@misc{DuemigVesteHagedornetal., author = {D{\"u}mig, Alexander and Veste, Maik and Hagedorn, Frank and Fischer, Thomas and Lange, Philipp and Spr{\"o}te, Roland and K{\"o}gel-Knabner, Ingrid}, title = {Organic matter from biological soil crusts induces the initial formation of sandy temperate soils}, series = {Catena}, volume = {122}, journal = {Catena}, doi = {10.1016/j.catena.2014.06.011}, pages = {196 -- 208}, abstract = {Different development stages of algae-dominated and moss-dominated biological soil crusts (BSCs) were sampled on a natural sand dune (b17 years old) and on an experimental sand dune (b8 years old) along a catena, including gradients of vegetation cover, location on the slope, as well as composition and thickness of BSC organisms in northeastern Germany. The accumulation of BSC-derived organic carbon (OC)was determined for bulk materials and fractions less than 63 μm. The OC composition was characterized by solid-state 13C NMR spectroscopy and the carbohydrate-C signature. 14C contents were determined to assess the origin and dynamics of OC. From the radiocarbon contents, two OC pools were differentiated: recent BSC-derived and lignite-derived "old" OC. Downward movement of OC into the underlying substratewas found only undermoss-dominated BSCs at the old sand dune. BSC-derived OC was mainly composed of carbohydrate-C and, to a lesser extent, alkyl C and N-alkyl C, with considerably higher contributions of alkyl C in the young dune, indicating differences in the composition of extracellular polymeric substances produced by the BSCs with age. This is consistent with higher proportions of water-soluble OC of moss-dominated BSCs at the old dune, which is leached in the underlying substrate and initiates soil formation. Because of the channeling effect of mosses, OC depth translocation along with suspended colloidal substances contribute to OC accumulation in substrates.}, language = {en} } @misc{SutLohmannRepmannRaab, author = {Sut-Lohmann, Magdalena and Repmann, Frank and Raab, Thomas}, title = {Retardation of iron-cyanide complexes in the soil of a former manufactured gas plant site}, series = {Journal of Environmental Science and Health, Part A}, volume = {50}, journal = {Journal of Environmental Science and Health, Part A}, number = {3}, issn = {1532-4117}, doi = {10.1080/10934529.2015.981116}, pages = {282 -- 291}, abstract = {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]).}, language = {en} } @misc{DimitrovaRepmannRaabetal., author = {Dimitrova, Tsvetelina and Repmann, Frank and Raab, Thomas and Freese, Dirk}, title = {Uptake of ferrocyanide in willow and poplar trees in a long term greenhouse experiment}, series = {Ecotoxicology}, volume = {24}, journal = {Ecotoxicology}, number = {3}, issn = {1573-3017}, doi = {10.1007/s10646-014-1398-0}, pages = {510}, abstract = {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.}, language = {en} } @misc{SutLohmannRepmannRaab, author = {Sut-Lohmann, Magdalena and Repmann, Frank and Raab, Thomas}, title = {Stability of Prussian Blue in Soils of a Former Manufactured Gas Plant Site}, series = {Soil and Sediment Contamination}, volume = {23}, journal = {Soil and Sediment Contamination}, number = {5}, issn = {1549-7887}, doi = {10.1080/15320383.2014.839626}, pages = {504 -- 522}, abstract = {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 (40-1718 mg kg-1). Column leaching, after four months of percolation, still yielded effluent concentrations exceeding the German drinking water limit (> 50 μg L-1) and the solubility of Prussian Blue reported in the literature (< 1 mg L-1) from both alkaline and acidic soils. Long-term (1344 h) 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.