchangeable Cd, and the lifting effect increased with the addition of filtrate, which was mainly reflected during 20~60 d. The content of soil available Cd(exchangeable Cd and carbonate bonded Cd) was increased significantly than the reference in the end of incubation experiment, while the content of unavailable Cd(residual Cd) had no obvious change during the whole incubation period. The mutual transformation between available Cd and potentially available Cd(iron-manganese oxide bonded Cd and organically bonded Cd) was mainly reflected from the mutual transformation between exchangeable Cd and Fe-Mn oxide bonded Cd or organically bonded Cd. There was a significant negative correlation between organically bonded Cd and exchangeable Cd.

关 键 词：土壤镉 化学形态 有效性 秸秆 

分 类 号：X53[环境科学与工程—环境工程]