白洋淀表层沉积物氮磷分布、储量及污染评价

白洋淀是雄安新区核心生态功能区,为查明白洋淀表层沉积物氮磷分布特征、储量及污染程度,系统开展了氮磷营养盐调查及污染评价。结果表明：白洋淀底泥层总氮含量为528.5~10566.5 mg/kg,均值为2859.91 mg/kg,总磷含量为425.7~2446.0 mg/kg,均值为789.22 mg/kg;过渡层总氮含量为318.5~4662.0 mg/kg,均值为1706.7 mg/kg,总磷含量为315.05~976.30 mg/kg,均值为598.97 mg/kg;表层沉积物总氮总储量为15.86×104 t,其中底泥层总氮储量为3.76×104 t,过渡层总氮储量为12.10×104 t;总磷总储量为5.54×104 t,其中底泥层总磷储量为1.02×104t,过渡层总磷储量为4.52×104 t。根据综合污染指数法评价结果,白洋淀湿地底泥层氮磷污染程度均为重度,过渡层除烧车淀为重度外,其余各淀泊均为中度或轻度。     

长江口水下三角洲表层沉积物有机质分布特征

根据对长江口水下三角洲31个表层样沉积物粒度、总有机碳(TOC)、总氮(TN)的测定,得出了粒度及有机质的分布特征,利用C/N比分析有机质来源及不同来源的贡献率。研究结果表明: 1)长江口水下三角洲表层沉积物平均粒径介于3~8Φ之间,存在由陆向海变细的趋势; 2)TOC含量在0.1% ~1.2% 之间,平均值为0.52%; TN含量介于0.02% ~0.08% 之间,平均值为0.057% 。TOC和TN含量的分布特征相似,具有自陆向海、由低至高的变化趋势,这主要是受到沉积物粒径的影响,但是TOC在崇明岛东侧和九段沙东侧有两个高值点,可能与人类活动或局地因素有关; 粒度校正之后,TOC含量在0.40% ~1.67% 之间,平均值为0.68%; TN的含量介于0.05% ~0.10% 之间,平均值为0.07% 。TOC含量在近岸地区略高,TN含量是北部地区略高于南部地区,并且TOC和TN都在崇明岛东侧和九段沙东侧有两个高值点; 3)C/N比值在6~16之间,平均值为9.6; 利用C/N比值估算得到的陆源有机碳含量在35% ~90% 之间,平均值为60% 。C/N比和陆源有机碳含量在长江口南支外围邻近海域表层沉积物中较高,表明南支带来了大量的陆源有机质入海,并呈舌状向东北方向凸出; 而在长江北支附近其值相对较低,表明北支径流影响相对减弱,潮流作用相对增强。研究表明,长江南支是主要的陆源有机质入海通道,而进入水下三角洲之后陆源有机碳分布受到了河口混合过程的显著影响。     

南极半岛西北海域表层沉积物中微植物有机质分布特征及其意义

南极半岛西北海域表层沉积特中，微植物有机质颗粒包括五种类型：现代孢粉、再沉积孢粉、具结构有机质残骸、无结构有机质颗粒以及海藻类。按成因可分为陆生物质和海生物质两大类。本文分析陆生微植物有机质、特别是再沉积孢粉和无结构有机颗粒的组分、丰度、时代及分布格局，指出区内表层沉积物可能属于近源补给成因，半岛陆架、南设德兰群岛岛架和岬湾等的水动力条件强于海峡中央，并探讨了物源与海流的关系。     

江苏潮间带表层沉积物重金属空间分布及污染评价

对采自江苏潮间带的824个表层沉积物中的重金属元素Cu、Pb、Zn、Cr、Cd含量进行测定,采用相关分析法对表层沉积物重金属来源进行了解析,根据海洋沉积物质量标准(GB 18668—2002)对沉积物进行分级评价,同时采用Hakanson潜在生态危害指数法进行污染评价。结果表明：江苏潮间带表层沉积物Zn、Pb含量均符合一类沉积物标准,Cr、Cd、Cu含量均符合二类沉积物标准;研究区Cu、Pb、Zn元素在物源或富集特征上具有相似性,Cd元素不受元素“粒度控制律”控制,其含量分布主要受人类活动影响;江苏潮间带表层沉积物重金属总体污染和潜在生态危害处于低风险级别,重金属潜在生态危害指数由大到小依次为Cd>Pb>Cu>Cr>Zn。     

