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1. Silylation: a reproducible method for characterization of non-extractable residues (NER) of organic chemicals in the assessment of persistence

Author

Hennecke, D., Kruse, M., Bräutigam, J., Meisterjahn, B., Klein, J., Claßen, D., Trapp, S., Kästner, Matthias, Libonati Brock, A., Schäffer, A., Hennecke, D., Kruse, M., Bräutigam, J., Meisterjahn, B., Klein, J., Claßen, D., Trapp, S., Kästner, Matthias, Libonati Brock, A., and Schäffer, A.

Abstract

Most, if not all, chemicals, biocides, pharmaceuticals and pesticides are known to produce non-extractable residues (NER) in solid environmental media like soil and sediment during degradation testing to various extents. Since it has been found that parent substances and relevant metabolites can be contained and potentially released from NER there is currently much debate on how to include NER in the environmental persistence assessment. Using radioactive or stable isotope labelled test substances, three types of NER can be experimentally discriminated: entrapped, sorbed or heavily sorbed (type I) having the potential to be released from the matrix. Type II NER, i.e. residues covalently bound to organic matter in soils or sediments, are being considered to have very low remobilisation potential. Type III NER (bioNER) are formed after degradation of the xenobiotic chemical and incorporation into natural biomolecules (anabolism) like amino acids and other biomass compounds, and are, thus, of no environmental concern. Silylation has been suggested as a methodology to differentiate types I and II NER but concern has been addressed that this procedure is not suitable for routine analysis, e.g. in the context of studies for authorisation and registration of chemicals. Here, we describe a readily applicable and reproducible experimental procedure to apply this method for the analysis of NER derived from bromoxynil, sulfadiazine and isoproturon, respectively. This method is able to distinguish between heavily sorbed and covalently bound residues of chemicals, biocides, pharmaceuticals and pesticides in soils and to subsequently identify residues of the parent substance entrapped in type I NER.

Published
2023

2. Critical evaluation of the microbial turnover to biomass approach for the estimation of biogenic non-extractable residues (NER)

Author

Trapp, S., Brock, A.L., Kästner, Matthias, Schäffer, A., Hennecke, D., Trapp, S., Brock, A.L., Kästner, Matthias, Schäffer, A., and Hennecke, D.

Abstract

Persistence is a key criterion for the risk assessment of chemicals. In degradation tests, microbial biodegradation of labeled test chemicals leads to the incorporation of the label in microbial biomass, resulting in biogenic non-extractable residues (bioNER), which are not considered as harmful in persistence assessment. The amount of bioNER can be estimated using the Microbial Turnover to Biomass (MTB) model. MTB estimates the biomass growth during productive degradation of a compound from theoretical growth yield and CO 2 -formation and gives an upper and a lower value for bioNER formation. We collected experimental data in order to test accuracy and precision of this estimation method. In total, 16 experimental studies were found in literature where bioNER was experimentally quantified. Hereof, 13 studies used the amount of label recovered from total amino acid (tAA) content as proxy for bioNER. Unfortunately, the comparison with experimental data was difficult due to the variety of employed methods. A conversion factor is required to extrapolate from tAA on bioNER, and this factor may vary during the experiment and between experiments. The bioNER formation for all compounds tested was calculated with the MTB method, and the outcome was compared to measured tAA as proxy for bioNER. The relation between predicted and measured bioNER was significant, but no better correlation was obtained than with CO 2 to tAA. The mean absolute error of the prediction (low MTB versus tAA) was 5% (unit applied label, %aL). Large deviations between experimentally determined bioNER and the calculated result for some compounds may indicate problems in the experimental determination of bioNER.

Published
2022

4. Risk Reduction of Chemical Residues in Soils and Crops - Impact Due to Wastewater Used for Irrigation (RESIDUE)

Author

Hennecke, D., Ortega Calvo, J. J., Drabkin, D., Schatten, R., Terytze, K., Maor, Y., Chefetz, N., Re, I., Balzarotti, M., and Weinfurtner, K.

