摘要
采用厌氧泥浆恒温培养实验 ,测定了添加 6种外源氧化铁后土壤中Fe(Ⅱ )和Fe(Ⅲ )浓度的变化 ,探讨了不同氧化铁的还原能力及其对土壤产H2 、产CO2 、产乙酸和产CH4 过程的影响。结果表明 :无定形氧化铁和纤铁矿易于被还原 ,两者的最终还原程度大体相同 ,但无定形氧化铁存在还原滞后现象 ;针铁矿、赤铁矿、Al取代针铁矿和Al取代赤铁矿难以被还原 ,表现出与对照相同的还原特征 ;铁还原能导致土壤中H2 和乙酸稳态浓度的降低 ,有效抑制了甲烷产生 ;添加Fe(OH) 3和纤铁矿后 ,Fe(Ⅲ )还原占总电子传递的贡献率由对照的 1 8.3 0 %增至 63 .3 2 %和 46.90 % ,而形成甲烷的电子传递贡献率由对照的 80 .92 %降至 3 5 .85 %和 5 2 .3 2 % ,Fe(Ⅲ )还原对电子的竞争消耗 。
The microbial reduction of ferrihydrite, lepidocrocite, hematite, goethite and Aluminum-substituted iron oxides were examined under anaerobic incubation by slurry experiment. The variation of the partial pressure of H 2, CO 2, CH 4 and the acetate concentration were determined. The results indicated that different iron oxides had been shown different reduced ability in slurry. The ferrihydrite and lepidocrocite were easily to be reduced, which had almost same reduced level, meanwhile in the addition of ferrihydrite, there was a reduced hysteresis. The goethite, hematite, Al-substituted goethite and Al-substituted hematite were difficult to be reduced, which showed a same characteristic of iron reduction with control. Iron reduction can cause the decrease of H 2 and acetate concentration, and then methane production was inhibited. By ferrihydrite and lepidocrocite addition, the contribution (%) of electron-transfer belong to iron reduction were respectively increased to 63.32% and 46.90% from 18.30% (control), however, the contribution (%) by methane production were respectively decreased to 35.85% and 52.32% from 80.92% (control). Because of election competing consummation of iron reduction, the methanogenesis was greatly inhibited.
出处
《土壤学报》
CAS
CSCD
北大核心
2003年第6期858-863,共6页
Acta Pedologica Sinica
基金
国家自然科学基金 (4 0 1 41 0 0 5 )
陕西省自然科学基金 (2 0 0 0SM1 1 )资助
