滇池沉积物有机磷形态分级特征

考察沉积物磷对湖泊富营养化贡献时,大量研究涉足无机磷,对有机磷的研究十分薄弱.针对滇池的33个沉积物样品,采用有机磷分级提取方法,将沉积物有机磷分为活性磷、中等活性磷、非活性磷等三种具有不同稳定性的有机磷.结果表明:排除滇池西北部外源污染严重的样品后,沉积物有机磷与总磷有自北向南逐渐降低的变化趋势,有机质与总磷、活性有机磷、中等活性有机磷以及非活性有机磷都表现出了显著相关关系.沉积物活性有机磷和中等活性有机磷与NaHCO3提取无机磷均显著相关,说明二者具有潜在的生物有效性.     

湖滨带的功能及其管理

湖滨带是水陆生态交错带的一种类型，具有重要的生态、社会和经济价值。湖滨带功能主要包括：缓冲带功能、生物多样性及生境保护功能、护岸功能和经济美学价值。湖滨带退化的原因主要是人为因素引起的生物群落结构的逆向演替及生态功能的下降，退化湖滨带生态恢复与重建的理论基础是恢复生态学。湖滨带管理的核心是湖滨带植被的正确管理，管理的目标是保护与湖滨带密切相关的各种资源和水生态系统，其管理措施主要包括：(1)建立植被缓冲带；(2)加强湖滨带规划和管理的政策研究；(3)加强湖滨带生态监测系统及生态评价指标体系的建设；(4)促进湖滨带管理的公众参与。     

太湖湖滨湿地沉积物氮磷与2种挺水植物氮磷的关系

在无锡太湖湖滨带布设3条样带、36个样点进行了调查,分析了表层沉积物（0~15 cm）和芦苇（Phragmites australis（Cav.）Trin.）、茭白（Zizania latifolia（Griseb.）Turcz.）2种挺水植物w（N）、w（P）的变化,揭示了沉积物N、P的空间分布以及与2种挺水植物N、P的关系。结果表明：（1）表层沉积物w（N）自上而下分别为7.89~4.24 mg.g-1（0~5 cm）、7.56~3.81 mg.g-1（0~10 cm）、7.61~3.77 mg.g-1（0~15 cm）,w（P）分别为1.293~0.532 mg.g-1（0~5 cm）、1.112~0.497 mg.g-1（0~10 cm）、0.952~0.471 mg.g-1（0~15 cm）。（2）生态修复区表层沉积物N、P的水平变化规律一致,按陆向辐射区-水位变幅区-水向辐射区依次递减,而从垂直变化来看,w（N）、w（P）均以表层最高,并依次向下层递减;硬质护坡区P的变化与之一致,但N的水平分布却按陆向辐射区-水位变幅区-水向辐射区依次递增,垂直分布呈现表层最低,并依次向下层递增变化。（3）2种挺水植物w（N）、w（P）不同,芦苇对N、P的吸收明显高于茭白（芦苇地上部分w（N）31.75~42.61 mg.g-1,地下部分w（N）13.57~18.21 mg.g-1;茭白地上w（N）14.78~23.57 mg.g-1,地下部分w（N）13.57~18.21 mg.g-1,而芦苇地上部分w（P）3.62~5.08 mg.g-1,茭白地上部分w（P）1.42~1.93 mg.g-1,地下部分w（P）0.35~0.57 mg.g-1）。2种挺水植物地上部分N、P吸收量远远大于地下部分吸收量。（4）相关分析表明,2种植物地下部分w（TP）与沉积物w（TP）呈正相关,而芦苇地下部分w（TP）与沉积物w（TP）相关性显著（P〈0.05）,说明芦苇根系对沉积物中的P具有强烈吸附作用。（5）2种植物对太湖中沉积物N、P分配有显著影响,生态恢复区沉积物中w（N）显著高于硬质护坡,而w（P）较硬质护坡显著降低,适度恢复水生植被可有效缓解湖泊水体的富营养化。     

