Biology subjects

Hellweg, S.

Publications and source records attributed to Hellweg, S..

3 recordsLinked to original sources

bioRxiv2025

Environmental impact of integrating decentralized urine treatment in the urban wastewater management system: A comparative life cycle assessment

As municipal wastewater treatment regulations become more stringent, integrating source-separated urine treatment into centralized urban wastewater management offers a hybrid solution. However, it is not clear how the environmental impacts of such hybrid systems compare to highly efficient centralized wastewater treatment plants (WWTPs) with low N2O emissions and electricity use. In this study, a consequential life cycle assessment was used to compare the environmental impact of three urine hybrid wastewater treatment systems - which combine decentralized urine treatment with a highly efficient central WWTP - to a centralized WWTP treating mixed wastewater (baseline). The studied urine treatment systems include partial nitrification & distillation, struvite precipitation & stripping/scrubbing, and partial nitritation/anammox. Additionally, the contribution of urine alkalinization to the overall impact was quantified. The results show that at least one hybrid scenario showed a lower environmental impact in 8 out of the 10 assessed impact categories. Global warming potential and marine eutrophication were found to be higher than the baseline. Additionally, it was identified that urine alkalinization increased the environmental impact of the treatment system in 7 out of the 10 impact categories. A Pareto frontier analysis was developed to guide decision makers on where hybrid solutions could be used as a strategy to reduce global warming impacts of conventional WWTPs. It was realized that using N2O emission factors of 75 WWTPs, 87% of centralized WWTPs had lower CO2 emissions compared to partial nitrification & distillation, and 91% compared to partial nitritation/anammox hybrid solutions. However, at energy demands of 1 kWh/PE and 2 kWh/PE, both hybrid solutions showed lower emissions than all the studied WWTPs. The study highlights the potential of hybrid wastewater treatment solutions to address specific environmental challenges in wastewater management and a strategy to reduce global warming impacts in WWTPs with high N2O emissions and electricity use. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=75 SRC="FIGDIR/small/636102v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@c97256org.highwire.dtl.DTLVardef@171989dorg.highwire.dtl.DTLVardef@da8e02org.highwire.dtl.DTLVardef@a151da_HPS_FORMAT_FIGEXP M_FIG Graphical abstract C_FIG

ecology↗

bioRxiv2024

Land-use impacts on plant functional diversity throughout Europe

AimGlobal biodiversity loss resulting from anthropogenic land-use activities is a pressing concern, requiring precise assessments of impacts at large spatial extents. Existing models mainly focus on species richness and abundance, lacking insights into ecological mechanisms and species roles in ecosystem functioning. To bridge this gap, we conducted an extensive analysis of the impact of human land use on vascular plant functional diversity, across diverse land-use classes and bioregions in Europe, comparing it to traditional metrics. Location: Europe Time period: 1992-2019 Major taxa studied: Vascular plants MethodsIntegrating extensive databases of vegetation plots with spatial data on land use and land cover, we paired plots from areas actively used and modified by humans with plots from natural habitats under similar environmental conditions. Using species occurrences and traits, in each plot we computed three complementary functional diversity metrics (functional richness, evenness, and divergence), species richness and abundance. We assessed the impact of land use by comparing the metrics in the paired plots. ResultsOur findings revealed that, compared to natural habitats, anthropogenic land use exhibits lower functional richness and divergence but higher functional evenness across most land-use classes and bioregions. The response of functional richness was more marked than the other two metrics and especially pronounced in croplands and urban areas and in northern bioregions. Functional richness exhibited a pattern that did not fully overlap with the trend in species richness, providing useful complementary information. Main conclusionsWe provide a large-scale precise assessment of anthropogenic land-use impacts on functional diversity across Europe. Our findings indicate that: (i) human disturbance significantly alters plant functional diversity compared to natural habitats; (ii) this alteration goes in the direction of functional homogenization; (i) functional diversity metrics complement traditional metrics by offering deeper insights into the ecological mechanisms in response to anthropogenic land use.

ecology↗

bioRxiv2018

A protocol for an intercomparison of biodiversity and ecosystem services models using harmonized land-use and climate scenarios

Abstract.To support the assessments of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), the IPBES Expert Group on Scenarios and Models is carrying out an intercomparison of biodiversity and ecosystem services models using harmonized scenarios (BES-SIM). The goals of BES-SIM are (1) to project the global impacts of land use and climate change on biodiversity and ecosystem services (i.e. natures contributions to people) over the coming decades, compared to the 20th century, using a set of common metrics at multiple scales, and (2) to identify model uncertainties and research gaps through the comparisons of projected biodiversity and ecosystem services across models. BES-SIM uses three scenarios combining specific Shared Socio-economic Pathways (SSPs) and Representative Concentration Pathways (RCPs) to explore a wide range of land-use change and climate change futures. This paper describes the rationale for scenarios selection, the process of harmonizing input data for land use, based on the second phase of the Land Use Harmonization Project (LUH2), and climate, the biodiversity and ecosystem service models used, the core simulations carried out, the harmonization of the model output metrics, and the treatment of uncertainty. The results of this collaborative modelling project will support the ongoing global assessment of IPBES, strengthen ties between IPBES and the Intergovernmental Panel on Climate Change (IPCC) scenarios and modelling processes, advise the Convention on Biological Diversity (CBD) on its development of a post-2020 strategic plans and conservation goals, and inform the development of a new generation of nature-centred scenarios.

ecology↗