scholarly journals Green Infrastructures in Stormwater Control and Treatment Strategies

Proceedings ◽  
2019 ◽  
Vol 48 (1) ◽  
pp. 7
Author(s):  
Bárbara Pereira ◽  
Luís Mesquita David ◽  
Ana Galvão
Keyword(s):  
Suspended Solids ◽  
Peak Flow ◽  
Water Cycle ◽  
Treatment Strategies ◽  
Green Roofs ◽  
Urban Environments ◽  
Urban Water ◽  
Flow Rates ◽  
Filter Strips ◽  
Stormwater Control

Green infrastructures can provide multiple benefits and play an important role in cities’ resilience to extreme stormwater events caused by climate change. Additionally, these techniques can contribute to the protection of transport infrastructures, averting major environmental and economical adversities. Stormwater can be treated through several processes, some processes being more effective than others for specific contaminants. A review of some of the most commonly used green infrastructures (GI) for stormwater management in urban environments was carried out, with emphasis on their efficiency in reducing peak flow rates, runoff volumes and the following pollutants: total suspended solids, heavy metals, total phosphorus and total nitrogen. The GI studied were green roofs, bioretention systems, filter strips, vegetated swales and trenches. In addition to the advantages in the urban water cycle, benefits of amenity and ecosystem services of these GI have also been identified. The discussion of the results and the comparative analysis of GI performance were carried out taking advantage of a table that summarizes the range of percentages of GI efficiency obtained in various studies for the different functions.

scholarly journals Experimenting Transition to Sustainable Urban Drainage Systems – Identifying Constraints and Unintended Processes in a Tropical Highly Urbanized Watershed

2020 ◽  
Author(s):  
Fernando Chapa ◽  
María Pérez ◽  
Jochen Hack
Keyword(s):  
Green Infrastructure ◽  
Water Cycle ◽  
Learning Experience ◽  
Water System ◽  
Urban Environments ◽  
Urban Systems ◽  
Urban Water ◽  
Negative Effects ◽  
Urban Water System ◽  
Local Decision

Green Infrastructure promotes the use of natural functions and processes as potential solutions to reduce negative effects derived from anthropocentric interventions such as urbanization. In cities of Latin America, for example, the need for more nature-sound infrastructure is evident due to its degree of urbanization and degradation of ecosystems, as well as the alteration of the local water cycle. In this study, an experimental approach for implementation of a prototype is presented. The experiment took place in a highly urbanized watershed located in the Metropolitan Area of Costa Rica. Initially, understanding the characteristics of the study area at different scales was achieved by applying the Urban Water System Transition Framework to identify the existing level of development of the urban water infrastructure, and potential future stages. Subsequently, preferences related to spatial locations and technologies were identified from different local decision-makers. Those insights were adopted to identify a potential area for implementation of the prototype. The experiment consisted on an adaptation of the local sewer to act as a temporal reservoir to reduce the effects derived from rapid generation of stormwater runoff. Unexpected events, not considered initially in the design, are reported in this study as a means to identify necessary adaptations of the methodology. Our study shows from an experimental learning-experience that the relation between different actors advocating for such technologies influences the implementation and operation of non-conventional technologies. Furthermore, the perception of security associated to green spaces was found as a key driver to increase the willingness of residents to modify their urban environments. In consequence, those aspects should be carefully considered as factors of designs of engineering elements when they are related to complex socio-ecological urban systems.

scholarly journals Green Roofs Effects on the Urban Water Cycle Components

2014 ◽  
Vol 70 ◽  
pp. 988-997 ◽  
Author(s):  
C. Lamera ◽  
G. Becciu ◽  
M.C. Rulli ◽  
R. Rosso
Keyword(s):  
Water Cycle ◽  
Green Roofs ◽  
Urban Water ◽  
Urban Water Cycle

scholarly journals An Effectiveness Study on the Use of Different Types of LID for Water Cycle Recovery in a Small Catchment

Land ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1055
Author(s):  
Heenyun Kim ◽  
Gunwoo Kim
Keyword(s):  
Peak Flow ◽  
Water Cycle ◽  
Unit Area ◽  
Low Impact Development ◽  
Green Roofs ◽  
Small Catchment ◽  
Permeable Pavements ◽  
Different Types ◽  
Runoff Rate ◽  
Development State

