太湖湖区敏感水域水质时空变化特征

摘要

于2010年1-10月在太湖主要湖口区与饮用水源地共10个湖区采集80个水样,分析水体NH3-N、TN、TP和CODMn含量的时空变化特征,并进行水质评价.结果表明,随时间变化,敏感水域NH3-N浓度较为稳定,TN浓度表现为4月较高,TP浓度表现为7月最高,CODMn浓度在1和3月(2月未测)明显高于其余月份.太湖西北部敏感水域NH3-N、TN、TP和CODMn浓度明显高于其余敏感水域.水质评价结果显示,太湖湖区部分敏感水域出现NH3-N、TN、TP和CODMn超标现象,其中TN和TP超标较为严重,超标率分别为91.7％和82.5％.各样点中以大浦港入湖口湖区污染最为严重,NH3-N、TN、TP和CODMn单项污染指数平均值分别为2.20、14.73、6.85和1.33.%During the period from January to October of 2010, 80 water samples were collected from 10 sampling sites scattered at the main inlets and drinking water sources of the Taihu Lake for analysis of characteristics of the Spatio-temporal variation of NH3-N, TN, TP and CODMn in the waters, and evaluation of water quality thereof. Results show that with the time going on, NH3-N concentrations in these sensitive waters remained almost unchanged, TN was relatively high in April, TP in July, and C0DMll significantly in January and March (no sample for February). Moreover, the sensitive waters located at Northwest Taihu Lake were higher than the others in concentration of NHj-N, TN, TP and CODMn. Water quality evaluation shows that NH3-N, TN, TP and CODM, concentrations in some sensitive waters were higher than the National Standard for Water Environmental Quality. TN and TP, in particular, 91.7% and 82. 5% of samples exceeded their respective standard. Among the sampling sites, the one at the inlet of Dapu Pier was the most seriously polluted with the arithmetical mean monomial pollution index for NH3 -N, TN, TP and CODMn being 2. 20, 14. 73 , 6. 85 and 1. 33 , respectively.