| 摘要: |
| 采用厌氧恒温培养试验，比较了4种水稻土中氧化铁的微生物还原状况。结果表明，4种不同来源水稻土中Fe(Ⅱ)生成量有较大差异，其中吉林和四川水稻土中铁还原迅速，而江西和广东水稻土相对较慢；还原反应达到平衡时的Fe(Ⅱ)积累量及铁还原快速期的平均反应速率由土壤中氧化铁的数量决定，并与无定形氧化铁和游离氧化铁的数量有关；4种水稻土中可还原铁占全铁及游离氧化铁的比例分别为7.73%～21.6%及10.0%～74.6%；广东水稻土的铁还原90％是利用无定型铁，而在四川和江西水稻土中，近乎50％的铁还原来自于晶体氧化铁；升高温度可促进土壤中Fe(Ⅱ)产生量，并且吉林水稻土对温度的响应最敏感；不同土壤的铁还原启动期、快速期和稳定期的时间有明显区别，并且与土壤中微生物菌数、土壤有机质及有机电子供体的数量密切相关。 |
| 关键词: 水稻土 铁还原 反应速率 |
| DOI： |
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| 基金项目:国家自然科学基金项目(40271067)；教育部博士学科点专项科研基金项目(20020712009) |
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| Microbial reducing characteristics of iron oxides in different paddy slurries |
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| Abstract: |
| Microbial Fe(Ⅲ) reduction in four different paddy slurries incubated anaerobically at constant temperature under lab condition was investigated.The results showed there were great distinct Fe(Ⅱ) productions in the incubation of four paddy slurries.Fe(Ⅲ) was reduced rapidly in Jilin and Sichuan paddy slurries and relatively slow in Jiangxi and Guangdong slurries.Equilibrious Fe(Ⅱ) accumulation and mean rate in rapid Fe(Ⅲ) reducing phase depended on iron oxides in paddies and correlated to amorphous and free Fe(Ⅲ).The percentages of reducible Fe(Ⅲ) in total Fe and free Fe(Ⅲ) of four paddy slurries were 7.73%-21.6% and 10.0%-74.6% respectively.In Guangdong paddy slurry,90 percentage of reduced Fe(Ⅲ) was from amorphous Fe(Ⅲ) while 50 percentage of reduced Fe(Ⅲ) was from crystalline iron oxides in Sichuan and Jiangxi paddies.Fe(Ⅱ) concentration increased significantly when temperature was raised and microbial Fe(Ⅲ) reduction in Jilin paddy slurry was sensitive mostly to temperature.Initiation,rapid reaction and steady phases in Fe(Ⅲ) reduction had apparent distinction in four paddy slurries and related closely to the quantities of microbe,organic matter and electron donor in paddies. |
| Key words: paddies iron reduction react rate |
