PYROPHOB (fire-resistant) is the name of an interdisciplinary research project that is running for five years from 2020 to 2025. In this project, eight institutions are investigating the ecological effects of wildfires and subsequent forest management strategies in pine forests (plantations) in Brandenburg (NE Germany), with the aim of formulating practical recommendations for managing fire-prone forests and the effective restoration of post-fire forest areas. We provide a brief overview of what is known about the effects of wildfire on abiotic and biotic parameters in temperate pine forests, as well as the effects of silvicultural treatments. To date, we know little about how different components of biodiversity are linked in post-fire forest ecosystems and how management affects their functioning. By describing the project, we illustrate the requirements for the implementation of such an applied research project. We emphasize the importance of the study design for dealing with interdisciplinary questions and for the quantitative synthesis of research results. The project comprises a set of standardised field plots in two wildfire areas covering different post-fire management options.Fifteen study sites were established, including two reference sites in unburned pine stands, each with ten study plots as replicates. In situ nitrogen mineralisation, litter decomposition tests and soil biological activity are used for soil biological characterisation. Microclimate data is measured continuously. Standing and lying dead wood and tree regeneration are recorded as key indicators of the success of forestry treatments. Further methods com-prise terrestrial laser scanning, remote sensing techniques as well as surveys of vegetation and above and below ground biomass. Identification of fruiting body-forming fungi, phytoparasites and ectomycorrhizal fungi is supported by marker gene sequencing. Faunistic indicators comprise predatory soil arthropods (pairs of emergence tents and soil traps), saproxylic beetles (flight traps and funnel traps), moths (automated window traps), mammals (camera traps), and breeding birds (visual and acoustic observation). We discuss the strengths and limitations of the project design. We are able to systematically capture short-term temporal shifts in parameters and trends in post-fire ecosystem development. Research in a real landscape with ongoing environmental changes and interventions pres-ents challenges for experimental design, data analysis and interpretation. The drivers of ecosystem development are rarely completely independent or perfectly balanced, and lack of replication is ine-vitable. The two fires did not occur in the same year and season, resulting in different initial conditions for the colonisation of the burned areas. Finally, a large part of one study area was again affected by a fire in 2022, which destroyed direct comparability with the other sites. Despite these obstacles the project has started to generate valuable results to address management and conservation challenges

An ever growing quantity of digestates produced from agricultural biogas facilities puts alternative use options, other than spreading those residues on agricultural land, into focus, particularly to protect the ground water from nitrogen leaching in intensively used regions. Within the framework of the FNR funded project Skarabäus, Brandenburg University of Technology (BTU) together with partners from the Institute of Agricultural and Urban Ecological Projects affiliated to Humboldt University Berlin (IASP) and the Humboldt University Berlin (HU) investigate whether biogas digestates could be converted to fertilizer products of defined composition to be used outside agricultural production particularly for gardening and landscaping. The project rationale is to agglomerate the separated digestates to produce a fertilizer which is flexible in the design of properties, easy to handle for application and effective to plant’s growth. Basically the tumble agglomeration was considered as the main process. The properties of the fertilizer product, particularly the nutrient content with respect to nitrogen, phosphorus and potassium, was thought to be adjusted by adding nutrient rich secondary materials like meat and bone meal, replaced powders from fire extinguishers and recycled material originating from waste water treatment during the agglomeration process. Experiments revealed that separated digestates could hardly be agglomerated due to the high amount of relatively large and inflexible fiber contained. The addition of binding agents like clay minerals strongly improved the agglomeration process. However, so far best results were achieved when separated digestates were composted prior to the agglomeration process. In this way no binding agents were necessary. Agglomerates produced from composted digestates showed a reasonable particle size distribution and nutrient- and organic matter content generally suitable for application in horticulture, given that future greenhouse and field experiments could also demonstrate the beneficial application.

