Methane in Water and Bottom Sediments of Lake Baikal

Water Resources - The distribution of methane concentration measured in 2014 and 2015 in different parts of Lake Baikal has been analyzed. In the period of expedition studies, methane concentration...     

Regional Retrospective Analysis of Water and Bottom Sediments in the Upper Volga

Water Resources - The dynamics of water quality in the Upper Volga was analyzed in the segment from the source to the Ivankovo Reservoir. It was found that the increase in anthropogenic stress in...     

Heavy Metals in the Water and Bottom Sediments of the Selenga River Delta

The overall concentration of Cu, Pb, Zn, Cr, Mn, and Fe are determined in the water and bottom sediments of the Selenga River delta. The concentration of Cu, Pb, and Zn is found to decrease in the lower course of the river, at the delta outlet. The concentration of Mn and Fe is found to decrease in the downstream direction from the river's upper course along the investigated delta arms, whereas the concentration of Zn and Cr in certain arms exceeds their concentration in the upper section of the delta.     

Physicochemical Properties of Bottom Sediments in Water Bodies in the Central and Southern Vietnam

Water Resources - The physicochemical characteristics of bottom sediments in inland water bodies in the Central and Southern Vietnam are presented for the first time, including particle-size...     

The environmental and biotic impact of the oil spill in Kerch Strait in November 2007

The effect of an emergency oil spill in Kerch Strait in November 2007 on the environment and biota in the southern Sea of Azov is analyzed based on the material of integrated expedition studies carried out by the Southern Scientific Center, RAS, before and after shipwrecks and during monitoring within a year after the emergency.     

Rating Water Quality in Sevastopol Bay by the Fluxes of Pollutant Deposition in Bottom Sediments

Sevastopol Bay is used as an example for the development of criteria for rating anthropogenic impact by elimination fluxes from the water area of post-Chernobyl (⁹⁰Sr, ¹³⁷Cs, ^239,240Pu) and natural (²¹⁰Pо) radionuclides, as well as mercury and organochlorine compounds. The differentiation of the bay water area into zones with different biogeochemical conditions and the balance approach to interpreting field observation data were used to assess the conditioning capacity of Sevastopol Bay ecosystem for conservative radioactive and chemical substances by elimination fluxes of pollutants into aqueous depot, which is the open part of the Black Sea and into the geological depot, i.e., its bottom sediment stratum.     

Oil Products in Bottom Sediments of Freshwater Bodies

The specific features of freshwater bodies are shown to facilitate the accumulation of oil products in bottom deposits. The oil product components are found to be represented by hydrocarbons and tars. The latter component can account for more than 50% of their total. The extent of bottom deposits pollution by oil products is assessed for a number of freshwater bodies in Russia.     

Hydrocarbons in the Suspension and Sediments of the Baltic Sea

The article gives the results of studying the concentration and composition of aliphatic and polycyclic aromatic hydrocarbons in suspension in surface waters at sections from the English Channel and Skagerak Strait to various regions of the Baltic Sea (2010–2015) and in water and bottom sediments of the southeastern part of the sea in the water area of the Kravtsovskoe field (2008–2015). In recent years, the surface waters of open areas of the Baltic Sea showed a decrease in hydrocarbon concentrations down to background levels (12–33 μg/L). The maximal concentration of hydrocarbons (in excess of the MAC) was recorded in different seasons in navigation areas, including the English Channel and Pregola R. mouth. In the zone of the Kravtsovskoe field, the concentration and composition of hydrocarbons in water depends on their inflow from the bank, and the same characteristics in bottom sediments, on the rate of their leakage from sediment stratum. A decline in these processes have led to a decrease in hydrocarbon concentrations in the sediments of a local area near D-6 platform to background levels (5–7 μg/g) and to the predominance of terrigenous, rather than petroleum, alkanes in hydrocarbon compositions.     

Heavy Metals in the Ivan'kovo Reservoir Bottom Sediments

Spatial and temporal variability of heavy metals concentrations in the Ivan'kovo Reservoir bottom sediments was studied. It was found that for the period of 1983–1998, their content largely decreased in many sections of the reservoir, with the exception of individual deep-water channel stretches and certain bays. The character of vertical distribution of microelements in the bottom sediments is shown to be related to the level of contamination and character and rate of water exchange in the reservoir.     

