以世界上最大的高原泥炭沼泽聚集区若尔盖泥炭沼泽区为研究对象,调查可溶性总铁浓度,并开展利用钙盐去除DOC的对照实验,研究泥炭沼泽区水体中对高含量溶解态铁的地球化学成因。结果表明:若尔盖地区水体呈碱性,其可溶性铁浓度远高于世界上其他非沼泽性河流和沼泽性河流。随着钙盐的加入,水样中有机质浓度显著下降(n=23,P=0.019 3〈0.05)。水样中可溶性铁和水溶性总酚的浓度无显著下降(n=23,P铁=0.168〉0.05,P酚=0.069 6〉0.05)。结果证实,泥炭沼泽源酚类物质是水体中铁离子的主要有机配体。因此,若尔盖泥炭沼泽区碱性水体中高含量溶解性铁的地球化学成因与沼泽释放的大量酚类物质与铁离子的络合作用有关。
Zoige Peatland is the world’s largest plateau peat accumulation area. The purpose of this study is to investigate the concentration of soluble iron and discuss causes of high concentration dissolved iron by setting up experiment of removal of DOC by means of adding calcium salt to study the role of DOC. Results showed that the concentration of iron in the rivers derived from wetland is significantly higher than river derived from forest areas and the other rivers derived from wetland.With calcium salt adding in,the organic content declined significantly(n=23,P=0.019 3<0.05),while there was no statistical difference on the content of soluble iron and total phenol(n=23,P iron=0.168>0.05,P phenol=0.069 6>0.05). Because of formation of the complex of phenolics and iron,the phenolics benefit the migration of iron in alkaline river. Geochemical cause of high levels of soluble iron is related to the complexation between iron and phenolics originated from the peatland.