Express Assessment of Water Toxicity Based on Bioassaying: Case Study of Surface-Water Bodies in St. Petersburg

A system of efficient on-line monitoring of the state of water in surface water bodies is developed. The expediency of using new general-purpose bioassays for the integral express evaluation of the natural-water toxic impact on living organisms is substantiated. Fundamentally new methods of bioassaying with gasteropoda from special laboratory cultures (“PRM-TESTS”) used as test organisms are presented. The results of complex hydrochemical and biological (toxicological) investigations with PRM-TESTS as applied to water bodies in St. Petersburg are discussed.__________Translated from Vodnye Resursy, Vol. 32, No. 4, 2005, pp. 425–434.Original Russian Text Copyright © 2005 by Kurilenko, Zaitseva.     

Bioindication role of higher plants in the diagnostics of aquatic ecosystems: Case study of small water bodies in St. Petersburg

The bioindication role of macropytes in the assessment of the environmental conditions of small water bodies under the conditions of a megalopolis is discussed. A comparative characteristic is given to the significance of macrophytes from different ecological groups, including hygrophytes (cattail, reed), hydrophyte (pondweed), and hydatophytes (Canada water weed, hornweed), growing in small water bodies in St. Petersburg, for the biogeochemical indication of environmental pollution by microelements (Fe, Mn, Zn, Cu, Cr, Ni, Pb, and Cd) and biogenic elements (K, Ca, Na, P, S). Possible mechanisms of detoxication of heavy metal ions in macrophyte organisms and their role in the stable functioning of water bodies in urban territory under the conditions of anthropogenic pollution are discussed. The prospects of the use of macrophyte groups for the bioindication of pollution and phytoremediation of aquatic ecosystems are analyzed.     

Centre for Baltic and arctic studies at St. Petersburg state University as a naional node of “University GIS network” in Russia

The possibilities of recent advantages in Geographical Information Systems (GIS) technology as a tool for multidisciplinary coastal zone research are discussed. International education in the new high technologies is one of the most urgent tasks for the University GIS Network.     

Inversion of Gravity Data for Imaging of a Sediment-basement Interface: A Case Study in the Northwestern Part of Bangladesh

Gravity data collected by the Geological Survey of Bangladesh are processed and interpreted for imaging of a sediment-basement interface over the northwestern part of Bangladesh. The observed gravity data are processed for discriminating gravitational fields contributed subtly from the shallow basement topographic feature with the twelve nodal piecewise cubic polynomial–based finite–element approach. In spectral analysis, the presence of a widely spread shallow basement feature has been detected and interpretation of gravity data using a two-dimensional gravity inversion technique indicates that its depth ranges from 0.041 km to 0.570 km relative to ground surface. In the northern part of the study area, the inferred basement configuration shows a general depression of the basement in the Takurgaon-Panchagar and Lalmonirhat districts and reaches a maximum depth of about 0.570 km. In the Nilphamari district and its southwestern part, the basement occurs at the most shallow depth due to its upliftment. However, the estimated sediment-basement interface depths are compared with the borehole and other geophysical interpretative information and are found to be consistent.     

The Handling of Hazard Data on a National Scale: A Case Study from the British Geological Survey

This paper reviews how hazard data and geological map data have been combined by the British Geological Survey (BGS) to produce a set of GIS-based national-scale hazard susceptibility maps for the UK. This work has been carried out over the last 9 years and as such reflects the combined outputs of a large number of researchers at BGS. The paper details the inception of these datasets from the development of the seamless digital geological map in 2001 through to the deterministic 2D hazard models produced today. These datasets currently include landslides, shrink-swell, soluble rocks, compressible and collapsible deposits, groundwater flooding, geological indicators of flooding, radon potential and potentially harmful elements in soil. These models have been created using a combination of expert knowledge (from both within BGS and from outside bodies such as the Health Protection Agency), national databases (which contain data collected over the past 175 years), multi-criteria analysis within geographical information systems and a flexible rule-based approach for each individual geohazard. By using GIS in this way, it has been possible to model the distribution and degree of geohazards across the whole of Britain.     

Noble gases in the St. Mesmin chondrite: Implications to the irradiation history of a brecciated meteorite

Helium, neon and argon were analysed in matrix samples and in different clasts of the polymict-brecciated LL-chondrite St. Mesmin. All clasts have high K-Ar ages with a mean value of4.40 ± 0.26Ga. One exotic H-group xenolith, however, has a K-Ar age of only1.36 ± 0.05Ga. The low age indicates that the St. Mesmin breccia was compacted to its present structure relatively late in its history and that the St. Mesmin meteorite developed from regolith material on the meteorite's parent body. This is further demonstrated by the high concentrations of solar noble gases in the matrix and the cosmic ray pre-exposure of one individual clast.     

