洱海水华高风险期水体氮磷变化及其指示意义  

Characteristics and Significance of Nitrogen and Phosphorus Variation During High Risk Period of Algal Bloom in Lake Erhai

作　　者：肖梦琦 倪兆奎 赵海超[4] 王圣瑞 XIAO Mengqi;NI Zhaokui;ZHAO Haichao;WANG Shengrui(Key Laboratory of Poyang Lake Environment and Resource Utilization,Ministry of Education,School of Resources Environmental and Chemical Engineering,Nanchang University,Nanchang 330031,China;Guangdong-Hong Kong Joint Laboratory for Water Security,Research Center of Water Science,Beijing Normal University at Zhuhai,Zhuhai 519087,China;Beijing Key Laboratory of Urban Hydrological Cycle and Sponge City Technology,College of Water Sciences,Beijing Normal University,Beijing 100875,China;College of Agricultural Science,Hebei North University,Zhangjiakou 075131,China;Yunnan Key Laboratory of Pollution Process and Management of Plateau Lake-Watershed,Kunming 650034,China)

机构地区：[1]南昌大学资源环境与化工学院,鄱阳湖环境与资源利用教育部重点实验室,江西南昌330031 [2]北京师范大学珠海校区水科学研究中心,粤港水安全保障联合实验室,广东珠海519087 [3]北京师范大学水科学研究院,城市水循环与海绵城市技术北京市重点实验室,北京100875 [4]河北北方学院农林科技学院,河北张家口075131 [5]云南省高原湖泊流域污染过程与管理重点实验室,云南昆明650034

出　　处：《环境科学研究》2021年第2期294-304,共11页Research of Environmental Sciences

基　　金：国家自然科学基金云南联合基金(No.U1902207);云南省高原湖泊流域污染过程与管理重点实验室开放基金项目(No.2020-02-2-W2,2020-124A-W2)。

摘　　要：为揭示水华高风险期水体氮磷变化对洱海的指示意义,结合洱海2009年、2013年和2018年采样检测数据及三维荧光、紫外光谱技术,研究了洱海上覆水氮磷组成和结构变化及影响因素.结果表明:(1)ρ(TN)和ρ(TP)均先降后升,由2009年氮磷以DON(0.231 mg/L,占36.90%)和DOP(0.016 mg/L,占42.05%)为主,转变为2018年以NH4+-N(0.197 mg/L,占32.89%)和PP(0.033 mg/L,占70.00%)为主,NH4+-N和溶解性有机氮磷质量浓度变化是引起氮磷变化的主要因子.各形态氮磷质量浓度空间变化差异较大,北部和中部湖区ρ(TN)、ρ(TP)及其增幅均大于南部湖区;ρ(DON)在北部和南部湖区总体呈下降的趋势,中部湖区ρ(DON)先降后升,增幅为3.32%;ρ(DOP)在北部和中部呈递减,南部湖区则先升后降,总体增加了70.21%;ρ(NH4+-N)在中部和南部湖区显著增加,北部湖区先降后升.(2)上覆水氮磷质量浓度及形态时空变化受外源负荷、内源释放和藻类生长共同影响,其中入湖河流是影响氮磷质量浓度变化的主因,且农村生活污染和农田面源污染影响也较大;有机氮磷变化主要受外源输入和湖泊微生物代谢影响,而ρ(NH4+-N)变化则主要受沉积物释放和藻类生长影响.(3)洱海水华高风险期上覆水腐殖化程度明显降低,有机氮磷分子量减小,而活性增加,一定程度上可促进藻类生长.研究显示,近10年洱海氮磷质量浓度有增加趋势,有机氮磷质量浓度虽有所下降,但其活性较高,藻类水华风险并未降低,除进一步加强外源负荷控制,关注TN和TP的同时,洱海保护治理还应关注有机氮磷输入以及中部和南部湖区沉积物氮磷释放的水质影响.In order to reveal the significance of the changes in nitrogen(N)and phosphorus(P),the changes in N and P forms and the structure of dissolved organic N(DON)and P(DOP)in Erhai Lake during the high algal bloom risk periods in September 2009,2013 and 2018 were studied by analysis of the scene sampling data,excitation-emission matrix fluorescence and ultraviolet-visible spectroscopy(UV-Vis).The results showed that:(1)DON and DOP were the dominant nutrient forms in 2009,with average concentration of 0.231 mg L(accounting for 36.90%of the TN)and 0.016 mg L(42.05%),respectively.Thereafter,NH 4+-N and particulate phosphorus(PP)became the dominant nutrient forms,and the average concentrations in 2018 were 0.197 mg L(32.89%)and 0.033 mg L(70.00%),respectively.The main factors causing the change of N were related to NH 4+-N and DON,while TP was closely associated with DOP.In addition,the spatial change of N and P forms showed great variability,andρ(TN)andρ(TP)in the northern and central areas were higher than those in the south areas.DON showed decrease trend in the northern and southern areas,while increased by 3.32%in the central area.DOP decreased in the north and middle areas while it increased by 70.21%in the south areas.NH 4+-N increased significantly in the central and southern areas.(2)The changes of N and P concentrations and forms in the overlying water were affected by external load,sediment release and algal growth,among which the rivers entering the lake were the main factors that affect the changes of N and P concentration,and the rural living pollution and non-point source pollution of farmland were also greatly affected.The variations of DON and DOP were mainly affected by exogenous load and microbial activities,while NH 4+-N was mainly affected by sediment release and algae growth.(3)The humification degree of the overlying water decreased obviously,the molecular weight of organic N and P decreased,and the activity increased,which promoted the growth of algae to a certain extent during the high risk peri

关 键 词：氮磷 形态组成 上覆水 水华高风险期 指示意义 

分 类 号：X524[环境科学与工程—环境工程]