This study aims at investigating the iron cyanide (CN) degradation potential of two natural bacterial isolates with the purpose of their application in iron CN phytoremediation. The strains were isolated from contaminated soil and incubated over 4 months with 50 mg L-1 CN (as ferrocyanide) as the sole iron and nitrogen source. Unlike previous reports, the study provides control for bacterial growth, biotic and abiotic CN losses. Bacterial growth, CN, ammonium, and nitrate concentrations were monitored regularly. Both strains grew less rapid with iron CN compared with the positive control. However, the growth was diauxic. The CN concentration in the media decreased with 20% and 25% respectively, while that in the sterile controls remained stable. Ammonium was detected in the media of both strains implying that a fraction of the initially applied ferrocyanide has been converted. The nitrogen lost from the system evened out with that in the cells at the end of the experiments. These results showed that the investigated strains were undoubtedly able to grow on iron CN as an alternative nitrogen source, but contrary to some previous findings, the iron CN utilization is much slower and takes place only after complete exhaustion of the cellular nitrogen reserves.

The cultivation of bioenergy plants in fertile, arable lands increasingly results in new land use conflicts with food production and cannot be considered as sustainable. Marginal lands have been frequently considered as potential alternatives for producing bioenergy from biomass. However, clear definitions and assessment methods for selecting marginal lands and for calculating potentials are still widely missing. The project “SEEMLA” aims at triggering the exploitation of currently underused marginal lands for biomass production for energy purposes. Study sites have been selected in different European countries: Germany, Greece, and Ukraine. The selected sites represent a wide variety of different types of marginal lands. Based on a soil assessment set given by the Muencheberg Soil Quality Rating (SQR) system potentially “marginal” sites have been investigated. The SQR system allows for clearly distinguishing between soils of higher and lower quality. Soils with SQR scores below 40 are regarded as “marginal”. They can be classified into different groups with regard to the importance of soil hazard indicators as evaluated by the SQR approach. The calculated SQR scores correlate significantly with biomass yields of bioenergy plants. Further, the SQR method was adapted for use in a GIS study on marginal-land potentials in Europe. Thus, 46 % of the investigated European area could be classified as “marginal” with SQR scores below 40. From that area 22.6 % can be considered as potentially suitable for producing renewable resources after eliminating protected sites or other places not suitable for any kind of land use. Taking the ecological demands of selected bioenergy plants into account it is possible to give first preliminary recommendations for regional crop cultivation. It can be concluded that Europe offers a large potential for renewable resources from marginal sites. However, the implementation into practice is often impeded by missing or varying policies and regulations. A proper implementation needs clear regulations and also incentives for farmers at the European level.

The detoxification of iron cyanide in a soil-plant system was investigated to assess the total cyanide extracted from contaminated soil and allocated in the leaf tissue of willow trees (Salix caprea). They were grown in soil containing up to 1000 mg/kg dry weight (dw) of cyanide (CN), added as 15N-labeled potassium ferrocyanide and prepared with a new method for synthesis of labeled iron cyanides. CN content and 15N enrichment were monitored weekly over the exposure in leaf tissue of different age. The 15N enrichment in the young and old leaf tissue reached up to 15.197‰ and 9063‰, respectively; it increased significantly over the exposure and with increasing exposure concentrations (p < 0.05). Although the CN accumulation in the old leaf tissue was higher, compared to the young leaf tissue (p < 0.05), the 15N enrichment in the two tissue types did not differ statistically. This indicates a non-uniform CN accumulation but a uniform 15N allocation throughout the leaf mass. Significant differences were detected between the measured CN content and the C15N content, calculated from the 15N enrichment (p < 0.05), revealing a significant CN fraction within the leaf tissue, which could not be detected as ionic CN. The application of labeled iron CN clearly shows that CN is detoxified during uptake by the willows. However, these results do not exclude other detoxification pathways, not related to the trees. Still, they are strongly indicative of the central role the trees played in CN removal and detoxification under the experimental conditions.

Isotopic labels are widely used to trace the fate and cycling of common environmental contaminants. Many of the labeled materials are not available commercially and, depending on the complexity of the substance, the label and the enrichment level, custom syntheses are costly. A simple, straightforward, and cost effective method for the preparation of a highly enriched, 15N-labeled potassium ferrocyanide (K4[Fe(C15N)6]*3H2O) has been developed to meet the requirements of related tracer experiments and minimize their costs. In this case, the 15N label was used to quantify iron cyanide detoxification (biodegradation and/or transformation) within soil-plant-systems. 15N-labeled potassium cyanide (KC15N) and a ferrous iron salt have been used for the synthesis. Extensive qualitative and quantitative analyses showed a product, entirely identical in its functional and elemental components to commercial non-labeled K4[Fe(CN)6]*3H2O and in its 15N enrichment to the KC15N used for its synthesis. To investigate their behavior and fate in various environmental compartments, other labeled iron or metal cyanide complexes might be synthesized in analogous manner.