云蒙湖表层沉积物重金属分布特征及风险评价

为了解云蒙湖表层沉积物中重金属的污染状况,选取云蒙湖沉积物中6种重金属(Cu、Zn、Pb、Cr、Cd、As)作为研究对象,测定并分析其在云蒙湖表层沉积物中的分布、来源及生态风险,以期为云蒙湖沉积物中重金属污染治理及饮用水安全保障提供依据。采用富集系数法、相关性分析及聚类分析对重金属来源进行分析,并选用富集系数法、地累积指数法和潜在生态危害指数法对重金属污染程度及潜在生态危害进行了评价。结果表明:云蒙湖表层沉积物中6种重金属Cu、Zn、Pb、Cr、Cd、As平均含量分别为20.9、73.1、23.1、62.0、0.4和4.5 mg/kg;与临沂市土壤背景比较,Cd、Zn和Cr的含量超过临沂市土壤背景值,Cd污染最严重。重金属来源分析结果显示:Cd受人类活动影响较大,可能与区域农业和林业施肥有关;Cu、Zn、Pb、Cr和 As这几种重金属以自然来源为主。综合富集系数法、地累积指数法和潜在生态危害指数法3种评价方法的结果得出,云蒙湖表层沉积物中Cd 为最主要的污染元素,且具有较强的生态危害。     

海南岛新村、黎安潟湖表层沉积物有机质分布与来源分析

通过对海南省陵水县新村港(33个)和黎安港(11个)表层沉积物样品的粒度、总有机碳(TOC)、总氮(TN)的测定分析, 得出了双潟湖表层沉积物的粒径与有机质的分布特征, 并利用C/N 比值计算了不同有机质来源的贡献率。研究结果表明:1)新村港和黎安港潟湖表层沉积物的平均粒径分别为0~8ø和6~8ø, 呈由岸及湖心粒径逐渐减小的趋势; 2)新村港表层沉积物TOC的含量介于0.027 % ~2.660 %, 平均值为1.06 %, TN的含量介于0.018 % ~1.461 %, 平均值为0.748 %, 在人类活动明显的村落附近区域TN值很高, 去除人类活动影响的这些值后, TOC和TN的空间分布均与平均粒径具有较好的相关性, 即呈湖中心含量较高、近岸含量较低的特征; 黎安港表层沉积物TOC的含量介于0.216 % ~1.950 %, 平均值为1.15 %, TN的含量介于0.019 % ~1.460 %, 平均值为0.45 %, 由于沉积物粒径空间分异小, TOC和TN的空间分布较均匀; 3)新村港表层沉积物C/N 比介于0.037~33.000之间, 平均值为4.73, 利用C/N 比估算得到陆源有机碳贡献率达1 % ~99 %, 平均值为47 % 。C/N 比值和陆源有机碳贡献率在新村港南北两侧近岸表层沉积物中比潟湖中心高, 这是由于北侧河流和南侧南湾岭陡坡雨水携带的植物碎屑为近岸沉积物提供了较为丰富的陆源有机质; 黎安港表层沉积物C/N 比介于1.1~11.5之间, 平均值为6.51, 整体值小于12, 有机质的C/N 比与陆源有机质贡献率的空间分布与新村港存在较大差异, 其有机质主要为海源。人类活动对新村港内有机质沉积影响明显。     

哈素海沉积物中氮和有机质的分布特征

针对哈素海富营养化日趋严重的现实,系统开展了湖泊沉积物中不同形态氮及有机质的空间分布和污染特征研究。结果表明,表层沉积物中TN、Org N、NH+4 N及有机质的水平分布均表现经向分异特征,Org N的分布特征主导了TN的水平分布格局,有机质与TN具有强相关性。沉积柱芯中TN随深度增加而递减,有机质和Org N与TN的垂向分布相似,尽管 NH+4 N的垂直变化分异较大,但仍表现于表层富集的特点。Org N为表层沉积物和沉积柱芯中氮的主导形态,NH+4 N为无机氮的主导形态,成岩过程中,沉积物中TN只有极少部分在发生矿化。沉积物中有机质主要来源于湖中芦苇等大型挺水植物及陆源输入。哈素海表层沉积物的氮污染对底栖生物已经产生了严重的生态毒性效应,对底栖生物群落及整个水生生态系统构成了严重威胁。     

