Analysis of the remediation of coal tar-contaminated groundwater using ex situ remediation

The article describes the remediation of contaminated groundwater during the ex situ remediation of coal tar contamination following the closure of a coking plant in the Moravian-Silesian Region (Czech Republic). The aim of the article is to point out the advantages of ex situ soil remediation via the excavation of the contaminated geological environment combined with thermal desorption, a method of removing contaminants both from soil and groundwater. Its advantage is the absolute qualitative and quantitative control over the contaminated soil with the possibility of precise segmentation into contaminated and non-contaminated soils. Next, all contaminated groundwater may be pumped off upon the construction of sealing walls to control groundwater flows. To excavate the soil, it is necessary to reduce the contaminated groundwater level inside the sealing walls and thus create conditions for the extraction of contaminated soils using standard machinery. In detail, the article describes the removal of the contaminated groundwater and compares the quality of the pumped and inflowing water before and after the remediation. The locality is characteristic of a high horizontal and vertical grain-size heterogeneity of gravel-sand, which led to a varying filtration coefficient affecting the capacities of pumped groundwater quantity during the remediation. At the start of the remediation process, the contaminant levels exceeded the limits by the Czech Environmental Inspectorate several times. The post-remediation monitoring showed that all the contaminant levels were below the limit. Surprisingly, the overall groundwater contamination amounted to 232.86 t of contaminants as non-aqueous phase liquids, and 6872.9 kg of dissolved contaminants. As much as 12,200 t of contaminants were removed from the soil.Web of Science1414art. no. 218

Microsatellite diversity of the Nordic type of goats in relation to breed conservation: how relevant is pure ancestry?

In the last decades, several endangered breeds of livestock species have been re-established effectively. However, the successful revival of the Dutch and Danish Landrace goats involved crossing with exotic breeds and the ancestry of the current populations is therefore not clear. We have generated genotypes for 27 FAO-recommended microsatellites of these landraces and three phenotypically similar Nordic-type landraces and compared these breeds with central European, Mediterranean and south-west Asian goats. We found decreasing levels of genetic diversity with increasing distance from the south-west Asian domestication site with a south-east-to-north-west cline that is clearly steeper than the Mediterranean east-to-west cline. In terms of genetic diversity, the Dutch Landrace comes next to the isolated Icelandic breed, which has an extremely low diversity. The Norwegian coastal goat and the Finnish and Icelandic landraces are clearly related. It appears that by a combination of mixed origin and a population bottleneck, the Dutch and Danish Land-races are separated from the other breeds. However, the current Dutch and Danish populations with the multicoloured and long-horned appearance effectively substitute for the original breed, illustrating that for conservation of cultural heritage, the phenotype of a breed is more relevant than pure ancestry and the genetic diversity of the original breed. More in general, we propose that for conservation, the retention of genetic diversity of an original breed and of the visual phenotype by which the breed is recognized and defined needs to be considered separately

Engineering-geological comparative analysis of four cases studies of waste landfills

Abstract The aim of the paper is to carry out a comparative engineering-geological study of four different waste landfills using the evaluation criteria for the geological subsoil as a natural sealing barrier. The study evaluates 4 localities (Velké Pavlovice, Kvítkovice, Prakšice and Horní Suchá) using three variants (based on two standards) which approach the geological barrier requirements as a combination of impermeability requirements based on a filtration coefficient limit value. and the required geometry represented by investigation depths. The research was carried out in landfills in Moravia, in the east of the Czech Republic. The study’s motivation is to point at the differences in engineering-geological investigations of waste landfills (as for the requirements for impermeable geological subsoil as a natural sealing barrier) when compared with other engineering structures (where the main goal is to evaluate load-bearing capacity and settlement). The purpose of the geological barrier is to prevent the spread of contamination, and the paper shows this can be approached differently, as shown in two different methodologies investigated herein. The first model (Model 1) assumes there is a 3-m-thick subsoil below the landfill’s footing bottom, which manifests impermeability characterized by the filtration coefficient Kf ≤ 1.0 * 10–9 m/s, or a 30-m-thick subsoil of Kf ≤ 1.0 * 10–8 m/s. The second model (Model 2) assumes a 1-m thick, impermeable subsoil massif of Kf ≤ 1.0 * 10–9 m/s. We found that none of the landfills in the four selected localities had an impermeable layer in the required depth (a filtration coefficient Kf from 1.8 * 10–9 to 3.9 * 10–9 m/s), and thus did not comply with the limiting conditions. As a result, an anthropogenic technical barrier had to be installed. An important goal of the study from an environmental point of view was to assess the existence of a suitable geological barrier under the proposed landfills. The most important criterion from this point of view is permeability. An additional technical objective of the project was also the assessment of the possible creation of a technical anthropogenic isolation barrier. In the event that the natural sealing barrier would not be sufficient. This was shown in all solved case studies of engineering geological investigations of waste landfills

