Field Screening Europe 2001

The ultimate goal of chemists is to perform analysis at a place where a sample is located rather than moving the sample to a laboratory, as is a common practice in many cases at present time. This approach eliminates errors and time associated with sample transport and storage, and therefore it would result in more accurate, precise, and faster analytical data. In addition to portability, two other important features of ideal field sample preparation technique are the elimination of solvent use and integration with a sampling step. These requirements are Solid Phase Microextraction (SPME). This technique integrates sampling with sample preparation and sample introduction to analytical instrument into a simple procedure and is capable of both spot and time averaged sampling. In SPME, for spot sampling, the fibre is exposed directly to a sample matrix. In the time weighted average technique the fibre remains in the needle during the exposure of the SPME device to the sample. The coating works as a trap for analytes that diffuse into the needle.

Detailed knowledge of the type, the total mass, and the location of contaminants is an essential prerequisite for the risk assessment and the characterization of actual and suspected contaminated sites regarding the required and type of measures to be undertaken (remediation, partial remediation, monitoring, registration). Furthermore, for a possibly required remediation of the subsurface, the knowledge of mass and distribution of these contaminants is the decisive factor to perform remediation measures as cost effective as possible and to ensure the success of these measures.

Since the passing of the German Ordinance on Soil Protection and Contaminated Sites (Bundes-Bodenschutz-und Altlastenverordnung, BBodSchV) in July 1999, the examination procedure for the risk assessment of the soil–groundwater pathway has changed. Contaminant discharge from the soil into the groundwater has replaced the total contaminant content in the soil as the basis for the assessment of risk potential. Risk assessment is undertaken in the intermediate area between the non-saturated and the water saturated zone in the soil.

Pollution is an important phenomenon for human activities and the planet’s life, and its effects appear immediately or after a time. There is a correlation and interdependence between soil, air, and water quality and human activities in the environment pollution [Morris]. Romania adhered to many conventions and agreements in respect to the environment. The process of Romania’s adhesion at European Union opened for us new possibilities for intensification of processes of protection, rehabilitation, and development of infrastructure for the environment.

In order to overcome the shortcomings of the conventional assessment procedure for contaminated sites, the possibility of using different sensor types was investigated in several research projects. The basic philosophy of the use of sensors in the field for these purposes is discussed in the contribution of Katrin Batereau in these proceedings (“On-Site Assessment of Contaminated Sites: Application of Sensors for On-Site Instrumentation”). In this part, the basic principle and the fields of application of the sensors are presented.

Especially in the last few years, field analytical techniques for the analysis of contaminated soils have been developed and applied. In comparison with conventional laboratory methods such techniques can offer distinct advantages concerning the costs and the time. Nevertheless, the knowledge in this analytical area can be classified as insufficient. Especially for the validation and standardization of the on site analytical techniques much work is still necessary.

This short version is an excerpt from the original German version, in which the different aspects are discussed in more detail. The original version includes tables as well as application examples.

In this paper attention is focused not just on technical problems related to monitoring of soil and groundwater. A view is also presented on the development process of innovative field screening techniques and the aspects hampering the introduction of this technology. Communication, acceptance by stakeholders, and economic aspects are important factors which require more attention.

Site exploration and characterization are the most essential part of investigations of contaminated soil, rock and ground water as well as waste itself. The basic need is that of identifying the contamination problem and its extent in general. The decisions on measures to be taken for redeveloping the site and monitoring the success of the measures requires considerable knowledge about the site.

In recent decades a series of sampling theories have been developed and verified for the quality assurance process in the primary material industries by numerous extensive investigations. The results have essentially influenced the standards and regulations. In the case of sampling and analysis of contaminated soils nothing equivalent has been done (Neeßf et al., 1997; Dück et al., 1999). In many cases the concentrations of contaminants are lower than those encountered in raw materials, and therefore the sampling of contaminated soils must be done with more care.

Over the last few years the Dutch Policy for soil remediation has changed significantly towards a more functional approach, as is stated by the BEVER committee (UPR BEVER, 1999). The strict enforcement of the multifunctionality principle leads to stagnation in the development of new city infrastructure and land use change. The present approach focuses on a cost effective remediation that will guarantee the desired use of the soil system in the near future. For mobile contaminants the basic principle to avoid inadmissible migration has to be fulfilled However, the new standard goal permits the use of the soil system outside the polluted volume as a reactor chamber as long as the remediation objective (a stable end situation) will be reached within a period of 3o years. In general this approach results in residual soil and groundwater contamination for which a soil quality management strategy is necessary. Boundary conditions require the avoidance of a threat of the surroundings and avoiding the restriction of activities above and below groundsurface.

