Paper plant effluent revisited-southern Lake Champlain, Vermont and New York

We used geologic and geochemical techniques to document the change with time of the distribution and concentration of contaminated bottom sediments in southern Lake Champlain near an International Paper Company plant. Our work, initiated in 1972, was expanded on behalf of Vermont citizens in a class-action suit against the International Paper Company. To update our 1972–1973 results, we collected nine cores in 1988 upstream and downstream from the paper plant effluent diffuser. Water content, volatile solids, organic carbon, and three ratios, Al/Si, Cl/Si, and S/Si, in addition to megascopic and microscopic observations, were evaluated to identify and trace the distribution of effluent and to measure the thickness of sediment affected by or containing components of effluent. Analyses were carried out on samples from the cores as well as from effluent collected directly from the plant's waste treatment facility. In 1973, two years after the plant opened, we cored near the diffuser; sediment contaminated with effluent was 4.5 cm thick. In 1988, in the same area, sediment contaminated with effluent was 17 cm thick. In 15 years, water content increased from 72 to 85 percent, volatile solids from 7 to 20 percent, and organic carbon from 2 to 12 percent. Cl/Si and S/Si were high only near the diffuser and were zero elsewhere. In the area of the diffuser, contaminated sediment appears to be accumulating at a rate of about 1 cm/yr. At a control location 22 km upstream (south) from the plant, the top, poorly consoli-dated layer was only 1 cm or less thick both in 1973 and in 1988. The class-action suit was settled in favor of the plaintiffs for $5 million.     

The early diagenesis of aliphatic hydrocarbons and organic matter in sedimentary particulates from Dabob Bay,Washington

Aliphatic hydrocarbon compositions were quantitatively characterized in plankton, sediment trap-collected particulate materials and sediments from Dabob Bay using high resolution glass capillary gas chromatography. The average net accumulation of individual hydrocarbons measured in a 1-yr series of sediment traps was compared with the net accumulation of corresponding compounds measured in three depth intervals of ²¹⁰Pb-dated bottom sediments. Systematic and rapid decreases in the net accumulation of individual hydrocarbons were observed from the sediment traps to the sediments. Most pronounced decreases were measured for planktonically derived hydrocarbon constituents (e.g. pristane and two unsaturated compounds) which are rapidly remineralized at or near the sediment-water interface. Consequently, the amount of each compound measured in deposited sediments is not necessarily a quantitative indication of its initial flux to the sediments. The n-alkanes (C_25,27,29,31). characteristic of terrestrial plant waxes, are the predominant hydrocarbons measured by 4–6 cm depth in these sediments and show reasonably constant net accumulation below this interval.Significant diagenetic alteration of the bulk organic matter contained in the average sediment trap particulate material is also noted through comparison with bottom sediments on the basis of organic C/N and δ¹³C measurements. Organic matter elementally similar to marine plankton is preferentially remineralized upon deposition of the sedimentary particulates. The residual organic matter remaining and buried in the bottom sediments closely resembles terrestrial organic matter.     

Suspended sediment transport,sedimentation, and resuspension in Lake Houston,Texas: Implications for water quality

Lake Houston is a man-made reservoir located northeast of Houston, Texas. The purpose of this investigation was to document suspended sediment transport, sedimentation, and resuspension in the lake with a view towards estimating the influence of sedimentation on water quality. Sediment traps were placed in strategic locations in the lake to collect suspended sediments. Samples were analyzed for bulk density, grain size, organic carbon, and a number of trace elements. These data were analyzed along with meteorological data to examine those factors which regulate suspended sediment input and dispersal, and the role of suspended sediments in controlling water quality within the lake. Sediment input to the lake depends primarily on the intensity of rainfall in the watershed. Sediment movement within the lake is strongly influenced by wave activity, which resuspends sediments from shallow areas, and by wind-driven circulation. The increased residence time of suspended sediments due to resuspension allows greater decomposition of organic matter and the release of several trace elements from sediments to the water column. Virtually all samples from sediment traps suspended between 1 and 5 m above the lake bottom contain medium to coarse silt, and even some very fine sand-sized material. This implies that circulation in Lake Houston is periodically intense enough to transport this size material in suspension. During winter, northerly winds with sustained velocities of greater than 5 m/sec provide the most suitable condition for rapid (<1 d) transport of suspended sediment down the length of the lake. Fluctuations in current velocities and the subsequent suspension/deposition of particles may explain variations in the abundance of coliform bacteria in Lake Houston.     

