垂向环流作用下湖泊沉积物磷迁移行为

以巢湖十五里河入湖河口原位底泥为研究对象,通过室内模型实验,模拟了垂向环流的动水条件下,溶解态无机磷(DIP)在泥水界面的释放-吸附过程,探讨了不同强度环流对河口底泥DIP迁移的影响行为.结果表明:垂向环流扰动会引起上覆水中溶解氧(DO)和悬浮颗粒物(SPM)含量明显上升,且其平衡浓度与扰动强度均呈正相关,但悬浮物中值...     

淡水沉积物中重金属对底栖生物毒性及其生物有效性研究

以淡水单孔蚓(Monopylephorous limosus)、伸展摇蚊(Chironomus tentans)为受试生物,以生长抑制率、死亡率、自断率为测试终点,研究了沉积物中5种重金属(Cu、Cd、Ni、Pb、Zn)对底栖生物的毒性效应,探讨了沉积物中酸挥发性硫化物(Acid Volatile Sulfide,AVS)和同时提取金属(Simultaneously Extracted Metals,SEM)与生物毒性之间的关系.结果表明:5种金属加标沉积物对淡水单孔蚓和伸展摇蚊的毒性顺序分别是Cd(LC50281 mg·kg-1)Ni(LC50646 mg·kg-1)Cu(LC50830 mg·kg-1)Pb(LC501040 mg·kg-1)Zn(LC501320 mg·kg-1);Cd(LC5026.3 mg·kg-1)Pb(LC50248 mg·kg-1)≈Cu(LC50256 mg·kg-1)Ni(LC50343 mg·kg-1)Zn(LC501400 mg·kg-1).当SEM/AVS1时,除Cd外其他4种金属对淡水单孔蚓、伸展摇蚊幼虫均表现出较为明显的毒性效应,而且Pb、Ni、Zn对两种生物的毒性效应与SEM/AVS值之间表现出良好的一致性,说明SEM/AVS可以较好的反映沉积物中重金属的生物有效性.     

Inhibitory effect of nitrobenzene on oxygen demand in lake sediments

Nitrobenzene is an important raw material and product,which presents a heavy threat to the ecosystem.The potential impacts of nitrobenzene on sediment oxygen demand (SOD) were studied in lake sediment ...     

上海市湖泊沉积物重金属的空间分布

上海快速城市化发展导致公园湖泊表层沉积物中重金属Cd、Hg、Cu、Pb和Zn含量出现富集,其最大值已超出各自土壤背景值3.8~5.8倍.这5种重金属的污染热点主要出现在核心城区的人口和交通密集区、浦西沿江老工业区以及郊区新兴工业区附近.基于土地利用类型、交通变量、人口密度和工业点源等预测变量构建了高精度的土地利用回归模型,推测沉积物中Cd和Pb浓度分别主要受路网密度和商业用地影响,Hg和Cu主要受商业用地和工业点源数影响,Zn主要受居住用地和工业点源数影响.     

沉积物中磷形态与湖泊富营养化的关系

应用乙二胺四乙酸法对长江中下游太湖、巢湖和龙感湖等3个湖泊表层沉积物中磷的形态进行连续提取和测定.结果发现,在表层沉积物中,3个湖泊钙磷的百分含量比较接近,占总磷的30%左右,太湖和巢湖铁磷的百分含量显著高于龙感湖,而龙感湖有机磷的相对含量较高,可达40%~50%.这3个湖泊沉积物中有机磷形态差别十分明显,其中太湖沉积物中的有机磷主要以酸可提取有机磷形式存在,巢湖沉积物中酸可提取有机磷约占总有机磷的一半,而龙感湖的有机磷大部分与腐殖酸结合.沉积物中酸可提取有机磷的释放可能又是一个导致湖泊富营养化的重要过程.     