}, language = {en} } @misc{GerwinRepmannSchaafetal., author = {Gerwin, Werner and Repmann, Frank and Schaaf, Wolfgang and Raab, Thomas}, title = {Bodenver{\"a}nderungen durch Waldbr{\"a}nde - Stoffvorr{\"a}te und Stoffverlagerungen}, series = {Jahrestagung der DBG 2022 "Grenzen {\"u}berwinden, Skalen {\"u}berschreiten" 5. - 8. September 2022 in Trier}, journal = {Jahrestagung der DBG 2022 "Grenzen {\"u}berwinden, Skalen {\"u}berschreiten" 5. - 8. September 2022 in Trier}, pages = {48}, abstract = {Die zur{\"u}ckliegenden trocken-heißen Sommer haben im S{\"u}den Brandenburgs zu zahlreichen Br{\"a}nden in den dominierenden Kiefernw{\"a}ldern gef{\"u}hrt, einige davon mit katastrophalen Ausmaßen. Dazu geh{\"o}ren die extremen Brandereignisse 2018 bei Treuenbrietzen sowie 2019 bei J{\"u}terbog und Lieberose, die zusammen weit {\"u}ber 1000 ha Waldfl{\"a}che zerst{\"o}rt und dabei auch Ver{\"a}nderungen der betroffenen Waldb{\"o}den verursacht haben. Das seit Mai 2020 von der FNR gef{\"o}rderte Verbundvorhaben Pyrophob befasst sich mit den Auswirkungen von Waldbr{\"a}nden im S{\"u}den Brandenburgs auf die Wald{\"o}kosysteme und mit waldbaulichen Maßnahmen, die mittelfristig zu einer Verringerung der Brandanf{\"a}lligkeit der W{\"a}lder beitragen sollen. Im Rahmen des auf eine f{\"u}nfj{\"a}hrige Laufzeit ausgelegten Verbundvorhabens finden bodenkundliche Untersuchungen auf zw{\"o}lf Versuchsfl{\"a}chen bei Treuenbrietzen und J{\"u}terbog statt. An beiden Standorten werden unverbrannte Referenzfl{\"a}chen mit einbezogen. Erg{\"a}nzend konnten bei Lieberose bereits 2019 nur kurz nach dem Brandgeschehen erste Bodenuntersuchungen durchgef{\"u}hrt werden. Die untersuchten Brandfl{\"a}chen bei J{\"u}terbog und Lieberose sind als Totalreservate ausgewiesen, auf denen auch nach dem Brand waldbauliche Maßnahmen vollst{\"a}ndig unterbleiben. Auf den Fl{\"a}chen bei Treuenbrietzen wurden verschiedene Behandlungsvarianten durchgef{\"u}hrt, zu denen auf einem Teil der Fl{\"a}chen die vollst{\"a}ndige Entfernung der abgestorbenen B{\"a}ume geh{\"o}rte, w{\"a}hrend auf anderen Teilfl{\"a}chen Totholz auf der Fl{\"a}che verblieb. Ziel der bodenkundlichen Arbeiten in Pyrophob ist zum einen eine Charakterisierung der direkten Auswirkungen des Brandes auf Humus und Mineralboden hinsichtlich des Stoffbestandes und bodenbiologischer Prozesse. Zum anderen wird der Stoffaustrag aus dem Oberboden erfasst. Der etwaige Einfluss der unterschiedlichen waldbaulichen Vorgehensweise auf die Bodenverh{\"a}ltnisse wird dabei als ein Indikator f{\"u}r die Auswahl geeigneter Maßnahmen ber{\"u}cksichtigt. In den verschiedenen Untersuchungsvarianten des Vorhabens wurden zu diesem Zweck Humus- und Mineralbodenprofile untersucht. Zudem wurden Mischproben aus dem Ober- und Unterboden entnommen und auf ihren Stoffhaushalt hin analysiert. Auf jeder Untersuchungsfl{\"a}che wurden je drei frei dr{\"a}nende Kleinlysimeter in 10 cm Bodentiefe installiert, um die zeitlichen Ver{\"a}nderungen der Sickerwasserzusammensetzung und die durch den Brand initiierten Stoffaustr{\"a}ge aus dem Oberboden zu quantifizieren. Erg{\"a}nzend finden Untersuchungen zu m{\"o}glichen Auswirkungen der Br{\"a}nde auf bodenbiologische Prozesse wie Streuabbau und Stickstoffmineralisation statt.}, language = {de} } @inproceedings{SutLohmannRepmannRaab, author = {Sut-Lohmann, Magdalena and Repmann, Frank and Raab, Thomas}, title = {Vertical movement of iron-cyanide complexes in soils of a former Manufactured Gas Plant site}, series = {European Geosciences Union, General Assembly 2015, Vienna, Austria, 13 April - 17 May 2015}, booktitle = {European Geosciences Union, General Assembly 2015, Vienna, Austria, 13 April - 17 May 2015}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, language = {en} }