Abstract

del Poster presentado en the SETAC Europe 31st Annual Meeting from 2–6 May 2021 in Seville, Spain., The current project is a cooperation of 5 partner from 4 European countries under the PRIMA research programme. It started in August 2020 and we are going to present the project concept and first project results. The goal of the projec is to enhance food quality/security by an evaluation of the risks associated with agricultural techniques, using sewage sludge for soil fertilization and treated wastewater for irrigation. Associated contaminants may reach the soils and plants, representing a risk to the consumer. In the project, we develop an improved treatment of waste materials prior to spreading based on biochar techniques. We study the fate and distribution of selected relevant contaminants from treatment of the waste materials until crop harvest. 14C-radiolabelled contaminants allow an advanced evaluation to extend the risk assessment for transformation products and bound residues. As an integral part of the project, soil qualities and sustainable use of waste materials in agriculture will be an important result of the study. To ensure practical relevance of the project, advancement will be pursued by the involvement of stakeholders (farmers¿ cooperatives, trade associations) to evaluate the applicability of the proposed technologies. Further, a user manual will be prepared that can serve as guidance on how to implement the research results in agricultural practise. As countries like Israel have no choice to use waste materials in agriculture, the project will support e.g. the Israel export agricultural business. In Spain and Italy basically the same applies: the high rate of treated sewage sludge and wastewater used in agriculture raises the same concerns. This demonstrates the project relevance, because it will provide new insights into the risk associated to this agricultural practice, as related to chemical pollution and food-safety issues. For countries like Germany, where water limitations might get more relevance in the future as a result of climatic change, the project will be of value for the safety and quality assessment of sewage sludge application in agriculture. Sewage sludge may find a broader application again if the risk for contamination can be reduced, because sewage sludge brings valuable organic matter and plant nutrients to soil.

Published
2021

13. Arthroskopie nach Plattenosteosynthese proximaler Humerusfrakturen – Materialentfernung, Arthrolyse und Therapie intraartikulärer Begleitpathologien

Author

Katthagen, JC, Hennecke, D, Jensen, G, Voigt, C, and Lill, H

Subjects
proximale Humerusfraktur, ddc: 610, Arthrolyse, Schraubenperforation, 610 Medical sciences, Medicine, Humeruskopfnekrose, Begleitpathologien, Materialentfernung
Abstract

Fragestellung: Trotz verbesserter Implantate und differenzierter Indikationsstellung kommt es nach Plattenosteosynthese proximaler Humerusfrakturen zu unbefriedigenden Verläufen mit persistierenden Beschwerden und Bewegungseinschränkungen. Die Schulterarthroskopie hat sich in den vergangenen[for full text, please go to the a.m. URL], Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2013)

Published
2013
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16. Arthroskopische Materialentfernung nach plattenosteosynthetisch behandelten proximalen Humerusfrakturen - Ergebnisse im Vergleich zur offenen Technik

Author

Katthagen, J.C., Hennecke, D., Voigt, C., Jensen, G., and Lill, H.

Subjects
ddc: 610, 610 Medical sciences, Medicine
Abstract

Fragestellung: Nach plattenosteosynthetisch versorgten proximalen Humerusfrakturen wird bei bis zu 25% der Patienten eine Materialentfernung (ME) notwendig. Die von uns entwickelte neue Technik der arthroskopischen ME bietet im Vergleich zur offenen ME die Vorteile der minimal invasiven Chirurg[for full text, please go to the a.m. URL], Deutscher Kongress für Orthopädie und Unfallchirurgie; 75. Jahrestagung der Deutschen Gesellschaft für Unfallchirurgie, 97. Tagung der Deutschen Gesellschaft für Orthopädie und Orthopädische Chirurgie, 52. Tagung des Berufsverbandes der Fachärzte für Orthopädie

Published
2011

17. Sorption-desorption of trinitrotoluene in soils: Effect of saturating metal cations

Author

Singh, N., Hennecke, D., Hoerner, J., Koerdel, W., Schaeffer, A., and Publica

Subjects
sorption, exchangeable cation, desorption, trinitrotoluene
Abstract

Clay minerals in soils control the sorption and mobility of nitroaromatics in munitions contaminated soils. Therefore, effect of exchangeable cations (NH4+, K+, Ca2+, and Al3+) on sorption-desorption of trinitrotoluene (TNT) was studied in two reference soils viz sandy loam and silty clay. Compared to control soils, K+ ion saturation significantly increased TNT sorption in both the soils, while other cations decreased TNT sorption. Effect of K+ saturation on sorption of TNT was more pronounced in organic matter poor sandy loam soil (seven times) then silty clay (two times). Desorption followed the reverse trend and greater amounts of sorbed TNT were retained in the K+ saturated soils.

