富营养化浅水湖泊沉水水生植被的衰退与恢复

对国外近年来有关富营养化浅水湖泊的退化与恢复方面的研究进展以及生物操纵作用作了述评,对有关富营养化湖泊沉水植被衰退的有代表性的３种假说也作了介绍。根据“八五”期间武汉东湖水生植被重建的研究工作和多年积累的湖泊水生植被调查资料,提出了长江中下游浅湖富营养化过程中沉水植被演替的模式。     

蟹、鱼网围混养对草型湖泊氮磷平衡的影响

富营养化是当今的水污染治理难题,而农业非点源磷污染与水体富营养化的发生有着密切的关系,目前农田生态系统中广泛存在的磷素投入过量和由此导致的土壤磷素积累加剧了磷素向水体的流失。本文根据国内外最新研究成果,分析了农田土壤磷素流失对水体富营养化的影响,指出了减轻农业非点源磷污染的重要性,对目前所采用的农业非点源磷污染重点控制区的确定方法和一些主要防治措施的效果进行了评述。     

湖北长湖富营养化状况及时空变化(2012-2013年)

为评估长湖水体富营养化程度,2012-2013年分4个季度对全湖区20个采样点的物理、化学和生物要素进行监测,在评价水质现状的基础上采用综合营养状况指数法和浮游植物细胞丰度指数法综合评价水体营养状况,并应用典型相关分析(CCA)方法揭示水体富营养化状况与湖泊理化要素之间的典型相关性.结果显示:4个季节长湖全湖区的水质均处于地表水IV类~劣V类水标准;综合营养状态指数值在49.54~82.55之间,浮游植物细胞丰度在2.88×106~61.73×106cells/L之间,均显示其处于富营养化状态;长湖富营养化状况的分布呈现一定的时空差异性;CCA分析显示,长湖理化要素变量可解释68.6%的水体富营养化状况变量的变异,影响其富营养化状况的主要理化因素有水体总磷、总氮、溶解氧、亚硝态氮、硝态氮浓度,水深和沉积物总磷、总氮含量.长湖水体富营养化主要是由于外源的磷污染,其次是氮污染,富营养化最严重的夏、秋季浮游植物的生长主要受氮营养限制,而冬、春季则部分受磷营养限制,部分属于过渡类型.因此,建议大力削减围网/围栏养殖量,同时考虑结合水生植物栽种等生态工程建设措施以降低长湖水体发生严重富营养化的风险,并进一步改善长湖的水质现状.     

丰水期鄱阳湖水体中氮、磷含量分布特征

以2011年7月份鄱阳湖实测数据为参考,对鄱阳湖丰水期总氮(TN)、总磷(TP)空间分布特征及其影响因素进行了分析,并就鄱阳湖氮、磷营养盐结构特征及其与叶绿素a的相关性进行了探讨.结果表明:鄱阳湖氮、磷含量已经达到了发生富营养化的条件,且TN含量呈现由东向西、由南向北逐渐降低的趋势;TP在几个主要的采砂区,尤其是南北湖交界处污染最严重.鄱阳湖以磷限制为主,氮污染相对比较严重,且氮、磷不是鄱阳湖藻类生长的限制性因素.TN同时受悬浮泥沙和水流作用的影响,在上游航道受水流影响较大,在入江水道则主要受陆源污染的影响.TP含量则主要受悬浮泥沙和采砂活动的影响,受水流作用影响相对较小.     

天津中心城区河网氮磷污染与富营养化特征

2013年底天津中心城区河道全部连通,形成中心城区河网.为了掌握河网形成后的水质状况,于2014年3月-2015年2月进行了为期1年的定点水质监测,并对其水体氮、磷时空分布及富营养化特征进行分析.结果表明,河网水体氮污染严重,以铵态氮(NH+4-N)为主;磷污染程度较轻,主要形态为磷酸盐(PO3-4-P);河网水体中氮、磷浓度顺水流方向均呈上游高、下游低的空间分布特征;氮、磷各项指标浓度时间变化趋势基本一致,3月均最高,10月均最低,冬季处于相对较低水平;与河网形成前相比,海河干流NH+4-N、总磷(TP)和PO3-4-P浓度年平均值分别下降6.5%、14.7%和16.4%,津河总氮、NH+4-N、硝态氮、TP和PO3-4-P浓度年平均值分别降低18.6%、34.5%、12.9%、31.6%和32.5%,表明河网形成后氮、磷污染程度较之前有所改善,其中津河改善较为明显;河网水体全年处于中度富营养状态,主要为磷限制性状态;河网富营养化防治应遵循以控制营养盐为主的控源、截污、水环境增容和生态补水策略.     

