Innovative use of a sediment dumping area by the port as a car yard

The Port of Kotka is situated by the Baltic Sea and the river Kymi. The river transports into the estuary sediments containing pollutants. The dredging and dumping of the polluted sediments are challenging tasks, which are strictly monitored by the environmental authorities. In this study, we show how a former dumping area was converted into a car storage area in an innovative way. The construction on wetland base was extremely challenging. The field was built by using tyre scrap, which weighs only a quarter of the stone material's weight. The advantage of frost season was used during the construction phase, which reduces the costs. The Port of Kotka's solution to use polluted dredged material and waste material, in order to economically reclaim new land, sets a good example that can be used in other ports as well.     

Quality of dredged material in the River Seine basin (France). I. Physico-chemical properties

In rivers, sediments are frequently accumulating persistent chemicals, especially for those that are more contaminated as a consequence of pressure related to environmental pollution and human activity. The Seine river basin (France) is heavily polluted from nearby industrial activities, and the urban expansion of Paris and its suburbs within the Ile de France region and the sediments present in the Seine river basin are contaminated. To ensure safe, navigable waters, rivers and waterways must be dredged. In this paper, the quality of the sediment dredged in 1996, 1999 and 2000 is discussed. Physico-chemical characteristics of the sediment itself and of the pore-water are presented. Seine basin sediments show very diverse compositions depending on the sampling site. Nevertheless, a geographic distribution study illustrated that the Paris impact is far from being the only explanation to this diversity, the quality of this sediment is also of great concern. The sediment once dredged is transported via barges to a wet disposal site, where the dredged material is mixed with Seine water in order to be pumped into the receiving site. This sort of dumping might be responsible for the potential release of contaminants to the overlying water from the significantly contaminated sediments.     

Quality of dredged material in the river Seine basin (France). II. Micropollutants

Dredging rivers is needed to ensure safe navigable waters, rivers and waterways. To anticipate the management of dredged materials in the case of the river Seine basin, the quality of the sediments in the river is checked every 3 years before dredging operations. The river Seine Basin is heavily submitted to pollution pressure from nearby industrial activities and urban expansion of Paris and its region. Here, the micropollutant content of the sediment sampled in 1996, 1999 and 2000 before dredging is discussed compared to regulatory standards. The results indicate that most of the sediment samples from the river Seine basin are lightly to moderately contaminated with organic and inorganic micropollutants (heavy metals, PAH, PCB), which makes the management after dredging easier. This pollution is strongly correlated with the organic matter content and to the fine fraction (<50 microm) of the sediment. These results can lead to other management options than the ones already used in the river Seine basin: (1) dumping of lightly to moderately polluted sediments in quarries; and (2) physical treatment (sieving, hydrocycloning) of contaminated sediments issued from 'hot spots'.     

Determination and speciation of copper and lead in sediments of a Mediterranean river (River Tenes, Catalonia, Spain)

Total concentrations of Cu and Pb and the speciation of these metals in sediments of the River Tenes are studied in order to establish the extent to which they are polluted and their capacity of remobilization. Five samples taken along the river were analyzed, major components of the sediments were studied using XRF and total Pb and Cu content were determined by AAS. In order to test the accuracy of the digestion methods used (triacid attack with nitric, perchloric and hydrofluoric acids or diacic attack with nitric and hydrochloric acids) for the determination of total trace metal, a standard reference material was also analyzed. Triacid attack is proposed to obtain good results. The results show a highly polluted area (1556 mg kg⁻¹ Cu and 1555 mg kg⁻¹ Pb) in the last sampling site analyzed. For metal speciation, the sequential scheme of Tessier et al. was used. From the results obtained, it can be concluded that Cu content in non-residual fraction is bonded mainly to organic matter, whereas non-residual Pb is mainly associated to iron and manganese oxides.     

