摘要
采用室内培养实验,观测淹水厌氧条件下分别添加及共同添加葡萄糖和不同制备来源的腐殖酸,对红壤中铁的异化还原作用的影响.结果表明,红壤单独培养条件下,Fe(Ⅱ)浓度培养前后没有发生变化.添加葡萄糖促进了铁的异化还原,培养至12 d其Fe(Ⅱ)浓度为培养前的25倍.腐殖酸不能作为电子供体促进铁的异化还原,单独添加时红壤中Fe(Ⅱ)浓度没有发生变化,而同时添加葡萄糖情况下,培养前期促进而后期减弱铁的异化还原,其Fe(Ⅱ)浓度增幅仅为单独添加葡萄糖处理的35%.腐殖酸的浓度对红壤中铁的异化还原作用有影响,浓度为2.00 g/kg时培养前期促进而后期减弱铁的异化还原,低浓度时(0.20和0.02 g/kg)影响很小.不同制备来源的腐殖酸对红壤中铁异化还原过程的影响不同.培养前期,从山西大同风化煤(HAs)、河南巩县褐煤(HAh)和云南昆明滇池底泥(HAk)中提取的腐殖酸都促进了红壤中铁的异化还原;培养后期,HAk依然发挥促进作用,其Fe(Ⅱ)浓度始终高于G处理,而添加HAs和HAh的处理培养至7 d Fe(Ⅱ)仅为单独添加葡萄糖处理的14%和25%,减弱了铁的异化还原.
Iron oxide is abundant in red soil. Reduction and oxidation of iron oxide are important biogeochemical processes. In this paper, we reported the effects of humic acid on dissimilatory iron reduction （DISSIR） in red soil by adding glucose or humic acid （ HA ）, under an anaerobic condition. Results indicated that DISSIR is weak for the red soil with a low content of organic matter, Glucose that act as electron donators promoted the process of DISSIR in red soil. HA added to soil solely didn＇t accelerate the DISSIR since it couldn＇t provide electron donators to microbe. However, adding of both glucose and HA promoted the DISSIR at the beginning of the incubation but then inhibited the process, which maybe caused by the effects of precipitation and adsorption of red soil. Concentrations of HA strongly affected the DISSIR, HA at low concentrations（0.20 and 0.02 g/kg） had weak effects, while HA at a high concentration （2.00 g/kg） promoted the process at the beginning and then inhibited it. HA extracted from different materials had distinct effects on the DISSIR. HA from Weathering coal of Datong in Shanxi Province （HAs）, lignite of Gongxian in Henan Province（HAh） and Dianchi Lake sediment in Kunming of Yunnan Province（HAk） all promoted the DISSIR at the beginning of the incubation. However, at the end of incubation, HAk with a low aromaticity still promoted the process, while HAs and HAh with a higher aromaticity weakened the DISSIR. This may be due to the increase in adsorption of soil with the aromaticity of HA.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2009年第1期221-226,共6页
Environmental Science
基金
国家自然科学基金项目(40471066)
关键词
淹水厌氧
红壤
铁异化还原
腐殖酸
anaerobic submerged condition
red soil
dissimilatory iron reduction（DISSIR）
humic acids（HA）
