摘要
为揭示三峡库区沉积物中磷形态的分布特征及其与沉积物理化指标的相关性，本文以香溪河为例，沿河流自上游向下采集沉积物样，应用五步连续提取法分层测定柱状沉积物中的磷形态，并对pH、有机质、粒度等与磷形态间进行相关性分析．结果表明：在水平方向，表层沉积物（0-4cm）的总磷（TP）排序为中游（XX06）〉上游（XX08）〉干支流交汇处（CJXX）〉下游（XX01）；在垂向分布上，中上游（XX08和XX06）各形态磷含量整体沿垂向递减，而下游和交汇处（XX01和CJXX）钙结合态磷（HCl一P）沿垂向递增．香溪河沉积物TP的含量范围为715-947mg／kg，HCl-P构成沉积物中磷的主要部分．生物有效性磷（BAP）占TP含量的20％-48％，CJXX沉积物中的BAP含量略低于支流．不同样点沉积物中磷形态与环境因素的相关性并不一致，中上游沉积物TP与BAP显著相关，氧化还原敏感性磷（BD-P）或BAP受氧化还原电位（Eh）影响较大；而下游和干支流交汇处的主要影响因素为pH值，BAP主要由金属氧化物结合态磷（NaOH—P）组成，二者相关性显著．在CJXX，伊利石含量随粒径的增加而减少，与石英和白云石变化规律相反．
Xiangxi River is chosen as the research object to reveal the vertical distribution characteristics of various phosphorous （P） fractions and the correlation between P fractions and physical-chemical indexes in sedi- ments of the Three Gorges Reservoir Area （TGRA）. Sediment cores are collected from the upper reach till the junction of the main stream and tributary along Xiangxi River. Five-step continuous extraction is applied to quantify various P fractions of different layers in sediments. The correlations among fractions with pH val- ues, organic matter and particle size are analyzed. The results show as follows. （1） In the horizontal scale, the order of total phosphorus （TP） concentrations in surface sediments （0-4 cm） is middle reach （XX06）〉 upper reach （XX08）〉 the junction of the main stream and tributary （CJXX）〉 lower reach （XX01）. In the vertical scale, the contents of various P fractions in XX08 and XX06 decline downwards, which is contrary with the trend of HC1-P contents in XX01 and CJXX; （2）TP content is between 715 mg/kg and 947mg/kg and HCl-P is the major P fraction. The contents of bioavailable phosphorus （BAP） account for 20-48% of TP, and the values are lower in CJXX than those in tributary; （3） The correlation between P fractions and environmental factors in different sampling sites vary. In XX08 and XX06, BD-P or BAP is greatly influenced by redox potential （Eh）, while in XX01 and CJXX, pH value is the most important factors. BAP is mainly composed of NaOH-P and the correlation between the two is extremely significant. In the sediments of CJXX, illite contents decrease with the increase of particle size, which is in contrast to the changes of quartz and dolomlte contents.
出处
《三峡大学学报（自然科学版）》
CAS
2016年第6期99-107,共9页
Journal of China Three Gorges University：Natural Sciences
基金
国家水体污染控制与治理科技重大专项(2012ZX07307-001)
重庆大学2015年研究生科研创新项目基金(CYB15041)
关键词
磷形态
沉积物
垂向分布
矿物组成
粒度
phosphorus fractions
sediment
vertical distribution
mineral composition
particle size