Low-Impact Development (LID) is alleviating the water cycle problems that arise from an increasing impervious surface area caused by urbanization. However, there is insufficient research on the application and analyses of LID techniques that are used for studying the management goals for water cycle restoration. The present study applied various LID techniques, utilizing the stormwater management model (SWMM) in the Naju-Noan Waterfront Zone Construction Project and studying its effects, aiming to restore the runoff that had increased due to urbanization to its pre-development state. The five LID techniques used in the analysis were permeable pavements, bioswales, rainwater gardens, green roofs, and planter boxes, which took up 36.2% of the total area. Our analysis showed that development increased the runoff rate from 39.4% to 62.4%, and LID reduced it to 34.7%. Furthermore, development increased the peak flow from 0.77 m³/s to 1.08 m³/s, and the application of LID reduced it to 0.78 m³/s. An effective reduction in the runoff and peak flow was shown in every recurrence period that was tested, and the bioretention cell type of LID showed the best effectiveness per unit area compared with permeable pavements and green roofs.

scholarly journals Rainwater storage in urban environments using green roofs

La Granja ◽  
2020 ◽  
Vol 32 (2) ◽  
pp. 54-71
Author(s):  
Nelson Andrés López Machado ◽  
Christian Gonzalo Domínguez Gonzalez ◽  
Wilmer Barreto ◽  
Néstor Méndez ◽  
Leonardo José López Machado ◽  
...  
Keyword(s):  
Peak Flow ◽  
Total Duration ◽  
Green Roofs ◽  
Urban Environments ◽  
Peak Time ◽  
Interesting Point ◽  
Soil Matrix ◽  
Bituminous Materials ◽  
Flood Zone ◽  
Runoff Hydrographs

This article discusses the use of green roofs as rainfall water storage in its soil matrix. The methodology is analytical based on mathematical models, where runoff produced in an urban area is compared with current conditions of ordinary roofs with ceramic or bituminous materials as the original scenario, against another where green roofs are used. The study area is located in the Palavecino municipality of Lara state in Venezuela, in the flood zone of Quebrada Tabure. In this research, a quantitative comparison of the direct runoff hydrographs of the proposed scenarios was used, obtaining as a main result the reduction of runoff between 60% and 80% according to the period of return. An interesting point of this research was the incorporation of the routing of hydrographs on the roofs, reducing even more the peak flow over 90%, and delaying the peak time of the generated hydrographs between 10 and 12 minutes while the total duration of the hydrographs increase more than three times.

scholarly journals The Urban Water Cycle as a Planning Tool to Monitor SARS-CoV-2: A Review of the Literature

2021 ◽  
Vol 13 (16) ◽  
pp. 9010
Author(s):  
Carlos Peña-Guzmán ◽  
María Andrea Domínguez-Sánchez ◽  
Manuel Rodríguez ◽  
Rama Pulicharla ◽  
Karen Mora-Cabrera
Keyword(s):  
Wastewater Treatment Plants ◽  
Water Cycle ◽  
Treatment Strategies ◽  
Global Scale ◽  
Urban Water ◽  
The European Union ◽  
Monitoring Strategies ◽  
The Usa ◽  
And Control ◽  
Urban Water Cycle

COVID-19 is a terrible virus that has impacted human health and the economy on a global scale. The detection and control of the pandemic have become necessities that require appropriate monitoring strategies. One of these strategies involves measuring and quantifying the virus in water at different stages of the Urban Water Cycle (UWC). This article presents a comprehensive literature review of the analyses and quantifications of SARS-CoV-2 in multiple UWC components from 2020 to June 2021. More than 140 studies worldwide with a focus on industrialized nations were identified, mainly in the USA, Australia, and Asia and the European Union. Wastewater treatment plants were the focus of most of these studies, followed by city sewerage systems and hospital effluents. The fewest studies examined the presence of this virus in bodies of water. Most of the studies were conducted for epidemiological purposes. However, a few focused on viral load and its removal using various treatment strategies or modelling and developing strategies to control the disease. Others compared methodologies for determining if SARS-CoV-2 was present or included risk assessments. This is the first study to emphasize the importance of the various individual components of the UWC and their potential impacts on viral transmission from the source to the public.

