http://bura.brunel.ac.uk/handle/2438/25432 Fri, 27 Mar 2026 20:18:29 GMT 2026-03-27T20:18:29Z http://bura.brunel.ac.uk/handle/2438/32937 Title: The pollution load of combined sewer overflows and risks to England’s waterbodies: Relating event duration monitoring data to discharge consents from wastewater treatment works Authors: Giakoumis, T; Voulvoulis, N Abstract: The increasing frequency of Combined Sewer Overflows (CSOs) has heightened public concern, triggered government action, and driven water authorities worldwide to commit to major infrastructure upgrades. In England, the installation of Event Duration Monitors (EDMs) has revealed how often and for how long spills occur annually, discharging untreated or dilluted sewage to the receiving environment. However, overflow frequency and duration are poor proxies for pollution loads or ecological risk. This study provides the first national estimation of pollution loads from individual CSOs and the risks they pose to receiving waterbodies, drawing on permitted effluent limits from connected Wastewater Treatment Works (WWTWs) and receiving waterbody characteristics. A source-pathway-receptor framework is used to classify risk across England’s wastewater systems in relation to CSO discharges and their impacts. The findings challenge the Environment Agency’s position that CSOs are not a primary driver of waterbody status failure, indicating their ecological impacts may be underestimated. For 2023, estimated aggregated CSO loads frequently surpassed those from the effluents of their WWTWs, with affected waterbodies receiving loads from CSOs four times higher for BOD and double for Suspended Solids. While nutrient loads exhibit lower relative contributions, the presence of wastewater systems where CSO loads equal or exceed treated effluent loads demonstrates that nutrient management strategies focusing solely on WWTWs risk overlooking a critical source. The study demonstrates how a systems approach integrating all available data, can strengthen evidence-based policy making, and support water companies in prioritising investments that can deliver measurable environmental improvements. Description: Data availability: Data are available as Electronic supplementary information.; All data used in this study are available through publicly accessible datasets (as cited). Data generated through the analyses are provided as Electronic Supplementary Information in the Supplementary Materials.; Supplementary files: Supplementary information: https://www.rsc.org/suppdata/d5/ew/d5ew00860c/d5ew00860c1.csv CSV (4518K). Supplementary information: https://www.rsc.org/suppdata/d5/ew/d5ew00860c/d5ew00860c2.xlsx XLSX (1503K). Supplementary information: https://www.rsc.org/suppdata/d5/ew/d5ew00860c/d5ew00860c3.csv CSV (855K). Supplementary information: https://www.rsc.org/suppdata/d5/ew/d5ew00860c/d5ew00860c4.pdf PDF (138K). Wed, 04 Mar 2026 00:00:00 GMT http://bura.brunel.ac.uk/handle/2438/32937 2026-03-04T00:00:00Z http://bura.brunel.ac.uk/handle/2438/32902 Title: Nano CaCO₃ seeding for improving properties of limestone calcined clay cement through in-situ carbonation Authors: Niu, Z; Zhou, X; Hou, P; Liu, M; Liang, S; Sun, Y; Zhao, Y; Wang, J Abstract: This study proposes an effective strategy to simultaneously enhance the mechanical performance and CO₂ sequestration capacity of limestone calcined clay cement (LC³) incorporating low-grade calcined clay through aqueous carbonation. 25% of the cement fraction in LC³ was subjected to aqueous carbonation for 10 to 40 mins with a water-to-solid ratio of 2.0, leading to the in-situ precipitation of nano-sized CaCO₃. A maximum CO₂ uptake of 15.78% was achieved after 40 min of carbonation. After mixing with the remaining materials of the LC³ formulation, the synergistic dilution and nucleation effects of in-situ nano CaCO₃ promoted the hydration of silicate and aluminate phases, thereby refining the pore structure of LC³. At 3 days, the fraction of fine capillary pores (10-50 nm) increased remarkably, reaching 54% and 60% after 30 and 40 min of carbonation, respectively, and this refinement was largely preserved at 28 days. Consequently, the 28-day compressive strength of LC³ mortars increased by 34.93% and 32.07% at carbonation durations of 30 and 40 min, respectively, compared with the control group. However, substantial consumption of portlandite during pre-carbonation constrained the later development of carboaluminate phases, which highlights a trade-off between enhanced early hydration and limited availability of secondary hydration products. These findings offer new insights into the role of in-situ CaCO₃ precipitation in modifying hydration and pore structure, demonstrating that aqueous carbonation is an effective route to enhance LC³ performance while facilitating CO₂ sequestration. Description: Data availability: Data will be made available on request.; This is a PDF of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability. This version will undergo additional copyediting, typesetting and review before it is published in its final form. As such, this version is no longer the Accepted Manuscript, but it is not yet the definitive Version of Record; we are providing this early version to give early visibility of the article. Please note that Elsevier’s sharing policy for the Published Journal Article applies to this version, see: https://www.elsevier.com/about/policies-andstandards/sharing#4-published-journal-article . Please also note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Fri, 27 Feb 2026 00:00:00 GMT http://bura.brunel.ac.uk/handle/2438/32902 2026-02-27T00:00:00Z http://bura.brunel.ac.uk/handle/2438/32825 Title: Copula-Based Bayesian Inference Approaches for Uncertainty Quantification for Hydrological Simulation Authors: Wang, F; Duan, R; Zhang, J; Zhai, M; Li, Y; Fan, Y; Xie, Y Abstract: In this study, an advanced copula-based Bayesian inference framework is proposed to characterize probabilistic features in hydrological simulations. Specifically, a Copula–Metropolis–Hastings (CopMH) algorithm is developed through integrating copula functions into the conventional Metropolis–Hastings (MH) algorithm within an interdependence-sampling framework. In CopMH, the interdependence structure among model parameters is quantified using copula functions, which are subsequently employed to generate proposal candidates. The proposed approach is then applied to uncertainty analysis in hydrological simulations of the Ruihe River watershed in Northwest China. The results indicate that, compared with the traditional MH, incorporating copula-based proposal distributions significantly improves convergence efficiency and simulation accuracy, as inter-parameter dependence is more effectively captured. All algorithms are independently repeated 15 times, and CopMH exhibits more robust and stable performance than MH. Furthermore, the intercorrelation analysis of hydrological model parameters reveals that interactive effects among parameters are ubiquitous. These findings highlight that consideration of the interrelationship among the parameters in hydrologic models is meaningful and necessary for uncertainty quantification of hydrological simulation. This study demonstrates the strong potential of the proposed CopMH approach for effectively quantifying and reducing parameter uncertainty in hydrological simulations. Description: Data Availability Statement: The raw data supporting the conclusions of this article will be made available by the authors on request.; Supplementary Materials: The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/hydrology13020050/s1. Algorithm S1: The pseudo code for MH and CopMH algorithm. Thu, 29 Jan 2026 00:00:00 GMT http://bura.brunel.ac.uk/handle/2438/32825 2026-01-29T00:00:00Z http://bura.brunel.ac.uk/handle/2438/32824 Title: Crude Microalgae Extract for Increased CO₂ Capture and Higher Biomass Production in Algal Cultivation Systems Authors: Berden-Zrimec, M; Lazar, D; Trontelj, D; Barampouti, EM; Mai, S; Malamis, D; Reinhardt, R Abstract: Efficient inorganic carbon supply is a common limitation in microalgal cultivation, particularly in waste-derived media such as anaerobic digestate. Carbonic anhydrase (CA) accelerates the interconversion of CO₂ and bicarbonate and may therefore enhance carbon utilisation under conditions where inorganic carbon is abundant but not readily available. In this study, crude CA-containing extracts (aCA) were prepared from Scenedesmus-dominated algal biomass, and CA activity was quantified using an esterase assay (EAA). Although EAA activities varied depending on biomass pretreatment (0.15–0.47 U g⁻¹ DW), the physiological response to extract addition was consistent. In batch cultures of Chlorella sorokiniana grown in diluted digestate, aCA supplementation increased the specific growth rate (SGR) by 21–82%. In contrast, stimulation in a mineral medium was minimal, indicating that the benefit of aCA addition is most apparent under reduced inorganic carbon availability. In semi-continuous cultivation, repeated extract addition sustained a higher biomass productivity over time (rather than a specific growth rate). These results demonstrate that crude microalgal extracts containing CA can improve growth performance in digestate-based cultures and may offer a simple, low-cost approach to enhancing inorganic carbon utilisation in waste-integrated algal production systems. Description: Data Availability Statement: The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding author. Mon, 02 Feb 2026 00:00:00 GMT http://bura.brunel.ac.uk/handle/2438/32824 2026-02-02T00:00:00Z