西安市景观水体调研及富营养化控制基础研究

发布时间：2018-09-03 13:49

【摘要】：本研究首先调查并评价了西安市六个景观水体的水质现状和富营养化程度;然后选取了两个典型景观水体,对其水质、浮游藻类和底泥进行了全年跟踪监测,在此基础上运用主成分分析法(PCA)和典范对应分析法(CCA)研究了其水质特征和优势藻之间的关系,并采用改进的模糊评价法和综合营养状态指数法分别评价了水质状况和富营养化状态;最后,采用生物滤池反应器对重度富营养化景观水体进行了快速处理。主要结论如下:(1)在调研的六个景观水体中,护城河为严重富营养化,兴庆湖和丰庆湖为中富营养化,南湖和汉城湖为轻富营养化,未央湖为中营养状态。此外,南湖优势藻为绿藻门,其他五个水体的优势藻均为蓝藻门。(2)丰庆湖和护城河水质变化呈现明显的季节性:丰庆湖水质冬季最好,夏季最差,主要污染物为COD,共检测到浮游藻类6门39属,优势藻为伪鱼腥藻、小球藻、鼓藻和弯型小尖头藻;护城河水质春夏季最差,主要污染物为TN、TP和NH3-N,共检测到浮游藻类7门53属,优势藻有栅藻属、鼓藻属、囊裸藻属、裸藻属、小环藻属、针杆藻属。因此,城市景观水体水质的最大特点是季节差异性和藻属差异性。此外,两水体底泥的氮磷含量也呈现出一定的季节性:丰庆湖底泥TN含量春季最高(11.04 mg/g)夏季最低(9.98 mg/g);而护城河底泥TN含量夏季最高(13.52 mg/g)冬季最低(8.76 mg/g);两者TP含量均夏季最高冬季最低,但护城河底泥夏季和冬季TP分别为丰庆湖底泥的3.95倍和2.36倍。(3)PCA及CCA分析结果表明:T、TP、TN、SD和DO是丰庆湖重要的水质因子;TN、PO43--P、COD、T和Chla与优势藻关系最为密切,其中TN、矿化度对伪鱼腥藻影响较大,T、COD对弯型小尖头藻影响较大,小球藻和鼓藻受T、TP、PO43--P、SD、NH3-N、pH影响较大。T、TP、TN、Chla、COD和DO是护城河重要的水质因子;T、TN、NH3-N、pH和矿化度对优势藻的影响较大,其中T对鼓藻和小环藻影响较大,T、SD和PO43--P对裸藻属和栅藻属影响较大;TP、COD、pH、TN、NH3-N、矿化度对针杆藻属和囊裸藻属影响较大。因此,不同水体藻类的水质影响因子各不相同。(4)在HRT为3h、气水比2:1条件下,护城河总排水经过曝气生物滤池处理后,Chla平均去除率为65.8%,藻密度平均去除率86.7%,COD的平均去除率为50.2%,TN平均去除率为10.9%,TP平均去除率为36.8%,NH3-N平均去除率达90%以上。此外,色度大幅降低,浊度平均去除率达83.3%。
[Abstract]:In this study, the water quality and eutrophication degree of six landscape water bodies in Xi'an were investigated and evaluated firstly, and then two typical landscape water bodies were selected to track and monitor their water quality, phytoplankton and sediment throughout the year. On this basis, principal component analysis (PCA) and canonical correspondence analysis (CCA) were used to study the relationship between water quality characteristics and dominant algae. The improved fuzzy evaluation method and the comprehensive nutrition state index method were used to evaluate the water quality and eutrophication respectively. Finally, the biological filter reactor was used to quickly treat the serious eutrophication landscape water. The main conclusions are as follows: (1) the moat is serious eutrophication, Xingqing Lake and Fengqing Lake are medium eutrophication, Nanhu Lake and Hancheng Lake are light eutrophication, and Weiyang Lake is medium eutrophication. In addition, the dominant algae in Nanhu Lake were Chlorophyta phylum, and the dominant algae in the other five water bodies were all cyanobacteria. (2) the water quality of Fengqing Lake and moat showed obvious seasonal changes: the water quality of Fengqing Lake was the best in winter and the worst in summer. The main pollutants were 6 phyla 39 genera of phytoplankton detected by COD, the dominant algae were Anabaena pseudocephala, Chlorella microphylla, Chlorella oblongata and Acanthopsis sinensis, and the water quality of moat was the worst in spring and summer, and the main pollutants were TN,TP and NH3-N, and there were 7 phyla and 53 genera of phytoplankton detected in the moat. The dominant algae are Sargassum, Drum, Cystis, Cyclophyta, Cyclopsis. Therefore, the most characteristic of urban landscape water quality is seasonal difference and algae difference. In addition, The content of nitrogen and phosphorus in sediment of two water bodies also showed certain seasonality: the content of TN in the bottom of Fengqing Lake was the highest (11.04 mg/g) in spring and the lowest in summer (9.98 mg/g), while the content of TN in sediment of moat was the highest (13.52 mg/g) in winter (8.76 mg/g), and the content of TP was the highest in summer (8.76 mg/g). However, the TP of moat sediment in summer and winter was 3.95 and 2.36 times of that in Fengqing Lake, respectively. (3) the results of PCA and CCA analysis showed that PCA and DO were the most important water quality factors in Fengqing Lake. The effect of TN, mineralization on Anabaena pseudocephala was significant. Chlorella and Chlorophyta were affected by the pH of TTPTPPO43-NN. TN, and DO were the important water quality factors of Moat. The pH and salinity of Chlorophyta and Chlorophyta were the most important factors affecting the dominant alga, while Chlorophyta and Chlorophyta were the most important water quality factors in the Moat, and the pH and salinity of Chlorella vulgaris and Chlorophyta were the most important water quality factors in the Moat River, and Chlorophyta had a great effect on the dominant algae. TSD and PO43--P have great influence on the genus Nymphocystis and P. sp., and TSD and PO43--P have a great effect on the genus Nymnymus, and the degree of mineralization has a great effect on the genus Cystis and the genus Cystis. Therefore, the factors affecting the water quality of algae in different water bodies are different. (4) when the HRT is 3 h and the ratio of air to water is 2:1, The average removal rate of CHLA and COD in the total drainage of moat was 65.8 and the average removal rate of COD was 50.2and TN was 10.9and the average removal rate of NH3-N was over 90% after being treated by biological aerated filter, and the average removal rate of algae density was 86.7% and the average removal rate of TN was 10.9% and the average removal rate of NH3-N was more than 90%. In addition, the chroma decreased significantly, and the average turbidity removal rate reached 83.3%.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X52

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