scholarly journals Chemical oxygen demand (COD) fractionation for process modelling considerations and optimization

2021 ◽  
Author(s):  
◽  
Thandeka Yvonne Sthembile Jwara
Keyword(s):  
Wastewater Treatment ◽  
Water Resources ◽  
Chemical Oxygen Demand ◽  
Nutrient Removal ◽  
Suspended Solids ◽  
Water Cycle ◽  
Oxygen Demand ◽  
Urban Water ◽  
Do Concentration ◽  
Urban Water Cycle

Wastewater treatment is a critical chain in the urban water cycle. Wastewater treatment prevents the toxic contamination of water bodies. The notable consequences of contamination are the loss of aquatic life, upsurge of eutrophication due to nutrient overload, and potential loss of human life as a result of waterborne diseases. Wastewater works (WWW) are therefore an intrinsic component of protecting the urban water cycle and ensuring that water resources are preserved for future generations. The operation of a WWW is subject to compliance with the national legislative requirements imposed by the Department of Water and Sanitation (DWS) to ensure the preservation of water resources. These requirements oblige water and sanitation departments to employ innovative design, control and optimization of WWW. Wastewater modelling packages have presented the opportunity to simulate the wastewater treatment processes in order to maintain and sustain legal compliance with the DWS. The successful implementation of a simulation package for wastewater process optimization and modelling depends on an accurate characterization also known as fractionation of the organic fractions of the WWW influents. This thesis is a result of a comprehensive study reported for Darvill wastewater work. Darvill WWW is a 60 ML/D plant which has been receiving flows of up to 120 ML/D. The importance of the study was to motivate for the upgrade of the wastewater work to account for the increased hydraulic, organic and nutrient loading into the plant. The study looked at the application of the World Engine for Simulation and Training (WEST) and all studies required to generate data that will serve as input with the understanding the current state of Darvill WWW in terms of performance. The study presents the fractionation outcomes of the primary wastewater effluent organic matter as chemical oxygen demand (COD) and the performance by assessing the biological nutrient removal process (BNR) using BNR efficiencies in addition to the development of the Darvill WWW WEST model with the aid of the probabilistic fractionator. The fractionation was achieved through the oxygen uptake rate experiments using the respirometry method. Experiments yielded the following results: biodegradable COD (bCOD) (70.5%) and inert COD (iCOD) (29.5%) of the total COD. Further characterization of the bCOD and iCOD yielded the readily biodegradable fraction (SS) at 75%, slowly degradable (XS) at 25%, particulate inert (XI) was 50.8% and the inert soluble SI at 49.2%. The COD fractions were used and served as input to the development and evaluation of the Darvill WEST model. Calculations of BNR efficiencies were used to evaluate the effects of high inflow to the biological treatability of the activated sludge for the period September 2016 - November 2017. It was found that at inflows above design capacity, the nutrient removal efficiency reduced from an expected 80-90% to an average of 40% with an average soluble reactive phosphorus (SRP) removal efficiency being 64%. A data input file for the period of January – June 2016 was created to serve as input into WEST to develop a baseline average model for the Darvill WWW plant. The model results predicted a mixed liquor suspended solids (MLSS) concentration of 6475 mg/L for the plant during the study period this was comparable with the plant MLSS concentration of 6700 mg/L at the time which was above the design concentration of 4500 mg/L. This was largely due to the plant operating under nutrient overload conditions. The final effluent (FE) concentration in the defractionation model was found to be COD = 41.28 mg/L, ammonia (NH3) = 22.02 mg/L, Total Suspended Solids (TSS) = 32 mg/L, SRP = 2.16 mg/L. Most of these results were expectedly non-compliant to the discharge limits imposed by the DWS with the exception of COD. The plant FE measurements were COD = 45.1 mg/L, NH3 = 3.4 mg/L, TSS = 20.9 mg/L, SRP= 6.67 mg/L. The COD and TSS prediction were comparable to the model prediction however there were limitations in the models ability to predict NH3 and SRP. The model does not account for changes in dissolved oxygen (DO) and temperature as these parameters are kept constant for the purpose of this study. The model assumes a temperature of 20 oC and a DO concentration of 2 mg/L for the aerobic reactor, 0.01 mg/L for the anaerobic reactor and 0.1 mg/L for the anoxic reactor. The model assumes that with the nutrient overload, oxygen compensation occurs within the reactor to maintain a constant DO concentration within the units. This limits the model in the prediction of actual instance where the overload would deplete the DO and where other competing reactions would give rise to greater non-compliances as well as biological growth’s impairment due to cold weather conditions.