滇池及其河口沉积物中重金属污染评价

本文对滇池及其入湖河口表层沉积物中As、Pb、Cd、Cr、Cu、Zn和Hg等重金属含量进行了分析,并采用地质累积指数法和潜在生态风险指数法评价了其污染程度和生态危害.结果表明,滇池草海北部重金属含量最高,草海及其河口重金属污染强度明显高于外海及其河口;以"全国土壤环境质量标准"为依据,As和Cd是沉积物中主要的超标污染物.地质累积指数法评价结果表明,草海及其河口沉积物中Cd达到了"严重"污染程度,是主要重金属污染物,其他金属总体处于"中度"以下污染程度;外海及其河口所有重金属基本处于"清洁"到"偏中度"污染程度.潜在生态风险评价结果表明,草海及其河口沉积物总体上达到了"很强"的潜在生态危害程度,而外海及其河口大部分区域总体属于"低度"危害程度.Cd是最主要的潜在生态危害重金属污染物,其次是Hg、As、Pb和Cu,而Zn和Cr对潜在生态危害指数的贡献率很小,在整个研究区域产生的潜在生态风险均为"轻微".相关性和主成分分析结果表明,滇池表层沉积物中Cu、Pb、Zn、Cd、Hg和As可能有相似的污染来源,而Cr主要受地球化学成分影响.     

东昌湖表层沉积物中氮的赋存形态

研究了东昌湖表层沉积物中可转化态氮(TTN)、非可转化态氮(NTN)以及可交换态氮(EN)、可矿化态氮(MN)的赋存特征.结果表明:(1)15个表层沉积物样品TN含量变化在1071.31—1450.55 mg.kg-1之间,与国内研究较多的非城市湖泊相比,底泥的营养水平并不是太高.(2)东昌湖表层沉积物的TTN平均963.55 mg.kg-1,NTN平均305.09 mg.kg-1.随着沉积物污染程度增高,TTN占TN比重减少,氮趋于稳定性强的形态发展.(3)东昌湖沉积物样品中EN平均47.68 mg.kg-1,沉积物MN平均210.72 mg.kg-1.随着东昌湖沉积物氮污染的积累,氮的生物有效性增强,氮的利用率提高.(4)东昌湖表层沉积物不同形态可转化态氮的释放顺序为离子交换态氮(IEF-N)→弱碱浸取态氮(WAEF-N)→强碱可浸取态氮(SAEF-N)→强氧化剂可浸取态氮(SOEF-N),在TTN中所占比例顺序依次为SAEF-N(50.52%)>SOEF-N(40.87%)>IEF-N(4.52%)>WAEF-N(4.09%).     

湖滨带植物群落对挟沙水体氮、磷污染物的截留效果

利用菖蒲(Gladiolus hybridus)、菱(Vallisneria spiralis)、黑藻(Hydrilla verticillata)、苦草(Vallisneria spiralis)、狐尾藻(Myriophyllum spicatum)及菹草(Potamogeton crispus)构建的人工湖滨带对挟沙水体氮、磷污染物的截留效果进行了研究。结果表明:人工湖滨带在截留水体悬浮泥沙颗粒物的同时可有效截留水体中的氮、磷营养物质,对防止富营养化具有积极的作用。一定的水力负荷下,滞留时间12h时,夏秋季节人工湖滨带对氮、磷的截留百分率分别为21.5%、34.8%,滞留24h时的氮、磷截留率分别为25%、31.1%。在冬春季节,滞留时间24h时,菹草对挟沙水体氮、磷的截留率分别为6.67%、10.83%,滞留时间48h时的总磷截留率为6.84%。不同水流滞留时间下人工湖滨带对挟沙水体氮磷的截留效果不同,滞留时间越长效果越明显,因此须保证一定的滞留时间才可取得较好的氮磷截流效果。人工湖滨带在截留径流氮、磷营养物的过程中,泥沙对氮、磷的吸附携带作用不容忽视。     