Infrared spectroscopy tracing of sediment sources in a small rural watershed (French Alps)

The present article describes a first attempt to use infrared spectroscopy to trace the origin of suspended river sediments. Fifty samples of the main potential sediment sources within a small catchment area (990 ha) in the French Alps were collected and compared with samples of suspended sediment from the river, collected on various dates during 2006 and 2007 using sediment traps. Two major categories of sediment source were identified: topsoils and river channel sediments. For the qualitative part of the study, each of these two main categories was divided into two sub-categories, that is to say, cultivated and pastureland topsoils, and riverbed and riverbank sediments. Discriminant analysis on the source samples showed that Diffuse Reflectance Infrared Fourier Transform (DRIFT) spectroscopy can be used to differentiate between the four potential source materials. To determine whether or not immersion in the river altered the infrared spectra of these source materials, we measured the infrared spectra of samples that had been immersed in the river, in litter bags, for periods of up to 24 days. Immersion did not cause any major changes in the infrared spectra. The contribution of each type of source material to the suspended sediment in the river was quantified using partial least squares (PLS) analyses of DRIFT spectra to compare actual river sediment samples with an experimental model. This model was produced from the DRIFT spectra of a range of calibration samples produced by mixing source material samples in different ratios. The predictions of the model were valid and fell within the confidence interval calculated for the calibration set. Comparisons between suspended sediment samples and the model indicate that the predominant source of the sediment is riverbank erosion, which, in this case, is probably due to trampling by cattle.     

Phosphorus release rates from sediments and pollutant characteristics in Han River, Seoul, Korea

The Han River is 469.7-km long and drains a 26219-km(2) watershed. The sediments in the river are highly polluted due to inputs from upstream tributaries as well as partially treated municipal wastewaters that are discharged to the river. The water quality and strategy for control are important because the river is the primary drinking water supply for the City of Seoul, as well as being a major source for irrigation and industrial water. The Jamsil submerged dam partitions the river to isolate an upstream area for drinking water, but also captures sediments. Samples from four sites were studied to determine sediment pollutant concentrations and phosphorus release rates. Phosphorus tends to desorb from sediments when the concentration of overlying water is less than 1.4 mg/l. Water column P concentrations range from 0.04 to 0.1 mg/l, which suggests that sediments will act as a P source. In a series of batch experiments, P was released at approximately 15-20 mg/m(2)week in the winter (1-5 degrees C) and as much as 90 mg/m(2)week in the summer (20-24 degrees C), and is also a function of pH and dissolved oxygen concentration. The sediment total phosphorus concentration, which averages 833 mg/kg, is evenly distributed among non-apatite-P (33%), apatite-P (32%) and residual-P (34%). An equilibrium model is proposed to describe release rate.     

Inorganic nitrogen metabolism in a eutrophicated tropical mangrove estuary

Investigation of the fate of inorganic nitrogen compounds in treated sewage effluent suggested that after discharge into an estuary primary production in the water column was at the expense of ammonium. Nitrate was only utilized during dissimilatory nitrate reduction by the sedimentary bacteria. Experiments with bottom sediments showed that nitrate reduction by the sedimentary bacteria could be described by Michaelis-Menten enzyme kinetics: and the measured kinetic characteristics revealed physiological adaptation to high nitrate concentrations of the nitrate reducing bacterial population near the sewer outfall, compared to the population in the sediment at the less polluted river mouth. It is suggested that the denitrifying capacity of mangrove sediments may make lagooning of secondary sewage effluent in mangrove areas a cheap tertiary treatment process to alleviate coastal eutrophication in the tropics.     

城市中小河道截污主要方式和工程实例

目前上海中小河道基本未设雨、污水分流系统,不仅河道自身污染严重,而且当水量较大或汛期时,给苏州河带来极大污染。为此必须加快实施中小河道的截污纳管工程。介绍了沿河边敷设截污管道和河道内敷设截污管道的两种主要方式,以及溢流设施和玻璃钢接头的形式和具体施工。最后介绍了长宁区中小河道截污纳管工程的实例。     

Comparative study on organic constituents in polluted and unpolluted inland aquatic environments—V: Organic carbons and hydrocarbons in sediments