Water footprint calculation: application to urban water cycle

2016 ◽  
Vol 10 (3) ◽  
pp. 213-216
Author(s):  
Y. Penru ◽  
D. Antoniucci ◽  
M. J. Amores Barrero ◽  
C. Chevauché
Keyword(s):  
Water Footprint ◽  
Water Cycle ◽  
Urban Water ◽  
Urban Water Cycle

Suspended Solids in and Turbidity of Runoff from Green Roofs

2011 ◽  
Vol 13 (sup1) ◽  
pp. 179-193 ◽  
Author(s):  
Susan Morgan ◽  
Isam Alyaseri ◽  
William Retzlaff
Keyword(s):  
Suspended Solids ◽  
Green Roofs

scholarly journals The benefits of planar circular mouths on suction feeding performance

2012 ◽  
Vol 9 (73) ◽  
pp. 1767-1773 ◽  
Author(s):  
Tyler Skorczewski ◽  
Angela Cheer ◽  
Peter C. Wainwright
Keyword(s):  
Prey Capture ◽  
Peak Flow ◽  
Mouth Opening ◽  
Suction Feeding ◽  
Flow Rates ◽  
Computational Fluid Dynamics Simulations ◽  
Enhance Efficiency ◽  
And Performance ◽  
Dynamics Simulations ◽  
Hydrodynamic Effects

Suction feeding is the most common form of prey capture across aquatic feeding vertebrates and many adaptations that enhance efficiency and performance are expected. Many suction feeders have mechanisms that allow the mouth to form a planar and near-circular opening that is believed to have beneficial hydrodynamic effects. We explore the effects of the flattened and circular mouth opening through computational fluid dynamics simulations that allow comparisons with other mouth profiles. Compared to mouths with lateral notches, we find that the planar mouth opening results in higher flow rates into the mouth and a region of highest flow that is positioned at the centre of the mouth aperture. Planar mouths provide not only for better total fluid flow rates through the mouth but also through the centre of the mouth near where suction feeders position their prey. Circular mouths are shown to provide the quickest capture times for spherical and elliptical prey because they expose the prey item to a large region of high flow. Planar and circular mouths result in higher flow velocities with peak flow located at the centre of the mouth opening and they maximize the capacity of the suction feeders to exert hydrodynamic forces on the prey.

Green roof hydrologic performance and modeling: a review

2013 ◽  
Vol 69 (4) ◽  
pp. 727-738 ◽  
Author(s):  
Yanling Li ◽  
Roger W. Babcock
Keyword(s):  
Peak Flow ◽  
Green Roof ◽  
Field Measurements ◽  
Green Roofs ◽  
Economic Benefits ◽  
Design Parameters ◽  
Technical Literature ◽  
Factors Affecting ◽  
Model Soil ◽  
Runoff Volume

Green roofs reduce runoff from impervious surfaces in urban development. This paper reviews the technical literature on green roof hydrology. Laboratory experiments and field measurements have shown that green roofs can reduce stormwater runoff volume by 30 to 86%, reduce peak flow rate by 22 to 93% and delay the peak flow by 0 to 30 min and thereby decrease pollution, flooding and erosion during precipitation events. However, the effectiveness can vary substantially due to design characteristics making performance predictions difficult. Evaluation of the most recently published study findings indicates that the major factors affecting green roof hydrology are precipitation volume, precipitation dynamics, antecedent conditions, growth medium, plant species, and roof slope. This paper also evaluates the computer models commonly used to simulate hydrologic processes for green roofs, including stormwater management model, soil water atmosphere and plant, SWMS-2D, HYDRUS, and other models that are shown to be effective for predicting precipitation response and economic benefits. The review findings indicate that green roofs are effective for reduction of runoff volume and peak flow, and delay of peak flow, however, no tool or model is available to predict expected performance for any given anticipated system based on design parameters that directly affect green roof hydrology.

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