Characteristics and distribution of phosphorus in surface sediments of a shallow lake

Phosphorus ( P ) in sediments plays an important role in shallow lake ecosystems and has a major effect on the lake environment. The mobility and bioavailability of P primarily depend on the contents of different P forms, which in turn depend on the sedimentary environment.Here, sediment samples from Baiyangdian (BYD) lake were collected and measured by the Standards, Measurements, and Testing procedure and Phosphorus-31 nuclear magnetic resonance spectroscopy (31P NMR) to characterize different P forms and their relationships with sediment physicochemical properties. The P content in the sediments varied in different areas and had haracteristics indicative of exogenous river input. Inorganic P (334–916 mg/kg) was the dominant form of P . The 31P NMR results demonstrated that orthophosphate monoesters (16–110 mg/kg), which may be a source of P when redox conditions change, was the dominant form of organic P (20–305 mg/kg). The distribution of P forms in each region varied greatly because of the effects of anthropogenic activities, and the regions affected by exogenous river input had a higher content of P and a higher risk of P release. Principal component analysis indicated that P bound to Fe, Al, and Mn oxides and hydroxides (NaOH-P) and organic P were mainly derived from industrial and agricultural pollution, respectively. Redundancy analysis indicated that increases in pH lead to the release of NaOH-P. Organic matter plays an important role in the organic P biogeochemical cycle, as it acts as a sink and source of organic P .     

易分解碳输入模式对沉积物共代谢效应的影响

通过构建室内微宇宙系统,运用稳定碳同位素示踪法,解析混合处理组中各有机组分代谢释放的CO2含量,探讨相对易分解碳源的输入对湖泊沉积物有机碳矿化过程的影响.结果表明:添加相对易分解碳源的处理组中,CO2排放量明显升高,较对照组分别提高了45.49％(单次添加组)、52.61％(重复添加组)和57.65％(连续添加组),分...     

底泥疏浚对湖泊沉积物的生态毒性效应的影响

采用淡水沉积物质量基准和微生物毒性试验方法,对疏浚前后五里湖沉积物提取液和全底泥沉积物的生态毒性进行了研究与分析.结果表明,疏浚后,沉积物中各重金属污染物的总体含量均显著降低,但是铬、铅和镍的含量仍然分布在阈值效应低值(TEL)和可能效应水平值(PEL)之间的灰色区域,仍可能对水体生态系统产生不良影响;疏浚后1个月,沉积物提取液中发光菌发光试验的EC50值降低约50%,毒性增加近1倍;与疏浚前相比,全底泥沉积物的细菌毒性试验的EC₅₀值降低11%～30%;全底泥月芽藻毒性试验的EC₅₀值也有显著降低.     

湖泊水库暴雨径流悬移质模拟研究

本文根据暴雨径流悬移质浓度变化特点，采用最小二乘法对暴雨期间污染源各监测数据进行回归分析处理，并考虑到表面风力，建立了湖泊水库暴雨径流是移质模型。对滇池湖泊某次暴雨过程的悬移质泥沙进行了模拟计算，得到了该次暴雨径流的泥沙淤积等值线分布图。计算结果表明，该模型应用于滇池湖泊是成功的，具有较强的通用性。     

Deformity frequencies of benthic marine diatoms associated with contaminated sediments in Hong Kong

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中国土壤和湖泊沉积物中钚同位素分布特征和应用研究

钚(Pu)是与核工业密切相关的、以痕量或超痕量存在于环境中的重要放射性核素。综述了近年来中国土壤和湖泊沉积物中^239+240Pu的分布特征、迁移行为及其在环境地球化学中的应用。结果显示:中国土壤和湖泊沉积物中^239+240Pu沉降通量分别为7.31~554.00和4.80~240.60 MBq/km²,因研究区域所处环境及纬度的差异而变化;²⁴⁰Pu/²³⁹Pu同位素比值分别为0.048~0.307和0.164~0.193,平均值分别为0.181±0.026和0.179±0.021;全球大气核试验沉降是中国土壤和湖泊沉积物中^239+240Pu的主要来源。作为重要的长寿命放射性核素,在今后的研究中应加强Pu同位素与其他放射性核素示踪技术(¹³⁷Cs、²¹⁰Pb和⁷Be示踪法等)、遥感技术以及传统研究方法相结合,有利于提升大尺度环境区域中Pu的分析精度,提高^239+240Pu放射性核素示踪技术的示踪效率。     