夏季滇池和入滇河流氮、磷污染特征

为探讨滇池入湖河流水体营养盐空间分布特征及其对滇池水体富营养化的影响,2014年7月采集了入滇4类典型河流(城市纳污型河流、城乡结合型河流、农田型河流、村镇型河流)及滇池水样,分析其氮、磷浓度.结果表明:4条入湖河流总氮(TN)、总磷(TP)、硝态氮和氨氮污染均较严重;河流水体中TN、TP平均浓度大小为:农田型河流(大河)村镇型河流(柴河)城乡结合型河流(宝象河)城市纳污型河流(盘龙江),其中农田型河流(大河)水体TN、TP污染最为严重;在夏季,4条入湖河流水体中TN、TP浓度从上游向下游增加趋势比较明显,表明氮、磷沿河流不断富集;氮磷比分析表明,夏季河流输入氮、磷营养盐有利于藻类的生长,并且滇池浮游植物生长主要受TN浓度限制;夏季滇池南部入湖河流水体的TN、TP浓度高于北部入湖河流,该特征与滇池水体中TN、TP污染分布状况相反,推测滇池北部富营养化的主要影响因素是内源释放.因此,在今后的滇池水体富营养化研究中,应对滇池内源释放进行深入研究.     

硫铝酸盐水泥去除微污染水体中磷的性能及机理

微污染湖泊、水库等水体中磷的去除已成为水质研究的主要方向.磷是造成水体富营养化的关键因素,其浓度较低时即可导致水体富营养化与水华的发生,许多除磷方法对低浓度磷的去除效果不佳.因此,我们从22种天然矿物、火山灰质材料和水硬性材料中,筛选出了能高效去除低浓度磷的硫铝酸盐水泥(代号R.SAC 42.5,简称R),该材料在中性...     

二维水质模型在武汉东湖引水工程中的应用

以"大东湖生态水网"工程的实施为契机,应用MIKE21软件对武汉东湖引水工程进行数值模拟.利用东湖2008年6月和7月实测的水深、TN和TP数据率定了模型参数(床底摩擦力和涡粘系数),并利用2010年7月实测数据建立水动力学模型和对流扩散模型,模拟了四种引水工况下模型运行35 d之后东湖水体中TN、TP浓度分布情况,并比较四种工况的模拟结果.结果表明:在设置两个引水口以及考虑风速影响的情况下,东湖水体中TN、TP浓度分布最均匀.对"大东湖生态水网"工程的实施具有一定的指导意义.     

抚仙湖富营养化初探

近二十年的水质监测资料研究分析表明,抚仙湖生态系统相当脆弱,出现了加速富营养化趋势,浮游藻类数量增加了2．6倍,Chl．a含量增加了3倍,透明度减小了将近一半,综合营养状态指数呈急剧上升,揭示了发生富营养化的危险性。促进因素主要有外来污染增加,氮、磷等营养盐在湖内迅速积累,湖泊生态系统过于简单、脆弱等因素,呼吁加大对抚仙湖污染防治的力度,防患于未然。     

2016—2020年长江中游典型湖泊水质和富营养化演变特征及其驱动因素

“十三五”时期,长江流域水环境质量改善明显,但湖泊水质和富营养化状况改善滞后.长江中游作为我国淡水湖泊集中分布区域之一,部分湖泊存在水环境质量恶化和富营养化加重问题.本文以长江中游区域国家开展监测的洪湖、斧头湖、梁子湖、大通湖、洞庭湖和鄱阳湖这6个典型湖泊为研究对象,科学评价其2016-2020年水质和富营养化时空变化特征及关键驱动因素,探讨其成因及治理对策.结果表明,“十三五”时期长江中游湖泊水质和富营养化程度存在较大差异,与2016年相比,2020年大通湖水质改善最为明显,梁子湖水质变差,总磷是影响长江中游湖泊水质类别的主要因子;洪湖富营养程度恶化最为严重,斧头湖次之,TLI(SD)对长江中游湖泊富营养化评价贡献最大.目前长江中游湖泊呈有机污染加重和叶绿素。浓度升高现象,洪湖、斧头湖和梁子湖主要与氮、磷营养盐浓度升高有关,而大通湖、洞庭湖和鄱阳湖受水文过程、流域纳污量和湖泊管理等非营养盐因素影响较大.总氮和总磷仍然是影响“十三五”时期长江中游湖泊水质和富营养化的最主要驱动力,且各湖泊总氮和总磷浓度变化均具有较强正相关性,建议开展河湖氮、磷标准衔接工作,提出河湖氮、磷标准限值或考核目...     

