Rainwater harvesting: model-based design evaluation

The rate of uptake of rainwater harvesting (RWH) in the UK has been slow to date, but is expected to gain momentum in the near future. The design of two different new-build rainwater harvesting systems are evaluated using a state-of-the-art continuous simulation modelling approach. The RWH systems were shown to fulfill between 36% and 46% of WC demand. It was found that design methods based on simple approaches (such as used in these two cases) generate tank sizes substantially larger than the simulation model. Comparison of the actual tank sizes and those calculated using the simulation model established that the actual tanks installed are oversized for their associated demand level and catchment size. The importance of catchment size was demonstrated, a factor neglected in the simpler methods commonly used in practice. Financial analysis revealed that RWH systems within large commercial buildings may be more financially viable that smaller domestic systems. A recommendation for a transition from the use of simple tools to simulation models is made

Benchmarking energy consumption and CO2 emissions from rainwater harvesting systems: an improved method by proxy

Subsequently published in Water and Environment Journal Vol. 26 (2), pp. 184–190 (2011). DOI: 10.1111/j.1747-6593.2011.00279.xThe definitive version is available at www3.interscience.wiley.comLife cycle analyses (LCAs) show the main operational energy contribution for rainwater-harvesting (RWH) systems come from ultraviolet (UV) disinfection and pumping rainwater from tank to building. Simple methods of estimating pump energy consumption do not differentiate between pump start-up and pump-operating energy or include pump efficiency parameters. This paper outlines an improved method incorporating these parameters that indirectly estimates pump energy consumption and carbon dioxide (CO2) emissions using system performance data. The improved method is applied to data from an office-based RWH system. Comparison of the simple and improved methods identified the former underestimates pump energy consumption and carbon emissions by 60%. Results of the improved method corresponded well to directly measured energy consumption and energy consumption represented 0.07% of an office building's total energy consumption. Consequently, the overall energy consumption associated with RWH systems is a very minor fraction of total building energy consumption

Reliability indicators for water distribution system design: comparison

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.When designing a water distribution system (WDS), it is imperative that the reliability of the network is taken into consideration. It is possible to directly evaluate the reliability of a WDS, although the calculation processes involved are computationally intensive and thus undesirable for some state-of-the-art, iterative design approaches (such as optimization). Consequently, interest has recently grown in the use of reliability indicators, which are simpler and faster to evaluate than direct reliability methods. In this study, two existing reliability indicators, the Todini resilience index and entropy for WDS, are examined by analyzing their relationships with different subcategories of reliability, namely the mechanical (network tolerance to pipe failure) and hydraulic reliability (network tolerance to demand change). The analysis is performed by generating comparable solutions through multiobjective optimization of cost against the chosen indicators using the well known Anytown WDS benchmark as a case study. It is found that WDS solutions with high entropy have increased mechanical reliability, yet are expensive and have poor hydraulic operation and water quality. In contrast, high resilience index networks are relatively cheaper and present reasonable hydraulic operational performance, yet have limited improvement in mechanical reliability. Both indicators appear to be correlated to hydraulic reliability, but each has its own associated disadvantages. Including minimum surplus head as an additional objective in the optimization of the reliability indicators appeared to improve the performance. When optimized together, a trade-off between the two indicators is identified, implying that significantly increasing both simultaneously is not possible, and thus a new indicator is recommended to account for both the mechanical and hydraulic reliability while ensuring reasonable standards of hydraulic operation.This work was supported by the UK Engineering and Physical Science Research Council as part of the Urban Futures Project (EP/F007426/1)

A framework for supporting rainwater harvesting in the UK

Numerous policy vehicles have been introduced in the UK promoting the use of rainwater harvesting (RWH). However, an 'implementation deficit' exists where legislation limits action by failing to provide adequate support mechanisms. This study uses an interdisciplinary approach to construct a framework to address the issue of overcoming this deficit. Evidence bases have identified six deficit categories, which confirm a lack of enabling of stakeholders. Outline recommendations, such as coordinated information provision and reconsideration of incentive schemes are made in relation to these categories to complete the framework for supporting RWH in the UK

Developing a decision support tool for the positioning and sizing of vortex flow controls in existing sewer systems

12th International Conference on Computing and Control for the Water Industry, CCWI2013This is the final version of the article. Available from Elsevier via the DOI in this record.This paper describes the development of a decision support tool for the positioning and sizing of vortex flow controls in existing sewer systems. The tool aims to prioritise the placement of vortex flow controls primarily within subcatchments with the greatest flood consequence rating and maximise the use of unused inpipe volumes during critical rainfall events. The decision support tool is intended for use in catchments where opportunities to implement SuDS and rainwater harvesting to defend against flooding are limited. The decision support tool is envisaged to identify potential strategies which could enhance flood resistance of sewer systems in a cost effective manner. © 2013 The Authors

Improvements in vortex flow control design to increase sewer network flood resistance

Copyright © 2013 IWA7th International Conference on Sewer Processes and Networks (SPN7), Sheffield, UK, 28-30 August 2013Flow controls are used within the water industry to manage the flow through sewer networks by attenuating flows at convenient or critical locations. Many sewer networks, regardless whether the systems have a flow control installed, are predicted to become stressed in the future due to the effects of climate change, population growth and urbanisation. This issue is compounded by the age of the Britain’s sewerage infrastructure as well as the cost and difficulty of replacing and upgrading the infrastructure. Statutory ‘Catchment Flood Management Plans’ have been introduced within the United Kingdom to tackle this issue by better understanding the flow path of flood water on a catchment scale. This paper discusses a method to maximise the use of the current sewerage infrastructure by installing flow controls, meaning a greater volume of the sewer network can be used for stormwater storage. This paper continues by describing a method of increasing a sewer network’s flood resistance by using vortex flow controls with a lower design flow-rate compared to an orifice plate. This paper then concludes by describing three case studies demonstrating the use vortex flow controls when retrofitting sewer networks as well as the impact of implementing the retrofit design method.EPSRCSTREAM IDCHydro Internationa