Horizontal and vertical variations in sedimentation and resuspension rates in a stratifying lake – effects of internal seiches

The temporal and spatial variations in the rate of sedimentation and sediment resuspension in Lake Rehtijärvi (southern Finland) were studied by sediment traps deployed in the stratifying and non‐stratifying regions of the lake. Both the gross sedimentation rate and the resuspension rate recorded by near‐bottom traps were significantly higher in the stratifying region (>20 m depth) than in the shallow part of the lake (2 m depth). These rate changes were caused by temporarily elevated hypolimnetic resuspension rates exceeding 40 g dry weight m^?2 day^?1 in July 2005, whereas in the shallow station no such peak was observed and the resuspension rate remained below 30 g dry weight m^?2 day^?1 throughout the study. The elevated resuspension rate in the hypolimnion could not be attributed to surface wave action or sediment disturbance by fish, but was due to the occurrence of internal seiches. The seiche amplitude was on average the highest in July, although the wind velocities were low; this was because winds temporarily were blowing along the longitudinal axis of the lake. Due to the steep slopes, the sediments of Lake Rehtijärvi are prone to redistribution and sediment focusing towards the accumulation areas also affected trap catches in the deep stations.     

Phosphorus fractions in sediment profiles and their potential contributions to eutrophication in Dianchi Lake

Dianchi Lake is a eutrophic lake in southwestern China. Sediment and the bottom water samples were taken from six sites in the east, west, south, north and center of the lake, respectively, in December 2002. Total phosphorus (TP) concentrations in sediments were high and reached a maximum value of 6.66 g/kg. There was a soluble reactive phosphorus (SRP) concentration gradient at the sediment–water interface. In the present study, sediment P was divided into loosely adsorbed P (NH₄Cl-P), redox-sensitive P (BD-P), metal oxides bound P (NaOH-P), calcium bound P (HCl-P), and organic P (Org-P). At three of the six sites selected, the concentrations of different P forms in sediments followed the order: NaOH-P, Org-P>HCl-P>BD-P>NH₄Cl-P in the profile, and in the southern lake the order was HCl-P>NaOH-P, Org-P>BD-P>NH₄Cl-P in the top 15 cm layers of the sediments. The sediment profiles showed that different forms of P had an increasing trend upward toward the sediment surface. There is a considerable potential for release from the sediment into the overlying water and sediment P could be the dominant factor determining the trophic status of the lake if the external load is reduced. An erratum to this article can be found at     

滇池湖泊磷负荷及其对水环境的影响

磷是滇池湖泊富营养化的限制性营养元素。滇池湖泊磷负荷来源一般可分为外环境发生源输入的磷负荷和内环境发生源输出的磷负荷两大类。累积在滇池湖泊内的磷,主要分布在水体与底部沉积物中,滇池湖泊水体中总磷浓度由北向南含量降低,底部沉积物中P2O5含量分布由北向南呈递增趋势。底部0-3m的沉积物P2O5含量由上至下呈明显递减趋势,表明滇池湖泊磷负荷逐年加重。近几年资料显示滇池湖泊单位面积磷负荷达1.52g/m2·a,超过总磷公认允许负荷量中危险值的11.7倍,滇池已成为富营养型湖泊。控制滇池富营养化,在解决入湖磷外负荷的同时,对湖泊底部沉积物中磷内负荷也应予以高度重视。     

Heavy metals in sediments of a large, turbid tropical lake affected by anthropogenic discharges

