Holger Weiss

Helmholtz-Zentrum für Umweltforschung | UFZ · Department of Environmental Informatics

The ubiquitous presence of the radioisotope radon (222Rn) and its short-lived progeny (218Po, 214Pb, 214Bi, 214Po) is challenging in two respects: (i) Radon is a major issue regarding health-related problems due to potentially elevated radiation exposure of humans in dwellings, and (ii) due to the mobility of radon the short-lived progeny may cause...

Radon-222 contributes to half of the natural radiation exposure of humans and is one of the main causes of lung cancer. Of particular importance for humans is the exposure to radon-222 indoors, which enters living and working areas from the soil air, e.g. through cracks in the foundations of buildings. An easy and efficient way to minimise indoor r...

The new German Radiation Protection Act (StrlSchG) of December 31, 2018 established a reference value of 300 Bq/m3 for the annual average radon activity concentration in buildings with recreation and living rooms as well as workplaces. It is expected that the reference value will be exceeded in a vast number of buildings throughout Germany and that...

The new German Radiation Protection Act (StrlSchG) of 31 December 2018 established a reference value of 300 Bq/m3 for the annual average radon activity concentration in buildings with recreation and living rooms as well as workplaces. It is expected that the reference value will be exceeded in a vast number of buildings throughout Germany and that...

Natural attenuation processes depend on the availability of suitable electron acceptors. At the megasite Zeitz, concentrations of the main contaminant benzene were observed to increase constantly in the lower aquifer to levels of more than 2.5 mM. This was accompanied by decreasing concentrations of sulphate (SO4²⁻), which has been previously shown...

The lack of safe drinking water worldwide has drawn the attention of decision makers to riverbank filtration (RBF) for its many advantages in purifying surface water. This study aims to develop a new model for RBF site selection used for drinking water supply under uncertainty. Five component utility functions were assessed. Ranking of the scaling...

Covering a plateau area of approximately 125,000 km², the Urucuia Aquifer System (UAS) represents a national strategic water resource in the drought-stricken Northeastern part of Brazil. Variations in terrestrial water storage (TWS) extracted using a three-model-ensemble from the Gravity Recovery and Climate Experiment (GRACE) mission showed a nega...

Sollen Sumpfpflanzen noch effektiver auf Gebäudedächern eingesetzt werden, sind detaillierte Kenntnisse zur Leistungsfähigkeit dieser Pflanzen, zum Gesamtgewicht, zur Klimawirkung und zu Effekten auf die Biodiversität nötig. Diese Parameter werden je nach Anforderung vom Labor bis zur Pilotanlage ermittelt.

Das Themenheft "Sumpfpflanzendächer" gibt einen Überblick über den Stand der Forschung und über praktische Erfahrungen mit dieser wenig bekannten Art der Dachbegrünung.

The new Radiation Protection Act (StrlSchG) of 31 December 2018 established a reference value of 300 Bq/m3 for the annual average radon activity concentration in buildings with recreation and living rooms and workplaces. It is expected that the reference value will be exceeded in a large number of buildings throughout Germany and that radon protect...

The new Radiation Protection Act (StrlSchG) of 31 December 2018 established a reference value of 300 Bq/m3 for the annual average radon activity concentration in buildings with recreation and living rooms and workplaces. It is expected that the reference value will be exceeded in a large number of buildings throughout Germany and that radon protect...

The paper presents an improved approach for investigating submarine groundwater discharge (SGD) based on radon mapping and radon mass balancing in the coastal sea. While the use of radon as an environmental tracer in SGD studies is well-established, we identified based on our longstanding experience six methodical shortcomings of the conventional a...

Elevated indoor radon concentrations (222Rn) in dwellings pose generally a potential health risk to the inhabitants. During the last decades a considerable number of studies discussed both the different sources of indoor radon and the drivers for diurnal and multi day variations of its concentration. While the potential sources are undisputed, cont...

Lacustrine groundwater discharge (LGD) and the related water residence time are crucial parameters for quantifying lake matter budgets and assessing its vulnerability to contaminant input. Our approach utilizes the stable isotopes of water (δ18O, δ2H) and the radioisotope radon (222Rn) for determining long-term average and short-term snapshots in L...

Quantification of submarine groundwater discharge (SGD) is essential for evaluating the vulnerability of coastal water bodies to groundwater pollution and for understanding water body material cycles response due to potential discharge of nutrients, organic compounds, or heavy metals. Here we present an environmental tracer-based methodology for qu...

Technical hexachlorocyclohexane (HCH) mixtures and Lindane (-HCH) have been produced in Bitterfeld-Wolfen, Germany, for about 30 years until 1982. In the vicinity of the former dump sites and production facilities, large plumes of HCHs persist within two aquifer systems. We studied the natural attenuation of HCH in these groundwater systems throug...

The management of water and land resources in the Distrito Federal (DF), Western Central Brazil is characterized by very dynamic changes of land use/land cover driven by economic development, population growth and climate change. This problem is addressed by the project IWAS-ÁGUA DF which aims at creating a scientific base for the sustainable manag...

