TY - GEN A1 - Ahmed, Naveed A1 - Martienssen, Marion A1 - Bryant, Isaac Mbir A1 - Vione, Davide A1 - Bruzzoniti, Maria Concetta A1 - Riedel, Ramona T1 - Investigation on UV Degradation and Mechanism of 6:2 Fluorotelomer Sulfonamide Alkyl Betaine, Based on Model Compound Perfluorooctanoic Acid T2 - ChemEngineering N2 - The UV treatment of 6:2 FTAB involves the mitigation of this persistent chemical by the impact of ultraviolet radiation, which is known for its resistance to environmental breakdown. UV treatment of PFOA and/or 6:2 FTAB, and the role of responsible species and their mechanism have been presented. Our investigation focused on the degradation of perfluorooctanoic acid (PFOA) and 6:2 fluorotelomer sulfonamide alkyl betaine (6:2 FTAB, Capstone B), using UV photolysis under various pH conditions. Initially, we used PFOA as a reference, finding a 90% decomposition after 360 min at the original (unadjusted) pH 5.6, with a decomposition rate constant of (1.08 ± 0.30) × 10−4 sec−1 and a half-life of 107 ± 2 min. At pH 4 and 7, degradation averaged 85% and 80%, respectively, while at pH 10, it reduced to 57%. For 6:2 FTAB at its natural pH 6.5, almost complete decomposition occurred. The primary UV transformation product was identified as 6:2 fluorotelomer sulfonic acid (6:2 FTSA), occasionally accompanied by shorter-chain perfluoroalkyl acids (PFAAs) including PFHpA, PFHxA, and PFPeA. Interestingly, the overall decomposition percentages were unaffected by pH for 6:2 FTAB, though pH influenced rate constants and half-lives. In PFOA degradation, direct photolysis and reaction with hydrated electrons were presumed mechanisms, excluding the involvement of hydroxyl radicals. The role of superoxide radicals remains uncertain. For 6:2 FTAB, both direct and indirect photolysis were observed, with potential involvement of hydroxyl, superoxide radicals, and/or other reactive oxygen species (ROS). Clarification is needed regarding the role of 𝑒−𝑎𝑞 in the degradation of 6:2 FTAB. KW - PFOA KW - 6:2 FTAB KW - decomposition KW - photolysis KW - scavenger Y1 - 2024 U6 - https://doi.org/10.3390/chemengineering8020032 SN - 2305-7084 VL - 8 IS - 2 ER - TY - GEN A1 - Riedel, Ramona A1 - Braun, Burga A1 - Böllmann, Jörg A1 - Martienssen, Marion T1 - Neuer Standard-Abbautests für synthetische Phosphonate T2 - BIOspektrum : Das Magazin für Biowissenschaften N2 - The evaluation of the ready biodegradation of organic substances is usually carried out using the standardised OECD test methods 301 (A–F). However, this can become a great challenge for substances such as aminophosphonates which are chemically imbalanced and do not automatically promote microbial growth in standardized tests. Here, we report on the development of a standardized batch test that is suitable for phosphonates and overcomes important obstacles of the test methods above-mentioned. Y1 - 2024 U6 - https://doi.org/10.1007/s12268-024-2194-x SN - 1868-6249 SN - 0947-0867 VL - 30 SP - 345 EP - 347 ER - TY - GEN A1 - Riedel, Ramona A1 - Commichau, Fabian M. A1 - Benndorf, Dirk A1 - Martienssen, Marion T1 - Biologischer Abbau von Aminophosphonaten T2 - BIOspektrum : Das Magazin für Biowissenschaften N2 - Application of commercial aminophosphonates such as glyphosate (GS) or chelating agents in detergent are daily used at large scale worldwide. Only little is known about the potential biodegradation of the latter. Here we describe the characterization of the new strain Ochrobactrum sp. BTU1 isolated from a LC/MS standard solution. The strain is capable to degrade all investigated aminophosphonates including GS. Y1 - 2024 U6 - https://doi.org/10.1007/s12268-024-2179-9 SN - 1868-6249 SN - 0947-0867 VL - 30 SP - 348 EP - 350 ER - TY - GEN A1 - Riedel, Ramona A1 - Meißner, Karsten A1 - Kaschubowski, Arne A1 - Benndorf, Dirk A1 - Martienssen, Marion A1 - Braun, Burga T1 - Laundry isolate Delftia sp. UBM14 capable of biodegrading industrially relevant aminophosphonates N2 - Phosphonates such as ethylenediaminetetra (methylenephosphonic acid) (EDTMP) and aminotris (methylenephosphonic acid) (ATMP) are used every day in water treatment processes or in household products. Their consumption is still increasing, regardless of the debates on their environmental impact. Here, the microbial characterisation and determination of the biodegradation potential of selected industrially relevant phosphonates for the isolate Delftia sp. UMB14 is reported. The opportunistic strain was isolated from a biofilm that was derived from a conventional washing machine using