Bathymetric monitoring of alluvial river bottom changes for purposes of stability of water power plant structure with a new methodology for river bottom hazard mapping (Wloclawek, Poland)

The aim of this research was to produce a new methodology for a special river bottom hazard mapping for the stability purposes of the biggest Polish water power plant: Wloclawek. During the operation period of the water power plant, an engineering-geological issue in the form of pothole formation on the Wisla River bed in the gravel-sand alluvium was observed. This was caused by increased fluvial erosion resulting from a reduced water level behind the power plant, along with frequent changes in the water flow rates and water levels caused by the varying technological and economic operation needs of the power plant. Data for the research were obtained by way of a 4-year geodetic/bathymetric monitoring of the river bed implemented using integrated GNSS (Global Navigation Satellite System), RTS (Robotized Total Station) and SBES (Single Beam Echo Sounder) methods. The result is a customized river bottom hazard map which takes into account a high, medium, and low risk levels of the potholes for the water power plant structure. This map was used to redevelop the river bed by filling. The findings show that high hazard is related to 5% of potholes (capacity of 4308 m(3)), medium with 38% of potholes (capacity of 36,455 m(3)), and low hazard with 57% of potholes (capacity of 54,396 m(3)). Since the construction of the dam, changes due to erosion identified by the monitoring have concerned approximately 405,252 m(3)of the bottom, which corresponds to 130 Olympic-size pools. This implies enormous changes, while a possible solution could be the construction of additional cascades on the Wisla River.Web of Science2017art. no. 500

Engineering-geological study of relationships between soil and rock workability, type and volume of excavated materials, and earthwork costs (six case studies)

Abstract The engineering-geological study deals with the study of significance and relationship of soil and rock workability (factor representing the engineering-geological structure of rock massif) and the remaining earthwork parameters influencing the cost of construction work, such as excavation type and its technology, and excavated cubic volume. The comparative tool was the cost of earthwork as it reflects the real value of the given parameters during the implementation of earthwork. Soil and rock workability is the most important parameter of rock massif engineering-geological structure during any earthwork. The investor pays the contractor for earthwork based on workability classes which have their accounting value expressed as a volume unit of earthwork per particular project. The research results arise from a comparison of 6 sewer system construction project case studies in the north-east of the Czech Republic. The research shows that the most important factor during the implementation of earthwork is the specific engineering-geological structure (52%), which reflects in the parameter of soil and rock workability classes, using which all earthwork is priced. The second most important factor (33%) is the type of excavation and its technology. The least important is the excavated cubic volume (15%), which means the overall cubic volume of earthwork. The results were obtained within three evaluation approaches, where the comparison unit was one cubic meter of excavated volume during earthwork

Investigation of a hazardous uncontrolled dumpsite in an oxbow lake of the Nitra River for pollution potential: a case study

