闽江河口潮滩沼泽湿地沉积物铁的形态和空间分布  

Fractions and the spatial distribution of iron in the sediments of tidal marsh in the Min River Estuary,Southeast China

作　　者：段勋 罗敏[1,2,3,4] 黄佳芳 刘育秀[3,4] 胡颖 DUAN Xun LUO Min(School of Environment and Resource, Fuzhou University, Fuzhou 350116 2. Postdoctoral Research Station of Ecology, Fujian Normal University, Fuzhou 350007 3. Key Laboratory of Humid Subtropical Eco-geographical Process of Ministry of Education, Fuzhou 350007 4. Research Center of Wetlands in Subtropical Region, Fujian Normal University, Fuzhou 350007)

机构地区：[1]福州大学环境与资源学院,福州350116 [2]福建师范大学生态学博士后科研流动站,福州350007 [3]湿润亚热带生态-地理过程教育部重点实验室,福州350007 [4]福建师范大学亚热带湿地研究中心,福州350007

出　　处：《环境科学学报》2017年第10期3780-3791,共12页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.41501252);国家级大学创新创业项目(No.201610386020);福建省自然科学基金(No.2016J05097);中国博士后科学基金(No.2016M602052)~~

摘　　要：滨海潮滩沉积物铁异化还原过程对有机质代谢及生源要素(C、N、P、S、O等)生物地球化学循环具有深远的影响.本文以闽江河口鳝鱼滩潮滩湿地为研究对象,对高、中、低潮滩0~80 cm深度内与铁异化还原相关的不同形态铁的含量和空间分布进行分析.结果表明,无定形Fe(Ⅲ)((39.3±5.3)μmol·g^(-1))和晶质Fe(Ⅲ)((84.2±10.7)μmol·g^(-1))主要分布在高潮滩,并沿着向海方向减少;铁的硫化物FeS((15.3±2.8)μmol·g^(-1))和Fe S2((6.0±1.1)μmol·g^(-1))集中分布在中、低潮滩;非硫Fe(II)((111.7±12.8)μmol·g^(-1))富集在整个潮滩剖面上,且含量随着深度增加而增加.孔隙水Fe^(2+)((3.7±0.7)mmol·L^(-1))与Fe S2、SO_4^(2-)和pH相关,说明Fe^(2+)可能与黄铁矿的水解有关.不同形态铁在高、中、低潮滩表现出显著的空间分布异质性.高潮滩铁异化还原的强度大于硫酸盐异化还原,但沿着向海方向,硫酸盐异化还原的潜势逐渐增加.本研究证明了潮汐水文和高程对潮滩湿地铁的迁移和转化具有重要的意义.Dissimilatory iron reduction has a profound influence on organic matter degradation and the biogeochemical cycling of biogenic elements（ e.g.,C,N,S,P,and O） in the sediments of coastal tidal marshes. This paper investigated fractions and the spatial distribution of iron in the 0 - 80 cm layer sediments of the Shanyutan tidal marsh of the Min River Estuary,Southeast China. The results suggeste that amorphous Fe（Ⅲ）（（ 39.3±5.3） μmol·g^-1）and crystalline Fe（Ⅲ）（（ 84.2±10.7） μmol·g^-1） are mainly distributed in the high tidal flat and decreases toward the sea. Iron sulfide Fe S（（ 15.3±2.8） μmol·g^-1） and Fe S2（（ 6.0±1.1） μmol·g^-1） were mainly enriched in the middle and low tidal flats. Non-sulfidic Fe（Ⅱ）（ 111.7±12.8） μmol·g^-1was detected throughout the tidal flats and increased with increasing depth. Porewater Fe^2＋（（ 3.7±0.7） mmol·L^-1） correlated with FeS2,SO4-（2-） and pH,indicating that the presence of porewater Fe^2＋may be related to pyrite hydrolysis. The different fractions of iron showed high spatial heterogeneity in the high,middle and low tidal flats,indicating that the intensity of iron reduction was greater than that of sulfate reduction in the high tidal flat; however,thesulfate reduction potential gradually increased toward the sea. This paper highlights the importance of the tidal hydrology and the elevation of the tidal flats in iron migration and transformation.

关 键 词：铁异化还原 硫酸盐异化还原 有机质代谢 潮滩湿地 闽江河口 

分 类 号：X13[环境科学与工程—环境科学] X17