Organic carbons and hydrocarbons were analysed for polluted sediments from Tama River and sludges from night soil and sewage treatment plants in the Tokyo area and unpolluted sediments from river and reservoirs from Chichi-jima Island in the Ogasawara (Bonin) Islands to characterize their features for polluted and unpolluted aquatic environments. In addition the relationships of the features of organic constituents between waters and sediments were given. The contents of n-alkanes (C₁₄-C₃₆). squalane and unresolved complex mixture of hydrocarbons (UCMH) for the sediments from Tama River ranged from 16 to 94, 0.86–15 and 250–1100 μ g⁻¹ dry base, which are much higher than those of the sediments from Chichi-jima Island. The major constituents of hydrocarbons in the sediments and sludges from the Tokyo area were mainly odd-carbon numbered n-alkanes and squalane, whereas those of the island were only odd-carbon numbered n-alkanes. Hydrocarbons as carbon (total content × 0.851. as C₂₀H₄₂, HCC)/total organic carbon (TOC), HCC/extractable organic carbon with ethyl acetate (EOC), squalane as carbon (SqC)/TOC. SqC/EOC and UCMH/n-Alkane (C₁₅-C₃₃) values for the sediments from Tama River were much higher than those of the sediments from the island, while carbon preference index (CPI_H) values for the sediments of Tama River were considerably lower than those of the island. It was thus indicated that HCC/TOC, HCC/EOC, UCMH/n-Alkane and CPI^H values should be the important indicators of hydrocarbon pollution for aquatic environments. In addition SqC/TOC and SqC/EOC ratios are apparently useful measures of urban-industrial activities on aquatic environments.The similarity of the nature of hydrocarbons of sediments and sludges from the Tokyo area indicated that the sewage contributed considerably to urban river sediments. Further it was also indicated that hydrocarbons were concentrated in sedimentary environments, although the features of hydrocarbons in sediments are generally similar to those of waters.     

从化学成分探讨三种固废物掺入页岩烧结砖可行性

传统的粘土材料具有生产能耗高、破坏耕地及自重较大等缺点,所以,国家提倡发展新型墙体材料。通过分析及对比淤泥、污泥和秸秆三种固体废弃物与页岩的化学成分,得出淤泥可替代部分页岩在制砖原料中大量掺入,污泥和秸秆可作为制砖造孔剂少量掺入。     

Erosion investigation and sediment quality measurements for a comprehensive risk assessment of contaminated aquatic sediments

In this paper, an assessment strategy is introduced which allows one to evaluate the ecological hazard of contaminated sediments in connection with the risk of in-stream erosion. Special techniques for sediment sampling, non-intrusive density profiling, and depth related measurement of erosion are presented, which, in combination with ecological aspects, lead to a comprehensive risk assessment of fluvial sediments. The strategy was applied to a lock-regulated reach of the River Neckar in Germany. The spatial pattern of contamination in the river reservoir was found to be remarkably heterogeneous. At some sites, very high heavy metal concentrations were detected at the sediment surface. A sudden increase in contamination with depth at other sites could be attributed to an erosional unconformity. The critical shear stress of erosion for old contaminated sediments is higher than for recently deposited material. Nevertheless, during major flood events, bottom shear stress in the river exceeds the critical shear stresses of erosion of all sediments. Accordingly, there is a substantial risk that old contaminated sediment can be mobilised from the reservoir and transported downstream.     

打浦路复线隧道明挖施工结合河道填堵技术研究

以上海打浦路隧道复线日晖港内工程为背景,对多种常规清淤方法进行比选,针对工程环境保护要求高等特点,提出了注水吸淤的工法,对清淤的关键施工技术围堰施工和注水吸於展开研究,对填浜产生的工后沉降进行分析并提出地基处理措施,研究结论可供类似工程参考。     

Clay mineral and heavy metal distributions in the lower estuary of Huelva and adjacent Atlantic shelf,SW Spain