鄱阳湖区水体氮、磷污染状况分析

通过系统测定鄱阳湖湖水、主要入湖口河水及部分农田水、地下水及城市污水氮磷含量,对其氮、磷污染状况进行了分析,同时对湖水及河水的氮、磷来源进行了初步讨论.结果表明,鄱阳湖区水体已达到一定程度的氮、磷污染,特别是饶河段氮含量较高(0.89-3.15mg/L),信江磷含量较高(0.098-0.22mg/L),而湖体的总氮、总磷含量也分别达到1.06±0.28mg/L和0.067±0.042mg/L,已具备富营养化的条件.     

Nutrient Budgets,Dynamics and Storm Effects in a Eutrophic,Stratified Baltic Lake

Between 1989 and 1998 the small eutrophic stratified Lake Belau was investigated intensively and multidisciplinarily. This article is a short, comprehensive summary and re‐evaluation of the hydrochemistry of the lake, with focus on nitrogen and phosphorus. In several aspects the lake can be regarded as a typical example of the glacial north German lakes. The 1960's and 1970's are characterised by heavy nutrient inputs and fast eutrophication. During the last two decades the external nutrient load, especially the phosphorus load into Lake Belau was significantly reduced. But phosphorus‐rich sediments and large areas with summerly anoxic sediment surface conditions cause intensive release of phosphorus from older deeper sediment layers. Annual budgets reveal that despite an average sediment accumulation of 3 mm a^?1 the lake has lost its function as net phosphorus sink and it is very likely that internal eutrophication by the sediments will keep the lake in its eutrophic state during the next decades. Despite that, monthly budgets of five vertical layers show that the main phosphorus supplier for the phosphorus depleted epilimnion during summer is the creek Alte Schwentine. The annual nitrogen budget indicates groundwater and interflow water as well as atmospheric input as additional important nitrogen sources. 36% (98 μmol m ^?2 h^?1 N) of all nitrogen input is lost to atmosphere mainly due to denitrification. The example of a heavy storm shows that about 10% of the annual nitrogen loss to the atmosphere can take place during a single day and in form of ammonia. The storm further made obvious that these unpredictable events can have strong impact on nutrient cycling and ecology in Lake Belau and the lake can become an unexpected nutrient source for downstream systems.     

白洋淀湿地不同植物群落区表层沉积物碳氮磷化学计量特征

白洋淀是雄安新区的核心生态功能区.为探究白洋淀不同植物群落区表层沉积物碳(C)氮(N)磷(P)化学计量特征,采集了96组表层沉积物样品开展对比分析.研究表明:白洋淀湿地表层沉积物总有机碳(TOC)含量均值为39.64 g/kg,范围为14.4～ 136.82 g/kg,总氮(TN)和总磷(TP)均值分别为2.62和0....     

Ecological risk assessment of eutrophication in Songhua Lake, China

The Songhua Lake in the Northeast China is chosen as a study case in this paper. Monitoring of samples and analysis 18 indexes related to the eutrophication in the Songhua Lake had been conducted in 2002–2004. Ecological risk assessment methods are employed here. The study results showed that total phosphorus and total nitrogen were main risk factors to impact on the eutrophication of the Songhua Lake, and influence of the phosphorus on the lake eutrophication was larger than that of nitrogen. Algal growth potential test was also conducted to validate the results. High phosphorus and high nitrogen concentrations were mostly distributed in Huifahekou and Jiaohe sites of the Songhua Lake. Threshold values of total phosphorus, total nitrogen and Chl-a concentrations from dose-effective examination were 0.065 mg/L, 0.843 mg/L, and 11.90 μg/L, respectively. The probability of the eutrophication appeared in the Songhua Lake was 0.69, of them, risk-free type area was 19.21% of total lake area, slight risk type area was 30.10%, middle risk type area was 16.50%, heavy risk type area was 25.8%, hyper risk type area was 8.39%. In order to control the eutrophication in the Songhua Lake, maximum permission discharges of total phosphorus and total nitrogen to the lake would be 2,123.78, 7,018.82 t/a, respectively.     