In situ screening and sampling tools are being used for reliable data collection on soil and groundwater contaminated areas. These tools are deployed from Cone Penetrometer (CPT) trucks and give exact simultaneous information about soil strata (tip resistance and friction ratio) and the vertical as well as horizontal distribution of the contamination plume. Maximum depths between 20–30 m bgl. are reached.

Urban soils are highly heterogeneous (Blume 1993; Gilbert 1994) and polluted by several anthropogenic sources of harmful substances. The urban pollution sources are of different kinds: Point sources such as petrol stations or line sources like streets that can contaminate intensively the soil directly and to an restricted extent. Diffuse urban soil pollution is caused, e. g., by household heating, industrial and traffic exhaust, scattered disposed waste and construction materials. The affected area of this kind of pollution can not be delimited by exact borders, especially not if the main pathway of pollution is the atmospheric way. In addition to that, urban diffuse soil pollution is natural background values. This study therefore deals with the challenge to differentiate between natural background, diffuse urban pollution and local contamination. Geostatistical methods are used to model spatial dependencies of element concentrations in urban soils and to detect locally contaminated sites.

The relation between capillary pressure and saturation, the so-called Pc-S relation describes the transport of a Non-Aqueous Phase Liquid NAPL in saturated sand. An on-site measurement of this curve is of interest to follow in-situ the extension of this type of contamination. As a preliminary study to possible application in the field of environmental on-site measurements, model tests have been performed in the GeoCentrifuge of GeoDelft. The use of a geo-centrifuge is very relevant to increase the driving force on fluids and therefore to accelerate the transport process at equal stresses in prototype and model. The purpose of this study is to measure ‘dynamic’ Pc-S curves related to the transport of a Dense Non-Aqueous Phase Liquid DNAPL in a saturated sand. To do so, one of the tasks is to design pressure transducers able to measure separately pressures of the DNAPL phase and of the water phase. Time Domain Reflectometry (TDR) sensors have been used to measure on-line change in water saturation in the sand. Direct capillary pressures can be measured by using a tensiometer. However, the use of these sensors is limited by the time response, which is too long to characterize mobile DNAPL, especially under the conditions of the centrifuge tests. In our tests, infiltration through a sand sample of 18 cm took place within ~10 minutes. As the capillary pressure is the pressure in the NAPL phase substracted by the one of the water phase, the capillary pressure can then be deduced from the separate measurements of these two types of pressures. Hence in that case, reasonable time response should be reached.

The Membrane Interface Probe (MIP) from Geoprobe Systems in Salina, Kansas, is a logging tool which can be driven into the soil to determine lithology and estimate the relative concentrations of VOC contaminations both in unsaturated and saturated zones(1). VOC molecules, present in the gaseous, dissolved, solid or free product phases move by diffusion through a heated semi-permeable membrane and are carried up to specific detectors at the surface. One implicit use of the MIP is to delineate subsurface contaminations in the three dimensions and/or to put in place samplers for site monitoring. Since the MIP probe is typically pushed at a rate of 30 cm/min, it has become the ideal tool for quick, semi-quantitative delineation of VOC plumes, allowing 5 profiles down to 20 meters to be done in one day, depending on the local geology.

With increasing efforts to develop groundwater resources and to remove groundwater contamination from fractured porous aquifer systems, understanding and characterizing physical processes as well as predicting groundwater flow and contaminant transport in the subsurface has become much more important in recent years. One primary goal in many of the recent groundwater studies is to derive the transport parameters which are characteristic for the system to be investigated with numerical models for groundwater flow and contaminant transport.

Since long ago people have been interested in ‘looking’ into the soil, searching for mineral deposits or groundwater, for geotechnical purposes, and more recently also because of contamination detection. Basically there are two ways of gathering information about the subsoil: sampling and in situ measuring. Because of the soft soils in the Netherlands in situ measurement with the help of push away equipment has been popular in the Netherlands since the 1930’s. In situ measurement has several advantages: there is generally less disturbance than during drilling and sampling (and no exposure to air!), and the method is generally fast, and consequently relatively cheap. On the other hand, sampling has the paramount advantage that one gets the sample literally ‘in one’s hand’, so that it can be examined and unexpected features can be discerned from the richness of the visual image.

