【摘要】：隨著社會經(jīng)濟的不斷發(fā)展,人們對生活品質和生態(tài)環(huán)境的要求也逐步升高,水景已是城市生態(tài)景觀必不可少的組成部分。優(yōu)美的水環(huán)境不但可以美化城市相貌,還能夠有效地改善水體周邊微氣候。但是,近年來景觀水體水質惡化以及出現(xiàn)富營養(yǎng)化現(xiàn)象,引起了不少新的環(huán)境問題。本文以曲江南湖景觀水系為研究對象,通過測定具有代表性采樣點連續(xù)四季的水質變化情況、沉積物基本性質以及采用模擬實驗研究沉積物中磷的釋放特性,綜合分析水體污染現(xiàn)狀。曲江南湖水化學特征以及不同形態(tài)的氮、磷在水體中的時空分布顯示,南湖屬偏堿性景觀水體,其水質具有高濁度、低礦化度的特點;水中主要陰、陽離子的含量濃度為:Ca2+Mg2+Na+K+,HCO3-SO42-Cl-,水化學類型為重碳酸鹽鈣Ⅰ型;水體中各形態(tài)的氮、磷隨季節(jié)變化規(guī)律是:總氮春夏季高而秋冬季低;硝酸鹽氮秋冬季含量高;氨氮、亞硝酸鹽氮含量夏季達到最大;磷含量春夏季較高;各形態(tài)的氮、磷下湖區(qū)偏高,東西分布相對均勻;同時對水質進行模糊綜合評價結果為Ⅳ類,氮為主要污染物。沉積物pH值在7.50~8.07之間,含水率高、有機污染小,總氮含量494.86~823.12mg/kg,有機氮屬Ⅱ類較清潔等級;總磷含量280.56~543.55mg/kg,采用SMT分級方法對沉積物中各形態(tài)磷進行了分析與研究,結果發(fā)現(xiàn)Ca-P是主要賦存形態(tài)。通過靜態(tài)模擬實驗探究了在不同環(huán)境條件(溫度、pH、溶解氧和擾動)下磷形態(tài)的變化,結果表明:Al-P、Ca-P較穩(wěn)定,但在酸性條件下會加速溶解;NH4-P在外力擾動下釋放量最大;Fe-P、Org-P受溶解氧、pH和溫度影響較大,各形態(tài)磷的吸附與釋放能力有明顯差異,對水體富營養(yǎng)化的影響不可忽視。本研究對曲江南湖水體環(huán)境污染及內(nèi)源磷釋放特征進行了分析,為制定水體污染控制策略和改善水質措施提供了新的依據(jù),具有重要的科學意義。
[Abstract]:With the continuous development of social economy, people's requirements for the quality of life and ecological environment are also gradually rising, waterscape has become an essential part of urban ecological landscape. The beautiful water environment can not only beautify the appearance of the city, but also effectively improve the microclimate around the water body. However, the deterioration of landscape water quality and eutrophication in recent years have caused many new environmental problems. Taking the landscape water system of Qujiang South Lake as the research object, this paper studies the characteristics of phosphorus release from sediments by measuring the changes of water quality, the basic properties of sediments and the characteristics of phosphorus release from sediments in successive seasons at representative sampling points. The present situation of water pollution is analyzed synthetically. The chemical characteristics of Qujiangnan Lake water and the spatial and temporal distribution of nitrogen and phosphorus in different forms showed that Nanhu Lake belongs to alkaline landscape water and its water quality is characterized by high turbidity and low salinity. The main anion and cationic concentration in water were as follows: Ca2 Mg2 Na K, HCO3-SO42-Cl-, hydrochemical type was bicarbonate calcium type 鈪，

本文編號：2364876