渤海湾西部海域表层沉积物重金属含量分布与评价

通过分析测定渤海湾100个站位表层沉积物中重金属元素的含量,探讨其分布特征及富集状况,并通过地累积指数法和潜在生态危害指数法对渤海湾西部岐口凹陷海域底质环境进行了评价。结果表明：渤海湾西部海域表层沉积物中As、Hg、Cu、Pb、Cd的平均含量分别为12．9×10－6、0．031×10－6、29．5×10－6、27．4×10－6、0．159×10－6。结合5种元素的地球化学图及地累积指数法分析表明,研究区表层沉积物整体上未受到As、Hg、Cu、Pb、Cd的污染,而在高值区Pb和Cu达到轻度污染的水平;潜在生态危害指数法的评价结果指明,重金属元素的潜在危害程度顺序是Hg＞Cd＞As＞Pb＞Cu,研究区重金属的潜在生态危害轻微,只有在高值区,Hg和Cd才达到中等程度的生态危害。     

金沙江攀枝花段水系沉积物中重金属的分布特征及污染评价

对攀枝花地区金沙江水系沉积物中九个重金属元素的地球化学特征及空间分布特征进行了分析研究,并对各重金属的污染程度进行了初步评价。研究发现,重金属在支流与金沙江交汇点下游处含量高于上游处,这说明金沙江有一定的自净化能力。通过分析可知,重金属的污染程度为:Cu>V>Ti>Mn>Cr>Zn>As>Co>Pb,其中Cu、V、Ti、Mn污染严重,Pb为轻度污染。污染最严重的地区是攀钢冶金区、攀钢选矿区、攀钢采矿区以及攀钢尾矿坝。     

太湖五里湖表层沉积物中不同形态磷的分布特征

利用连续提取法(SEDEX)详细调查了太湖五里湖表层沉积物中不同形态磷的组成和分布特征。结果显示：其中磷的含量较高，受人为污染输入的影响较大，并且已经有了一定的释放。总磷的变化范围为2．05～4．05mg/g。平均约为2．80mg/g。总磷主要由无机磷组成(70％～90％)，大多数无机磷为CDB溶液提取的铁结合态磷(75％～85％)。CDB溶液的n(Fe)／n(P)都较小(2．0～5．3)。说明CDB溶液提取的铁主要是以无定形态存在的，并且铁与磷酸盐之间的吸附可能已经达到了平衡状态。除底部个别样品以外。多数样品n(Gorg)／n(Norg)较小(8．8～10．6)，所有样品的n(Gorg)／n(Porg)都较大(135～320)，表明沉积物在早期成岩作用过程中，湖泊内源自生有机质降解时有机磷优先释放。无机磷，特别是铁结合态磷，在氧化还原条件变化的情况下。能够通过沉积物一水体界面被再次释放到水体中去，这可能对湖泊的水体质量和营养状况有一定的影响。     

珠江中下游颗粒有机质的碳氮℃稳定同位素、氨基酸和木质素组成及其地球化学意义

从东江到珠江口采集了悬浮颗粒物,通过测定总有机质的元素（TOC、TN）、同位素（δ13C、δ15N）组成以及生物标志物（氨基酸、木质素）等地球化学性质,来揭示颗粒有机质的来源和组成。结果表明,浮游生物（13%-52%）和土壤（45%-77%）是珠江颗粒有机质的主要来源,植物（0%-11%）对颗粒物的贡献较小。颗粒有机质含有高比例的氨基酸碳（TAAC）,说明浮游生物对颗粒物的重要性。氨基酸的降解指数（DI）在-0.51到0.79之间,说明这些水生来源有机质的降解程度比较小。木质素的降解参数（Ad/Al、3,5-BD/V）较大,表明珠江颗粒有机碳的陆源来源主要是土壤。在颗粒物中检测到了少量的二氨基庚二酸（Dapa）,说明细菌对颗粒有机碳也有所贡献。不同环境中颗粒物的木质素组成主要与颗粒物丰度和粒径有关：（1）相对于河流,水库颗粒物中的木质素含量显著偏低,降解程度更高;（2）相对于中游,下游颗粒物丰度较高,木质素含量较高。     

Quantification and characterization of condensed organic matter in sediments from the Pearl River Delta and Estuary, South China

Nonhydrolyzable carbon （NHC） and black carbon （BC） were measured upon treatments with the HCl/HF/trifluoroacetic acid method, and with the combustion method at 375 ℃, respectively in three contaminated soils from the urban area of Guangzhou and twenty-two bulk and size-fractionated sediments from the Pearl River Delta and Estuary, China. The isolated NHC and BC fractions were also characterized using elementary analysis, radiocarbon accelerated mass spectroscopy （AMS）, solid state ^13C cross-polarization and magic angle spinning unclear magnetic resonance spectroscopy （^13C-CP/MAS NMR）, Fourier transformed infrared spectroscopy （FTIR）, and Raman microspectrometry. The results showed that the NHC and BC accounted for 25.6%-84.7 % and 4.14%-17.3%, respectively, of the total organic carbon （OC） with averages of 51.9% and 11.2% in the soils and sediments. For the less contaminated, low OC fiver and estuary sediments （WR and C08）, the OC and NHC concentrations increased with decreasing particle size.     