 Bottom-water data and trace metal concentration of Cu, Cr, Ni, Pb, Co, Zn, and organic matter in surficial sediment samples from 13 sampling stations of Lake Chapala in Mexico were studied. The lake is turbid with a great amount of flocculated sediments as a result of wind mixing, sediment re-suspension, and Lerma River discharges. Al distribution pattern in sediments was used as an indicator of the Lerma River discharges into Lake Chapala. The highest values of Cu (33.27 ppm), Cr (81.94 ppm), Pb (99.8 ppm), and Zn (149.7 ppm) were detected in sediments near the lake outlet. The bioavailable metal fraction is low for all metals except Pb, which shows 65–93% of the total metal concentration in bioavailable form. The minimum energy zone in the lake was related to organic matter concentration and was located in the SE part of the lake. An analysis of the studied parameters shows two zones: eastern zone (fluvio-deltaic) and central-western zone (lacustrine). Received: 9 September 1998 · Accepted: 16 November 1998     

Modern Sedimentation of Phosphorus and Its Microbial Decomposition and Concentration: An Example from Dianchi Lake, Yunnan, China

Dianchi Lake is one of the lakes with the richest phosphorus source in the world, in which the P2O5 content in the bottom sediments reaches averagely 0.51 wt % and maximally 1.92%. Studies indicate that this: extremely P-rich state is attributed mainly to the large volume (as high as hundred thousands of tons) of phosphatic matter coming into the lake as many rivers feeding the lake pass through a vast area of phosphate-mining districts, which then undergo weathering and particularly some human activities, including waste water discharge. When phosphatic matter enters the lake, its grained parts are firstly decomposed by phosphorus-decomposing bacteria, and finally accumulated in some geographically special parts of the lake, such as a bay area where water flow is much more slower than elsewhere in the lake. With the involvement of phosphorus-concentrating bacteria, the accumulated phosphates in the bottom sludge ultimately form phosphate minerals through deep-burial diagenesis.     

Spatial variations and distributions of phosphorus and nitrogen in bottom sediments from a typical north-temperate lake,China

Concentrations and vertical distributions of total nitrogen (TN), total phosphorus (TP) and their different forms in sediments obtained from nine locations of Lake Dalinouer in September 2008 were analyzed. The results demonstrated that TP in surface sediments ranged from 0.493 to 0.904 g/kg, and inorganic phosphorus was the main fraction of total phosphorus, ranging from 335 to 738 mg/kg. Simultaneously, the autogenetic calcium phosphorus (ACa-P) was the main fraction of inorganic phosphorus, ranging from 145.4 to 543.2 mg/kg. Vertical distribution of different phosphorus forms in different sediment cores was distinguishing, and most of them tended to increase toward the surface sediment, indicated that the phosphorus concentration was related to the humanity with a certain extent. The relationships between TP and occluded phosphorus and ACa-P were significant. Nitrogen in the sediment was composed mainly of organic nitrogen, accounting for grater than 80 % of TN. NO₃ ^?-N was the dominate fraction of inorganic nitrogen in the surface sediment, ranging between 51 and 346 mg/kg (151.1 ± 104.4 mg/kg), and accounting for between 2.2 and 17.7 % of total sediment nitrogen (6.2 ± 5.6 %). The ratio of organic carbon and TN in sediment was in range of 6.0–25.8 and presented a tendency of lake centre >lake sides, indicating that nitrogen accumulated in the sediments from lake sides came mainly from terrestrial source and nitrogen was mainly autogenetic in lake centre. Ratio of N:P in all sampling sites was below 14, indicated that N was the limiting nutrient for algal growth in this lake.     

Geo-environmental appraisal of the Meda creek,Saurashtra, Gujarat

Water chemistry, sediment texture, clay mineralogy and foraminiferal contents from the bottom of Meda creek were studied to assess the geo-environmental status of the creek. Water quality data for three seasons suggests domination of marine environment as pH remained above 8 and salinity above 35‰ throughout. Clay dominate the bottom sediments, except near mouth. Montmorillonite, illite and kaolinite are the major clay minerals in the sediments. In absence of any source rock in the catchment of the Meda creek, the presence of illite and kaolinite indicates their transportation and depositions from near coastal waters during high tides. Ammonia sp. is the most dominating foraminifera. Reworked forms as well as angular asymmetric forms of foraminifera were dominant in clay rich areas of the creek.     

