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Now showing items 31-40 of 43
Aufsatz
Small villages and their sanitary infrastructure—an unnoticed influence on water quantity and a threat to water quality in headwater catchments
(2023-11-16)
In rural catchments, villages often feature their own, separate urban water infrastructure, including combined sewer overflows (CSOs) or wastewater treatment plants (WWTPs). These point sources affect the water quantity and quality of the receiving low order streams. However, the extent of this impact is rarely monitored. We installed discharge and water quality measurements at the outlet of two small, neighbouring headwater catchments, one that includes a village, a WWTP, and two CSOs, while the other is predominantly ...
Aufsatz
Soil respiration under different N fertilization and irrigation regimes in Bengaluru, S-India
(2023-09-15)
Rapid urbanization in many countries of the Global South has led to intensification of urban and peri-urban agriculture (UPA) whose effects on the soils’ physical, chemical, and microbial properties have been hardly studied. We therefore investigated the effects of different intensity levels, exemplified by three rates of mineral nitrogen (N) addition and irrigation on CO₂ emissions in typical crops during the wet (Kharif) and dry (Rabi) season on a Nitisol in Bengaluru, S-India. Respiration data were collected from ...
Aufsatz
Disentangling the practice of landscape approaches: a Q-method analysis on experiences in socio-ecological production landscapes and seascapes
(2023-03-23)
Landscape approaches are gaining momentum in both scientific and policy agendas. However, landscape approaches comprise a multitude of concepts, approaches and principles, which are in part similar, in some parts different or even contradictory. In this paper, we used a Q-method questionnaire to explore how landscape approaches are understood and employed in 45 case studies of socio-ecological production landscapes and seascapes derived from the International Partnership for the Satoyama Initiative (IPSI), as well ...
Aufsatz
A hitchhiker’s guide: estimates of microbial biomass and microbial gene abundance in soil
(2024-03-19)
Information on microbial biomass carbon (MBC) is crucial to assess their stocks and role for plant nutrient release in soil. Next to fumigation-extraction, molecular methods are routinely used to estimate the contribution of fungi, bacteria, and archaea to the soil microbial community. However, more information on the links between these different indices would deepen the understanding of microbial processes. The current study is based on 11 datasets, which contain MBC and MBN data obtained by fumigation-extraction ...
Aufsatz
Embedding plural values in value chains to enhance sustainability in the management of cork oak landscapes
(2023-07-19)
Context
The management of Portuguese agroforestry landscapes is currently focused on specialised cork and cattle production. Sustainable landscape management is increasingly discussed as an effective option to foster the multifunctionality of these landscapes. Such management requires consideration of multiple values connected to the landscape and to the products stemming from it.
Objectives
The aim of this study is to (1) assess the importance of specific values related to cork and to the cork production ...
Aufsatz
Fluorescence microscopic investigation of PCE superplasticiser adsorption in calcined clay blended cement
(2024-03-31)
Global efforts to minimise carbon dioxide emissions are also leading to attempts to use calcined clays (CC) as a partial substitute for cement in concrete. While the hydration mechanism of such CC blended cements is now well understood, the range of effective admixtures like polycarboxylate ethers (PCE) is limited. There are PCE types that promise relatively high effectiveness, but the mechanisms of action are not yet sufficiently understood. For a detailed understanding of the adsorption of such PCEs, spatially ...
Aufsatz
Water quality footprint of agricultural emissions of nitrogen, phosphorus and glyphosate associated with German bioeconomy
(2023-11-02)
Fertiliser and pesticide application can cause extensive environmental damage. We use the water quality footprint to express nitrogen, phosphorus and glyphosate emissions from agriculture in volumes of water needed to virtually dilute pollution and apply the approach to agricultural imports for the German bioeconomy in 1995 and 2020. In total, the virtual German water quality footprint corresponds to 90 times the volume of Lake Constance. If water pollution had to be eliminated by dilution in export countries supplying ...
Aufsatz
Optimization of the bicinchoninic acid assay for quantifying carbohydrates of soil extracellular polymeric substances
(2023-12-23)
Background and aims
The bicinchoninic acid (BCA) method was not yet applied on soil extracts of extracellular polymeric substances (EPS) to quantify polysaccharides, although this might be possible by introducing a cleavage step to produce monosaccharides. A pre-extraction with CaCl₂ to remove interfering substances is usually performed before extracting EPS. The main objective of this study was to optimize the BCA assay for total carbohydrates quantification by applying a hydrolysis step to the EPS extracts, while ...
Aufsatz
Correlation between the activation energy of PLA respectively PLA/starch composites and mechanical properties with regard to differ accelerated aging conditions
(2024-02-22)
Within this research semi-crystalline polylactide and composites with 50 wt.% native potato starch were compounded and injection molded. The material was mechanically characterized by tensile, three-point bending, and Charpy impact tests. These tests were carried out in the freshly molded state and after 332 and 792 h of storage at accelerated temperature or humidity. The respective activation energy was calculated by applying the Flynn-Wall-Ozawa method. The focus of the study was to investigate the correlation ...
Aufsatz
Modelling competitive adsorption of organic micropollutants onto powdered activated carbon in continuous stirred tank reactors for advanced wastewater treatment
(2024-05-21)
This work investigates the validation and application of a competitive model approach for full-scale wastewater treatment plants (WWTP) with external recirculation of partially loaded powdered activated carbon (PAC) for removal of organic micropollutants (OMP). It is based on the ideal adsorbed solution theory (IAST) for multisolute mixtures combined with calibration of fictive organic components and correction of single-solute model parameters for OMP by use of the tracer model (TRM). Adsorption kinetics are represented ...