Articles publicats (Química, Física i Ciències Ambientals i del Sòl)
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- ItemOpen AccessIsotopy, micromorphology and composition of pedogenic gypsum in loess-palaeosol sequences in the Ebro Valley as a combined paleoenvironmental proxy(Elsevier, 2026) Álvarez Morales, Daniela; Playà, E.; Artieda, O.; Rodríguez Ochoa, Rafael; Olarieta, José Ramón; Poch, Rosa M.The loess palaeosol sequences in the Ebro valley are associated with arid and semi-arid climates in the past, where the main pedogenic process is the mobilisation of carbonate and gypsum through the soil, resulting in secondary accumulations. Due to the fact that, in this context, the conservation of palaeoenvironmental indicators is very limited, the objective of this research is to explore the potential of pedogenic gypsum to provide with information about the palaeoenvironmental conditions affecting its development and preservation. This study has consisted in the sampling and analysis of pedogenic gypsum accumulations from five Loess-Palaeosol Sequences (LPS) applying several approaches and analytical techniques. Traditional methods based on the morphological study of gypsum and supported by micromorphological research have been applied, allowing us the observation of crystalline shapes, pedofeatures and mineral arrangements. We also performed isotopic analyses of pedogenic gypsum, including the isotopic signature of the stable sulphate (δ34S, δ18O) and gypsum hydration water (δ2H, δ18O). Besides, the minor and trace elements composition (Ba, Sr, Na, K, and Mg) was also analysed. Despite the difficulties when analysing pedogenic gypsum, due in part to its high solubility, our results show that the intensity of the dissolution/reprecipitation processes combined with the loess sedimentation rates determine gypsum characteristics and distribution in the studied loess profiles. Besides helping to determine the gypsum primary source areas, isotopic and micromorphological analyses suggest possible regional and temporal paleoclimatic differences (more/less arid) from the close or more open systems of gypsum in relation to meteoric water. In addition, the minor and trace elements composition suggests the presence of fluid and solid inclusions in the gypsum crystals of some horizons. This corresponds to gypsum formation in a medium with water rich in sulphates and other salts, and an increased proportion of primary gypsum in the sediment, in contrast to the precipitation of gypsum in unsaturated water. The combination of different methods has confirmed that pedogenic gypsum is a potential tool for improving palaeoenvironmental knowledge in arid and semi-arid regions. However, due to its limitations, it is recommended to combine additional techniques and indicators to use pedogenic gypsum as an effective palaeoenvironmental proxy.
- ItemOpen AccessSustainable Lipase Immobilization on Eggshell Membrane Carriers: Economic and LCA Insights at Laboratory Scale(MDPI, 2026-01) Stjepanović, Marija; Ostojčić, Marta; Strelec, Ivica; Velić, Natalija; Tran, Nghiep Nam; Hessel, Volker; Escribà i Gelonch, Marc; Budžaki, SandraThis study presents a comprehensive economic and environmental evaluation of immobilized lipases produced on eggshell membrane-based carriers from eggshell waste, based on laboratory-scale experiments. By integrating economic analysis (EA) and life cycle analysis (LCA), the key factors affecting the economic viability and environmental impact of the process were identified, supporting sustainable and circular biorefinery concepts. The EA estimated the total process cost at EUR 25.63 for 15 g of product, while the effective net cost was negative (EUR −14.81) due to the valorization of anhydrous calcium chloride as a valuable by-product. The effective net cost reduction from by-product valorization of the immobilized lipase was estimated at 0.99 EUR/g as the minimum selling price (MSP). When expressed per unit of enzymatic activity, the immobilized lipase on the eggshell waste membrane-based carrier shows a substantially lower cost (EUR/U) compared with representative commercial immobilized lipases, demonstrating clear catalytic cost-efficiency advantages. The cradle-to-gate life cycle assessment, conducted using ReCiPe 2016 quantification methods, highlighted electricity consumption during drying as the primary environmental hotspot, accounting for up to 57% of the global warming potential. Sensitivity and uncertainty analyses showed that energy consumption strongly influences the impact in terms of climate change and fossil resource depletion, while the impact of chemical use was minimal. These results show that energy-efficient process optimization, especially in the drying phase, is crucial for further improving environmental and economic performance. These results indicate that optimizing energy efficiency, especially during the drying phase, is crucial for further improving the production process of immobilized lipases on eggshell membrane-based carriers, both environmentally and economically.