Late Pleistostene-Holocene sedimentation in lakes of central Transbaikalia: Implications for climate and environment changes

We present integrated mineralogical, geochemical, and palynological data for Late Pleistocene-Holocene bottom sediments of Lake Arakhlei located in the Beklemishev tectonic basin in the southern Vitim Plateau (central Transbaikalia). The sediment samples were studied by X-ray diffractometry (XRD), Fourier-transform infrared (FTIR) spectroscopy, laser particle sizing, spore-pollen analysis, radiocarbon (¹⁴C AMS) dating, and XRF spectrometry. The cored 128 cm long section of lake sediments consists of two units: One is composed mainly of layered silicates (illite-smectite, illite, chlorite, chlorite-smectite, muscovite, and kaolinite) and organic matter (OM) but no carbonates from 0 to 80 cm and the other contains authigenic Ca-Mg carbonates (up to 30%) of Mg-calcite and excess-Ca dolomite from 80 to 128 cm. The sediments also contain a rare mineral weddellite CaC₂O₄2H₂O discovered for the first time in Transbaikalian lakes. The evolution of Lake Arakhlei and its drainage basin comprised four stages, with pollen zones that mark the Late Pleistocene and Holocene climate history of the Beklemishev basin. The reconstructed history of Lake Arakhlei for the past ~ 15,500 years followed general climatic changes in the Northern Hemisphere. Thus, integrated research, including detailed analysis of mineral components and spore-pollen assemblages in lake sediments, is a workable tool for studying climatic controls of continental sedimentation.     

Diagenesis of Organic Matter in the Top Layer of the Sediments of the Peter the Great Bay in Hypoxia Locations

During Cruise 62nd of the R/V “Professor Gagarinsky” in September, 2014, the carbonate system of sediments and contents of nutrients and organic carbon in pore water were studied in two geochemical stations located in hypoxia areas in the Peter the Great Bay. It was established that the concentrations of silica, phosphorus, and ammonium increase by 5, 10, and 20 times, respectively, with sediment depth to 70–80 cm. The alkalinity, dissolved inorganic carbon, and the partial pressure of carbon dioxide significantly increase with depth, while рН value and organic matter (ОM) decrease. Changes in the chemical composition of pore water with sediment depth (0–80 cm) are caused by anaerobic microbial degradation of OM, concentration of which in the top sediment layer is 2–3%. The degradation products of OM in the bottom waters of bay and pore waters of bottom sediments indicate that its main sources are diatoms. During hypoxia, the oxygen demand rate by sediment surface near Furugelm Island is estimated to be 5 mmol/(m² day). A combination of such factors as downwelling circulation, the absence of photosynthetically active radiation, and the high oxygen demand rate at the water/sediment interface provides hypoxia formation in the depressions of the Peter the Great Bay bottom topography.     

浅水湖泊沉积物中磷的地球化学特征

对太湖不同污染状况和生态系统状况的湖区沉积物中磷的地球化学形态及其分布进行了研究。结果发现,沉积物的理化性质和磷的化学形态一般都在表层下深5～15cm发生明显的转折;草型湖区、藻型湖区、开阔湖面的大湖区沉积物的理化性质、间隙水中的磷浓度及沉积物中磷的形态存在较大的差异。东太湖沉积物间隙水磷浓度和交换态磷含量都显著低于其他湖区;风浪扰动相对剧烈的开阔湖面湖区沉积物中磷的沉积规律也不同于梅梁湾藻型湖区和东太湖草型湖区。研究表明,浅水湖泊中水生生物状况、风浪扰动状况对沉积物中磷的地球化学行为有至关重要的影响。     

Source and Biogeochemical Distribution of Organic Matter in Surface Sediment in the Deep Oligotrophic Lake Fuxian,China