Published
2008

18. Mobility and degradation of trinitrotoluene/metabolites in soil columns

Author

Singh, N., Hennecke, D., Hörner, J., Kördel, W., Schäffer, A., and Publica

Abstract

There has been increasing interest in enhancing natural attenuation of munitions-contaminated soils. Present study reports the effect of increasing soil organic matter content on fate and mobility of trinitrotoluene (TNT) and metabolites in soil columns. This study was performed using 30-cm-long columns containing a top 5 cm of contaminated soil as a source layer and an uncontaminated soil (25 cm) adjusted to 0.5, 1.0, 1.5 and 3.0% organic carbon (OC) content using compost. Contaminated soil layer was fortified with uniformly ring-labeled C-14-trinitrotoluene (TNT) or 2,4-dinitrotoluene (DNT); in total there were 8 treatments. Columns were leached with synthetic rain water under unsaturated flow conditions in downside up direction. There was significant increase in the retention of both C-14-TNT and C-14-DNT in soils with increasing soil OC content and in 3.0% soil OC content column < 1% TNT/DNT was recovered in the leachate. Further, degradation of TNT and metabolites from contaminated soil was significantly increased and resulted in greater soil-bound residues. Formation of monoamino-dinitrotoluene (ADNTs), diamino-mononitrotoluene (DANTs) and monoamino-mononitrotoluene (ANTs) metabolites was greatly enhanced with increase in OC content of soils. Study suggests that increasing OC content of contaminated soil to 3.0% significantly enhanced the reduction of nitroaromatics to more polar amine metabolites and the formation of soil-bound residues.

Published
2008

19. Bioassays for the ecotoxicological and genotoxicological assessment of contaminated soils (results of a round robin test). Part 1: Assessment of a possible groundwater contamination

Author

Hund-Rinke, K., Kördel, W., Hennecke, D., Eisenträger, A., Heiden, S., and Publica

Subjects
bioassay, ecotoxicity, aquatic test system, genotoxicity, soil extract, soil assessment
Abstract

For the assessment of contaminated or remediated soils, in addition to chemical analyses, ecotoxicological tests are performed which focus on the retention function of soils (determined by tests with aqueous soil extracts) and on the habitat function (determined by tests with soil). While numerous standardized test guidelines exist to investigate effects by chemical substances, respective test procedures for soil assessments are lacking. To close this gap, a round robin test was performed to support standardization. Four contaminated soils were tested using a total of fifteen test systems including ecotoxicological and genotoxicological tests with soil extracts and soil. The results obtained from the test with soil extracts are presented in this article.

Published
2002

21. Bioassays for the ecotoxicological and genotoxicological assessment of contaminated soils (results of a round-robin test). Part 2: Assessment of the habitat function of soils - tests with soil microflora and fauna

Author

Hund-Rinke, K., Kördel, W., Hennecke, D., Achazi, R., Warnecke, D., Wilke, B.-M., Winkel, B., Heiden, S., and Publica

Subjects
microorganism, Fauna, bioassay, ecotoxicity, terrestrial test system, soil assessment
Abstract

For the assessment of contaminated or remediated soils, aside from chemical analyses, ecotoxicological tests are performed which focus on the retention function of soils (determined by tests with aqueous soil extracts) and on the habitat function (determined by tests with soil). Whereas numerous test exist as standardized guidelines for identifying the effect of chemicals, this is not the case for the assessment of soil quality. A round-robin test was performed to monitor the comparability of the results from ecotoxicological test methods on soils and to facilitate the standardization of corresponding test methods. Four contaminated soils were tested using a total number of fifteen test systems, including ecotoxicological and genotoxicological tests with soil extracts and soil. In the second part of this publication series, the results obtained from the tests with soil micro-organisms and soil fauna are presented.

Published
2002

24. Curvature Effects on Film Cooling With Injection Through Two Rows of Holes

Author

DARMSTADT UNIV OF TECHNOLOGY (GERMANY)GAS TURBINES AND FLIGHT PROPULSION, Jung, K., Hennecke, D. K., DARMSTADT UNIV OF TECHNOLOGY (GERMANY)GAS TURBINES AND FLIGHT PROPULSION, Jung, K., and Hennecke, D. K.