As a contribution to an Integrated Water Resources Management (IWRM) project in Distrito Federal, Brazil, we address several aspects for a credible downscaling of near-surface air temperature and precipitation using the Statistical DownScaling Model (SDSM4.2). For instance, we apply a detailed screening of predictors, consider the end user needs in...

Available climatological information of Distrito Federal does not satisfy the requirements for detailed climate diagnosis, as they do not provide the necessary spatial resolution for water resources management purposes. Annual and seasonal climatology (1971–2000) of precipitation from 6 meteorological stations and 54 rain gauges from Central Brazil...

Available climatological information of Distrito Federal does not satisfy the requirements for detailed climate diagnosis, as they do not provide the necessary spatial resolution for water resources management purposes. Annual and seasonal climatology (1971–2000) of precipitation from 6 meteorological stations and 54 rain gauges from Central Brazil...

A key challenge for climate projection science is to serve the growing needs of impact assessments in an environment with substantial differences in the projections of climate models and an increasing number of relevant climate model results. In order to assist the assessment of water resources impacts under future climate change, this work provide...

The International Water Research Alliance Saxony (IWAS) is addressing the global challenges concerning water quality in the areas of drinking water and sanitation, agricultural irrigation and the quality of surface and ground waters, as well as developing specific ecosystem-relevant services to be implemented on an exemplary basis in selected model...

The complex interactions between water resources, land-use change and water technologies are a major issue in many emerging countries of Southern America. Usable water resources are affected by natural conditions, such as, strong seasonal contrasts and high climatic variability, and rapid changes of land use and land cover that is caused by the dra...

The complex interactions between water resources, land-use change and water technologies are a major issue in many emerging countries of Southern America. Usable water resources are affected by natural conditions, such as, strong seasonal contrasts and high climatic variability, and rapid changes of land use and land cover that is caused by the dra...

The microbial oxidation of sulfide is a key reaction of the microbial sulfur cycle, recycling sulfur in its most reduced valence state back to more oxidized forms usable as electron acceptors. Under anoxic conditions, nitrate is a preferential electron acceptor of this process. Two enzymatic pathways have been proposed for sulfide oxidation under n...

The Guarani aquifer system (GAS) represents one of the biggest aquifers in the world and is the most relevant groundwater resource in South America. For the first time, by combining field and laboratory measurements, a high-resolution aquifer analog model of fluvial–aeolian sediments of the GAS in São Paulo State (Brazil) is constructed. Three para...

Unlabelled: Accumulation of volatile organic compounds (VOCs) that migrate inside buildings from underlying contaminated soils and groundwater poses human health risks. VOCs intrusion into buildings driven only by diffusion was reproduced by a laboratory-scale experiment. Effective diffusion coefficients and fluxes of a group of selected chlorinat...

In situ radio-frequency heating (ISRFH) combined with soil vapor extraction was demonstrated at a contaminated field site of a former hydrotreatment plant in Zeitz near Leipzig. The project was carried out in several phases including cold soil vapor extraction for comparison. During the test, a soil volume of about 300m3 was heated to an average te...

In the framework of the IWAS/Água-DF project, this study focuses on changes in mean surface air temperature and accumulated precipitation in Central Brazil over the past 40 years. It has two main objectives: (1) comparison between two climatological periods (2001–2010 and 1971– 2000) and (2) trend analysis of climate variables. Time series of meteo...

In order to understand the groundwater dynamics and to improve the management of water resources in the Federal District of Brazil, this research proposes a 3D groundwater flow model to represent the groundwater level and flow system. The selected test site was the Pipiripau catchment. The development of the model was based on available geological,...

A large-scale groundwater contamination characterises the Pleistocene groundwater system of the former industrial and abandoned mining region Bitterfeld/Wolfen, Eastern Germany. For more than a century, local chemical production and extensive lignite mining caused a complex contaminant release from local production areas and related dump sites. Tod...

Available climatological information of Central Brazil does not satisfy the requirements for detailed climate diagnosis, as they do not provide the necessary spatial resolution for water resources management purposes. Annual and seasonal climatology (1971-2000) of precipitation from 6 meteorological stations and 54 rain gauge stations from Central...

One of the largest urban agglomerations in Brazil is the capital Brasilia and its surrounding area. Due to fast urban sprawl and accelerated land use changes, available water supplies are near their limits. The water supply depends largely on surface water collected in reservoirs. There are increasing concerns regarding water shortages due to sedim...

In scope of an IWRM concept for the Federal District, Western Central Brazil we developed a planning support tool, which enables non-experts to test the effects of land-use and land-cover change (LULCC) on landscape processes and landscape functions (LPF) related to sediment generation and retention. For this purpose we developed the web-based tool...

The Voigtländer camera production site in Braunschweig was operated until 1972. The facility’s use of chlorinated solvents for grease removal led to significant soil and groundwater contamination. The investigation and remediation methods that have been used at the site have not resulted in an acceptable level of remediation. Given the heterogeneou...