巢湖湖滨带沉积物间隙水溶解性有机质的光谱特征与时空差异

利用三维荧光光谱(3DEEM)和平行因子分析法(PARAFAC)研究巢湖湖滨带沉积物间隙水中溶解性有机质(DOM)含量组成、剖面分布特征及主要来源。结果表明,间隙水中DOM含有3种荧光组分,包括类腐殖质组分C1(275 nm, 365 nm/467 nm)、类腐殖质组分C2(330 nm/407 nm)和类酪氨酸组分C3(275 nm/319 nm)。在空间分布上,远岸带DOM总荧光强度均值为(0.432±0.306) RU,低于近岸带DOM总荧光强度均值[(0.583±0.478) RU],同时近岸带荧光强度均值大于湖心点,各点位垂直剖面上荧光强度随沉积物深度呈现下降趋势;在时间分布上,沉积物间隙水夏季DOM总荧光强度均值为(0.390±0.301) RU,小于冬季[(0.584±0.453) RU];此外,近岸带DOC浓度高于远岸带,远岸带DOC浓度高于湖心点,冬季各断面DOC浓度高于夏季;随着沉积物深度的增加,DOC浓度首先呈现升高趋势后迅速随深度增加而降低,在底泥界面10 cm以下保持稳定状态;冬季腐殖化指数(HIX)高于夏季,荧光指数(FI)和生物源指数(BIX)表明沉积物间隙水DOM受到内源中生物源与外源污染中陆源的共同影响,受到内源中生物源影响更大。该研究可为巢湖湖滨带水环境管理与面源污染控制提供一定参考。     

滇池沉积物中重金属污染特征及其生态风险评估

采集了滇池北部和中心区域2根柱状沉积物样品,分析其常量元素（Fe、Mn、Al、Ti、Ca、K）、微量元素（Ba、Sr、Cu、Pb、Zn、V、Cd）剖面分布特征,并采用H？kanson潜在生态危害指数法对典型重金属（Cd、Cu、Zn、Pb）进行了污染潜在生态风险评估。结果表明：沉积物中常量元素以Fe2O3、CaO及Al2O3为主,MnO、K2O及TiO2含量较少,变化范围是Fe2O3为8.0～14.9%、MnO为0.1～0.2%、Al2O3为9.0～20.1%、TiO2为1.5%～2.8%、CaO为0.4～21.7%、K2O为1.5～2.0%;微量元素Pb, Cd, Zn, Ba, Cu, Sr 及V含量均较高,变化范围是Pb为73.8～105.3 mg·kg^-1、Cd为1.0～3.4 mg·kg^-1、Zn为123.4～210.6 mg·kg^-1、Ba为264.8～435.7 mg·kg^-1、Cu为77.5～133.5 mg·kg^-1、Sr为34.9～137.5 mg·kg^-1以及V为177.7～284.7 mg·kg^-1。尤其表层0～12 cm内（1950 s以后）,各元素含量值均明显高于12 cm以下各值,20世纪50年代后滇池流域内工农业发展及污染物输入是造成金属元素含量累积的主要因素。沉积物中典型重金属Cu、Zn、Pb、Cd污染潜在生态风险评估结果：Cu、Zn和Pb处于中度污染,且C if 值越接近表层（0～12 cm）其值越高,这表明自1950S后污染程度不断加重,其中 Cd 累积与污染比较严重,分析多种元素的多因子污染参数之和C d表明滇池沉积物中多种元素污染整体处于“较高”污染程度,分析多种元素的潜在生态风险指数RI表明滇池沉积物中重金属潜在生态风险处于“很高”水平。同时,滇池北部沉积物中重金属潜在危害较严重且近年来污染有加重趋势。     

人工景观生态湖滨净化带植物的遴选

对水生植物处理生活污水的效果等展开了一些初步的研究。利用盆栽试验,比较了香蒲、美人蕉等8种水生植物的净化效果,所选的8种植物对污水均有不同程度的去除效果。挺水植物对污水的净化效果和耐污能力均优于沉水植物。利用水生植物处理生活污水,5 d的停留时间可以使污水达到较好的去除效果。挺水植物中美人蕉和水竹对污水的净化效果比香蒲和灯心草更好;沉水植物中伊乐藻的净化效果最好。植物对污水的净化效率有明显的季节差异,冬季污水净化效率低于夏秋两季,沉水植物在不同季节脱氮除磷效果有显著的差异。     

Spatial distribution of phosphorus forms in sediments with different distances to the estuary of the Dianchi Lake,China

Effects of human activity on the distribution of phosphorus (P) forms were investigated for the sediments and porewaters in Daqinghe Estuary of Dianchi Lake, China. The concentrations of total P (TP), inorganic-P (I-P),and organic-P (Org-P), and the ratio of iron-bound P (Fe-P)/calcium-bound P (Ca-P) in the sediments decreased with the increasing distance from the sampling site to the estuary. This is probably due to the flocculant materials, e.g., ferric and aluminous salts, usually being added in the wastewater treatment processes. The concentration of ammonia in the sediment porewaters significantly decreased with the increasing distance from the sampling site to the estuary. Both concentrations of total nitrogen and nitrogen in the sediment porewaters decreased to some content with the increasing distance from the sampling site to the estuary. However, the concentrations of nitrate, dissolved total P (DTP), and TP did not have strong relationship with the distances from the sampling sites to the estuary. Pollution load and water quantity also had an important influence on the concentrations of P in sediments and its interstitial water in estuary sedimentary area.     

