TY - JOUR A1 - Steidl, Jörg A1 - Lischeid, Gunnar A1 - Engelke, Clemens A1 - Koch, Franka T1 - The curse of the past BT - What can tile drain effluent tell us about arable field management? JF - Agriculture, Ecosystems & Environment N2 - One challenge for modern agricultural management schemes is the reduction of harmful effects on the envi-ronment, e.g. in terms of the emission of nutrients. Sampling the effluent of tile drains is a very efficient way to sample seepage water from larger areas directly underneath the main rooting zone. Time series of solute con-centration in tile drains can be linked to agricultural management data and thus indicate the efficacy of individual management measures. To that end, the weekly runoff and solute concentration were determined in long-term measurement campaigns at 25 outlets of artificial tile drains at 19 various arable fields in the German federal state of Mecklenburg-Vorpommern. The study sites were distributed within a 23,000 km(2) region and were deemed representative of intense arable land use. In addition, comprehensive meteorological and man-agement data were provided. To disentangle the different effects, monitoring data were subjected to a principal component analysis. Loadings on the prevailing principal components and spatial and temporal patterns of the component scores were considered indicative of different processes. Principal component scores were then related to meteorological and management data via random forest modelling. Hydrological conditions and weather were identified as primary driving forces for the nutrient discharge behaviour of the drain plots, as well as the nitrogen balance. In contrast, direct effects of recent agricultural management could hardly be identified. Instead, we found clear evidence of the long-term and indirect effects of agriculture on nearly all solutes. We conclude that tile drain effluent quality primarily reflected the soil-internal mobilisation or de-mobilisation of nutrients and related solutes rather than allowing inferences to be drawn about recent individual agricultural management measures. On the other hand, principal component analysis revealed a variety of indirect and long-term effects of fertilisation on solutes other than nitrogen or phosphorus that are still widely overlooked in nutrient turnover studies. KW - Agricultural management KW - Tile drains KW - Nitrate KW - Phosphorus KW - Water KW - pollution KW - Multivariate statistics KW - Random forest modelling Y1 - 2021 U6 - https://doi.org/10.1016/j.agee.2021.107787 SN - 0167-8809 SN - 1873-2305 VL - 326 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Malinowski, Radostaw A1 - Höfle, Bernhard A1 - Koenig, Kristina A1 - Groom, Geoff A1 - Schwanghart, Wolfgang A1 - Heckrath, Goswin T1 - Local-scale flood mapping on vegetated floodplains from radiometrically calibrated airborne LiDAR data JF - ISPRS journal of photogrammetry and remote sensing : official publication of the International Society for Photogrammetry and Remote Sensing N2 - Knowledge about the magnitude of localised flooding of riverine areas is crucial for appropriate land management and administration at regional and local levels. However, detection and delineation of localised flooding with remote sensing techniques are often hampered on floodplains by the presence of herbaceous vegetation. To address this problem, this study presents the application of full waveform airborne laser scanning (ALS) data for detection of floodwater extent. In general, water surfaces are characterised by low values of backscattered energy due to water absorption of the infrared laser shots, but the exact strength of the recorded laser pulse depends on the area covered by the targets located within a laser pulse footprint area. To account for this we analysed the physical quantity of radio metrically calibrated ALS data, the backscattering coefficient, in relation to water and vegetation coverage within a single laser footprint. The results showed that the backscatter was negatively correlated to water coverage, and that of the three distinguished classes of water coverage (low, medium, and high) only the class with the largest extent of water cover (>70%) had relatively distinct characteristics that can be used for classification of water surfaces. Following the laser footprint analysis, three classifiers, namely AdaBoost with Decision Tree, Naive Bayes and Random Forest, were utilised to classify laser points into flooded and non-flooded