基于Web of Science和CNKI的湖泊沉积物文献计量分析

为了解湖泊沉积物研究领域现状和未来发展趋势,采用信息可视化、网络分析的研究方法,以Web of Science（WoS）和中国知网（CNKI）数据库中近35年（1985—2019年）湖泊沉积物研究领域的论文作为数据来源绘制社会网络图谱,剖析湖泊沉积物研究领域的发展动态、研究热点及前沿趋势。结果表明：WoS数据库近35年来湖泊沉积物研究领域的发文量呈显著上升趋势,发文量位居前3的国家依次为美国、中国和德国;近5年中国发文量较高,但发文总被引频次相对较低;Bindler R、Birks H J B和Bakke J为该领域以第一作者发文量排名前3的作者,Journal of Paleolimnology、Hydrobiologia和Limnology and Oceanography为发文量排名前3的期刊。CNKI数据库的发文量滞后于WoS数据库,国内研究者有偏向于投稿国外期刊的趋势;CNKI数据库中湖泊沉积物研究领域发文量最高的期刊为《湖泊科学》,张恩楼、金章东和薛斌为发文量排名前3的作者。国内外湖泊沉积物研究领域的研究热点大致相同,主要包括沉积物重金属和有机物的污染与风险评估、湖泊沉积物与气候变化研究等方面,未来该领域在正定矩阵因子分析模型和多元统计方法包括相关性分析、聚类分析、因子分析等方向的研究有待进一步加强。     

原位技术控制湖泊沉积物中磷释放的研究

通过实验室模拟试验研究曝气供氧、沸石覆盖和硝酸钙等原位控制东洞庭湖沉积物磷释放技术效果,试验结果表明:好氧时,曝气供氧对上覆水磷浓度的控制效果较差,当溶解氧320%,水中磷浓度不随溶解氧含量的增加而增加,控制效果依次为:硝酸钙原位处理>沸石覆盖>曝气3未处理;厌氧时,控制效果依次为:硝酸钙原位处理>曝气>沸石覆盖>未处理;扰动条件下,控制水体中磷浓度效果依次为:投加硝酸钙原位处理>沸石覆盖>曝气>未处理,但硝酸钙处理在不同水力作用下保持上覆水磷浓度稳定性不如沸石覆盖;沸石覆盖和硝酸钙原位处理都增大了水体耗氧量,其中以硝酸钙处理最为显著,可使水体复氧功能减弱.     

Rates and processes affecting As speciation and mobility in lake sediments during aging

Sediments from an arsenic(As) contaminated groundwater vent site were used to investigate As( Ⅲ) binding, transformation and redistribution in native and iron oxide amended lake sediments using aging spiked batch reactions and a sequential extraction procedure that maintains As(V) and As( Ⅲ) speciation. In the native sediments, fractionation analysis revealed that 10% of the spiked As( Ⅲ) remained intact after a 32-day aging experiment and was predominantly adsorbed to the strongly sorbed(NH_4H_2PO_4 extractable) and amorphous Fe oxide bound(H_3PO_4 extractable) fractions. Kinetic modelling of the experimental results allowed identifying the dominant reaction path for depletion of dissolved As( Ⅲ) to As( Ⅲ)absorbed on to the solid phase, followed by oxidation in the solid phase. Arsenite was initially adsorbed primarily to the easily exchangeable fraction((NH_4)_2SO_4 extractable), then rapidly transformed into As(V) and redistributed to the strongly sorbed and amorphous Fe oxide bound fractions. Oxidation of As( Ⅲ) in recalcitrant fractions was less efficient. The iron oxide amendments illustrated the controls that iron oxides can have on As( Ⅲ) binding and transformation rates. In goethite amended samples As( Ⅲ) oxidation was faster and primarily occurred in the strongly sorbed and amorphous Fe oxide bound fractions. In these samples,19.3 μg Mn was redistributed(compared to the native sediment) from the easily exchangeable and crystalline Fe oxide bound fractions to the strongly sorbed and amorphous Fe oxide bound fractions, indicating that goethite may act as a catalyst for Mn(Ⅱ) oxidation, thereby producing sorbed Mn( Ⅲ/Ⅳ ), which then appears to be involved in rapidly oxidizing As( Ⅲ).     

Spatial and historical distribution of organic phosphorus driven by environment conditions in lake sediments