洱海沉积物不同分子量溶解性有机氮空间分布及光谱特征

利用超滤技术对洱海沉积物溶解性有机氮(DON)进行分子量分级,探究了DON各组分空间分布特征,并运用紫外-可见吸收光谱和三维荧光光谱对其结构进行了表征.结果表明,洱海沉积物总DON含量ω(DON)为23.46—61.40 mg·kg-1,平均值为37.19 mg·kg-1,空间分布总体呈现南部>北部>中部的趋势;分子量大于1K Da的大分子组分ω(>1KDa)占ω(DON)的比例为79.1%—93.0%,即洱海沉积物DON是以大分子为主.沉积物DON各组分的芳香性及腐殖化程度较高,芳香环取代基中活性官能团种类较多,且南部芳香性及腐殖化程度最高,北部芳香环取代基种类最多;大分子组分DON含有类富里酸荧光物质,其来源于陆源输入和微生物降解共同作用.由此可见,洱海沉积物DON主要由大分子物质组成,其腐殖化程度较高且含类富里酸荧光物质,而此类DON对藻类的生物有效性较低,这可能是洱海沉积物氮含量较高而上覆水氮浓度较低的原因之一,即沉积物DON分子组成及其结构特征可在一定程度上作为湖泊营养水平的衡量指标.     

Comprehensive evaluation of heavy metal contamination of sediment in Lake Dianchi by using modified AHP method and Cs dating

Through the use of general sampling and measurement by ¹³⁷ Cs dating, problems regarding the absence of monitoring data can easily be resolved. Further, weighted values need to be determined while Environment Quality Comprehensive Index (EQCI) is commonly used as applied in environmental quality comprehensive evaluation. In order to overcome the subjectivity in determining weights, the modified Analytical Hierarchy Process (AHP) method was designed. The modified AHP method involved the following key procedures: First, the parameters y_i1 and y_i2 were calculated based on the monitoring data; second, the factors were put in order according to the symbol and value of y_i1 and y_i2; third, the continuous odd integers, which represented the importance of factors, were given to factors according to their seating order; and, fourth, the factor weights were determined from the pair-wise comparison matrix calculated by the ratio of the given odd integers. Therefore, the weights were completely based on the monitoring data. In the present study, the comprehensive quality of sediments in five sections of Lake Dianchi were evaluated and the results indicated that the current contamination of sediments in each lake section is much more serious than at any other time in history.     

滇池湖泊生态系统水动力学模拟

针对滇池富营养化状况,依据滇池生态环境建设规划,在以前研究工作的基础上,综合考虑湿地植物、底泥、水域条件变化,根据水动力学原理建立了垂向平均的二维生态系统水动力学模型,模拟了滇池现有水体、拆除防浪堤水域扩展后水体和滇池湿地建成后总水体3种情况的流场和浓度场,以及入滇河道达标排放后的水质浓度场,分析了湿地植物和水域扩展对滇池流场的影响,以及水域扩展、湿地植物、入湖河流达标排放对滇池水质的影响。结果表明,水域拓展对滇池流场的影响是局部的,湿地植物对滇池流场的影响主要发生在湿地区域。水域拓展对滇池水质具有一定影响,TN、TP平均质量浓度由2.08和0.19 mg.L-1(现有水体)降至1.69和0.16 mg.L-1;人工湿地建设对滇池水体TN、TP浓度影响较大,湿地建成后平均质量浓度降至0.76和0.05 mg.L-1,基本达到GB 3838—2002《地表水环境质量标准》Ⅲ类水质标准;人工湿地建设完成并且入滇池河流达标排放后,TN、TP平均质量浓度分别降至0.17和0.01 mg.L-1,水质明显改善。因此,人工湿地建设及入滇池河流的达标排放对滇池生态环境的改善具有重要作用。     

Comprehensive evaluation of heavy metal contamination of sediment in Lake Dianchi by using modified AHP method and 137Cs dating

