阿哈水库沉积物-水界面磷、铁、硫高分辨率空间分布特征  

High-resolution Distribution Characteristics of Phosphorous,Iron and Sulfur Across the Sediment-Water Interface of Aha Reservoir

作　　者：孙清清[1,2] 陈敬安[1] 王敬富[1] 杨海全[1] 计永雪[1,2] 兰晨[1,2] 王箫[3] 

机构地区：[1]中国科学院地球化学研究所环境地球化学国家重点实验室,贵阳550081 [2]中国科学院大学资源与环境学院,北京100049 [3]贵州师范大学地理与环境科学学院,贵阳550025

出　　处：《环境科学》2017年第7期2810-2818,共9页Environmental Science

基　　金：国家自然科学基金项目(41403113);贵州省应用基础研究计划重大项目(黔科合J重大字[2015]2001号);贵州省科技计划项目(黔科合[2016]支撑2802号);贵州省科学技术基金项目(黔科合J字[2014]2163号)

摘　　要：选取贵州典型高原亚深水型湖库阿哈水库为研究对象,利用薄膜扩散梯度技术获取夏季分层期不同湖区沉积物-水界面磷、铁、硫的原位、二维高分辨分布信息,并结合水化学及沉积物磷形态分析,探讨了沉积物P-Fe-S分布规律及控制因素.结果表明:沉积物-水界面DGT-P的浓度变化范围0.00~0.43 mg·L^(-1),DGT-Fe的浓度变化范围0.00~2.83 mg·L^(-1),DGT-S的浓度变化范围0.00~0.10 mg·L^(-1).阿哈水库沉积物孔隙水磷、铁、硫浓度在垂向分布上没有显著的相关性,DGT-P、DGT-Fe甚至还呈反向变化,这与很多湖泊的研究结果存在明显差异,其原因可能是阿哈水库沉积物具有很高的Fe/P和Fe/S比值,过剩的Fe导致还原态S以FeS/FeS_2形式沉淀后,P仍然被Fe(Ⅲ)固定在沉积物中.阿哈水库沉积物磷形态以Na OH-SRP和BD-P为主,Na OH-SRP含量变化范围为192~604 mg·kg^(-1),平均值约为392 mg·kg^(-1),BD-P含量变化范围为143~524mg·kg^(-1),平均值约为225 mg·kg^(-1).阿哈水库底层水体长期处于厌氧环境,Fe、S地球化学循环对沉积物内源磷释放起着重要控制作用.In situ two-dimension, high-resolution distribution of phosphorus（P）, iron（Fe）, sulfur（S） from the sediment-water interface was investigated in different areas of Aha Reservoir, a typical sub-deep water lake, using diffusive gradients in thin films（DGT） technique, combining with water chemistry and sedimentary phosphorus speciation analysis, aimed to discuss the distribution and control factors of P-Fe-S in sediments. DGT-P ranged from 0.00 mg·L-1 to 0.43 mg·L-1. DGT-Fe rangd from 0.00 mg·L-1 to 2.83 mg·L-1. DGT-S ranged from 0.00 mg·L-1 to 0.10 mg·L-1. There was no significant correlation among the concentrations of P, Fe, S in the sediment pore water of Aha Reservoir, which is markedly different from the results of previous studies. We hypothesize that the high ratios of Fe/P and Fe/S induced the direct reaction of surplus Fe（Ⅲ） with S2-, yielding FeS and/or FeS2, while P was firmly fixed in sediments by Fe（Ⅲ）. NaOH-SRP（ranging between 192 and 604 mg·kg-1） and BD-P（ranging between 143 and 524 mg·kg-1） were the two major fractions of P in sediments. Since the environment for the bottom layer of water in Aha Reservoir is anoxic, the geochemical cycle of Fe and S potentially has a massive impact on the activation and migration of sedimentary P.

关 键 词：阿哈水库 沉积物-水界面 薄膜扩散梯度技术 磷 硫 铁 

分 类 号：X524[环境科学与工程—环境工程]