conventional detergents containing phosphonates. In antimicrobial susceptibility testing, the strain was only susceptible to sulfonamide, tetracycline, and chloramphenicol. Physiological and biochemical characteristics were determined using the BIOLOG EcoPlate assay. Most importantly, the strain was shown to convert D-malic acid and D-mannitol, as confirmed for strains of Delftia lacustris, and thus the new isolate could be closely related. Biodegradation tests with different phosphonates showed that the strain preferentially degrades ATMP and EDTMP but does not degrade glyphosate (GS) and amino (methylphosphonic acid) (AMPA). A specific gene amplification confirmed the presence of phnX (phosphonoacetaldehyde hydrolase) and the absence of PhnJ (the gene for the core component of C–P lyase). The presence of PhnCDE is strongly suggested for the strain, as it is common in Delftia lacustris species. Y1 - 2024 U6 - https://doi.org/10.3390/microorganisms12081664 SN - 2076-2607 VL - 12 IS - 8 ER - TY - GEN A1 - Sohail, Norman A1 - Riedel, Ramona A1 - Dorneanu, Bogdan A1 - Arellano-García, Harvey T1 - Prolonging the Life Span of Membrane in Submerged MBR by the Application of Different Anti-Biofouling Techniques T2 - Membranes N2 - The membrane bioreactor (MBR) is an efficient technology for the treatment of municipal and industrial wastewater for the last two decades. It is a single stage process with smaller footprints and a higher removal efficiency of organic compounds compared with the conventional activated sludge process. However, the major drawback of the MBR is membrane biofouling which decreases the life span of the membrane and automatically increases the operational cost. This review is exploring different anti-biofouling techniques of the state-of-the-art, i.e., quorum quenching (QQ) and model-based approaches. The former is a relatively recent strategy used to mitigate biofouling. It disrupts the cell-to-cell communication of bacteria responsible for biofouling in the sludge. For example, the two strains of bacteria Rhodococcus sp. BH4 and Pseudomonas putida are very effective in the disruption of quorum sensing (QS). Thus, they are recognized as useful QQ bacteria. Furthermore, the model-based anti-fouling strategies are also very promising in preventing biofouling at very early stages of initialization. Nevertheless, biofouling is an extremely complex phenomenon and the influence of various parameters whether physical or biological on its development is not completely understood. Advancing digital technologies, combined with novel Big Data analytics and optimization techniques offer great opportunities for creating intelligent systems that can effectively address the challenges of MBR biofouling. KW - Membrane bioreactor (MBR) KW - quorum sensing (QS) KW - quorum quenching (QQ) KW - moving bed biofilm reactor (MBBR) KW - moving bed biofilm membrane reactor (MBBMR) KW - model-based anti-fouling strategies Y1 - 2023 UR - https://www.mdpi.com/2077-0375/13/2/217 U6 - https://doi.org/10.3390/membranes13020217 SN - 2077-0375 VL - 13 IS - 2 ER - TY - GEN A1 - Riedel, Ramona A1 - Krahl, Kathrin A1 - Buder, Kai A1 - Böllmann, Jörg A1 - Braun, Burga A1 - Martienssen, Marion T1 - Novel standard biodegradation test for synthetic phosphonates T2 - Journal of Microbiological Methods N2 - Determination of biodegradation of synthetic phosphonates such as aminotris(methylenephosphonic acid) (ATMP), ethylenediamine tetra(methylenephosphonic acid) (EDTMP), or diethylenetriamine penta(methylenephosphonic acid) (DTPMP) is a great challenge. Commonly, ready biodegradability of organic substances is assessed by OECD 301 standard tests. However, due to the chemical imbalance of carbon to phosphorus synthetic phosphonates do not promote microbial growth and, thus, limiting its biodegradation. Therefore, standard OECD test methods are not always reliable to predict the real biodegradability of phosphonates. In the presented study, we report the development of a standardized batch system suitable to synthetic phosphonates such as ATMP, EDTMP, DTPMP and others. The novel standard batch test is applicable with pure strains, activated sludge from different wastewater treatment plants (i.e., municipal and industrial), and with tap water as inoculum. We optimized the required calcium and magnesium exposure levels as well as the amount of the start inoculum biomass. We demonstrated that our test also allows to determine several parameters including ortho-phosphate (o-PO43􀀀 ), total phosphorus (TP), ammonium (NH4+) and total organic carbon (TOC). In addition, also LC/MS analyses of cell-free medium is applicable for determining the mother compounds and metabolites. We applied our optimized standardized batch with selected phosphonates and evidenced that the chemical structure has a major influence of the microbial growth rates. Thus, our novel batch test overcomes drawbacks of the OECD 301 test series for determination of easy biodegradability for stoichiometric imbalanced organic compounds such as phosphonates. Y1 - 2023 U6 - https://doi.org/10.1016/j.mimet.2023.106793 SN - 1872-8359 SN - 0167-7012 VL - Vol. 212 SP - 1 EP - 13 ER - TY - GEN A1 - Riedel, Ramona A1 - Commichau, Fabian M. A1 - Benndorf, Dirk A1 - Hertel, Robert A1 - Holzer, Katharina A1 - Mardoukhi, Mohammad Saba Yousef A1 - Noack, Laura A1 - Martienssen, Marion T1 - Biodegradation of selected aminophosphonates by the bacterial isolate Ochrobactrum sp. BTU1 T2 - Microbial Research N2 - Aminophosphonates, like glyphosate (GS) or metal chelators such as ethylenediaminetetra(methylenephosphonic acid) (EDTMP), are released on a large scale worldwide. Here, we have characterized a bacterial strain capable of degrading synthetic aminophosphonates. The strain was isolated from LC/MS standard solution. Genome sequencing indicated that the strain belongs to the genus Ochrobactrum. Whole-genome classification using pyANI software to compute a pairwise ANI and other metrics between Brucella assemblies and Ochrobactrum contigs revealed that the bacterial strain is designated as Ochrobactrum sp. BTU1. Degradation batch tests with Ochrobactrum sp. BTU1 and the selected aminophosphonates GS, EDTMP, aminomethylphosphonic acid (AMPA), iminodi(methylene-phosphonic) (IDMP) and ethylaminobis(methylenephosphonic) acid (EABMP) showed that the strain can use all phosphonates as sole phosphorus source during phosphorus starvation. The highest growth rate was achieved with AMPA, while EDTMP and GS were least supportive for growth. Proteome analysis revealed that GS degradation is promoted by C-P lyase via the sarcosine pathway, i.e., initial cleavage at the C-P bond. We also identified C-P lyase to be responsible for degradation of EDTMP, EABMP, IDMP and AMPA. However, the identification of the metabolite ethylenediaminetri(methylenephosphonic acid) via LC/MS analysis in the test medium during EDTMP degradation indicates a different initial cleavage step as compared to GS. For EDTMP, it is evident that the initial cleavage occurs at the C-N bond. The detection of different key enzymes at regulated levels, form the bacterial proteoms during EDTMP exposure, further supports this finding. Y1 - 2024 U6 - https://doi.org/10.1016/j.micres.2024.127600 SN - 0944-5013 VL - 280 SP - 1 EP - 12 ER - TY - GEN A1 - Riedel, Ramona A1 - Schowarte, Julia A1 - Semisch, Laura A1 - Gonzalez Castano, Miriam A1 - Ivanova, Svetlana A1 - Martienssen, Marion A1 - Arellano-Garcia, Harvey T1 - Improving the photocatalytic degradation of EDTMP: Effect of doped NPs (Na, Y, and K) into the lattice of modified Au/TiO2 nano-catalysts T2 - Chemical Engineering Journal N2 - This study presents the photocatalytic degradation of the aminophosphonate ethylenediaminetetra(methylenephosphonic acid) (EDTMP) with a range of different doped nanoparticles (NP). The photocatalysts were based on TiO2 benchmark P25 and gold (Au) doped either with sodium (Na), potassium (K) or yttrium (Y). The synthesized photocatalysts were characterized via TEM, XRF, XRD, UV-DRS (band gap estimation) and N2-physisorption. Photocatalytic pre-screening at pH values of 3, 7 and 10 indicated highest o-PO4 release of EDTMP at pH 7 and 10 for NP either doped with K or Y. The results of LC/MS analysis showed that the NPs doped with 5 % Y (Au2/Y5/P25) resulted in the fastest degradation of EDTMP. The target compound was completely degraded within 60 min, 4 times faster than photochemical treatment of unadulterated EDTMP. Importantly, also the transformation products were accelerated by the photocatalytic treatment with Au2/P25 either doped with 5 % Y or 10 % K. The results of scavenger experiments indicated that the enhanced photocatalytic degradation of EDTMP is primarily attributable to the presence of hydroxyl radicals in the bulk and to a lesser extent to •O2− and electron-holes (h+) at the surface of the catalysts. The study demonstrates that the catalytic efficiency of TiO2 nanocomposites is significantly influenced by the choice of dopants, which affect particle size, band gap, and photocatalytic activity. Yttrium