东北哈尼泥炭沼泽中酚酸的组成、 酚铁相互作用及其环境意义
Effect of Phenolic Acids Derived from Peatland on Surface Behavior of Iron and Its Significance：A Case Study in Hani Peatland

大量研究表明,溶解性有机质与铁的螯合对生物可利用性铁的输出有重要影响.然而,对于天然有机质,尤其是泥炭沼泽 源的酚类物质,与铁相互作用的地球化学机制仍然缺乏研究.以长白山西麓哈尼泥炭沼泽为研究对象,调查了泥炭沼泽源水体 可溶性总铁、亚铁、水溶性总酚等理化指标.同时,测定了泥炭中酚酸的组成及含量,分析对比泥炭与土壤中铁的主要赋存形 态.并开展了酚铁相互作用模拟实验,研究了泥炭沼泽源水体中酚铁相互作用机制.结果表明:哈尼泥炭沼泽水体中亚铁浓度 与水溶性总酚浓度显著相关,说明水溶性总酚对亚铁的存在及运移有重要影响.哈尼泥炭中含有原儿茶酸、咖啡酸、没食子酸、 龙胆酸、丁香酸、阿魏酸、对羟基苯甲酸、对香豆酸、水杨酸、香草酸等多种酚酸.其中,具有儿茶酚或没食子酰基结构的原儿茶 酸、咖啡酸和没食子酸能与亚铁形成稳定螯合物,是泥炭沼泽源水体中 F e(Ⅱ)保持稳定并可以远距离迁移的关键.研究还表 明,原儿茶酸、咖啡酸、没食子酸和龙胆酸对 F e(I I I)有显着的还原作用,有利于沼泽区水体中的保持较高 F e(I I I)和 F e(Ⅱ)浓 度.哈尼泥炭中铁主要以活动态(可交换态、络合态和无定形态)为主,为铁的迁移、转化和循环奠定了基础.鉴于泥炭沼泽在全 球的分布面积巨大以及亚铁对海洋生物有促进作用,酚酸对铁的作用机制对陆地系统向海洋输送生物可利用铁具有重要意 义,并对碳循环、硫循环以及气候变化有重要影响.
The influence of dissolved organic matters as metal chelators on the bioavailable iron input to the ocean has been widely reported by several studies. However, natural dissolved organic matters, especially the phenolics originated from peatlands and geochemical interactions with iron remains poorly understood. Hani peatland, as the national nature reserve in Jilin Province, is located in the central Longgang Mountain on the west side of Changbai Mountains. Physiochemical characteristics of water samples collected from rivers in Hani, including total dissolved iron, ferrous iron, dissolved organic carbon and pH etc., were detected in the field. Inner connections of these indexes were demonstrated through multivariate statistical analysis and simulation experiments on geochemical interactions between iron and phenolic acids were conducted in laboratory. Results show that total dissolved phenol plays an important role in the existence and transportation of ferrous iron. Ten phenolic acid, including protocatechuic acid, caffeic acid, gallic acid, gentisic acid, syringic acid, ferulic acid, p-hydroxybenzoic acid, p-coumaric acid, salicylic acid and vanillic acid, were detected by high performance liquid chromatography. Simulation experiments reveal that phenolics bearing either catechol or galloyl moiety groups (protocatechuic acid, caffeic acid and galllic acid) could chelate ferrous iron, which is the geochemical cause of high concentration of dissolved iron and is crucial for iron transport in peatland. Reducing action of phenolics to Fe(III) is also responsible for maintaining high concentration of Fe(II) and Fe(III) in rivers drained from peatland. Considering the wide distribution of peatlands globally, the higher concentration of Fe in peatlands, and the enhancement of marine organisms by Fe, the complexation and reductive actions between iron and phenolics originated from peatlands are of important significance to global iron cycle coupled with