金盆水库表层沉积物中营养盐的分布特征与迁移转化

发布时间：2018-06-14 18:46

  本文选题：表层沉积物 + 营养盐　； 参考：《西安建筑科技大学》2017年硕士论文

【摘要】：为探明黑河金盆水库表层沉积物中营养盐的分布与迁移转化规律以及扬水曝气系统对内源污染的改善效果,对金盆水库上覆水体及表层沉积物的理化性质(水温(T)、溶解氧(DO)、p H值、水深(H)、含水率、粒度)、表层沉积物的营养盐含量(氮、磷形态、有机质)等指标进行了为期一年的监测。重点研究了:(1)黑河金盆水库表层沉积物营养盐分布特征;(2)磷形态分布及不同季节变化规律;(3)营养盐的污染评价及其污染来源;(4)磷的迁移规律;(5)扬水曝气系统对黑河金盆水库内源污染的改善效果。得到以下主要结论:(1)金盆水库上覆水体温度在6.15~13.35℃之间波动;p H值除夏季偏弱酸性,其它季节偏碱性;DO浓度季节性变化显著,介于0.48~9.73mg/L之间,夏季最低至0 mg/L;间隙水及上覆水中正磷酸盐含量夏季最高。含水率较高,表明水体扰动下很容易再悬浮。平均粒径季节变化不显著,但总体粒径偏细,说明水库水体的水动力较弱。(2)金盆水库表层沉积物中总氮(TN)含量为424~1460 mg/kg,从上游到库区,TN含量先减小后增加,有机质(OM)平均含量为7.02%,其分布特征与TN一致。总磷(TP)含量的空间分布差异并不显著,与其它湖库相比,TN含量相对较小,TP和OM含量均处于中等水平,说明金盆水库水体面临一定的污染风险。(3)表层沉积物TP含量为987~1326 mg/kg,无机磷(IP)是沉积物中磷的主要成分,占总磷(TP)的62.5%~78.9%;Ca-P是IP的主要组成成分,占总磷的46.5%-71.4%。表层沉积物TP空间分布特征总体表现为库区大于入库。IP与TP变化趋势基本一致,且TP的变化主要由IP决定,IP的增减因Ca-P和Fe/Al-P而改变。(4)金盆水库不同季节TP含量冬季最高,夏季最低;OP含量冬季明显高于其他季节;IP含量与TP变化一致;Al/Fe-P含量冬季最低,Ca-P随季节变化不明显。不同季节各形态磷含量大小均为Ca-POPAl/Fe-P。(5)金盆水库各采样点中TN、TP和OM含量对底栖生物的生态毒性均处于最低级别,说明沉积物已受污染,对环境有潜在的危害;碳氮比(TOC/TN)变化范围为30.0~58.3,表明金盆水库表层沉积物中OM均来源于高等陆生植物。OM与TN、TP均呈极显著正相关,与TN相关性更高,表明金盆水库表层沉积物有机质的矿化过程与氮磷,尤其是氮的物质来源和沉积变化过程关系更密切。(6)扬水曝气系统运行期间,上覆水及间隙水氨氮、总氮和总磷浓度显著降低。各监测点表层沉积物中磷形态(TP、OP)、TN和有机质含量基本呈现出一个逐步降低的过程。Al/Fe-P在运行期间有较小的增加,曝气器运行对Ca-P含量的影响不明显。扬水曝气系统运行提高了表层沉积物中微生物的总体代谢活性及其对碳源的利用。
[Abstract]:In order to find out the distribution, migration and transformation of nutrients in the surface sediments of Heihe Jinpan Reservoir and the effect of raising water aeration system on the improvement of internal pollution, The physical and chemical properties of the overlying water and surface sediments of Jinpan reservoir were monitored for one year, such as water temperature, dissolved oxygen, water depth, water content, grain size and nutrient content (nitrogen, phosphorus form, organic matter) in surface sediments. In this paper, the distribution characteristics of nutrient salt in the surface sediments of the Jinpan Reservoir of the Heihe River are studied in detail. The distribution of phosphorus forms and the regularity of variation in different seasons are studied. The pollution evaluation of nutrient salt and its pollution source are discussed in this paper. (5) the aeration system of raising water is used to treat the black water. Improvement effect of Internal pollution in River Jinpan Reservoir. The main conclusions are as follows: (1) the overlying water temperature of Jinpan Reservoir fluctuates between 6.15 ~ 13.35 鈩，

本文编号：2018591