Through the use of general sampling and measurement by ¹³⁷ Cs dating, problems regarding the absence of monitoring data can easily be resolved. Further, weighted values need to be determined while Environment Quality Comprehensive Index (EQCI) is commonly used as applied in environmental quality comprehensive evaluation. In order to overcome the subjectivity in determining weights, the modified Analytical Hierarchy Process (AHP) method was designed. The modified AHP method involved the following key procedures: First, the parameters y _i1 and y _i2 were calculated based on the monitoring data; second, the factors were put in order according to the symbol and value of y _i1 and y _i2; third, the continuous odd integers, which represented the importance of factors, were given to factors according to their seating order; and, fourth, the factor weights were determined from the pair-wise comparison matrix calculated by the ratio of the given odd integers. Therefore, the weights were completely based on the monitoring data. In the present study, the comprehensive quality of sediments in five sections of Lake Dianchi were evaluated and the results indicated that the current contamination of sediments in each lake section is much more serious than at any other time in history.     

Distribution of aromatic amines,phenols, chlorobenzenes,and naphthalenes in the surface sediment of the Dianchi Lake,China

• The total organic pollutant concentrations in sediment were 27.4-1620 ng/g. • The phenol concentrations were relatively high in the sediment of the Dianchi Lake. • Average total concentrations decreased as follows: Caohai>Waihai>Haigeng Dam. • 1,4-dichlorobenzene, 3- or 4-methylphenol, 1,2,4-trichlorobenzene might be risks. Organic pollutants are widespread environmental pollutants with high toxicity, persistence, and bioaccumulation. Our aim was to investigate the distribution of aromatic amines, phenols, chlorobenzenes, and naphthalenes in the surface sediment of the Dianchi Lake, China. Nineteen surface sediment samples were collected from the Dianchi Lake, and 40 types of organic pollutants were analyzed via gas chromatography–mass spectrometry. The total organic pollutant concentrations in the surface sediment of the Dianchi Lake varied from 27.4 to 1.62 × 10³ ng/g. The concentrations of phenols were much higher than those in other water bodies but still within a controllable range, whereas the concentrations of the other organic pollutant classes were similar or even lower. The detection ratio of 3- or 4-methylphenol was the highest (100.00%) among the pollutants. The average total organic pollutant concentrations decreased in the following order: Caohai (540 ng/g)>the middle of Waihai (488 ng/g)>the edge of Waihai (351 ng/g)>Haigeng Dam (90.4 ng/g). Pearson analysis showed a strong correlation among 1-methylnaphthalene, 2-methylnaphthalene, 1,3-dinitronaphthalene, and 1,4-dinitronaphthalene (p<0.01). Caohai, the north lakeshore of Waihai and the south of Waihai showed higher risk because of high concentration; meanwhile, 1,4-dichlorobenzene, 3- or 4-methylphenol and 1,2,4-trichlorobenzene were more likely to cause risks.     

五里湖不同疏浚深度沉积物对氮磷释放的影响

对太湖东五里湖区污染沉积物样模拟了3种不同疏浚深度(0cm、30cm和60cm)下的60d形态氮磷释放实验,并对沉积物间隙水中氮磷的变化进行了分析。研究结果表明:疏浚与未疏浚比较,疏浚初期的0~10d内,沉积物对上覆水NH4 -N、NO2--N和TN释放增大,NO3--N释放减小,与疏浚后沉积物扩散层变薄和好氧环境的抑制有关,而对PO43--P、TP疏浚后次日出现短暂的释放现象外,此后均处于明显的磷释放受抑状态;疏浚约10d后,沉积物各氮磷形态释放出现分异现象,沉积物对水体的TN和TP释放受到显著抑制,其中20d后上覆水中NH4 -N含量的上升和PO43--P的缓慢增加,预示着底泥疏浚后仍有内源负荷回复的可能。     

应用物种敏感性分布法分析太湖及天目湖水体的生态风险

采用物种敏感性分布法(SSDs法),应用水生生物急性和慢性毒性数据计算了31种污染物在水中和其中疏水物质在沉积物中的预测无效应浓度(PNECwater和PNECsed),通过收集以往报道的16种污染物在太湖和天目湖的环境浓度,用商值法求得物质的风险商并进行排序.结果发现:蒽、菲、萘、荧蒽、阿特拉津和马拉硫磷在太湖的梅梁湾和五里湖具有很大的生态风险;毒死蜱、三丁基锡氧化物和环己锡虽无环境浓度报道但很有可能具有风险.