The soil in the vicinities of former Manufactured Gas Plant (MGP) sites is commonly contaminated with iron-cyanide complexes (ferric ferrocyanide). The phenomenon of cyanide mobility in soil, according to the literature, is mainly governed by the dissolution and precipitation of ferric ferrocyanide, which is only slightly soluble (<1 mg L(-1)) under acidic conditions. In this paper, retention properties of the sandy loam soil and the potential vertical movement of the solid iron-cyanide complexes, co-existing with the dissolution, sorption and precipitation reactions were investigated. Preliminary research conducted on a former MGP site implied colloidal transport of ferric ferricyanide from the initial deposition in the wastes layer towards the sandy loam material (secondary accumulation), which possibly retarded the mobility of cyanide (CN). A series of batch and column experiments were applied in order to investigate the retardation of iron-cyanide complexes by the sandy loam soil. Batch experiments revealed that in circumneutral pH conditions sandy loam material decreases the potassium ferro- and ferricyanide concentration. In column experiments a minor reduction in CN concentration was observed prior to addition of iron sulfide (FeS) layer, which induced the formation of the Prussian blue colloids in circumneutral pH conditions. Precipitated solid iron-cyanide complexes were mechanically filtered by the coherent structure of the investigated soil. Additionally, the reduction of the CN concentration of the percolation solutions by the sandy loam soil was presumably induced due to the formation of potassium manganese iron-cyanide (K2Mn[Fe(CN)6]).

Phytoremediation of sites contaminated with iron cyanides can be performed using poplar and willow trees. Poplar and willow trees were grown in potting substrate spiked with ferrocyanide concentrations of up to 2,000 mg kg−1 for 4 and 8 weeks respectively. Soil solution and leaf tissue of different age were sampled for total cyanide analysis every week. Chlorophyll content in the leaves was determined to quantify cyanide toxicity. Results showed that cyanide in the soil solution of spiked soils differed between treatments and on weekly basis and ranged from 0.5 to 1,200 mg l−1. The maximum cyanide content in willow and poplar leaves was 518 mg kg−1 fresh weight (FW) and 148 mg kg−1 FW respectively. Cyanide accumulated in the leaves increased linearly with increasing cyanide concentration in the soil solution. On the long term, significantly more cyanide was accumulated in old leaf tissue than in young tissue. Chlorophyll content in poplar decreased linearly with increasing cyanide in the soil solution and in leaf tissue, and over time. The inhibitory concentration (IC50) value for poplars after 4 weeks of exposure was 173 mg l−1 and for willow after 8 weeks of exposure—768 mg l−1. Results show that willows tolerate much more cyanide and over a longer period than poplars, making them very appropriate for remediating sites highly contaminated with iron cyanides.

Soil contamination with iron-cyanide complexes is a common problem at former manufactured gas plant (MGP) sites. Dissolution of the cyanide, from Prussian Blue (ferric ferrocyanide), creates an environmental hazard, whereas the risk of groundwater contamination depends on the stability of dissolved iron-cyanide complexes. Lack of a standard leaching method to determine the water-soluble (plant-available) cyanide fraction generates potential limitations for implementing remediation strategies like phytoremediation. Applicability of neutral solution extraction to determine the water-soluble cyanide fraction and the stability of Prussian Blue in surface and near-surface soils of an MGP site in Cottbus, undersaturated and unsaturated water conditions, was studied in column leaching and batch extraction experiments. MGP soils used in the long-term tests varied according to the pH (5.0-7.7) and the total cyanide content (40-1718mg kg(-1)). Column leaching, after four months of percolation, still yielded effluent concentrations exceeding the German drinking water limit (> 50g L-1) and the solubility of Prussian Blue reported in the literature (< 1mg L-1) from both alkaline and acidic soils. Long-term (1344h) extraction of MGP soils with distilled water was sufficient to dissolve 97% of the total cyanide from the slightly alkaline soils and up to 78% from the acidic soils. Both experiments revealed that dissolution of ferric ferrocyanide under circum-neutral pH and oxic water conditions is a function of time, where the released amount is dependent on the soil pH and total cyanide content. Unexpectedly high and continuous solubility of Prussian Blue, both in acidic and slightly alkaline MGP soils, implies the need to introduce an additional cyanide fraction (readily soluble fraction) to improve and specify cyanide leaching methods. Long-term extraction of cyanide-contaminated soil in neutral solution seems to be a promising approach to evaluate the potential hazard of groundwater pollution at the MGP sites.