The chemistry of sedimentary organic phosphorus (OP) and its fraction distribution in sediments are greatly influenced by environmental conditions such as terrestrial inputs and runoffs. The linkage of OP with environmental conditions was analyzed on the basis of OP spatial and historical distributions in lake sediments. The redundancy analysis and OP spatial distribution results suggested that both NaOH-OP (OP extracted by NaOH) and Re-OP (residual OP) in surface sediments from the selected 13 lakes reflected the gradient effects of environmental conditions and the autochthonous and/or allochthonous inputs driven by latitude zonality in China. The lake level and salinity of Lake Hulun and the runoff and precipitation of its drainage basin were reconstructed on the basis of the geochemistry index. This work showed that a gradient in weather conditions presented by the latitude zonality in China impacts the OP accumulation through multiple drivers and in many ways. The drivers are mainly precipitation and temperature, governing organic matter (OM) production, degradation rate and transportation in the watershed. Over a long temporal dimension (4000 years), the vertical distributions of Re-OP and NaOH-OP based on a dated sediment profile from HLH were largely regulated by the autochthonous and/or allochthonous inputs, which depended on the environmental and climate conditions and anthropogenic activities in the drainage basin. This work provides useful environmental geochemistry information to understand the inherent linkage of OP fractionation with environmental conditions and lake evolution.     

水葫芦修复富营养化湖泊水体区域内外底栖动物群落特征

于2010年8~10月对滇池白山湾人工控制性种养的约70hm2的水葫芦区、近水葫芦区和远水葫芦区采样分析,探讨了水葫芦种养工程区域内外底栖动物群落结构特征.结果表明,在水葫芦区、近水葫芦区及远水葫芦区,底栖动物总密度分别为294.5,159,261ind/m2,其中寡毛类的霍甫水丝蚓(Limnodrilus hoffmeisteri)为绝对优势种,分别占各自区域总密度的68.3%,59.6%和86.0%.逐步回归分析显示,水体总磷(TP)和底泥非稳定态磷(Labile-P)与霍甫水丝蚓密度呈显著性正相关(P < 0.01),表明霍甫水丝蚓对水体的富营养状况有很好的指示作用.水葫芦区物种组成及生物多样性指数均高于近水葫芦区和远水葫芦区(P < 0.05),在水葫芦区、近水葫芦区和远水葫芦区分别共采集到底栖动物14种、10种和6种;Shannon-Wiener多样性指数分别为1.10,0.57和0.54.种植水葫芦后,在水葫芦区及近水葫芦区,10月份的Margalef、Shannon-Wiener、Simpson和Peilou指数较8月份和9月份有显著性增加(P < 0.05),而远水葫芦区,却未出现类似的结果.一定面积控制性种养水葫芦对大型富营养化湖湾水体无脊椎底栖动物群落结构未表现出不利影响.     

温度对湖泊沉积物中沉水植物残体厌氧分解的影响

淡水湖泊水生植物残体的腐烂分解过程为沉积物中的异养微生物提供了重要的碳源,但是目前关于温度对沉水植物残体有机质分解的影响研究还不够深入.本研究通过室内微宇宙模拟实验,研究了4℃和25℃时马来眼子菜残体在沉积物中厌氧分解特征及其主要的微生物代谢途径.结果表明,温度对马来眼子菜残体的分解影响显著,25℃实验组沉积物中总有机碳（TOC）和纤维素去除率显著高于4℃实验组.25℃实验组沉积物初始腐殖质占TOC比例为18.23%±1.47%,90 d后达到约46%,这说明微生物对马来眼子菜残体的分解促进了沉积物腐质化.此外,温度升高促进了纤维素降解细菌（如拟杆菌门,Bacteroidetes）的生长繁殖,且硫酸盐还原细菌（如GOUTA19、脱硫球菌属（Desulfocuccus）、LCP-6、HB118）和铁还原细菌（如地杆菌属,Geobacter）是沉积物中主要的优势菌种.在25℃条件下,微生物硫酸盐还原、铁还原和产甲烷作用占马来眼子菜残体厌氧代谢的比例分别达到37.3%、27.8%和10.3%.综上所述,本研究表明温度升高促进了沉积物中马来眼子菜残体的厌氧分解,且微生物硫酸盐还原、铁还原和产甲烷过程在其厌氧分解过程中发挥了重要作用.     

珠江广州段水体、沉积物及底栖生物中的多氯联苯

对珠江广州江段水体、沉积物及底栖生物体内多氯联苯有机污染物进行了初步的调查研究.结果表明,广州江段7个样点水体中多氯联苯类有机污染物平均含量为2.3ng/L,各点含量无显著差异;沉积物中多氯联苯类有机污染物平均含量为31.52g/kg,各点有显著差异,其中以广州江段南航道y03样点最高,达65.31g/kg;底栖生物体内多氯联苯含量平均为181.77g/kg,其中也以y03样点最高,达317.37g/kg.多氯联苯在水体、沉积物及生物体3者之间存在明显的富集和放大作用.