In earlier times only monitoring wells were available for the detection of the extension of a dissolved plume. Groundwater was extracted and pumped to the soil surface. Recently, several new techniques have become available for sampling groundwater. These techniques can reach depths of about 30 to 50 m and even 100 m, depending on the mechanical resistance of the soil’s layers. One of these new techniques is the Groundwater Sampling Probe (GSP). The technique is based on the so called Cone Penetration Test (CPT) and dissolved plumes located at greater depths can be characterised. Application of this technique delivers a representative sample, which can be analysed directly on site. On-line, on site screening makes it possible to carry out the site investigation in a more or less interactive manner. Such a process of investigation saves time, is more reliable and saves money.

Delineation and remediation of subsurface contamination have become a major focus of environmental science during the past ten years. Owing to the high cost of installing groundwater wells, soil-gas monitoring is often used as a preliminary technique for determining the presence and extent of underlying groundwater contamination and to assist in the design of monitoring well networks. This practice is based on the assumption that volatile contaminants in groundwater are transported upward in sufficient quantity to be detected in the overlying soil-gas. Several field studies have indicated that mass exchange between the saturated and unsaturated zones does occur (Rivett 1995; Dagvis 1998; Lahvis et al. 1999), but the relationship between contaminant concentrations in the groundwater and the soil-gas is not entirely understood.

Localization and characterization of volatile organic pollutants in soils is the aim of a rapid on-site analysis. In order to evaluate the potential of an electronic nose for direct online detection of volatile soil pollutants. Model gas exposures and practical tests were performed using KAMINA, the Karlsruhe MicroNose with two different sampling assemblies in direct sniffing mode. Odor testing with an electronic nose is nothing else than gas analysis of usually complex gas ensembles in an integral manner. Contrary to the classical description of a gas mixture as a sum of components with individual concentrations the electronic nose detects the gas ensemble as an entity with an integral concentration. However, similar to human odor perception the integral can be quantitatively divided into components which themselves may be complex mixtures. Owing to the measuring principle all pollutants are detectable as long as their volatility makes them appear in the gas phase. Therefore the term ‘odor’ should be understood as a pollutant signature in the gas phase no matter whether the human nose can smell it or not.

Ion mobility spectrometry (IMS) permits the fast detection of organic compounds by fieldable and hand-held devices. Ion mobility spectrometers are suitable as a field monitor method owing to: the technical parameters of devices (power supply, size, weight);the measuring conditions (ambient pressure, air as drift gas); andthe fast information content of measurements (high sensitivity, recording of ion mobility spectra).

Bioremediation is a cost effective technology that is applicable to many different types of organic and inorganic contaminants. Natural attenuation and enhanced reductive dechlorination are two new methods of bioremediation that are being implemented for site cleanup. Natural attenuation involves biological, chemical, and physical processes that occur naturally and without human intervention to effect site cleanup. Enhanced reductive dechlorination involves the in situ application of electron donors such as molasses, lactic acid, volatile fatty acids, or commercial products to promote biological generation of hydrogen and subsequent reductive dechlorination of organic compounds such as trichloroethene (TCE).

For the in situ detection and analysis of oils (petroleum products and vegetable oils) in soils we developed a family of mobile LIF spectrometers (Oil Pollution Transportable Independent Monitoring System, OPTIMOS) designed for field usage. In the full version, the OPTIMOS consists of a Nd:YAG laser (combination with a dye laser optional), an ICCD (intensified charge coupled device) multichannel detection system and flexible waveguide technology (see the contribution by Hengstermann et al. for more experimental details). We have characterized various versions of the OPTIMOS, including simpler configurations with UV light emitting diodes (LED’s) as the light source and photomultiplier tubes (PMT’s) or photodiodes as detectors. Figure 1 shows the LIF spectra of different petroleum products on a German soil (Ahhorizon). The spectra were recorded with a setup consisting of a N₂-laser as the excitation light source, a monochromator / photomultipier combination as the detector and a fibre optical sensor head. Currently, we are improving and expanding the OPTIMOS performance by focusing on: optimized calibration procedures, software-assisted quantification;multi-wavelength excitation (tunable lasers, e.g. dye lasers);improved field performance (ruggedness, reduction in size, weight and electrical power demand);user friendly, ergonomic spectrometer setup.

Why determine the concentration of soil pollution by sampling in the field and analysis in the laboratory? Why not measure directly in the soil where the pollution is found? We do not do so because there is a lack of generally available in situ measurement techniques. But times are changing!