This paper deals with the engineering-geological investigation of uncontrolled dumpsites that are abundant in post-communist countries. The sites may be redeveloped in an optimal manner by using the applied methodology of engineering-geological investigations. The research tool is a case study dealing with hazardous uncontrolled dumpsites chemically contaminated by various substances, particularly carcinogenic chromium. The dumpsite is located in the alluvial sediments of an oxbow lake of the Nitra River in the Slovak Republic. The hazard is seen in the fact that the alluvial sediments are permeable and thus the contamination may spread easily. At the same time, it is located near a river, which makes the hazard greater. Apart from the risk of contamination, another risk is related to the methane generated by the dumpsite and thus the risk of self-ignition. In order to identify the uncontrolled dumpsite body, the research was grounded in the different physical properties of the diverse geological environments. Quasi-homogenous blocks of the dumpsite body and its alluvial surroundings were well identified by using the combined three geophysical methods, namely dipole electromagnetic profiling (DEMP), electrical resistance tomography (ERT) and spontaneous polarization (SP). In order to eliminate the risk of contamination spread, redevelopment measures for the uncontrolled dumpsite in the form of sealing walls and surface sealing foil were proposed. A system of methane drainage boreholes was proposed to eliminate the risk of self-ignition. The methodology in this case study is well applicable for other uncontrolled dumpsites, which is an important outcome of the study.Web of Science1921art. no. 4

Engineering–geological investigation of the river bottom near a dam’s stabilization threshold based on two different evaluation methodologies

The article concerns engineering and geological studies of the river bed near the threshold stabilizing the water flow of the Wloclawek hydroelectric power plant in Poland. We paid attention to the differences in river erosion behind the dam, as one section of the study area was dominated by erosion of potholes and the other by sedimentation of river material. A protective threshold (partly concrete, partly gabion) was built to stabilize the water flow and optimize the hydrological regime near the dam. As a result of the erosion process (behind part of the hydroelectric power plant) and sedimentation (behind part of the weir), this threshold is constantly being destroyed. This threatens uncontrolled changes in water level, instability of water masses and, consequently, constitutes a threat to the stability of the hydrotechnical structure. The principal aim of the study is to propose a new methodology to perform a risk assessment and to indicate how to protect the threshold structure. Initially, geodetic and bathymetric measurements were performed of the river bed, potholes and the threshold. Then the results were analysed, the risks were estimated and two independent risk assessment procedures were proposed. One suggestion concerning the area of potholes was to backfill them to protect the threshold made of concrete slabs. In the second section, there is a sedimentation of the river material around the gabion threshold, which is damaged, especially during flooding. To protect this gabion threshold, a different approach has been taken of modelling the water flow based on digital bottom models (DBMs). An engineering-geological investigation of one river bottom benefited from two types of protection features (a concrete threshold and gabion threshold) using two different methodologies to evaluate hazard and design subsequent protection of the thresholds. The results of our study support the structure's managers in maintaining its safety.Web of Science811art. no. 2

Geographical contrasts of Y‐chromosomal haplogroups from wild and domestic goats reveal ancient migrations and recent introgressions

International audienceBy their paternal transmission, Y-chromosomal haplotypes are sensitive markers of population history and male-mediated introgression. Previous studies identified biallelic single-nucleotide variants in the SRY, ZFY and DDX3Y genes, which in domestic goats identified four major Y-chromosomal haplotypes, Y1A, Y1B, Y2A and Y2B, with a marked geographical partitioning. Here, we extracted goat Y-chromosomal variants from whole-genome sequences of 386 domestic goats (75 breeds) and seven wild goat species, which were generated by the VarGoats goat genome project. Phylogenetic analyses indicated domestic haplogroups corresponding to Y1B, Y2A and Y2B, respectively, whereas Y1A is split into Y1AA and Y1AB. All five haplogroups were detected in 26 ancient DNA samples from southeast Europe or Asia. Haplotypes from present-day bezoars are not shared with domestic goats and are attached to deep nodes of the trees and networks. Haplogroup distributions for 186 domestic breeds indicate ancient paternal population bottlenecks and expansions during migrations into northern Europe, eastern and southern Asia, and Africa south of the Sahara. In addition, sharing of haplogroups indicates male-mediated introgressions, most notably an early gene flow from Asian goats into Madagascar and the crossbreeding that in the 19th century resulted in the popular Boer and Anglo-Nubian breeds. More recent introgressions are those from European goats into the native Korean goat population and from Boer goat into Uganda, Kenya, Tanzania, Malawi and Zimbabwe. This study illustrates the power of the Y-chromosomal variants for reconstructing the history of domestic species with a wide geographical range