Association of blood lipids, cortisol and Hemodynamics Under stress: A possible role in early Atherogenesis

Introduction: High blood cholesterol is claimed as a risk factor but recently it is accepted that cholesterol is increased under psychological stress. When raised in blood, cholesterol plays role in atherosclerosis formation; a role which is being debated since last many decades but still various questions is un-answered. Role of stress in early atherogenesis with association to alteration in blood lipids has been proposed but the available literature is scanty on the subject. Objective: To explore the association of alterations in blood lipids, cortisol level and hemodynamics under mental stress in youth with no apparent heart disease. Methodology: 114 male participants were selected from 397 volunteers as per ‘selection criterion’ approved by scientific committee. The volunteers were examined two times: during stress task as ‘stress-study’ and during non-stress period as ‘control’ according to ‘paired sample’ design. Thus, 56.54% apparently healthy subjects were included with exclusion ratio of 43.58%. All experiments were conducted under standard methods at LINAR-Larkana and Physiology Department of Sindh University, Jamshoro. Blood sample were taken between 9.00 am to 12.00 pm. Results: Cortisol, systolic and diastolic blood pressures and heart rate were significantly increased during stress session. Different lipid levels were changed with different significant values. Correlations of some altered lipid levels with raised values of hemodynamics and cortisol detected were positive and significant. Conclusion: Most changes in the level of variables were found prone to be “atherogenic in pattern” due to psychological stress. This work may pave a way for better understanding of relationship in between lipid alterations, mental stress and early atherogenesis. For that further studies are needed.   Key Words: Cholesterol, Hemodynamics, Cortisol, psychological stress

A stochastic sewer model to predict pipe flows and pollutant loads in an urban drainage system

[EN] This work implemented a stochastic sewer model (SIMDEUM-WW) to forecast dry weather sewer flows and pollutant loading, from probabilistic household demand patterns based on information about inhabitants and appliance usage. The probabilistic outputs were fed into MIKE URBAN (DHI) for hydrodynamic and water quality simulations. The MIKE URBAN model consists of a 1D sewer network model. The model was validated against field measurement data and the results show that the SIMDEUM-WW can adequately calculate wastewater and pollutant loading. However, the SIMDEUM-WW was originally calibrated on households in the Netherlands such that errors were observed in the UK application. The uncertainties in actual flow and pollutant loading also contributed to the inaccuracy of modelling results.Addison-Atkinson, W.; Chen, A.; Memon, F.; Hofman, J.; Blokker, M. (2024). A stochastic sewer model to predict pipe flows and pollutant loads in an urban drainage system. Editorial Universitat Politècnica de València. https://doi.org/10.4995/WDSA-CCWI2022.2022.1478

Quantifying flood model accuracy under varying surface complexities

This is the final version. Available on open access from Elsevier via the DOI in this recordData availability: Data will be made available on request.Open Access experimental datasets used in this paper are available at https://zenodo.org/communities/floodinteract/Floods in urban areas which feature interactions between piped and surface networks are hydraulically complex. Further, obtaining in situ calibration data, although necessary for robust simulations, can be very challenging. The aim of this research is to evaluate the performance of a commonly used deterministic 1D-2D flood model, calibrated using low resolution data, against a higher resolution dataset containing flows, depths and velocity fields; which are replicated from an experimental scale model water facility. Calibration of the numerical model was conducted using a lower resolution dataset, which consisted of a simple rectangular profile. The model was then evaluated against a dataset that was higher in spatial resolution and more complex in geometry (a street profile containing parking spaces). The findings show that when the model increased in scenario complexity model performance was reduced, though most of the simulation error was < 10% (NRMSE). Similarly, there was more error in the validated model that was higher in spatial resolution than lower. This was due to calibration not being stringent enough when conducted in a lower spatial resolution. However, overall the work shows the potential for the use of low-resolution datasets for model calibration.Engineering and Physical Sciences Research Council (EPSRC

Nano-antivirals: A comprehensive review

Nanoparticles can be used as inhibitory agents against various microorganisms, including bacteria, algae, archaea, fungi, and a huge class of viruses. The mechanism of action includes inhibiting the function of the cell membrane/stopping the synthesis of the cell membrane, disturbing the transduction of energy, producing toxic reactive oxygen species (ROS), and inhibiting or reducing RNA and DNA production. Various nanomaterials, including different metallic, silicon, and carbon-based nanomaterials and nanoarchitectures, have been successfully used against different viruses. Recent research strongly agrees that these nanoarchitecture-based virucidal materials (nano-antivirals) have shown activity in the solid state. Therefore, they are very useful in the development of several products, such as fabric and high-touch surfaces. This review thoroughly and critically identifies recently developed nano-antivirals and their products, nano-antiviral deposition methods on various substrates, and possible mechanisms of action. By considering the commercial viability of nano-antivirals, recommendations are made to develop scalable and sustainable nano-antiviral products with contact-killing properties