In building rubble recycling plants the incoming amount of building rubble and soil excavation is about the order of 2000 t per day. If the pollution burden of a delivery of rubble exceeds the threshold value determined by LAGA (’Länderarbeitsgemeinschaft Abfall’ Interstate study group on waste disposal) appropriate recycling is not allowed and the plant operator has to refuse acceptance. Similary, waste deliveries to normal waste disposal sites are only allowed to be deposited if the pollution thresholds for disposal sites are not exceeded. Therefore, if further treatment in recycling plants or in disposal sites is intended, the incoming building rubble should be classified into toxic waste, waste of disposable and of recycable quality. As classical analytical techniques cannot be carried out on-site with acceptable analysis time, waste samples suspected of being contaminated are usually transferred to an analytical laboratory for investigation, causing high costs and taking too much time. Therefore a screening analysis is demanded to rapidly characterize the content of toxic organic components in building rubble as aliphatic, monocyclic, chlorinated and polycyclic aromatic hydrocarbons within a few minutes only. Using a gas sensor system with the ability to discriminate gases in combination with thermal desorption of the organic pollutants out of the solid waste could be such a screening instrument.

In assessing pollutants of the environment there arises the problem not only of on site determination of contaminants in soil or water but as well of pollutants impact on living matter to predict the harmful biological effect. Plants are regarded as suitable objects for this purpose (Schubert, 1986; Kovalevsky, 1991). General methods of bioindication and biomonitoring used in current ecology researches are mainly focused on damages in aquatic and forest ecosystems (Sergeichik, 1991) and are less developed for terrestrial agrophytocenosis inspection. That is why terrestrial herbaceous plants both wild and cultivated ones call for more involvement in Field Screening.

Fluorescence spectroscopy is a sensitive method for the detection of anthropogenic fluorescent pollutants, e.g., oils and fuels or polycyclic aromatic hydrocarbons (PAH), in our environment. However, for applications with fibre optical sensor systems static emission spectra do not always provide sufficient information due to their broad and featureless character. In the case of complex mixtures of fluorophores and chromophores, the fluorescence emission spectra and fluorescence lifetime show a pronounced dependence from the excitation wavelength. Hence additional orthogonal dimensions such as decay time and variable excitation wavelengths are needed. The objective of this work is to utilize a combination of static and dynamic fluorescence spectroscopy, i.e., time resolved excitation emission (TEE) fluorescence spectroscopy, for a fibre optical sensor system. The obtained trilinear data arrays, i.e., fluorescence intensity vs. time, excitation, and emission wavelength, provide then a multitude of information about the excited molecules and their local environment.

The need of screening tools for on site field analysis leads to an increasing interest for the use of x-ray fluorescence (XRF) analysis. Different studies performed in 2000 show a systematic comparison between the different instrument techniques available in the market. Beside the design of the instruments concerning excitation source, sample presentation and detection system also the use of the calibration strategy is important.

Covering layers of enough water storage ability used for landfill re-cultivation and for biological sealing of old depositions as well as their water draining planting greenery lead to a crucial decrease of the penetration of water, induced by atmospheric phenomena and weather, into the layers below. That means that the covering layers with their material characteristics and technical-technological structure basically have ecological functions additionally to their landscape-architectural aspects, whereby economical boundary conditions have to be considered.

The reliable and representative environmental monitoring and the on line monitoring of waste water purification processes require rapidly responding in situ measuring systems with high operational stability. Known chemo- or biosensors can only seldom applied for in situ monitoring without sample conditioning and other pretreatment steps. Sensor based determination procedures have to be adapted to the sample matrix and recalibrated. Many analytes must be converted into species, which can be detected with the needed sensitivity. Especially under the conditions of process monitoring the reliability of any measuring/detecting system depends decisively on the automated calibration, which takes the sample matrix into consideration. Because, on the other hand, the measurability of any process parameter requires both short response times and high precision, immersion probes with integrated in situ calibration and integrated sample conditioning were constructed. In this paper gasdialytically working immersion probes were presented. At the point of sampling the analyte is immediately converted into a volatile form, which is separated through the microporous and hydrophobic membrane layer of a thin hollow fiber. The acceptor solution contains a converting and/or and an indicator reagent, which can, however, also admixed after the separation step. Therafter the analyte or a product of conversion is detected fluorimetrically or chemiluminometrically. Both detection principles enable the highly sensitive detection in relatively wide concentration ranges.

In France and Belgium large ancient industrial regions are seriously concerned by brownfield management, and particularly by sites the soils of which have been polluted at the time of former coke activities (exploitation and treating, coke works, gasworks,...).

Groundwater is populated by a diverse fauna, the so called stygofauna. In Europe nearly 2000 species are known, which exclusively live in the groundwater (Rumm& Schminke2000). Stygofauna is highly adapted to its living space, but our knowledge of ecology and distribution is poor (Hahn& Friedrich1999). One of the reasons for that is, that there are no standardized methods of sampling stygofauna yet. Up to today quite different methods are used for sampling stygofauna, each has special advantages and disadvantages. Studies comparing methods of sampling stygofauna are rare. Thus the results of the different investigation on stygofauna are hardly comparable.