中等实验规模下不同营养环境对苦草(Vallisneria natans)生长的影响

本实验分别选用武汉东湖中营养和富营养湖区的湖水和底泥,并在水柱中添加氮或磷以设置高营养、中营养、中营养添加磷、中营养添加氮等四种营养环境.测定这四种营养条件下栽培苦草(Vallisneria natans)的生长和生化指标变化,探讨不同营养环境对苦草生长的影响机制.实验结果表明,苦草的生物量、叶数和新芽数等生长指标在中营养环境最高,中营养环境添加磷次之,中营养环境添加氮较低,在高营养环境最低;苦草可溶性糖和游离氨基酸含量在高营养环境中最高,在中营养环境、中营养环境添加磷和中营养环境添加氮等处理间没有明显差异.结果分析表明,高营养环境影响苦草的碳氮代谢水平并抑制苦草生长,这可能是由于苦草过量富集高营养环境中的氮素造成的;中营养环境中氮的升高会在一定程度上抑制苦草的生长,而磷的升高对苦草生长没有明显抑制作用.     

云南阳宗海大气氮、磷沉降特征

大气氮、磷沉降是湖泊水体氮、磷入湖的重要途径之一.为了解阳宗海氮、磷沉降对湖泊富营养化的潜在影响,于2012年5月-2014年4月通过监测阳宗海大气氮、磷沉降,估算氮、磷的大气沉降通量,揭示阳宗海大气氮、磷沉降随时间变化的特征,分析其来源、影响因素等.由于阳宗海是磷限制湖泊,本研究在估算大气氮、磷沉降通量的基础上,特别比较了大气磷沉降入湖量与非点源磷的入湖量,以此评估大气沉降输入磷对湖泊富营养化的潜在影响.研究结果表明:阳宗海总氮年平均沉降通量为248 mg/m~2,春、夏、秋和冬季平均分别为200、306、274和214 mg/m~2,其中夏季沉降通量最大,原因与降雨量增加有关;总磷年平均沉降通量为24 mg/m~2,春、夏、秋和冬季平均分别为18、31、19和27 mg/m~2.大气磷沉降与输入阳宗海的总磷量相比很小,对阳宗海富营养化影响较小.     

The large-scale flux of nutrients from land to water and the eutrophication of lakes and marine waters

The large-scale flux of nitrogen and phosphorus in modern society is coupled to the exponentially growing world population. During the last three decades there has been a several-fold growth in use of nitrogen (N) and phosphorus (P), for example, for agriculture production, in chemical products such as in detergents, and as food additives. Feeding a growing population means increased human nutrient excretion.

The mobility of N differs from that of P. For the easily mobile nitrate ion, river exports are positively correlated to the size of local human populations. P on the other hand is fixed in different systems, at least temporarily. Modern agro-ecosystems accumulate about 60% of the annual input of P. The Stockholm region representing an urban ecosystem served by dephosphatation in sewage, accumulated about 80% of imported P during 1990. With increasing accumulation there is an apparent risk for increasing non-point source pollution.

In some shallow recipient lakes the sediments have been saturated with P. Even after the reduction of external loading these lakes are exporting more P than they are importing. Lakes normally are traps for P.

In order to prevent damage to natural resources and to stop the large-scale flux of nutrients from land to water, the world population growth rate must be decreased and a number of measures taken: agricultural structures must be changed including new concepts for the use of fertilizers; new municipal sewage treatment processes must be developed permitting high-degree recycling of nutrients; unnecessary use of nutrients must be stopped, for example, in detergents and by reducing nutrient additives in food and drinks. Cola drinks, for example, contain 180 mg P l⁻¹, a concentration about 350 times higher than that of the effluent (0.5 mg P l⁻¹) from modern sewage treatment plants operating with dephosphatation. Financial resources and effort are required to stop large-scale eutrophication of marine waters.     

骆马湖营养盐收支

根据对骆马湖1998年度营养盐（氮,磷）收入和支出的研究,结果表明,入湖氮,磷量分别为15764．78t和1035．53t,其中通过河道入湖的氮磷量最大,其年入湖氮磷量分别为13598．05t和942．35t,分别占总来源量的86．3％和91．0％,氮,磷在骆马湖湖体中的滞留量和沉降量较,滞留量分别为1532．65t和221．63t,分别占总来源量的9．7％和21．4％,沉积量分别为205．47t和199．95吨,分别占总业源量的1．3％和19．3％,湖水氮,磷蓄积变化大,湖水浓度升高较快,氮磷负荷较大,年平均负荷量分别为总氮42．04％g/m^2和总磷2．76g/m,^2。