Cumulus cloud energetics as revealed in a numerical model of cloud dynamics: Part II. Computational results

A numerical model of atmospheric convection is used to investigate the effects of the birth, growth, and death of a cumulus cloud on the temporal and spatial characteristics of atmospheric energy content. Energy in the forms of latent and thermal enthalpy of water vapor, thermal enthalpy of dry air and of condensed liquid, and potential and kinetic energy is computed. Changes in the energy content and the vertical flux of energy are mapped in the vertical plane passing through the cloud axis and are summed horizontally and vertically over the domain to show the rearrangements.It is found that the relative importance of different forms of energy is a function of position with respect to the cloud. Energy related to the presence of water vapor accounts for most of the changes in the vicinity of the cloud. Convection tends to decrease the potential instability of the atmosphere, the amount of decrease being determined by the total energy released during condensation regardless of whether it falls as rain. The time for the departure from neutral stability to be reduced by 10 percent of its initial value is estimated to be about one hour.     

Estimating groundwater discharge to surface waters using heat as a tracer in low flux environments: the role of thermal conductivity

Analytical modelling of heat transport was used to address effects of uncertainty in thermal conductivity on groundwater–surface water exchange. In situ thermal conductivities and temperature profiles were measured in a coastal lagoon bed where groundwater is known to discharge. The field site could be divided into three sediment zones where significant spatial changes in thermal conductivity on metre to centimetre scale show that spatial variability connected to the sediment properties must be considered. The application of a literature‐based bulk thermal conductivity of 1.84 Wm^?1 °C^?1, instead of field data that ranged from 0.62 to 2.19 W m^?1 °C^?1, produced a mean overestimation of 2.33 cm d^?1 that, considering the low fluxes of the study area, represents an 89% increase and up to a factor of 3 in the most extreme cases. Incorporating the uncertainty due to sediment heterogeneities leads to an irregular trend of the flux distribution from the shore towards the lagoon. The natural variability of the thermal conductivity associated with changes in the sediment composition resulted in a mean variation of ±0.66 cm d^?1 in fluxes corresponding to a change of ±25.4%. The presence of organic matter in the sediments, a common situation in the near‐shore areas of surface water bodies, is responsible for the decrease of thermal conductivity. The results show that the natural variability of sediment thermal conductivity is a parameter to be considered for low flux environments, and it contributes to a better understanding of groundwater–surface water interactions in natural environments. Copyright © 2015 John Wiley & Sons, Ltd.     

Biocides in Relation to Water Pollution. Part 2: Bioassay Studies of Few Biocides to a Fresh Water Fish,Channa gachua.

The present paper deals with the determination of LT_m values of zolone, rogor, sumithion and abate for Channa gachua by conducting static bioassay experiments. The TL_m values for zolone came out to be 0.08275 mg/l, 0.08225 mg/l, 0.0815 mg/l and 0.0810 mg/l; for rogor 5.155 mg/l; 4.955 mg/l, 4.65 mg/l and 4.475 mg/l; for sumithion 12.60 mg/l, 12.50 mg/l, 12.30 mg/l and 12.20 mg/l and for abate 217.25 mg/l, 225.575 mg/l, 221.575 mg/l and 217.25 mg/l for 24, 48, 72 and 96 hours, respectively. Relative susceptibility indicates that this fish is not susceptible to zolone and less to rogor, sumithion and abate, respectively. Present studies also show that increased temperature and pH increase the toxicity of all the biocides, but increased hardness of water decreases the toxicity of biocide solutions. The safe concentrations for zolone, rogor, sumithion and abate came out to be 0.02437 mg/l, 1.3733 mg/l, 3.6907 mg/l and 66.678 mg/l, respectively.     

Large strain deformation studies using polycrystalline magnesium as a rock analogue. Part I: grain size paleopiezometry in mylonite zones

The results of large strain deformation studies of polycrystalline magnesium are reported. Shear zones develop at temperatures below 0.65 Tm for strain rates between 10^?4?10^?5 s^?1. The zones are characterised by small recrystallised grains and are analogues of mylonite zones in crustal and mantle rocks. Their development is marked by a stress drop but the recrystallised grains in the zones do not re-equilibrate and remain equilibrated to the peak stress. However, the recrystallised grains in the areas bordering the shear zones undergo a strain dependent coarsening and their sizes re-equilibrate to the relaxed stresses at natural strains of 1. The geological implications of these results are discussed.     