The Huelva estuary, on the south-western Spanish Atlantic coast, is an environment strongly polluted by acid mine drainage and industrial effluents. Clay mineralogy, heavy metal and particle-size distribution in estuarine and adjacent shelf sediments have been analyzed in order to identify the sources and transport pathways of the contaminated sediments. The estuarine sediments consist of detrital terrigenous minerals (illite, kaolinite, quartz, feldspars, dolomite and heavy minerals) derived from river catchments and coastal erosion, with biogenic components (calcite and aragonite) and minor authigenic minerals (pyrite and possibly gypsum). Mineral distribution pattern in the estuary-shelf system is controlled by grain-size sediment, physico-chemical conditions of waters and hydrodynamic factors. Important proportions of fine-grained sediments highly enriched in sulphide-associated heavy metals are supplied by the Tinto-Odiel river system. Most of these sediments are trapped when river waters reach the estuary because of flocculation processes during estuarine mixing, thus the estuary acts as a storage basin for metallic pollutants. In terms of public health, this estuary is well above recommended safety guidelines for most metals. Although the shelf sediments show metal concentration levels close to background values, eventually, a metallic plume emerges from the estuary to ocean, and consequently elevated metal concentrations can be locally detected on the inner shelf.     

Mercury in the River Nura and its floodplain, Central Kazakhstan: I. River sediments and water

The River Nura in Central Kazakhstan has been heavily polluted by mercury originating from an acetaldehyde plant. Mercury in the riverbed is mainly associated with power station fly ash, forming a new type of technogenic deposit. A systematic survey of the bed was carried out to establish the location, extent and nature of the contaminated sediments, and to evaluate the potential for sediment transport. The bed sediments were found to contain very high concentrations of mercury, particularly in the first 15 km downstream of the source of the pollution. Average total mercury concentrations in this section of the river are typically between 150 and 240 mg/kg, falling rapidly with increasing distance downstream. The estimated total volume of silts in the riverbed between Temirtau, the origin of the pollution, and Intumak Reservoir, located 75 km downstream, has been calculated as 463500 m3, containing an estimated 9.4 tonnes mercury. Forty-six percent of the total volume of contaminated silts containing almost 95% of the mercury are located in the upper 25 km of the river, however. The data clearly support the hypothesis that large quantities of polluted sediment are not transported long distances downstream but are removed from the aquatic environment in times of flood and deposited on the low-lying lands adjacent to the river. This process, however, does not stop mercury moving further downstream in the water column.     

Landslide and mudflow disaster in disposal site of surplus soil at Higashi-Hiroshima due to heavy rainfall in 2009

The collapse of a filling occurred due to heavy rain in Higashi-Hiroshima City׳s Shiwa District at about 5:30 am July 25th, 2009. The filling was made of surplus soils, and it contained a mass of water supplied from rainfall and ground water flow of a permeable layer at the bottom of the filling. The collapsed soil flowed down and destroyed a house. In this paper, the cause of this disaster is discussed. The site of the disaster was used as the dumping site of surplus soils, after several changes of ground formation. The history of the geographical change was reconstructed by the image processing of old map, aerial photographs, result of 3-dimentional laser survey carried out after collapse and the measurement of thickness of collapsed soil by dynamic cone penetration test. According to the result of processing, the shape and the size of the filling before collapse was reconstructed. The relationship between the rainfall and the groundwater in the river sediments layer over which the filling was constructed was determined. A stability analysis of the filling was conducted considering the rise of the groundwater level in the filling and the laboratory measured strength parameters. The results of the stability analysis showed that the collapse would have taken place when the groundwater level rose by about 9 m due to the supply of groundwater through the river sediments layer.     

Oligomictic alluvial aggregates: petro-mineralogical and geochemical evaluation of sandy gravel formations on the middle course of the Danube (Hungary)

This paper evaluates the applicability of Hungarian oligomictic alluvial gravel formations at two sections of the Danube river for construction use. The classification of these aggregates is more challenging than monomictic rock aggregates due to their heterogeneous nature. Multi-source clastic sediments cannot be characterized by single values of physical properties but only a distribution, and they are generally less predictable than monomictic materials. The possible applications in concrete manufacturing were evaluated by complex macro-microscopic petrographic, heavy mineral and nuclear analytical geochemical investigations. The two regions falling on the middle course of the Danube have similar sandy gravel formations, applicable as aggregates for conventional and unconventional concrete building purposes or road construction. Their utilization in open-air constructions might be problematic due to their probable alkali-silica reactivity.