Activities by the Department of Defense (DOD) sometimes have resulted in groundwater contamination. These contaminants are usually either fuels, metals, or halogenated solvents. The subsurface is heterogeneous. Under the best of circumstances, investigating the subsurface has been an endeavor marked with technical difficulties and uncertainty. Investigating the subsurface in remote areas can be extremely difficult and expensive. Drilling wells requires specialized knowledge and equipment. Prior to drilling, utility surveys have to be performed, drilling locations determined, drilling permits obtained, and drilling crews lined up often months in advance. Difficulties commonly are encountered with both traditional drilling and push-technology equipment and with subsurface conditions that exist. Derived wastes such as drill cuttings and purge water must be handled in an appropriate manner. Areas of concern located in sites with difficult terrain or beneath heavily wooded areas, in riparian corridors, or marshes are often not sampled.

The Tree Fruit Research and Extension Center (WTFREC), located in Wenatchee, Washington, includes a former U.S. Public Health Service/EPA pesticide test plot area and a laboratory drain field, in addition to an active university tree fruit research and extension center. As a result of pesticide weathering experiments the test plot had been contaminated with organochlorine, organophosphorus, and other pesticides above known levels of concern for human health and the environment. The US Environmental Protection Agency (EPA), Washington State University (the current property owner), and Washington Department of Ecology determined that remediation of the test plot area was necessary. The EPA requested the U.S. Army Corps of Engineers, Seattle District (USACE), to propose, design, and implement the characterization and remediation.

The River Rhine is one of the most anthropogenetically stressed ecosystems in Europe. Between 1817 and 1879 the watercourse was already heavily under construction to improve water discharge according to the plans of J. G. Tulla. In the following decades diverse additional engineering measures were performed, with the consequence of an increase of current velocity and intense bottom erosion along the free flowing stretches, and minimization of current in the backwaters of the several newly built dams. Targets were improvement of flood control, generation of hydroelectric power, and shipping traffic, on the price of almost complete lost of the ecological function of the floodplain area. Pollution with diverse inorganic and organic chemical compounds from urban and industrial discharge increased severely in the 50’s and 6o’s of the past century. The ecological quality reached its lowest level in the 6o’s and 70’s. Fish deaths were the order of way. On the experience of the deteriorated river channel (pollution, flooding, local groundwater lowering, ecological impoverishment) intense investments in purification plants on the Rhine and its catchment area were done and proved positive. Restoration aspects for the river and the floodplain were focussed since 1988. Quality and diversity of species of fish and macrozoobenthos has improved visibly. However, in November 1986 a heavy pollution wave, caused by the Sandoz accident, contaminated the Rhine water and riverbed with various insecticides. Particularly the macrozoobenthos was heavily influenced (Braukmann et al. 1987).

The development of new analytical techniques for fast, simple, and also low-cost on site determinations of harmful substances is one topic in the broad range of the support activities of the “Deutsche Bundesstiftung Umwelt” (DBU, German Federal Environment Foundation). The term ‘low cost’ means, that the total of all costs of the analytical technique is less than 10.000 Euro.

The quality of air is one of the most important factors that affect life quality and public health. Many sources of pollution are threatening this precious good, e.g., emissions from traffic and industry, but natural particles like pollen, spores, viruses or bacteria as well. To get an adequate impression of the degree of the air pollution, monitoring of all pollutants or at least of the most relevant ones (considering their amount and their harmfulness to human health) would be necessary. By determining only one class of compounds little can be concluded on the total effect of the pollutants on human health. Additionally synergistic effects of different pollutants may lead to increased derogation. One example from recent literature is the potential of polycyclic aromatic hydrocarbons (PAHs) to induce allergies (Diaz-Sanchez 1997, Bömmel et al. 2000).

Recently we introduced a first prototype system for quasi-continuous analysis of organic compounds in water based on SPME coupled to GC. The system showed some disadvantages with regard to calibration and sample preparation, for example in pH adjustment. These limitations were overcome in a complete redesign of the instrumental setup (Grote et al, 1999). The instrumental set-up was now based on a stopped-flow approach. Moreover, all analytical steps (sampling, extraction and analysis) were completely automated. Finally, remote control of the analyzer was possible. The system was tested with industrial waste water (a very difficult matrix) using direct SPME (i.e., insertion of the fiber Into the aqueous phase). However, extensive testing of the automated analyzer in the field all revealed some shortcomings. As a result of the aggressive waste water matrix, the performance of the extraction fiber decreased steadily during 1–2 weeks of automated operation.