- ItemOpen AccessForensic hydro-meteorological analysis of an extreme flash flood: the 2016-05-29 event in Braunsbach, SW Germany(Elsevier, 2018) Bronstert, Axel; Agarwal, Ankit; Boessenkool, Berry; Crisologo, Irene; Fischer, Madlen; Heistermann, Maik; Köhn-Reich, Lisei; López Tarazón, José Andrés; Moran, Thomas; Ozturk, Ugur; Reinhardt-Imjela, Christian; Wendi, DadiyortoThe flash-flood in Braunsbach in the north-eastern part of Baden-Wuerttemberg/Germany was a particularly strong and concise event which took place during the floods in southern Germany at the end of May/early June 2016. This article presents a detailed analysis of the hydro-meteorological forcing and the hydrological consequences of this event. A specific approach, the “forensic hydrological analysis” was followed in order to include and combine retrospectively a variety of data from different disciplines. Such an approach investigates the origins, mechanisms and course of such natural events if possible in a “near real time” mode, in order to follow the most recent traces of the event. The results show that it was a very rare rainfall event with extreme intensities which, in combination with catchment properties, led to extreme runoff plus severe geomorphological hazards, i.e. great debris flows, which together resulted in immense damage in this small rural town Braunsbach. It was definitely a record-breaking event and greatly exceeded existing design guidelines for extreme flood discharge for this region, i.e. by a factor of about 10. Being such a rare or even unique event, it is not reliably feasible to put it into a crisp probabilistic context. However, one can conclude that a return period clearly above 100 years can be assigned for all event components: rainfall, peak discharge and sediment transport. Due to the complex and interacting processes, no single flood cause or reason for the very high damage can be identified, since only the interplay and the cascading characteristics of those led to such an event. The roles of different human activities on the origin and/or intensification of such an extreme event are finally discussed.
- ItemOpen AccessRare flash floods and debris flows in southern Germany(Elsevier, 2018) Ozturk, Ugur; Wendi, Dadiyorto; Crisologo, Irene; Riemer, Adrian; Agarwal, Ankit; Vogel, Kristin; López Tarazón, José Andrés; Korup, OliverFlash floods and debris flows are iconic hazards in mountainous regions with steep relief, high rainfall intensities, rapid snowmelt events, and abundant sediments. The cuesta landscapes of southern Germany hardly come to mind when dealing with such hazards. A series of heavy rainstorms dumping up to 140 mm in 2 h caused destructive flash floods and debris flows in May 2016. The most severe damage occurred in the Braunsbach municipality, which was partly buried by 42,000 m3 of boulders, gravel, mud, and anthropogenic debris from the small catchment of Orlacher Bach (~6 km2). We analysed this event by combining rainfall patterns, geological conditions, and geomorphic impacts to estimate an average sediment yield of 14,000 t/km2 that mostly (~95%) came from some 50 riparian landslides and channel-bed incision of ~2 m. This specific sediment yield ranks among the top 20% globally, while the intensity-duration curve of the rainstorm is similarly in the upper percentile range of storms that had triggered landslides. Compared to similar-sized catchments in the greater region hit by the rainstorms, we find that the Orlacher Bach is above the 95th percentile in terms of steepness, storm-rainfall intensity, and topographic curvatures. The flash flood transported a sediment volume equal to as much as 20–40% of the Pleistocene sediment volume stored in the Orlacher Bach fan, and may have had several predecessors in the Holocene. River control structures from 1903 and records of a debris flow in the 1920s in a nearby catchment indicate that the local inhabitants may have been aware of the debris-flow hazards earlier. Such recurring and destructive events elude flood-hazard appraisals in humid landscapes of gentle relief, and broaden mechanistic views of how landslides and debris flows contribute to shaping small and deeply cut tributaries in the southern Germany cuesta landscape.
- ItemOpen AccessInfluence of naturally high fine sediment loads on aquatic insect larvae 2 in a Montane River(Taylor & Francis, 2011) Buendia, C.; Gibbins, Chris N.; Vericat Querol, Damià; López Tarazón, José Andrés; Batalla, Ramon J.La sedimentación de finos asociada a la actividad humana es una fuente importante de deterioro ecológico en los ríos. Sin embargo, existe escasez de información sobre si los sedimentos finos asociados a procesos naturales resultan en un deterioro similar. Evaluamos el efecto de los sedimentos finos en la composición taxonómica y la abundancia de larvas de insectos en un río que recibe altos aportes como resultado de áreas de tierras baldías naturalmente erosionables. Se utilizó como referencia una subcuenca adyacente, que no experimenta altos aportes de sedimentos pero que, por lo demás, es similar. Se observaron marcadas diferencias en la densidad de insectos y la riqueza de taxones entre las dos subcuencas. La abundancia de varios taxones de insectos disminuyó a medida que aumentaba la proporción de material del lecho que comprendía finos. Se observó una disminución similar en la métrica EPT. Los sedimentos finos ejercieron una influencia dominante y homogeneizadora en la estructura de la comunidad en las áreas del lecho donde se encontraban en altas concentraciones. Entre el 24 % y el 36 % de la variabilidad general en la estructura de la comunidad podría explicarse por las condiciones sedimentarias. En lugares donde el contenido de sedimentos finos era limitado, otras variables del hábitat influyeron en la estructura de la comunidad de insectos, y los conjuntos de parches fueron generalmente más diversos y heterogéneos.