Iron-cyanide (Fe-CN) complexes have been detected at Manufactured Gas Plant sites (MGP) worldwide.The risk of groundwater contamination depends mainly on the dissolution of ferric ferrocyanide.In order to design effective remediation strategies, it is relevant to understand the contaminant's fate and transport in soil, and to quantify and mathematically model a release rate.The release of iron-cyanide complexes from four contaminated soils, originating from the former MGP in Cottbus, has been studied by using a column experiment.Results indicated that long-term cyanide (CN) release is governed by two phases: one readily dissolved and one strongly fixed.Different isotherm and kinetic equations were used to investigate the driving mechanisms for the ferric ferrocyanide release.Applying the isotherm equations assumed an approach by which two phases were separate in time, whereas the multiple first order equation considered simultaneous occurrence of both cyanide pools.Results indicated varying CN release rates according to the phase and soil.According to isotherm and kinetic models, the long-term iron cyanide release from the MGP soils is a complex phenomenon driven by various mechanisms parallely involving desorption, diffusion and transport processes.Phase I (rapid release) is presumably mainly constrained by the transport process of readily dissolved iron-cyanide complexes combined with desorption of CN bound to reactive heterogeneous surfaces that are in direct contact with the aqueous phase (outer-sphere complexation).Phase II (limited rate) is presumably driven by the diffusion controlled processes involving dissolution of precipitated ferric ferrocyanide from the mineral or inner-sphere complexation of ferricyanides.CN release rates in phase I and II were mainly influenced by the pH, organic matter (OM) and the total CN content.The cyanide release rates increased with increasing pH, decreased with low initial CN concentration and were retarded by the increase in OM content.

Vicinities of manufactured gas plants were often contaminated with solid iron–cyanide complexes as a result of the coal gasification process. During the remediation of affected soils, knowledge about contaminant concentrations is crucial, but laboratory methods are often expensive and time consuming. Rapid and non-destructive field methods for contaminant determination permit an analysis of large sample numbers and hence, facilitate identification of ‘hot spots’ of contamination. Diffuse near infrared reflectance spectroscopy has proven to be a reliable analytical tool in soil investigation. In order to determine the feasibility of a Polychromix Handheld Field Portable Near-Infrared Analyzer (FP NIR), various sample preparation methods were examined, including homogenizing, sieving, drying, and grinding. Partial least squares calibration models were developed to determine near infrared (NIR) spectral responses to the cyanide concentration in the soil samples. As a control, the contaminant concentration was determined using conventional flow injection analysis. The experiments revealed that portable near-infrared spectrometers could be a reliable device for detecting cyanide concentrations >2,400 mg kg−1 in the field and >1,750 mg kg−1 after sample preparation in the laboratory. We found that portable NIR spectrometry cannot replace traditional laboratory analyses due to high limits of detection, but that it could be used for identification of contamination ‘hot spots’.

Der Einsatz eines feldportablen Rontgenfluoreszenzanalysators (FP RFA) vom Typ NITON XL3t, zur Messung von Schwermetallen und Hauptelementen in Bodenproben wurde am Beispiel eines ehemaligen Rieselfelds untersucht. Die Gegenuberstellung der RFA Daten zu nasschemisch gewonnenen Messwerten zeigte insbesondere fur die Elemente Kupfer, Blei und Zink eine starke Korrelation zwischen beiden Datensatzen. Die Elemente Calcium, Kalium, Phosphor und Magnesium konnten im untersuchten Messwertbereich nicht befriedigend analysiert werden. Die in-situ Messung ergab mit Labordaten vergleichbare Messwerte und Messwertverteilungen, wenngleich im Feld z.T. deutlich hohere Metallgehalte bestimmt wurden.