Retention of fly ash-derived copper in sediments of the Pandu River near Kanpur,India

A coal-based thermal power plant is situated on the bank of the Pandu River, which is a tributary to the Ganges near Kanpur. River sediments downstream from the ash pond outfall are contaminated by fly ash. In order to establish the role of soils and sediments in retaining fly ash-derived heavy metals, copper was investigated as a model metal. A maximum concentration of 70 ppm Cu could be leached from the fly ash, confirming that it is a major source of this metal. Soil samples and river sediments were examined for Cu adsorption in the natural state as well as after treatment with H₂O₂, EDTA, and H₂O₂ followed by EDTA. The organic fraction of the samples was determined, and it had a major control on removal of Cu from a solution with 10^–4 M initial concentration. Further characterization of organic matter indicated that with reference to natural samples, the humic acid fraction had a copper enrichment factor in the range 9.1–15.1. The factor for fulvic acids, in contrast, was between 3.5 and 5.5. This leads to the conclusion that river deposits rich in humic acids would withstand relatively high metal loads. Only when the metal input exceeds the maximum retention potential, would the metal be fractionated into the aqueous phase and act as a potential biocide.     

Characterization of organic matter in surface sediments of the Mackenzie River Basin, Canada

The particulate organic matter in < 63 µm surface sediments from the Mackenzie River and its main tributaries was studied using Rock-Eval pyrolysis and organic petrology. The organic matter in the sediments is dominated by refractory residual organic carbon (RC) of mainly terrigenous nature, as indicated by abundant inertinite, vitrinite, and type III kerogen. Sediments from the tributaries contained significantly more algal-derived organic matter than from the main channel of the river, highlighting the importance of low-energy system dynamics in the tributaries, which allows modest algal production, more accumulation, and better preservation of autochthonous organic matter. This is particularly true for tributaries fed by lacustrine systems, which showed the highest S1 and S2 fractions, and consequently higher total particulate organic carbon (POC) in the basin. Organic petrology of the sediment samples confirms abundant liptinitic materials (i.e., fat-rich structured algae, spores and pollen, cuticles, and resins). Forest fire and coal deposits are also confirmed to contribute to the basin. Assuming that suspended and fine surfacial sediments have a similar OC composition, the Mackenzie River is estimated to deliver a total POC flux of 1.1 Mt C/yr to its delta, of which 85% is residual carbon with liptinitic OC (S1 + S2) and S3 accounting for another 9% and 6%, respectively.     

Optical characteristics and solar photodegradation of dissolved organic matter in Arkansas River, USA

Dissolved organic matter （DOM）, a mixture of numerous organic compounds of 30 to 300000 D, exists in all natural water resources including rivers, lakes and oceans, and plays a very important role in global carbon cycle and ecology. The DOM molecules absorb UV light strongly in short wavelengths and prevent microorganisms from being damaged by solar UV irradiation. Meanwhile, the large DOM molecules are then photodegraded into inorganic carbon and smaller organic molecules which are easier for bacterioplankton to digest. The Arkansas River is one of the largest rivers in the US, and a major input of organic materials to the Mississippi River and Gulf of Mexico. However, the photochemical properties of the DOM in the river water have not been investigated. To study this photodegradation process of the Arkansas River, water samples from the river were collected, filtered, sealed into quartz flasks, and exposed to sunlight for up to 15 hours. Some samples were retrieved from the flasks at certain time intervals. The intensity of the sunlight was measured during the exposure process at 30 min to 1 hr intervals. UV-vis absorption, fluorescence emission, 3D fluorescence spectra and DOM concentrations were determined for all retrieved samples. It was found that the total DOM concentration decreased while the dissolved inorganic carbon （DIC） concentration increased in the samples. UV absorption and fluorescence intensity of DOM decreased exponentially. The disappearance rate of UV absorption varied with wavelength. The loss of integral fluorescence was about 2.6 times that of the UV absorption at the excitation wavelength. In addition, the quantum yields also decreased, and the peak position of 3D fluorescence scan shifted to shorter wavelength.     