The source, quantity and quality of sedimentary organic matter (SOM) were investigated in the surface sediments of Lake Fuxian, a deep oligotrophic lacustrine system in China. Granulometry, biochemical organic composition, bulk organic proxies and their stable isotopes were determined in the surface sediments (0–4 cm). The values of δ¹³C, δ¹⁵N and atomic ratio of total organic carbon to total nitrogen (TOC/TN) indicated that the sediments in the large partial lake were influenced by autochthonous organic matter. The concentrations of TOC, protein (PRT) and total hydrolysable amino acids may be mainly modulated by phytodetritus sinking from euphotic zones since they correlated significantly with chlorins. Otherwise, the lack of correlation between chlorins concentrations and carbohydrate (CHO) and lipid (LIP) indicated that the latter may have an additional terrestrial source. The highest sediment quantity was found in the deepest station NC owing to its fine sediment. Stations near northwestern shore accumulated more SOM than other littoral stations, which was in accordance with sewage discharge strength. Degradation quality indices, such as chlorin index, degradation index, PRT/CHO, and LIP/CHO, were in general agreement in showing the degraded status of SOM in Lake Fuxian. No clear spatial patterns were found in sediment degradation quality, which may be influenced by bottom oxygen concentration in the deep stations.     

南流江河口水下三角洲表层沉积物端元分析及其沉积动力环境意义

沉积物粒度分布特征可揭示沉积动力环境。基于广西南流江河口水下三角洲的粒度分析数据,采用Folk分类法进行分类,应用端元分析对其粒度数据进行分解,探讨了南流江河口水下三角洲的物源和现代沉积动力环境。结果表明,研究区表层沉积物可划分为9类,其中含砾沉积物5类,不含砾沉积物4类,沉积物类型与河口环境动力特征相吻合。端元分析结果显示,研究区有5个不同类型的端元,分别代表着5种类型的沉积物动力环境:端元1反映了风浪和潮流对表层沉积物的动力作用;端元2指示了外海涌浪对表层沉积物的作用过程;端元3代表了南流江冲淡水引起的表层沉积物的输运;端元4代表了大陆架残留沉积物;端元5为干扰端元,可能是由于工程建设等人类活动所引起的。利用端元分析探讨复杂环境(如小型山溪性河口)下的沉积动力环境时,一方面需要综合考虑研究区域的物源与环境动力特征;另一方面可以结合参数拟合、粒径趋势分析等研究手段。     

Mobility of trace elements between the river water,the sediments,and the pore water of Las Catonas Stream,Buenos Aires Province,Argentina

The composition of river water, sediments, and pore waters (down to 30 cm below the bed) of Las Catonas Stream was studied to analyze the distribution of trace elements in a peri-urban site. The Las Catonas Stream is one of the main tributaries of Reconquista River, a highly polluted water course in the Buenos Aires Province, Argentina. The semi-consolidated Quaternary sediments of the Luján Formation are the main source of sediments for Las Catonas Stream. The coarse-grained fraction in the sediments is mainly composed of tosca (calcretes), intraclasts, bone fragments, glass shards, quartz, and aggregates of fine-grained sediments together with considerably amounts of vegetal remains. The clay minerals are illite, illite–smectite, smectite, and kaolinite. For the clay-sized fraction, the external surface area values are mostly between 70 and 110 m²g^?1, although the fraction at 15 cm below the bottom of the river shows a lower surface area of 12 m²g^?1. The N₂ adsorption–desorption isotherms at 77 K for this sample display a behavior indicative of non-porous or macroporous material, whereas the samples above and below present a typical behavior of mesoporous materials with pores between parallel plates (slit-shaped). As, Cr, Cu, and Cd concentrations increase down to 15 cm depth in the sediments, where the highest trace element and total organic carbon (TOC) concentrations were found, and then decrease toward the bottom of the core. Except for As, the levels of the other heavy metals show higher concentration in surficial waters than in pore waters. Distribution coefficients between the sediments, pore water, and surficial water phases indicate that As is released from the sediments to the pore and surficial waters. Cu content strongly correlates with TOC (mainly from vegetal remains), suggesting that this element is mainly bound to the organic phase.     

