scholarly journals Modelling Rainwater Harvesting and Greywater Reuse for Tank Size Optimizations

10.29007/zwnv ◽  
2018 ◽  
Author(s):  
Sara Simona Cipolla ◽  
Marco Maglionico

In the light of water shortages, frequently affecting many regions worldwide, domestic rainwater harvesting and greywater reuse systems represent an alternative source to provide non-potable water in buildings, reducing the water demand from mains water supply systems. This study fits this framework providing a methodology, based on a hydraulic/hydrological model developed by means of the EPA’s Storm Water Management Model, which allow optimizing the system design by giving the opportunity to the user to consider different catchments surfaces (impervious, gravel and green roofs), plant's configurations, user’s habits, water end-uses, and climate conditions. The model has used to model a residential building, located in the city of Bologna (Italy), and equipped with a hybrid greywater/rainwater system. Continuous simulations were performed with 13 years daily rainfall data, and the long-term performance of different system combinations were evaluated. The case study showed a non-potable water saving efficiency of 75.86%, which accounts by 26.71% mains water withdrawal. The final goal of this paper is those of presenting the hydrological/hydraulic model that has been used as engine of a calculator tool for sizing and planning hybrid rainwater/greywater systems.

2014 ◽  
Vol 15 (2) ◽  
pp. 248-255 ◽  
Author(s):  
Domniki Stratigea ◽  
Christos Makropoulos

Recent years have seen a growing interest in more distributed approaches towards stormwater management, often integrated with other forms of distributed management of urban water such as water demand management technologies. This paper focuses on the role of green roofs (GR), rainwater harvesting (RWH) and greywater reuse and their integration at the building level. A number of models were developed to simulate these systems, and provide design curves able to simultaneously minimise both total runoff volumes and the amount of potable water used in the building (for irrigation and toilet flushing). The models developed were applied to the design of stormwater infrastructure for the building of the National Gallery, in Athens, Greece. A sensitivity analysis of various model parameters was conducted, with results suggesting, inter alia: (i) a significant decrease of total runoff volumes for rainfalls of medium-to-small return periods; (ii) a significant influence of the plant factor on water requirements (with implications for selecting vegetation for GR in a Mediterranean climate); and (iii) a significant impact of latent heat peaking during the months of June and July. The trade-off, on runoff volumes, between percentage of green roof area and the dimensions of the water storage tank was also investigated. The results suggest that the most preferable solution for conserving potable water was RWH combined with greywater recycling, while for runoff minimisation the best option was the combination of green roof and greywater recycling.


Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 546 ◽  
Author(s):  
Jéssica Kuntz Maykot ◽  
Enedir Ghisi

This article aims to present an economic feasibility and user satisfaction analysis of a rainwater harvesting system in a multi-storey residential building (where there is rainwater to supply toilets) located in Florianópolis, southern Brazil. This research used detailed methods and also considered the opinion and habits of users regarding the use of a rainwater harvesting system. The water end-uses were estimated through questionnaire survey in each flat. The potential for potable water savings was estimated using computer simulations. Simulations were performed using the computer programme Netuno, version 4 and economic feasibility analyses were performed considering different rainwater demands. Analyses associated with the habits of the residents, the satisfaction of users and the importance of saving potable water were also carried out. Showers were responsible for the highest share (54.2%) of water consumption in the flats, followed by the other end-uses: washing machine (21.3%), kitchen tap (9.3%), toilet flush (9.2%) and washbasins (2.6%). The most economically feasible system, which presented lower payback and higher internal rate of return, corresponds to the system sized to supply rainwater only to toilet flushing. Such a system would need a rainwater tank with a capacity smaller than the capacity of the one currently in use. In general, residents expressed satisfaction regarding the rainwater harvesting system installed in the building. The study is important because, besides obtaining water end-uses in the flats, it also investigates the perception of residents related to rainwater harvesting, which has been little explored in the scientific literature.


Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2351 ◽  
Author(s):  
Cureau ◽  
Ghisi

This article aims to estimate the reduction of potable water consumption and sewage generation in the city of Joinville, southern Brazil. Four strategies were considered to promote potable water savings: replacement of conventional toilets with dual-flush ones, greywater reuse, rainwater harvesting, and the combination of these three strategies. Residential, public, and commercial sectors were assessed. The potential for potable water savings ranged from 1.7% to 50.5%, and the potential for sewage generation reduction ranged from 2.1% to 52.1%. The single-family residential sector was the most representative for water savings and sewage generation reduction. The public sector would be the least contributor to such reductions. It was found that in the city of Joinville, for low non-potable water demands, greywater reuse was the most viable strategy to save water. When non-potable demand is high and there is a large catchment area, it is recommended to install rainwater harvesting systems. It was concluded that there is a high potential for potable water savings and reduction of sewage generation if measures were adopted in Joinville, but it is necessary to evaluate which strategy is the most appropriate for each building.