Enzymatic and Microbial Degradation of Organic Matter in Lake Hongfeng, Guizhou Province, China

1IntroductionEnzymaticandmicrobialdegradationoforganicmatterhasabearingnotonlyonearlydiagene sis,butalsoonelementcyclingandmicrobedistributioninlakesediments.Somereportsshowedtheabundancevariationsoforganicmatterinsediments (BurdigeandGardner,1998;ArthurandDean ,1998;WanGuojiangetal.,2 0 0 0 ) .However,duetothecomplexchemicalcompositionoforganicmatter,mechanismsofenzymaticandmicrobialdegradationandvariationsofeachchemicalcomponentneedtobestudiedfurther.Underanoxiccondition ,SO2 -4 isanimpo…     

青海湖底沉积物的矿物物相及有机质保存研究

盐湖沉积环境是烃源岩发育的重要地质环境。本文以青海湖湖底沉积物为例，根据有机质与粘土矿物含最及矿物表面积的关系，分析了矿物学因素对盐湖相富有机质沉积物中有机质保存的影响。研究发现：湖底沉积物中有机质丰富，为上层水中的浮游生物和南河流携带束的陆地高等植物两种来源。矿物物相分析发现沉积物中粘土矿物含量达到32．4％，以伊利石为主。沉积物经密度分离后测试发现，有机碳含量与粘土矿物含量及矿物表面积之间具有很好的正相关性，说明粘土矿物吸附是青海湖底沉积物中有机质的主要赋存形式。     

Inorganic pollution of the sediments of the River Torrens, South Australia

The River Torrens plays a vital role in the economic, social and environmental life of South Australia. The river rises on the Adelaide Hills and flows west across the Adelaide Plains, bisecting the city of Adelaide and reaching the sea at the Gulf of St Vincent. The bed sediments of the Torrens were sampled from its headwaters to the coast and analysed for cadmium, chromium, copper, lead, phosphorus and zinc. With the exception of chromium, the concentration of every metal investigated lies above the national trigger value for sediment quality at some point along the course of the river. The sediments of the headwaters exhibit high values of copper and zinc, although these probably reflect natural background conditions rather than pollution. By contrast, in the residential areas that dominate the Adelaide Plains, almost every site is contaminated by lead and zinc, some to well beyond the point of biological damage. Several residential sites, notably those downstream of the city of Adelaide, are also polluted by cadmium. Within the industrial zone around the city, every site is contaminated by lead and zinc, with concentrations at some locations far beyond the threshold for ecological damage. Several industrial sites are also polluted by cadmium and copper. There are no national guidelines against which to assess the phosphorus content of the sediments. However, there is strong evidence that human activities have had a significant impact on phosphorus levels in the river. Major cyanobacterial blooms along the lower Torrens have been linked to the release of nutrients from the sediments, and phosphorus concentrations in the water have reached dramatic levels. Much of this contamination appears to be a consequence of past pollution practices. In particular, the severe pollution along the reach immediately to the west of the city may be largely attributed to the former concentration of metallurgical and chemical industries in that area. These problems are likely to persist indefinitely as modifications to the flow behaviour of the river mean that bed sediments are neither being moved downstream and flushed out of the system nor diluted by mixing with relatively uncontaminated deposits.     

Forms and bioavailability of phosphorus associated with natural organic matter

Natural organic matter （NOM） is an important ingredient in soil which can improve physical, chemical, and biological properties of soils and nutrient supplies. In this study, we investigated the spectral features and potential availability of phosphorus （P） in the IHSS Elliott Soil humic acid standard （EHa）, Elliott soil fulvic acid standard Ⅱ （EFa）, Waskish peat humic acid reference （WHa）, and Waskish peat fulvic acid reference （WFa） by fluorescence spectroscopy, FT-IR, solution 31P NMR, 3-phytase incubation and UV irradiation. We observed more similar spectral features between EHa and EFa as well as between WHa and WFa than between the two humic acids or two fulvic acids themselves. Phosphorus in WHa and WFa was mainly present in the orthophosphate form. However, only about 5% was water soluble. After treatment by both UV irradiation and enzymatic hydrolysis, soluble orthophosphate increased to 17% of WHa P, and 10%o of WFa P. Thus, it appears that a large portion of P in Waskish peat humic substances was not labile for plant uptake. On the other hand, both orthophosphate and organic phosphate were present in EHa and EFa. Treatment by both UV irradiation and enzymatic hydrolysis increased soluble orthophosphate to 67% of EHa P and 52% of EFa P, indicating that more P in Elliott soil humic substances was potentially bioavailable. Our results demonstrated that source （soil vs. peat） was a more important factor than organic matter fraction （humic acid vs. fulvic acid） with respect to the forms and lability of P in these humic substances.