Leaks in the bottom composite liner of landfill or chemical waste disposal containments may lead to the penetration of contaminated leachate through the barrier and transport of toxic substances into the surrounding soil and groundwater. Therefore continuous surveillance of landfill liners and the identification of leaks are essential parts of waste management. For other large technical installations, e.g., chemical production plants, tank farms, or pipelines extensive leakage monitoring is even more imperative, because fast detection and localization of a leak is required to prevent the release of huge amounts of hazardous chemicals and new contamination of the environment. However, fast identification of a leak position in a chemical waste disposal site may be difficult, e.g., if the site is lined with an underground geomembrane most leaks are point sources, not widespread. Owing to the large spatial extension of such technical facilities, comprehensive and distributed monitoring techniques are necessary. In this context fiber-optic chemical sensor systems with distributed sensing cables buried under the liner, e.g., in a grid–type of scheme, could be a valuable tool.

Fast on site identification of hazardous compounds for correct assessment of possible risks to the population and the environment is essential in case of fire and chemical disasters. The aim of our development has been to establish new simple sample preparation and analytical procedures based on a semi-automatic Gas Chromatograph/Mass Spectrometer system (GC/MS) to detect gases, volatile and semivolatile organic compounds (VOC, SOC). The procedures should make it possible to perform sampling and analysis in less than 10 minutes. The project includes the following objects of research [1,2]: helicopter based emergency responsestandard procedures for air, water and soil analysisadvanced software for skilled fire fighterswireless data transferfield study experience

Chlorinated semi volatile organic compounds (SVOCs), for example the pesticides hexachlorobenzene, lindane (and its isomers) or DDT (and its metabolites) which have been used worldwide very extensively in the past, now occur as ubiquitous air pollutants. They are relatively stable in the atmosphere and can undergo medium to long range transport. In contrast to many other pesticides, the abovementioned chlorinated substances have high bioaccumulation potential and can cause direct or indirect effects on non-target plants, terrestrial and aquatic organisms and even on local human populations [Unsworth et al., 1999]. Because prediction of transport and fate of these substances (and thus of their actual or time–integrated atmospheric concentrations) is not exact enough, an extensive monitoring of persistent chlorinated SVOCs is necessary.

The domestic waste site Karlsruhe-West was equipped in 1993 with a surface sealing system. This system mainly consists of a mineral clay liner (thickness 0.60 m) with an underlying capillary barrier and an upper gravel layer (thickness 0.15 m). To supervise the water balance and the fluxes of the different layers a lysimeter of 10 m x 40 m was integrated in the testfield on the landfill The stratification of the lysimeter is depicted in figure 1. As a result of the flux measurements a leakage of the mineral clay liner was presumed in 1997. In order to detect such a leakage and to possibly specify its reason (fissures, dislocations etc.) geoelectric and ground penetrating radar (GPR) measurements were carried out.

The fact that the soil composition exerts substancial influence on the capacity of restraining pollutant of organic and inorganic compounds has been sufficiently described in literature. But there is no mention of the influence on an actual soil matrix and its behaviour according to the elution of heavy metals or extraction of the PAH and their measuring. Which components in mineral-and material-composition have the largest effect on the regaining rate? Active smectites and sorptive minerals as well as organic compounds in certain soils lead to detect less organic compounds compared to the actual contents. For example regaining rates of only 60% hydrocarbons can be determined in clayey soils. This can lead to false estimations during the investigation and evaluation of contaminated soils and its re-utilisation. Therefore the main point of investigation in one of the research projects sponsored by the Deutsche Bundestiftung Umwelt (DBU) was to proof the influence of individual material compositions for different substrates.

The mine dumps from no longer used potash mines in the North Thuringian area represent not only an aesthetic but also an ecological problem. The mining dumps with sizes up to 65 ha consist to 70-80% of easily soluble rock salt. Through the raining water, the salts with a concentration from up to 350 g/L reach into the groundwater or in surface waters and represent a permanent endangering of the ecosystem.

Mobility and extraction behaviour of contaminants in soil are linked with specific properties of the soil matrix. These properties are mainly a consequence of local pedogenesis and thereby a function of the soil type (1,2). Starting point of the following investigation are soil profiles with distinct soil horizons that are taken from selected locations.

Mineral oil hydrocarbons belong to the most frequently found contaminants in soil samples, e.g., on former military sites. Because of their ecotoxicity and the hazard for ground water a remediation of contaminated sites is necessary. [1] During the investigation concerning the extent of pollution and for the supervision of sanitation measures a field screening method, which gives information about the degree of contamination within a short period of time, would be advantageous. It could help to save time and thereby reduce costs, because decisions about further action could be met without delay.