Some Environmental Consequences of Soil Dumping in the Black Sea as a Result of Dredging Operations in Kerch Strait

The results of monitoring performed by Southern Research Institute of Marine Fisheries and Oceanography (YugNIRO) in 1990–1998 in the course of dredging operations with dumping in the Black Sea of soils dredged in Kerch Strait are analyzed. The study covered the soil physical properties and particle size distribution; the extent of the soil pollution by heavy metals, oil products, and organochlorine compounds; the amounts of such pollutants delivered into the sea with these soils; the extent of pollution of water and bottom sediment in the zone of soil dumping offshore Kerch Strait. The amounts of pollutants entering the Black Sea as a result of soil dumping are compared with those entering the sea from other pollutant sources, and the extent of environmental pollution in the dumping zone is compared with the background level of the sea pollution. The admissible rates of soil dumping are estimated, and potential consequences of this process are predicted.     

Core Sampler for Soft Bottom Sediments with Lower Closing Mechanism

A novel sediment core sampler is represented. It is suitable for liquid sediments and for undisturbed sediment cores with a large core diameter from shallow and deep waters.     

Environmental Effects of the Bottom Sediments of the Senezh Reservoir

The formation and accumulation of bottom sediments in the Senezh Reservoir are discussed on the basis of field observations. Data on the bottom sediment thickness, the rates of accumulation, and the concentrations of organic substances, metals, petroleum products, and organic pollutants are presented. The bottom sediments of the reservoir are demonstrated to be still no source of secondary pollution.     

Studying the Concentration of Microplastic Particles in Water,Bottom Sediments and Subsoils in the Coastal Area of the Neva Bay,the Gulf of Finland

Water Resources - The concentration of microplastic particles (with size from 100 µm to 5 mm) and their chemistry were studied in water, subsoils and sediments in the coastal area of the Neva...     

Peculiarities of Heavy Metals Accumulation in the Bottom Sediments and Higher Aquatic Plants of the Ivan'kovo Reservoir

Concentrations of heavy metals in the bottom sediments of the Ivan'kovo Reservoir bays are analyzed. The role of higher aquatic plants in the processes of heavy metals accumulation and transformation in bottom sediments is studied. Uneven distribution of microelements in the bottom sediments is found to be typical of the bays, which is related to the character of heavy metals input in the bays and to processes occurring inside the bays themselves.     

武汉东湖沉积物孔隙度与含水量

对采自武汉东湖Ⅰ站、Ⅱ站的沉积物采用一种新的方法计算孔隙度:拍摄扫描式电子显微镜(SEM)图像,采用局部区域阈值化的方法对图像进行阈值化(thresholding)处理,运用自编程序求出孔隙度的垂直变化.结合含水量的垂直变化,分析孔隙度与含水量之间的关系,并对影响它们垂直变化的因素进行了讨论.结果表明:SEM图像局部区域阈值化法是研究沉积物孔隙度的有效方法;孔隙度与含水量表层较大,从表层到底层呈明显的下降趋势;孔隙度(K)与含水量穴H雪有比较好的正相关.运用拟合的相关方程式,可以由较易获得的东湖Ⅰ站和Ⅱ站的含水量反推较难获得的孔隙度.     

Chlorinated Hydrocarbons in Sediments of the Elbe Catchment Area – Analytical Methods and Status of Pollution

A survey was conducted to determine the status of pollution of surficial sediments in the Elbe catchment area (Germany, Czech Republic) for the period 1992 to 1994. Chlorinated benzenes, PCBs, DDT and its metabolites, and HCH isomers were determined by GC/ECD following a simultaneous steam distillation-extraction procedure. Most of the investigated compounds showed increased concentration levels in sections of the Elbe or its main tributaries exceeding the target value II (quality criteria ARGE Elbe). Patterns of chlorinated hydrocarbons could be traced back from the Elbe into tributaries, and in some cases, links between patterns and inputs or long-term effects of former chemical production sites were supposed.     

Long-Term Dynamics of the Concentrations of Organochlorine Compounds and Mercury in the Bottom Sediments of the Chernorechenskoe Reservoir

Water Resources - The accumulation of organochlorine compounds (OCs) and mercury in the bottom sediments of the Chernorechenskoe Reservoir since the mid-1960s to 2008 has been studied....