2015 ◽  
Vol 21 (4) ◽  
pp. 623-635 ◽  
Author(s):  
Daniel Słyś ◽  
Agnieszka Stec

Abstract Climate change, improper use of water resources, surface waters pollution as well as increase of water requirements are the results of growing population of people in the world. It causes water deficiency in majority of countries in the world, including Poland. Due to the water pollution advanced technologies for its treatment are in demand, what leads to increase of water price. In this connection, there are more often taken actions to reduce water consumption by using rainwater to flush toilets, wash cars, do laundry or water green areas. This publication presents results of Life Cycle Cost analysis of two variants of water supply systems designed for multi-family residential building situated in Rzeszow. In line with LCC methodology the calculations were made throughout the whole life-cycle of the building considering initial investment outlays intended for construction of water supply system as well as operation and maintenance costs. In the first of analyzed variants it was assumed that the system would be fed by municipal water supply network. In the second variant rainwater harvesting system for domestic use was additionally applied. Rainwater stored in the tank would be used in sanitary installation to flush toilets, what leads to lowering the costs of municipal water purchase, reducing fees for rainwater discharge to sewage system and consequently is beneficial for financial standing of the examined building.


Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 673 ◽  
Author(s):  
Sara Simona Cipolla ◽  
Margherita Altobelli ◽  
Marco Maglionico

this study proposes the results of a research activity devoted to the analysis and development of methodologies, models and strategies, which allow integrating decentralized solutions such as rainwater harvesting, greywater reuse systems, and green technologies in buildings. A methodology based on a hydraulic/hydrological model developed by means of SWMM is presented. It allows estimating the optimal size of the storage tanks, considering the overall efficiency of the system, and calculating the wastewater overflows reduction. This study is carried out within the Work Package three (WP3) of the GST4Water project funded by the Emilia-Romagna Regional Council (Italy) through the European Regional Development Fund 2014–2020 ERDF—ROP.


2020 ◽  
Vol 19 (2) ◽  
pp. 127-134
Author(s):  
Isnardo Arenas-Navarro ◽  
Efrén David Montes ◽  
SofíaMargarita Serrano-Pinilla ◽  
Diego Andrés Rueda-Ordoñez

The access to water is critical in agricultural and livestock production.In the dry season, the water supply systems are under stress and have placed the region of La Mesa de Los Santos(Santander-Colombia) as susceptible to economic impacts due towater shortages, mainly caused by high demand ingrowth population, agriculture and the poultry production.Currently, the poultry production suffers from water shortages and has beensuppliedwith liquid in tanker trucks duringthe dry season, presenting a significant added cost to the farmers. The implementation of a rainwater-harvesting (RWH) system could reduce the water stress on the poultry industrial production of the region. The main objective of this research was to develop a mathematical model to identify the numbers of poultry grown cycles that a rainwater harvesting (RWH) system could potentially feed in an average year of precipitations. The analyses performed here considered daily rainfall data ranged from 2010 to 2018 obtained from the weather stations in La Mesa de Los Santos. The results of this research can be helpful to the entrepreneurs and policymakers by evaluating the importance of water management and the opportunity to take advantage of rainwater as a resource for sustainable poultry production, currently an important alternative to the value chain in the agricultural, livestock and industrial sector of the region.


2014 ◽  
Vol 15 (2) ◽  
pp. 271-277 ◽  
Author(s):  
Liaw Chao-Hsien ◽  
Huang En-Hao ◽  
Chiu Yie-Ru

Green roof systems have been suggested to ease the growing urban environmental problems resulting from rapid urbanization. However, the irrigation of green roofs heavily depends on using precious potable water and consequently generates negative environmental effects. Rainwater has been recommended to address this dilemma, but the design method has not been well developed. In this study, the major design factors of a rainwater harvesting system for green roof irrigation systems are examined, and a simulation-based mathematical model is established to elucidate the correlation between tank volume and system performance. The optimal system design and probability distribution of the potable water replacement rate are also discussed on the basis of a case study of a university building in Keelung, Northern Taiwan. The results show that the optimal tank volume, potable water replacement rate, and probability of exceedance are 9.41 m3, 92.72%, and 88.76% (±1SD), respectively. In addition, the economic performance is identified to be feasible. Hence, the design method has been verified to be a useful tool to ease the urban environmental issues.


Hydrology ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 9
Author(s):  
Md. Rezaul Karim ◽  
B. M. Sadman Sakib ◽  
Sk. Sadman Sakib ◽  
Monzur Alam Imteaz

Despite numerous studies on residential rainwater tank, studies on commercial rainwater tank are scarce. Corporate authorities pay little heed on this sustainable feature. With the aim of encouraging corporate authorities, this study presents the feasibility and economic benefits of rainwater harvesting (RWH) in commercial buildings in the capital city of Bangladesh, where water authority struggles to maintain town water supply. The analysis was conducted using a daily water balance model under three climate scenarios (wet, dry and normal year) for five commercial buildings having catchment areas varying from 315 to 776 m2 and the storage tank capacity varying from 100 to 600 m3. It was found that for a water demand of 30 L per capita per day (lpcd), about 11% to 19% and 16% to 26.80% of the annual water demand can be supplemented by rainwater harvesting under the normal year and wet year climate conditions, respectively. The payback periods are found to be very short, only 2.25 to 3.75 years and benefit–cost (B/C) ratios are more than 1.0, even for building having the smallest catchment area (i.e., 315 m2) and no significant overflow would occur during monsoon, which leads to both economic and environmental benefits. Though the findings cannot be translated to other cities as those are dependent on factors like water price, interest rate, rainfall amount and pattern, however other cities having significant rainfall amounts should conduct similar studies to expedite implementations of widescale rainwater harvesting.


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