The sensitive, selective and long term stable detection of hydrogen peroxide is of great interest both in environmental and biochemical analysis. The chemiluminescence detection is one of the most sensitive methods with a very wide determination range but also very low selectivity. Many reductants and complexants can interfere strongly. Therefore the aim of this paper was to combine the high sensitivity of the chemiluminescence detection with the selectivity of a membrane separation step. Because of its high selectivity against nonvolatile interferents the gas diffusion across microporous and hydrophobic membrane layers was chosen. Frenzel et al.(2000) proposed a flow through analytical set-up with a dialysis cell with an integrated photodiode to detect H₂O₂ chemiluminometrically and achieved a detection limit of appromimately 30 µM.

Soil and groundwater contamination can cause serious damage of existing ecosystems or at least restrict the possible use of land or water. Depending on the mobility of contaminants and their toxicity either remediation measures are required in order to avoid further damages for the environment or, if the pollution is not connected with high risk potential, it can be left to natural attenuation. In both cases an intensive control of the contamination and its further behaviour, transport or migration is necessary. These require generally a comprehensive monitoring network with regular sampling and chemical analysis.

Owing to their hazardous potential and their wide distribution in the environment, petroleum hydrocarbons (PH’s) [1] and polycyclic aromatic compounds (PAC’s) are playing an important role in environmental analysis. With LIF spectroscopy in combination with fiber optical sensors fast and sensitive on site and in situ measurements of these compounds are possible [2].

The soil water content has a dominant influence on the dielectric permittivity E of porous media because of the high permittivity of water compared with the matrix. The well known Maxwell’s relation which is valid for most natural soils combines the permittivity and the phase velocity v of electromagnetic waves where co is the velocity of light in vacuum, 1$$\varepsilon = \left( {\frac{{c_0 }} {\nu }} \right)^2 \cdot $$ Thus the water content can be quantified by determining this velocity. There exists a wide variety of possibilities to determine the phase velocity of the ground penetrating radar waves, whereby two of them will be introduced in the following section.

Refrigerator systems, heat pumps and air conditioning facilities have to be monitored for coolant leakages to enable alarms and precaution if certain concentration levels are exceeded (pre-alarm: 200vpm, main alarm: 1000vpm). Nowadays metal oxide gas sensors of the tin oxide type are preferably used as sensor elements due to their good sensitivity, long-term functionality and low application costs. In general, however, a still unsolved problem of automatic safety control by monitoring of flammable and hazardous gases in air is the gas identification capability and the reliability of this type of sensor at changing temperature and humidity conditions. In the case of ammonia used as coolant medium we present a novel and economic sensor system which enables both ammonia identification and concentration determination under variing air humidity. This will reduce the risk of false alarms drastically.

The project reported deals with the efficient and economic monitoring of volatile organic compounds in groundwater. The measuring system is based on a novel optical technique for online and in situ monitoring. Goal of the project is to demonstrate the sensor principle for an effective monitoring of chlorinated and polycyclic hydrocarbon target analytes and to test the measuring system in a field application. The so called EWALD sensor uses Evanescent Wave Attenuation with Laser Diodes. The analytes are detected sensitively and selectively by their fingerprint absorption in the mid-infrared.

This poster addresses the problem of measuring strongly adsorbable and volatile substances directly in bore holes. A chemical company, DSM Geleen, faces the problem of an old contamination in deeper soil regions (< 30 m) that covers an unknown area of their premises. As a first step the contamination has to be evaluated by quantification of the geometrical boundaries and the mass of contaminating substances adsorbed onto soil and diluted in soil water.

On-site investigations are expected to give fast information on the hazardous potential of soil or landfill material. While most of the common field analytical methods will measure the total contamination a solid environmental sample, leaching tests are a means to gain information on the behaviour of especially the water-soluble and groundwater-available pollutants. Thus they should be an important and critical part of nearly any site investigation program.

A detailed knowledge of the preferential transport paths is very important for the characterisation of contaminated sites as well as for the planning of site remediation. For instance, the knowledge of the spatial extension of these paths is a prerequisite for a reliable evaluation of the natural attenuation behaviour. In the case of the installation of funnel & gate system for the remediation of the groundwater the knowledge of the preferential transport can significantly contribute to an optimisation of the system and in this way to a minimisation of the cost.

