旱作褐土中铁氧化物的厌氧还原动力学特征  

DYNAMICS OF ANAEROBIC REDUCTION OF IRON OXIDES IN UPLAND CINNAMON SOILS

作　　者：孙丽蓉[1] 王旭刚[1] 郭大勇[1] 王利朋[1] 刘素云[1] 郭永新[1] 

机构地区：[1]河南科技大学农学院,河南洛阳471003

出　　处：《土壤学报》2013年第1期106-112,共7页Acta Pedologica Sinica

基　　金：国家自然科学基金项目(41101215);河南省科技攻关项目(11210211007);河南科技大学实验技术开发基金项目(SY1011040)资助

摘　　要：异化铁还原是厌氧环境中有机物降解的重要微生物过程,不仅影响Cr、U等无机污染物在环境中的迁移,还与CH4、N2O、H2S等温室气体的释放关系密切。本文选择7个旱作褐土样品,采用泥浆厌氧恒温培养的方法,研究了旱作褐土中氧化铁的厌氧还原特征,结果表明旱作褐土在淹水条件下可以发生铁氧化物的异化还原,其还原潜势介于4.47～5.95 mg g-1之间,还原速率常数介于0.15～0.27 d-1之间。褐土中部分晶态铁氧化物可在这一过程中被还原,游离铁的平均还原率为41.95%。经过40 d厌氧培养后,99.26%的NO-3和88.82%的SO24-被还原。还原过程的速率常数k、Vmax、Tmax随着土壤有机碳含量增加而增加,还原潜势与土壤SO24-含量呈显著负相关关系。Dissimilatory iron reduction is an important microbial process of the degradation of organic matter in anaerobic environment. It not only affects transloeation of some inorganic pollutants, like Cr and U, but also is closely related to emission of greenhouse gases, such as CH4, N2O,H2S, etc.. Samples of cinnamon soils, collected from upland farmlands at 7 different locations, were prepared into slurry and then put under anaerobic incubation, to study characteristics of the anaerobic reduction of iron oxide in these soils. Results show that dissimilatory reduction of iron oxide occurred in the cinnamon soils under submergence, with reducing potential ranging from 4.47 to 5.95 mg g 1 and a reduction rate constant between 0. 15 and 0. 27 d -1. In the soils, a portion of crystalline iron oxide was reduced during the process and the mean reduction rate of free iron reached 41.95%. After 40 days of incubation, 99.26% of the NO3- and 88.82% of the SO42- in the soils were reduced. And the rate constant, Vmax and Tmax of the iron reduction was positively related to soil organic carbon content, and the reducing potential negatively related to soil SO42- content.

关 键 词：旱作褐土 铁氧化物 厌氧还原 氮硫循环 

分 类 号：S153.4[农业科学—土壤学]