Evaluating Surface Runoff Responses to Land Use Changes in a Data Scarce Basin: a Case Study in Palas Basin,Turkey

Water Resources - In this study, hydrologic regimes of the Palas basin have been investigated with land use/land cover (LULC) change. To investigate the relationship between precipitation and...     

Interaction between Surface and Subsurface Waters: Case Study of a Region in Kazakhstan

The results of field studies are used to establish the factors that control the interaction between surface water and unconfined groundwater in the region, to study the process of their interaction, and to propose empirical relationships for transient flow. Combined model calculations were also made, and their results and other formulas were compared with the results of field studies conducted by other researchers in large river valleys under dry and moderate climate conditions.     

Simple Methodology for Estimating the Groundwater Recharge Potential of Rural Ponds and Lakes Using Remote Sensing and GIS Techniques: a Spatiotemporal Case Study of Roorkee Tehsil,India

Water Resources - Groundwater resources are depleting at an alarming rate all over the world. Therefore, ensuring water security is the foremost priority of every nation. This paper presents a...     

Approaches to the identification of the origin of heavy metals in bottom sediments and standardization problems: Case study of two SDPP reservoirs in ural region

Concentrations of seven metals in bottom sediments of water-cooling reservoirs of Yuzhnoural’skaya and Troitskaya SDPPs, as well as of less polluted Verkhneural’skoe Reservoir (Chelyabinsk province) are studied. Small samples taken during one season were used as an example to consider three variants of data analysis: comparison with regional control, search for pair correlations between metals, and multidimensional approach. The usefulness of factor analysis for revealing the sources of metals supply to water bodies is demonstrated. The origin of three identified groups of metals is considered from the viewpoint of SDPP operation (for Fe and Pb), correlation with organic matter (for Cu, Zn, Mn), and washing out from nickel-bearing components of soil (for Ni and Co). The problem of choice of monitoring indicators corresponding to the objective of the study is discussed.     

Geochemical Assessment of a Subtropical Reservoir: A Case Study in Curitiba,Southern Brazil

Suspended particles and dissolved substances in water provide reactive surfaces, influence metabolic activity and contribute to the net sediment deposition. It therefore plays an important part in the ecology and quality of the water mass. The water quality in reservoirs is crucial and it is naturally maintained by flushing and sedimentation, which continuously remove phosphorus from the water. In some reservoirs, however, these removal processes are countered by recycling of ions which could play a key role to start and/or maintain the eutrophic state. The combination of macro‐, trace‐ and microanalysis techniques can be useful to trace pollution sources through a chemical fingerprint, whether be during an acute environmental disaster or a long‐term release of pollutants. The water quality and total metal content of reservoir sediments were assessed in a reservoir, situated in the capital of the Paraná State, in the South‐Eastern part of Brazil. The goal of this paper was to determine the metal presence in the sediment and metal and ionic speciation in the Green River reservoir water. Water and bed sediment samples, collected from various sites during 2008 and 2009, were investigated using XRF, ICP‐OES, ICP‐MS, XRD and zeta potential measurements. Based on the results, the heavy metal concentration and chemical composition of the suspended matter in the water samples, as well as the sediment's chemical composition will be discussed.     

Application of AMD to the Determination of Crop Protection Agents in Drinking Water. Part IV: Fundamentals of a Confirmatory Test

A method is described for the determination of fifteen active ingredients of plant protecting products in ground-, raw, and drinking water. After extraction and enrichment of the pesticides from the water sample with solid-phase extraction, the extract is fractionated on silica-coated TLC plates, first in a so-called screening gradient by AMD (automated multiple development). The detection of the pesticides is performed by UV multidetection. Positive results from the first separation are confirmed by a second separation on silica in an AMD gradient of distinctly different selectivity, compared to the first separation. Following this strategy, it is possible to distinguish nearly all nonvolatile, from water extractable, active ingredients of plant protecting products in the market. UV spectra are taken for further confirmation of positive results. In most cases, this is possible even at the limit of determination. All chromatograms and spectra shown are raw data, resulting from the confirmatory test DIN 38407 part 11, in the laboratory of one participant*). The method is standardized in the meantime as DIN V 38407-11.