Intensive industrial development causes transformational processes in ecosystems. Only 0.3–3.0% of natural systems areas remained undamaged under industrial technologies influence in the Ukrainian industrial regions disturbed systems (Bulakhov, 2000). Simple and quick methods of contamination level determination are needed to launch wide scale activities aimed at the disturbed ecosystems restoration and environment normalization. A lot of analytical methods are used to determine these levels, but all of them are complex and require expensive equipment. The higher vertebrates which are super sensitive to the metallurgical, mining and chemical emissions can be used as well.

Polycyclic aromatic hydrocarbons (PAH) are widely occuring compounds with mutagenic and carcinogenic properties and belong to the mostly environmental contaminants besides the mineral oil hydrocarbons. The laboratory analysis of PAH is time consuming and expensive. Therefore the environmental analysis, e.g. the investigation of soil pollution is increasingly faced with the demand for faster and less expensive methods especially for on site investigations. Therefore in a co-operation project, sponsored by the Deutsche Stiftung Umwelt together with other participants it will be developed a low cost technique of the PAH determination in the field by using a modified method of thin layer chromatography (TLC), a so called field TLC (FTLC). Among the available chromatographic techniques TLC has the advantages of being comparatively simple, rapid, robust and inexpensive, allows high sample throughput and simultaneous processing of sample and standards.The first results of our investigations are presented.

Mapping of subsurface contamination is one of the most important aims of environ–mental geophysics. For this purpose great efforts have been and will be carried out in the development of non-destructive geophysical mapping and monitoring techniques. In the growing field of different measurement devices the Ground-Penetrating RADAR (GPR) managed to get in the line of the most promising tools. Beside the goal of detecting a possible contamination the estimation of the degree of contamination be–comes more and more important. Therefore a diploma thesis at the Geophysical In–stitute (GPI) of the University Karlsruhe in co-operation with the Department of Ap–plied Geology (AGK), University of Karlsruhe and the Institute of Meteorology and Climate Research (IMK), Karlsruhe Research Center, was promoted to examine the invertability of dielectric permittivity data with regard to contaminations.

The importance of spectroscopic on site analytics will increase in the near future on the basis of currently available compact spectrometers for the visible and near infrared region with their easy handling and on the basis of great methodical spectroscopic variability and corresponding accessories. The modern instrumental analytics needs small, compact, reliable and efficient measuring possibilities for liquids and other media in real time and with easy and fast sampling and conditioning. Fast and accurate detection techniques of toxicological pollutants in ground and drinking water get an increasing importance. For instance, spectroscopical methods, which are based on fibre-optical solutions, using various forms of immersion probes in the UV/VIS- and NIR-region have been achieved a stable place. Medical applications have special analytical demands with respect to small volumina in the nl-and sub-nl-region. The middle infrared region (2.5 – 50 pm) is especially suited for a highly efficient optical environmental analysis, for instance, in the on site analytics of organic pollutants. With progress in the microsystem technology new possibilities are opened to use highly sensitive and specific detection principles in compact arrangements. Methods like spectrophotometry in the UV/VIS at low temperatures allowing narrow bandwidth or especially MIR-methods seems to be suitable optimally.

Comprehensive validation of any measurement method is required in order to make different methods comparable and acceptable in front of the law. Each method validation aims at obtaining suitable indicators for assessing the efficiency of an analytical procedure, i.e., in particular those indicators that characterize analytical errors. Correctness and precision of the data, the limit of detection and determination, retrieval rates, test specificity, matrix dependency of the test results, the method’s robustness in case of smaller or larger deviations in performing the analysis and the correspondence with reference procedures are the essential criteria for assessing a procedure in the framework of method validation. However, these criteria should not to be considered separately, but should be combined into an overall concept in order to be able to distinguish between essential and unessential sources of error. The so called top–down uncertainty concept of the Analytical Methods Committee of the Royal Society of Chemistry (AMC: M. Thompson) is particularly suitable as mathematical basis for such an assessment concept, because it splits the analytical error into different error components and assigns them to individual uncertainty components, that are described in detail later.

The demand of government and consultants to have a fast and reliable system to determine the heavy metal content in soil samples is still growing. The interest in analysis and control of soil samples on the field leads to the evaluation of the applicability of ED-XRF (energy–dispersive X-ray spectrometry) as a field analytical technique. In this paper field analysis of soil samples by ED-XRF, resulting in a fast gathering of reliable data, was investigated based on a case study.

Nitrate and its decay products converted in the human body are unhealthy. Therefore, intense nitrate pollution, particularly of drinking water, must be avoided. 5o mg per litre are considered to be the acceptable limit, but for infants this limiting value should be classified as already precarious.