Abstract

The adiabatic film cooling effectiveness on convex and concave curved surfaces (as a model for suction and pressure side film cooling of gas turbine blades) with two staggered rows of injection holes are investigated by using a mass transfer technique. Additionally measurements on a flat plate are made for comparison. Two different radii of curvature (R/D = plus or minus 60, plus or minus 120) and two streamwise distances of the rows (12D and 24D) with film cooling holes inclined at 40 degrees are considered. The blowing rates are varied in a wide range from 0.25 to 2.0 and the main stream Reynolds numbers (Re(sub D)) between 10000 and 50000. At low and moderate blowing rates the effectiveness is enhanced on convex and reduced on concave curved surfaces compared to results obtained on the flat surface. At high blowing rates the effectiveness is not greatly influenced by surface curvature. The effect of curvature was found to be negligible between the two rows and reduced downstream of the second row compared to results described in the literature for single row injection., Also see ADM001490. Presented at RTO Applied Vehicle Technology Panel (AVT) Symposium held in Loen, Norway on 7-11 May 2001. Published in RTO-MP-069(I). The original document contains color images.

Published
2003

25. Active Stall Avoidance of an Axial Compressor Stage

Author

DARMSTADT UNIV OF TECHNOLOGY (GERMANY)GAS TURBINES AND FLIGHT PROPULSION, Wagner, S., Hennecke, D. K., DARMSTADT UNIV OF TECHNOLOGY (GERMANY)GAS TURBINES AND FLIGHT PROPULSION, Wagner, S., and Hennecke, D. K.

Abstract

An active stall avoidance system was designed comprising a stall recovery controller a nonlinear compressor operating point controller and a scheme for switching between these two. Different control schemes with respect to stall removal and switching have been developed and implemented on a real- time computer. The system's capability of successful stabilization of a stalled compressor with respect to performance loss was demonstrated by several experiments conducted on a low-speed axial compressor stage. The experiments were analyzed in detail and governing parameters of stall recovery and performance are identified. Finally improvements for the control scheme are suggested., Pres: Symposium RTO Applied Vehicle Tech Panel (AVT), Braunschweig, Germany,p16-1/16-10,8-11 May 2000. This article is from ADA395700 Active Control Technology for Enhanced Performance Operational Capabilities of Military Aircraft, Land Vehicles and Sea Vehicles (Technologies des systemes a commandes actives pour l'amelioration des performances operationnelles des aeronefs militaires, des vehicules terrestres et des vehicules maritimes)

Published
2001

44. Experiments on a Shrouded, Parallel Disk System with Rotation and Coolant Throughflow.

Author

MINNESOTA UNIV MINNEAPOLIS HEAT TRANSFER LAB, Yu,J. P., Sparrow,E. M., Eckert,E. R. G., Hennecke,D. K., Shamsundar,N., MINNESOTA UNIV MINNEAPOLIS HEAT TRANSFER LAB, Yu,J. P., Sparrow,E. M., Eckert,E. R. G., Hennecke,D. K., and Shamsundar,N.

Abstract

The heat transfer and fluid flow characteristics of a cylindrical enclosure having both rotating and stationary walls were investigated in the presence of coolant throughflow. The research was motivated by cooling applications in cavities and enclosures which may be situated adjacent to the rotating shaft in gas turbines, compressors, and similar devices. The local heat transfer coefficients on the rotating disk were found to increase with increasing rotational speed, increasing coolant flow rate, and decreasing spacing. (Author)

Published
1972

48. Impact of different sterilisation techniques on sorption and NER formation of test chemicals in soil.

Author

Süßmuth R, Shrestha P, Andrea Diaz Navarrete C, Wege FF, Achten C, and Hennecke D

Subjects
Adsorption, Gamma Rays, Phenanthrenes chemistry, Soil Pollutants chemistry, Soil Pollutants analysis, Sterilization methods, Soil chemistry, Biodegradation, Environmental
Abstract

Standard OECD tests are used to generate data on biodegradation (OECD 307) and sorption (OECD 106) of test chemicals in soil. In such tests, data on abiotic degradation using sterile samples are utilised to investigate any losses due to abiotic processes. The data from sterile samples are also used to interpret results and findings of non-sterile samples, especially in the context of sorption and non-extractable residue (NER) formation. However, to ensure the comparability of the data obtained from sterile and non-sterile experiments, effects of sterilisation on the soil matrix should be minimal. The objective of this study was to investigate the efficiencies of different sterilisation techniques and the impact of the sterilisation on sorption and NER formation in soil. In this study, experiments in accordance with OECD 307 and OECD 106 guidelines were performed with two soils covering wide range of soil characteristics and treated with the three sterilisation techniques autoclaving, gamma(γ)-radiation and adding 1% (w/w) sodium azide. As a test item, 14 C-labelled phenanthrene and bromoxynil was used for OECD 307 test, whereas non-labelled phenanthrene and atrazine was used for OECD 106. The sterilisation efficiencies were investigated using traditional viable plate count and molecular approaches (RNA extraction method). The results suggest that none of the tested techniques resulted in completely sterilised soil with autoclaving being the most efficient technique. Adding sodium azide led to most inefficient sterilisation and a significant increase (0.56 units) in soil pH. OECD 307 results showed differences in NER formation of the test chemicals, especially for soil poisoning and γ-radiation, which could be due to inefficient sterilisation and/or change in soil physico-chemical properties. OECD 106 results suggest that none of the sterilisation techniques considerably affected sorption behaviour of the test chemicals. Based on our results, we recommend autoclaving as most suitable sterilisation technique., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Published
2024
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49. Integrating bioavailability measurements in persistence testing of partially biodegradable organic chemicals in soil.