at low concentrations (i.e., 5 wt% Y) doping emerged as particularly effective, enhancing both the visible light absorption and h+ separation, leading to superior photocatalytic performance in the degradation of EDTMP. The Au content also plays a crucial role in enhancing the photocatalytic efficiency. However, the combination of Au and Na doping was found to be less effective for this photocatalysis in aqueous media, potentially due to larger particle sizes and insufficient dopant contents. In conclusion, the findings emphasise the necessity of optimising both the selection of dopants and the design of catalysts in order to enhance photocatalytic applications. KW - EDTMP KW - Nanoparticles KW - Phosphonate KW - TiO2 KW - Yttrium Y1 - 2025 UR - https://www.sciencedirect.com/science/article/pii/S1385894725009088?via%3Dihub U6 - https://doi.org/https://doi.org/10.1016/j.cej.2025.160109 VL - 506 ER - TY - GEN A1 - Martienssen, Marion A1 - Riedel, Ramona A1 - Kühne, Tom T1 - Contribution of professional cleaning to indoor air and sewage pollution T2 - Sustainable Chemistry Y1 - 2024 U6 - https://doi.org/https://doi.org/10.3390/suschem5040019 VL - 5 IS - 4 SP - 275 EP - 286 ER - TY - GEN A1 - Böllmann, Jörg A1 - Riedel, Ramona A1 - Martienssen, Marion T1 - Inhibition of Pseudomonas aeruginosa with silver in a new synthetic medium : investigation on the MIC, growth rate and lag-phase at the lower limit T2 - Journal of microbiological methods N2 - The antimicrobial properties of silver are well-known and widely applied. Although it is known, that silver interacts and binds on complex organic substances like proteins, many experiments on the sterilisation efficiency and inhibiting properties are still carried out in complex culture media. Given, that silver is often applied in environments with no or few organic substrates, like cooling circuits or in the treatment of tap and process water, further insight on the minimum inhibition concentration and lethal concentration at those conditions is of interest. We have developed a defined medium for the standard bacterium Pseudomonas aeruginosa that is free of complex organic carbon with equal cultivation properties like commonly used nutrient solutions. With this medium we could narrow the range of the MIC between 2.5 μg to 10 μg∙L−1, which very much overlaps with the bactericidic concentration depending on the initial concentration of bacteria cells. These results might help to optimise the technical application of silver. We further observed a delayed growth of bacterial cultures of up to three days compared to silver free controls, which is caused either by a partial sterilisation down to theoretical one surviving cell or by a prolonged lag phase. Based on these observations we recommend a prolonged incubation for experiments on sterilisation with silver and the use of defined media, which do not interact with the disinfecting agent. KW - Silver KW - Minimum inhibition concentration KW - Disinfection KW - Defined medium KW - Lag-phase Y1 - 2025 U6 - https://doi.org/https://doi.org/10.1016/j.mimet.2025.107095 SN - 1872-8359 VL - 230-231 SP - 1 EP - 9 PB - Elsevier Bv CY - Amsterdam ER - TY - GEN A1 - Schowarte, Julia A1 - Riedel, Ramona A1 - Safdar, Muddasar A1 - Helle, Sven A1 - Fischer, Thomas A1 - Arellano-García, Harvey T1 - Photocatalytic degradation of PFOA with porous lanthanoid perovskites nano catalyst T2 - Chemie - Ingenieur - Technik : CIT N2 - Perfluorooctanoic acid (PFOA), a persistent environmental pollutant, poses significant health and ecological risks. This study investigates for the first time the photocatalytic degradation of PFOA using novel doped perovskite catalysts under polychromatic UV–VIS irradiation with a peak emission at 366 nm. A series of nickel- and lanthanide-doped perovskites (NiMn2O4, LaMnO3, NdMnO3, and their nickel-doped variants) were synthesized via a facile co-precipitation technique and characterized using X-ray diffraction (XRD), UV–VIS diffuse reflectance spectroscopy (UV–VIS-DRS), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM–EDX), N2-physisorption, and microwave plasma atomic emission spectroscopy (MP-AES). Photocatalytic experiments revealed that Ni/NdMnO3 exhibited the highest degradation efficiency toward PFOA, likely due to its small band gap energy of 1.5 eV, facilitating efficient C–C bond cleavage. KW - Lanthanoids KW - Perovskites KW - PFAS KW - PFOA KW - Photocatalysis Y1 - 2025 U6 - https://doi.org/10.1002/cite.70027 SN - 1522-2640 SP - 1 EP - 11 PB - Wiley-VCH GmbH CY - Weinheim ER -