澄湖SC7孔沉积物粘土矿物特征及其古地理意义

苏州澄湖湖底残留有一条NNW—SSE延伸且已被淤平的古河道。通过对湖心区古河道段SC7孔沉积物的粘土矿物XRD分析及与湖底硬粘土（Q3）、湖岸区沉积（Q4）和长江口滩地现代沉积的比较,表明古河道充填沉积中的粘土矿物主要为伊利石,其次为高岭石、绿泥石、蛭石,还有少量蒙皂石及蛭石/绿泥石混层矿物;其中的伊利石和绿泥石含量均明显偏高,高岭石含量则偏低,伊利石结晶度也较高。粘土矿物组合兼具太湖流域地带性粘土矿物和长江口沉积物的特点,表明古河道充填沉积既有来自本流域表层物质和澄湖扩大过程中的湖岸崩积,也受到长江物源的影响。这一沉积过程也说明古河道在最大海侵时涨潮流和洪水引起海水和江水的频繁倒灌,直至淤塞和淹废。     

Intense pyrite formation under low-sulfate conditions in the Achterwasser lagoon, SW Baltic Sea

In comparison to similar low-sulfate coastal environments with anoxic-sulfidic sediments, the Achterwasser lagoon, which is part of the Oder estuary in the SW Baltic Sea, reveals unexpectedly high pyrite concentrations of up to 7.5 wt%. Pyrite occurs mainly as framboidal grains variable in size with diameters between 1 and 20 μm. Pyritization is not uniform down to the investigated sediment depth of 50 cm. The consumption of reactive-Fe is most efficient in the upper 20 cm of the sediment column, leading to degrees of pyritization (DOP) as high as 80 to 95%.Sediment accumulation in the Achterwasser takes place in high productivity waters. The content of organic carbon reaches values of up to 10 wt%, indicating that pyrite formation is not limited by the availability of organic matter. Although dissolved sulfate concentration is relatively low (<2 mmol/L) in the Achterwasser, the presence of H₂S in the pore water suggests that sulfate is unlikely to limit pyrite authigenesis. The lack of free Fe(II) in the pore waters combined with the possibility of a very efficient transformation of Fe-monosulfides to pyrite near the sediment/water interface suggests that pyrite formation is rather controlled by (i) the availability of reactive-Fe, which limits the FeS formation, and by (ii) the availability of an oxidant, which limits the transformation of FeS into pyrite. The ultimate source for reactive-Fe is the river Oder, which provides a high portion of reactive-Fe (∼65% of the total-Fe) in the form of suspended particulate matter. The surficial sediments of the Achterwasser are reduced, but are subject to oxidation from the overlying water by resuspension. Oxidation of the sediments produces sulfur species with oxidation states intermediate between sulfide and sulfate (e.g., thiosulfate and polysulfides), which transform FeS to FeS₂ at a significant rate. This process of FeS-recycling is suggested to be responsible for the formation of pyrite in high concentrations near the sediment surface, with DOP values between 80 and 95% even under low sulfate conditions.A postdepositional sulfidization takes place in the deeper part of the sediment column, at ∼22 cm depth, where the downward diffusion of H₂S is balanced by the upward migration of Fe(II). The vertical fluctuation of the diffusion front intensifies the pyritization of sediments. We suggest that the processes described may occur preferentially in shallow water lagoons with average net-sedimentation rates close to zero. Such environments are prone to surficial sediment resuspension, initiating oxidation of Fe-sulfides near the sediment/water interface. Subsequent FeS₂ formation as well as postdepositional sulfidization leads to a major pyrite spike at depth within the sediment profile.     

Dissolved silica budget in the North basin of Lake Lugano

We studied the dissolved silica cycle in the water column of the North basin of Lake Lugano, Switzerland/Italy. Lake Lugano is a meromictic, eutrophic lake, permanently stratified below 100-m depth. A one-box model was used to calculate a silica mass-balance over 1993, based on various lake measurements, such as sediment traps, sediment cores, water analysis and biota countings. We found that the North basin of Lake Lugano is at steady state as far as dissolved silica is concerned. The primary source of dissolved silica in the lake is river input (about 80%), with diffusion from bottom sediments and groundwater input also playing a role. Atmospheric input is negligible. The main export of dissolved silica occurs via biogenic uptake by diatoms and final burial of their frustules in the bottom sediment. Loss of dissolved silica through the lake outflow only represents 15% of the total output. Of the total amount of Si exported to the lake bottom through diatom sinking, less than 20% is re-supplied to the surface water by diffusion. Thus, the lake acts as an important permanent sink for silica. The long residence time of dissolved silica in the lake (7 years) is related to the strong physical stratification of the lake. Only about 10% of the standing stock are available to phytoplankton uptake.