     

Streambed Sediment as a Barrier to Groundwater Pollution: Insights from Fieldwork and Modelling in the River Thames Basin

Integrated fieldwork and modelling has been undertaken to assess the vulnerability of riverside wells to pollution when river water is contaminated. Results highlight the importance of streambed sediments as a barrier to groundwater pollution by river water. The bed of the River Thames is lined with brown and grey organic-rich silts of low hydraulic conductivity (about 0.002 m/d). A 3-D model for solute transport in stream-aquifer systems was developed and applied to two riverside sites in the middle Thames valley. Model results indicate that well-water quality would only breach EC limits if the river was heavily polluted for a week or even a month (clearly an unlikely scenario). Sensitivity analyses showed the models to be far more sensitive to streambed parameters than to aquifer parameters. Thus it would be more sensible to focus fieldwork on the measurement of streambed properties than on the more usually measured aquifer parameters.     

A preliminary study of mercury contamination in the surface soil and river sediment of the Roscio District, Bolivar State, Venezuela

The present study constitutes a comparison of mercury in surface soil and river sediments of a contaminated and an uncontaminated area of Venezuela. In the contaminated area, gold prospectors have been using mercury to separate gold from auriferous sand and rock powders for many years. The baseline level of mercury in the river sediments of the uncontaminated area (Manzanares River, Sucre State) was 0.06 micrograms g-1, while in the contaminated area in the Roscio District of Bolivar State the concentration varied from 0.12 to 129 micrograms g-1. In the river sediments the average level of mercury was 0.71 micrograms g-1 and in the surface soil of the working areas 37 micrograms g-1, which shows a significant increase in the mercury level in the contaminated areas. This high level of mercury in the soil and sediments constitutes a serious risk to public health in the contaminated area, where the local people use the water for drinking and other domestic purposes; moreover, they also consume fish from these rivers.     

Simulation of PO4---;P balance in a shallow and polluted river

A sophisticated and one-dimensional model to simulate the concentration of PO₄---;P (x,i) in a shallow and polluted river is presented; the model incorporates, other than the convection and dispersion, various physico-chemical and biochemical reactions of phosphorus sinks and sources.With reference to the field data on Tama-gawa, which penetrates through the metropolitan area of Tokyo, the model is confirmed to represent the concentration of PO₄---;P fairly well in the mid-region except for the mountainous origin and its estuary.A material balance of PO₄---;P, the calculation of which is made possible from the model, reveals that about 15% of the daily phosphorus input into the region is fixed by algae on the river bottom, while about 54% of the input flows downstream without being fixed. The balance also discloses that phosphorus decrease due to adsorption on to suspended solid and the increase attributable to hydrolysis of condensed phosphates in the water can be disregarded, respectively. The rest of PO₄---P balance amounting to about 30% is composed of adsorption on to the river-bed, seepage into the groundwater and release from the non-viable algal decomposition.The model is also used to simulate the PO₄---;P concentration in the region under various conditions. Though naive, the most effective means to decrease the concentration is found, from the model, to be to curtail as much as possible the phosphorus inflow from tributaries.     

A bacterial methylmercury-mineralizing activity in river sediments

A bacterial activity involving mineralization of methylmercury was found in bottom sediments of the river Sambre (Belgium), in a zone highly polluted with inorganic mercury. The possibility, shown by other authors and ourselves, that biological production of toxic methylmercury compounds occurs in such a medium gives a great ecological significance to this finding.Some properties of this mineralizing activity were studied at the community level in the laboratory.The mineralizing capacity of the community can be increased in response to increased concentrations of methylmercury, probably by means of the selection of methylmercury-resistant bacterial species, among which the organisms responsible for the transformation constitute only a part.Because of this adaptation, it is suggested that some equilibrium can be reached between the degradation of methylmercury and its addition to, or its production in, mineral mercury polluted environments.