Author

Posada-Baquero R, Fernández-López C, Hennecke D, and Ortega-Calvo JJ

Subjects
Soil chemistry, Biological Availability, Prospective Studies, Pyrenes, Biodegradation, Environmental, Carbamazepine, Soil Pollutants analysis, Environmental Pollutants
Abstract

Overestimation of risk is one of the main problems in environmental risk assessments if only total concentration of organic pollutants is considered. In this study, we integrated bioavailability measurements into persistence testing of pollutants in soil to show that it is the key to have a more realistic environmental risk assessment (ERA). To this integration, two standardized methods were used: OECD 307, as persistence test, and ISO 16751: 2020, to bioavailability measurements based on 20 h extractions with a strong adsorbent (Tenax), using pyrene and carbamazepine as model test substances. Because the ISO method was initially designed for nonpolar compounds with log K ow  > 3, a slight adaptation was necessary for carbamazepine (log K ow  = 2.7), assuming this also as an extension of the applicability domain of the method. During the biodegradation of these compounds, the mineralization extents did not exceed 4 %, giving rise to transformation products. Therefore, the bioavailability measurements covered both the parent compound and the metabolites produced. In the case of pyrene, the partial transformation carried out by a specialized microbial inoculum accounted for, respectively, 32 % or 40 % of the initial concentration (4 mg kg -1 ) in unamended or compost-amended soil. Only 1 % was present as hydrophilic transformation products that were not trapped by Tenax, but partitioned into the water. The nonbioavailable residue increased in both soils after biodegradation. The distribution of chemicals in the different phases of the system was the key to assess more realistically the shifts in bioavailability during persistence testing. The same procedure was carried out for carbamazepine where an additional desorption study showed a slower desorption rate of the parent compound after incubation. In this case, 25 % of transformation products was mobilized to the aqueous phase. Our results show that bioavailability measurements provide valuable information when integrated in persistence testing, therefore contributing to realism in prospective ERA scenarios., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Published
2024
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50. Improved closed test setup for biodegradation testing of slightly volatile substances in water-sediment systems (OECD 308).

Author

Shrestha P, Hughes CB, Camenzuli L, Lyon D, Meisterjahn B, Hennecke T, Griffiths M, and Hennecke D

Subjects
Organisation for Economic Co-Operation and Development, Geologic Sediments chemistry, Biodegradation, Environmental, Solvents, Water chemistry, Water Pollutants, Chemical analysis
Abstract

Standardized biodegradation testing methods, like the OECD 308 Aerobic and Anaerobic Transformation in Aquatic Sediment Systems, generate data on biodegradation required during environmental risk and hazard assessment of chemicals under different European and international regulations. However, difficulties arise when applying the OECD 308 guideline for testing hydrophobic volatile chemicals. Especially the use of a co-solvent (like acetone) as a measure to facilitate the application of the test chemical in combination with a closed setup to reduce losses due to volatilization tend to deplete/restrict the amount of oxygen in the test system. The result is a low oxygen or even anoxic water column in the water-sediment system. Thus, the degradation half-lives of the chemical generated from such tests are not directly comparable to the regulatory half-life values for Persistence assessment of the test chemical. The aim of this work was to further develop the closed setup to improve and maintain aerobic conditions in the water phase of the water-sediment systems for testing slightly volatile hydrophobic test chemicals. This improvement was attained by optimizing the test system geometry and agitation technique to maintain aerobic conditions in the water phase in a closed test setup, investigating appropriate co-solvent application strategy, and trialing the resulting test setup. This study shows that when using a closed test setup for OECD 308 tests, agitation of the water phase overlaying the sediment and the test item application using low co-solvent volume is critical for maintaining an aerobic water layer., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Published
2023
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