The world's ever-growing energy demand will lead to the installation of new coal-fired power plants At least part of the coal combustion residue (CCR) generated in the coming years will be disposed of, adding to the large number of CCR disposal sites generated in the past and reinforcing the need for sound assessment and management of associated risks Physical and chemical composition of CCR varies considerably depending on the quality of the feed coal, the combustion technology, fraction considered, and the method of disposal Related risk pathways include (i) aerial routes, i e., dust resuspension (Cr-VI), emanation of radioactivity (Rn associated with U and Th series), and Hg volatilization threatening ani mal and human health, (ii) phytoaccumulation (B, Se, Mo. As) and plant toxicity (B) with subsequent effects on animals (e g, Mo-induced hypocuprosis, As and Se toxicity) and humans (e.g. selenosis. food chain), and (iii) effluent discharge and percolation to groundwater and rivers (suspended solids, unfavorable pH. high Se, B, Hg, and As-III concentrations) Recent and projected changes of CCR composition due to emerging clean coal technologies require close monitoring as the concentration of volatile elements such as Hg and Se. solubility (Hg, Cd, Cu) and volatilization (Hg, NH3) of some pollutants are likely to increase because of higher retention in certain fractions of CCRs and concurrent changes in pH (e g, by mineral carbonation) and NH3 content These changes require additional research efforts to explore the implications for CCR quality, use, and management of risk associated with disposal sites

In the city of Tuzla, located in Bosnia and Herzegovina, a coal fired thermo electric power plant is operated by the company JP ELEKTROPRIVERDA BIH TERMOELEKTRANA “TUZLA”. High amounts of ash are produced by the power plant, which are currently disposed into settlement ponds bordered by dams in natural valleys. A total of four ash disposal sites covering an area of approx. 170 ha have been established during the last decades.

The deposition of coal combustion residues consumed large areas in the West Balkans. The release of effluent water from coal ash deposits contaminates ground and surface waters. Toxic trace elements entering the food chain and dust dispersion by wind erosion may negatively affect the health of local people and wild life. The aim of the RECOAL project was to assess the actual risk associated with the abundant coal ash disposal sites in the West Balkan area and to develop and test innovative low-cost methods for remediation of coal ash deposit surfaces and treatment of effluent waters. The initial project phase was devoted to risk assessment and socio-economic problem analysis. Low cost technologies were developed in bench scale experiments. Thereafter potentially feasible technical solutions were tested in the field. This included the application of amendments and cover soils to reduce transfer of toxic elements and installation of a passive aeration cascade and filter systems to reduce the pollutant load and pH of alkaline ash disposal leachate. Moreover, pollutant lowuptake crops and cultivars were identified for minimising the risk of food chain contamination. Special emphasis was put on socio-economic aspects related to the problem and its remediation. Local people were involved throughout the whole project duration. The information gathered was used to compile decision tools for a handbook which shall be accessible to local authorities, stakeholders and problem holders.

The deposition of coal combustion residues consumed large areas in the West Balkans. The release of effluent water from coal ash deposits contaminates ground and surface waters. Toxic trace elements entering the food chain and dust dispersion by wind erosion may negatively affect the health of local people and wild life. The aim of the RECOAL project was to assess the actual risk associated with the abundant coal ash disposal sites in the West Balkan area and to develop and test innovative low-cost methods for remediation of coal ash deposit surfaces and treatment of effluent waters. The initial project phase was devoted to risk assessment and socio-economic problem analysis. Low cost technologies were developed in bench scale experiments. Thereafter potentially feasible technical solutions were tested in the field. This included the application of amendments and cover soils to reduce transfer of toxic elements and installation of a passive aeration cascade and filter systems to reduce the pollutant load and pH of alkaline ash disposal leachate. Moreover, pollutant low-uptake crops and cultivars were identified for minimising the risk of food chain contamination. Special emphasis was put on socio-economic aspects related to the problem and its remediation. Local people were involved throughout the whole project duration. The information gathered was used to compile decision tools for a handbook which shall be accessible to local authorities, stakeholders and problem holders.