太湖西岸出入湖河口氮磷消减特征

河流水体污染物消减作用是降低其入湖通量的重要方式,为探明太湖河流氮磷污染物消减速率时空变化特征,研究采用自主研发的原位培养装置,开展了太湖西岸出入湖河口总氮绝对消减速率(TNR_绝)、总氮相对消减速率(TNR_相)、总磷绝对消减速率(TPR_绝)、总磷相对消减速率(TPR_相)的变化特征研究。结果表明:西北部和西部河流夏、秋季TNR_绝和TPR_绝高于春、冬季,南部河流则为秋、冬季高于春、夏季。夏季西部和西北部河流TNR_绝和TPR_绝高于南部,冬季则相反,春、秋两季空间差异不明显。颗粒态总氮(PTN)浓度及水温是TNR_绝时空差异性的主要影响因素。TP浓度是TPR_绝的季节差异性的主要原因,不同季节TPR_绝空间差异的主要影响因素不同,春、夏、秋、冬四季主要影响因素分别为p H等水体物理性质、TP浓度和SS浓度、SS浓度、TP浓度。TNR_绝和TPR绝及其初始浓度是TNR_相和TPR_相时空差异的主要原因。

CHARACTERISTICS OF NITROGEN AND PHOSPHORUS REDUCTION IN THE INLET RIVERS AROUND WEST LAKE TAIHU

Reducing rivers nitrogen and phosphorus is an important method that can control the lakes nitrogen and phosphorus pollution.In order to explore the spatial and temporal variations of rivers nitrogen and phosphorus reduction rates around the Lake Taihu,total nitrogen (TN) and total phosphorus (TP) absolute reduction rates (Ra) and relative reduction rates (Rr) were measured through self-developed in-situ devices in the inlet rivers around west Lake Taihu in four seasons between 2014 and 2016.The TNRa of northwest and west rivers in summer or autumn were higher than those in spring or winter,and theTNRa of south rivers in autumn or winter were higher than those in spring or summer.In the summer the TNRa and TPRa of northwest and west rivers were significantly higher than that southwest rivers,and the rates of south rivers in winter were significantly higher than others (P＜0.05).The rivers spatio-temporal TNRa differences were affected by particalate total nitrogen (PTN) and the seasonal water temperatures.The seasonal TPRa difference of was caused by seasonal difference of TP concentrations.The main reasons that affect season TPRa were various.The spring main factors were water physical properties such as pH,and the summer factor were TP and suspended solids;whereas the main autumn and winter factors were only suspended solids and TP,respectively.Those Lake Taihu rivers TNRr and TPRr were affected by TNRa and TPRa and its initial TN and TP concentration.