基于氮磷比解析太湖苕溪水体营养现状及应对策略  

The current water trophic status in Tiaoxi River of Taihu Lake watershed and corresponding coping strategy based on N/P ratio analysis

作　　者：聂泽宇[1] 梁新强 邢波 叶玉适 钱轶超 余昱葳 边金云 顾佳涛 刘瑾[1] 陈英旭[1] 

机构地区：[1]浙江大学水环境研究院,杭州310029 [2]浙江省水体污染控制与环境安全技术重点实验室,杭州310029 [3]绍兴市环境监测中心站,绍兴312000

出　　处：《生态学报》2012年第1期48-55,共8页Acta Ecologica Sinica

基　　金：国家水体污染控制与治理科技重大专项(2008ZX07101-006;2009ZX07528-005-003);国家自然科学基金资助项目(40901142)

摘　　要：生态化学计量学是评价水体营养状态的重要手段,利用其氮磷比指标探讨了我国太湖主要入湖河流苕溪的营养状态。野外监测结果显示,苕溪水体氮素超标严重,磷素污染轻度,硝酸盐、颗粒态磷为氮磷的主要赋存形态,且氮磷浓度呈现相似的季节变化规律,表明苕溪主要受农业面源污染影响。氮磷比分析表明,苕溪水体春、秋季处于磷素限制状态,夏季适合藻类生长,冬季低温条件下不利于藻类的大量繁殖;苕溪生物量增长受磷素限制,线性拟合亦显示其氮磷比主要受磷素波动的调控;苕溪干流大面积暴发蓝藻水华的风险较部分支流及死水区低,苕溪水入湖后,特别是夏季其暴发风险将显著提高。针对苕溪水体的富营养化现状,提出若干条水质改善应对策略。Ecological stoichiometry is an important measurement to evaluate water trophic status.In this study,the ratio of nitrogen to phosphorus（N/P,an index of stoichiometry） was used to assess the nutrient conditions of Tiaoxi River which is the main inflow river of Taihu Lake.The results from field monitoring data showed that nitrogen contents in Tiaoxi River were much higher than surface water quality standards in China but phosphorus pollution was relatively light.The average concentration of total nitrogen（TN） was up to 3.5 mg/L,which was worse than Grade V（2mg/L） of national surface water quality standards in China,while the average concentration of total phosphorus（TP） was 0.18 mg/L,which met the water quality requirement of Level Ⅲ（0.2 mg/L）.In addition,nitrate and particulate phosphate were the main pollutants in Tiaoxi River.The average content of nitrate was up to 2.1 mg/L,indicating that Tiaoxi River was in a high oxidation environment and its self-purification ability was strong,whereas the mean value of dissolved phosphate（DP） was low（0.07 mg/L）.Nutrients concentrations presented the similarly seasonal variations.The maximum concentration of TN was in winter,and the minimum level was in spring and autumn.The dynamic changes of TP concentration were roughly similar to TN,but TP presented a sharp decline in spring and fell to the lowest level throughout the year.Furthermore,correlation analysis also showed certain correlations among different nutrients index.TN and TP,DP were significantly positively correlated,indicating that the ways for nutrients inputs to Tiaoxi River were substantially the same,which suggested that Tiaoxi River was mainly influenced by agricultural non-point source pollution.TN/TP ratio represents the nutrients structure in Tiaoxi River for phytoplankton growth.According to the previous studies,TN/TP7 and TN/TP30 were used to categorize the different trophic status of nitrogen and phosphorus limitation in aquatic ecosystem,respectively.The N/P ratios showed

关 键 词：苕溪 氮磷比 水质现状 富营养化 水质改善 

分 类 号：X524[环境科学与工程—环境工程]