classes and to derive the map of flooding extent. The performance of the classifiers is highly dependent on the set of laser points features used. Best performance was achieved by combining radiometric and geometric laser point features. The accuracy of flooding maps based solely on radiometric features resulted in overall accuracies of up to 70% and was limited due to the overlap of the backscattering coefficient values between water and other land cover classes. Our point-based classification methods assure a high mapping accuracy (similar to 89%) and demonstrate the potential of using full-waveform ALS data to detect water surfaces on floodplain areas with limited water surface exposition through the vegetation canopy. (C) 2016 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS). Published by Elsevier B.V. All rights reserved. KW - ALS KW - LiDAR KW - Point cloud KW - Inundation KW - Full-waveform KW - Water Y1 - 2016 U6 - https://doi.org/10.1016/j.isprsjprs.2016.06.009 SN - 0924-2716 SN - 1872-8235 VL - 119 SP - 267 EP - 279 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Machatschek, Rainhard Gabriel A1 - Heuchel, Matthias A1 - Lendlein, Andreas T1 - Hydrolytic stability of polyetherimide investigated in ultrathin films JF - Journal of materials research : JMR / Materials Research Society N2 - Increasing the surface hydrophilicity of polyetherimide (PEI) through partial hydrolysis of the imide groups while maintaining the length of the main-chain was explored for adjusting its function in biomedical and membrane applications. The outcome of the polymer analogous reaction, i.e., the degree of ring opening and chain cleavage, is difficult to address in bulk and microstructured systems, as these changes only occur at the interface. Here, the reaction was studied at the air-water interface using the Langmuir technique, assisted by atomic force microscopy and vibrational spectroscopy. Slow PEI hydrolysis sets in at pH > 12. At pH = 14, the ring opening is nearly instantaneous. Reduction of the layer viscosity with time at pH = 14 suggested moderate chain cleavage. No hydrolysis was observed at pH = 1. Hydrolyzed PEI films had a much more cohesive structure, suggesting that the nanoporous morphology of PEI can be tuned via hydrolysis. KW - 2D materials KW - Membrane KW - Polymer KW - Water KW - Nanostructure Y1 - 2021 U6 - https://doi.org/10.1557/s43578-021-00267-6 SN - 0884-2914 SN - 2044-5326 VL - 36 IS - 14 SP - 2987 EP - 2994 PB - Springer CY - Berlin ER - TY - JOUR A1 - Fortes Martín, Rebeca A1 - Thünemann, Andreas F. A1 - Stockmann, Jörg M. A1 - Radnik, Jörg A1 - Koetz, Joachim T1 - From nanoparticle heteroclusters to filament networks by self-assembly at the water-oil interface of reverse microemulsions JF - Langmuir : the ACS journal of surfaces and colloids / American Chemical Society N2 - Surface self-assembly of spherical nanoparticles of sizes below 10 nm into hierarchical heterostructures is under arising development despite the inherent difficulties of obtaining complex ordering patterns on a larger scale. Due to template-mediated interactions between oil-dispersible superparamagnetic nanoparticles (MNPs) and polyethylenimine- stabilized gold nanoparticles (Au(PEI)NPs) at the water-oil interface of microemulsions, complex nanostructured films can be formed. Characterization of the reverse microemulsion phase by UV-vis absorption revealed the formation of heteroclusters from Winsor type II phases (WPII) using Aerosol-OT (AOT) as the surfactant. SAXS measurements verify the mechanism of initial nanoparticle clustering in defined dimensions. XPS suggested an influence of AOT at the MNP surface. Further, cryo-SEM and TEM visualization demonstrated the elongation of the reverse microemulsions into cylindrical, wormlike structures, which subsequently build up larger nanoparticle superstructure arrangements. Such WPII phases are thus proven to be a new form of soft template, mediating the self-assembly of different nanoparticles in hierarchical network-like filaments over a substrate during solvent evaporation. KW - Emulsions KW - Liquids KW - Nanoparticles KW - Water KW - X-ray scattering Y1 - 2021 U6 - https://doi.org/10.1021/acs.langmuir.1c01348 SN - 0743-7463 VL - 37 IS - 29 SP - 8876 EP - 8885 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Unuabonah, Emmanuel Iyayi A1 - Agunbiade, Foluso O. A1 - Alfred, Moses O. A1 - Adewumi, Thompson A. A1 - Okoli, Chukwunonso P. A1 - Omorogie, Martins O. A1 - Akanbi, Moses O. A1 - Ofomaja, Augustine E. A1 - Taubert, Andreas T1 - Facile synthesis of new amino-functionalized agrogenic hybrid composite clay adsorbents for phosphate capture and recovery from water JF - Journal of Cleaner Production N2 - New hybrid clay materials with good affinity for phosphate ions were developed from a combination of biomass-Carica papaya seeds (PS) and Musa paradisiaca (Plantain peels-PP), ZnCl2 and Kaolinite clay to produce iPS-HYCA and iPP-HYCA composite adsorbents respectively. Functionalization of these adsorbents with an organosilane produced NPS-HYCA and NPP-HYCA composite adsorbents. The pH(pzc) for the adsorbents were 7.83, 6.91, 7.66 and 6.55 for iPS-HYCA, NPS-HYCA, iPP-HYCA and NPP-HYCA respectively. Using the Brouer-Sotolongo isotherm model which best predict the adsorption capacity of composites for phosphate, iPP-HYCA, iPS-HYCA, NPP-HYCA, and NPS-HYCA composite adsorbents respectively. When compared with some commercial resins, the amino-functionalized adsorbents had better adsorption capacities. Furthermore, amino-functionalized adsorbents showed improved adsorption capacity and rate of phosphate uptake (as much as 40-fold), as well as retain 94% (for NPS-HYCA) and 84.1% (for NPP-HYCA) efficiency for phosphate adsorption after 5 adsorption-desorption cycles (96 h of adsorption time with 100 mg/L of phosphate ions) as against 37.5% (for iPS-HYCA) and 35% (for iPP-HYCA) under similar conditions. In 25 min desorption of phosphate ion attained equilibrium. These new amino-functionalized hybrid clay composite adsorbents, which were prepared by a simple means that is sustainable, have potentials for the efficient capture of phosphate ions from aqueous solution. They are quickly recovered from aqueous solution, non-biodegradable (unlike many biosorbent) with potentials to replace expensive adsorbents in the future. They have the further advantage of being useful in the recovery of phosphate for use in agriculture which could positively impact the global food security programme. (C) 2017 Elsevier Ltd. All rights reserved. KW - Composite adsorbents KW - Sustainable KW - Phosphate recovery KW - Water KW - Desorption kinetics Y1 - 2017 U6 - https://doi.org/10.1016/j.jclepro.2017.06.160 SN - 0959-6526 SN - 1879-1786 VL - 164 SP - 652 EP - 663 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Omorogie, Martins O. A1 - Babalola, Jonathan Oyebamiji A1 - Unuabonah, Emmanuel I. A1 - Song, Weiguo A1 - Gong, Jian Ru T1 - Efficient chromium abstraction from aqueous solution using a low-cost biosorbent: Nauclea diderrichii seed biomass waste JF - Journal of Saudi Chemical Society N2 - Toxic Cr(III) which poses environmental hazard to flora and fauna was efficiently abstracted by low-cost Nauclea diderrichii seed biomass (NDS) with good sequestral capacity for this metal was investigated in this study. The NDS surface analyses showed that it has a specific surface area of 5.36 m(2)/g and pHpzc of 4.90. Thermogravimetric analysis of NDS showed three consecutive weight losses from 50-200 degrees C (ca. 5%), 200-400 C (ca. 35%), >400 degrees C (ca. 10%), corresponding to external water molecules, structural water molecules and heat induced condensation reactions respectively. Differential thermogram of NDS presented a large endothermic peak between 20-510 degrees C suggesting bond breakage and dissociation with the ultimate release of small molecules. The experimental data showed kinetically fast biosorption with increased initial Cr(III) concentrations, indicating the role of external mass transfer mechanism as the rate controlling mechanism in this adsorption process. The Langmuir biosorption capacity of NDS was 483.81 mg/g. The use of the corrected Akaike Information Criterion tool for ranking equilibrium models suggested that the Freundlich model best described the experimental data, which is an indication of the heterogeneous nature of the active sites on the surface of NDS. N. diderrichii seed biomass is an easily sourced, cheap and environmental friendly biosorbent which will serve as a good and cost effective alternative to activated carbon for the treatment of polluted water and industrial effluents. (C) 2012 King Saud University. Production and hosting by Elsevier B.V. All rights reserved. KW - Biomass KW - Equilibrium KW - External mass transfer KW - Kinetics KW - Adsorption KW - Water Y1 - 2016 U6 - https://doi.org/10.1016/j.jscs.2012.09.017 SN - 1319-6103 SN - 2212-4640 VL - 20 SP - 49 EP - 57 PB - Elsevier CY - Amsterdam ER -