The separate, advanced treatment of hospital wastewater might be a promising approach to prevent the dissemination of residual compounds of high environmental concern, like pharmaceuticals, viruses and pathogenic microorganisms. This study investigates the performance of a full-scale, on-site treatment plant, consisting of a membrane bioreactor and a subsequent ozonation, at a German hospital. We analysed the elimination of pharmaceutical residues, microbiological parameters and SARS-CoV-2 RNA fragments. Additionally, we conducted an orienting study on the practicability of implementing targeted wastewater monitoring at a hospital. Our results demonstrate that after 10 years of stable operation, the treatment plant works highly efficiently regarding the elimination of pharmaceuticals and bacterial indicators. Elimination rates for pharmaceutical substances were above 90%, and log reductions of up to 6 log10 units for microbiological parameters were achieved. SARS-CoV-2 RNA could be detected and quantified in the influent but not in the effluent. The RNA load in the raw wastewater showed good correspondence with COVID-19 case numbers in the hospital. We showed that the full-scale on-site treatment of hospital wastewater is technically feasible and contributes to sustainable hospital effluent management and that monitoring biological markers on the building level might be a useful complementary tool for disease surveillance.

Wastewater monitoring for SARS-CoV-2 is a valuable tool for surveillance in public health. However, reliable analytical methods and appropriate approaches for the normalization of results are important requirements for implementing state-wide monitoring programs. In times of insufficient case reporting, the evaluation of wastewater data is challenging. Between December 2021 and July 2022, we analyzed 646 samples from 23 WWTPs in Thuringia, Germany. We investigated the performance of a direct capture-based method for RNA extraction (4S-method) and evaluated four normalization methods (NH₄-N, COD, N_tot, and PMMoV) in a pooled analysis using different epidemiological metrics. The performance requirements of the 4S method were well met. The method could be successfully applied to implement a state-wide wastewater monitoring program including a large number of medium and small wastewater treatment plants (<100,000 p.e) in high spatial density. Correlations between wastewater data and 7-day incidence or 7-day-hospitalization incidence were strong and independent from the normalization method. For the test positivity rate, PMMoV-normalized data showed a better correlation than data normalized with chemical markers. In times of low testing frequency and insufficient case reporting, 7-day-incidence data might become less reliable. Alternative epidemiological metrics like hospital admissions and test positivity data are increasingly important for evaluating wastewater monitoring data and normalization methods. Furthermore, future studies need to address the variance in biological replicates of wastewater.

Greywater reuse presents a promising strategy for reducing potable water demand and supporting the irrigation of urban green infrastructure, yet its implementation in early planning phases remains limited by fragmented regulations, data gaps, and the absence of practical decision support tools. This study develops a comprehensive evaluation matrix based on Multi-Criteria Decision Analysis (MCDA) to assess the feasibility of greywater reuse in residential district development. The framework integrates eight domains (legal, technical, infrastructural, ecological, economic, and social factors) and is complemented by automated supporting worksheets for water balance, ecological indicators, and economic parameters. Application of the matrix to two contrasting residential case studies demonstrated its diagnostic value: the new-build district in Dortmund showed a high reuse potential, strongly influenced by favourable infrastructure conditions and ecological indicators, whereas the existing building in Weimar yielded a moderate potential due to infrastructural constraints and lower greywater availability. Sensitivity analyses further revealed that local water tariffs, intended-use scenarios, and stakeholder weightings substantially affect outcomes. Overall, the results show that the matrix supports transparent early-stage decision-making, identifies critical bottlenecks, and strengthens governance-oriented integration of greywater reuse in sustainable urban development.

Multi-criteria decision analysis (MCDA) is widely applied in the planning of technical infrastructure, including water systems, which are increasingly affected by global environmental change. This study develops and applies a comprehensive evaluation matrix for assessing the potential of greywater reuse in residential district development for irrigating urban green spaces. Greywater reuse is increasingly recognized as a sustainable and resource-efficient alternative to conventional freshwater supply, particularly for irrigating. The proposed framework integrates regulatory, technical, infrastructural, ecological, economic, and social criteria, enabling a systematic assessment of site-specific potentials and constraints. The results demonstrate that the matrix can effectively support planning processes, enhance risk evaluation, and strengthen stakeholder acceptance. Overall, the approach provides a robust decision-support instrument for promoting greywater reuse in ecologically oriented urban development.

This study addresses the need for reliable methods in wastewater-based antimicrobial resistance monitoring by comparing three sample preparation approaches for analyzing intracellular DNA (iDNA) and extracellular DNA (exDNA) in raw wastewater: a filtration-based method, a centrifugation-based method, and a combination of the two (combined). We evaluated method repeatability, operational time, usability, consumable costs, qualitative workflow characteristics, and descriptive recovery. Selected antibiotic resistance genes (ARGs) (sul1, bla_OXA48 group, bla_VIM1 group, vanA, tetW, QnrS1) and the mobile genetic element intI1 were quantified by digital PCR. Most target signals occurred in the iDNA-enriched fraction (>98%). Filtration and the combined method received higher usability scores than centrifugation, whereas the combined workflow required approximately 15% higher consumable costs. Storage effects were target-, fraction-, and temperature-dependent. No common holding time satisfied the complete two-sided operational acceptance criteria. Considering decreases in relative recovery alone, storage at 5 °C for up to six days did not reduce any mean recovery below its target- and fraction-specific lower limit. Storage at −20 °C produced decreases in iDNA recovery after 24 h. These findings offer practical guidance for PCR-based AMR monitoring in wastewater.