Broadband spectral induced polarization (SIP) measurements were conducted at a former hydrogenation plant in Zeitz (NE Germany) to investigate the potential of SIP imaging to delineate areas with different BTEX (benzene, toluene, ethylbenzene, and xylene) concentrations. Conductivity images reveal a poor correlation with the distribution of contami...

The purpose of this study is to characterise the alluvial sediments and to quantify sedimentation rates of a small river system, the Ribeirão do Torto in Central Western Brazil. The study area provides an excellent opportunity to examine the effect of land use on sedi-mentation rates in the region for the first time and thus contributes to understa...

Groundwater long-term monitoring (LTM) is required to assess groundwater remediation and human health risk at sites with severe groundwater contamination. Groundwater LTM network optimization requires sampling at existing wells, data management, remediation, and risk reduction activities, costing mi lions of Euros. The study of monitoring network o...

An antimony speciation method was optimized using HPLC-ICP-MS and EDTA as eluent with the aim to minimize the carbon intake into the ICP-MS system and to lower the limits of detection. The flow rate was significantly decreased to 0.4 mL min-1 by using a HPLC column with a smaller inner diameter (Hamilton PRP X-100, 150 mm x 2.1 mm, 10 μm). This res...

The variability of hydrogeochemical conditions can affect groundwater microbial communities and the natural attenuation of organic chemicals in contaminated aquifers. It is suspected that in situ biodegradation in anoxic plumes of chloroethenes depends on the spatial location of the contaminants and the electron donors and acceptors, as well as the...

The remobilization of antimony and vanadium from previously loaded commercial granular ferric-hydroxide GEH material (intended for water treatment) was examined by using a sequential extraction procedure and three different leaching systems to evaluate their physicochemical mobility and potential availability under different simulated environmental...

The project IWAS-ÀGUA DF focuses on creating the scientific base for an IWRM concept for the Brasília region. A focus of the study is the dynamic land-use/land-cover change which has caused severe impacts on water resources, while effects of climate change during the last three decades are thought to be rather moderate. Effects on water quantity ar...

Water resources in the Federal District of Brazil are subject to considerable pressure. Major stress factors are population growth and land-use changes. The project IWAS-ÁGUA DF aims at creating a scientific basis for the sustainable management of water resources in the sense of Integrated Water Resources Management (IWRM).The first step was to doc...

Land-use/cover change (LUCC) and climate change are major controlling factors for water resources in the Distrito Federal in Western Central Brazil. Dynamic LUCC in the region has severe impacts on water resources, while climate changes during the last three decades is thought to have only moderate effects. LUCC affects water quantity mostly during...

A common approach for remediation of groundwater contamination with volatile organic compounds (VOCs) is contaminant stripping by means of in situ air sparging (IAS). For VOC stripping, pressurized air is injected into the contaminated groundwater volume, followed by the extraction of the contaminant-loaded exhaust gas from the vadose soil zone and...

Two akaganeite materials were tested for the removal of antimonate, trimethyl antimonate, arsenate, arsenite, and dimethyl arsenate from water: a commercial product (GEH) and a synthesized akaganeite. The two materials show similar q(max) values, but differ in their K(L) values. This could be a result of their different crystal sizes indicated by s...

Importance of Land Use Changes for an Integrated Water Resource Management – a Case Study from Western Central Brazil The project IWAS-ÀGUA DF focuses on creating the scientifi c base for an IWRM concept for the Brasília region. A focus of the study is the dynamic land-use/ land-cover change which has caused severe impacts on water resources, while...

The demands of the EC Water Framework Directive are opening new possibilities for the application of investigation methods that were formerly used only at contaminated sites. This work describes the application of Direct Push (DP) techniques for the recording and geostatistical processing of high resolution groundwater quality profiles. These profi...

Groundwater polluted with phenylarsenicals from former warfare agent deposits and their metabolites was investigated with respect to the behavior of relevant arsenic species. Depth profiles at the estimated source and at about 1km downgradient from the source zone were sampled. The source zone is characterized by high total arsenic concentrations u...

The IWAS Água DF Project is a bilateral cooperation project initiated in 2009, coordinated by German and Brazilian institutions, with the main objective to develop an Integrated Water Resource Management System, in order to guarantee the safe water supply of the Federal District of Brazil and its surrounding urban areas. In this project a working p...

Radon-222, a naturally-occurring radioisotope with a half-life of 3.8 days, was used to estimate groundwater discharge to small lakes in wetland-dominated basins in the vicinity of Fort McMurray, Canada. This region is under significant water development pressure including both oil sands mining and in situ extraction. Field investigations were carr...

The arsenic species hexafluoroarsenate has been described as a contaminant of surface waters of anthropogenic origin. Here, we undertake to identify the most sensitive biological receptor among several sentinel aquatic species used in eco-toxicological assessment and to understand toxicity in terms of internal dose. Therefore, a screening of short-...

The extensive production of chemical warfare agents in the 20th century has led to serious contamination of soil and groundwater with phenyl arsenicals at former ammunition depots or warfare agent production sites worldwide. Most phenyl arsenicals are highly toxic for humans. The microbial degradation of phenylarsonic acid (PAA) and diphenylarsinic...