Spatial and numerical analysis of the parameters influencing potential for potable water savings made using rainwater harvesting: case of the Paris agglomeration

2016 ◽  
Vol 30 (1-2) ◽  
pp. 70-76 ◽  
Author(s):  
Ali Belmeziti ◽  
Bernard de Gouvello
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.


2017 ◽  
Vol 18 (4) ◽  
pp. 1497-1504 ◽  
Author(s):  
E. Ghisi ◽  
L. P. Thives ◽  
R. F. W. Paes

Abstract The objective of this study is to assess the investment feasibility analysis of rainwater harvesting in a building located in Brazil. Rainwater was used to supply toilets, cleaning and irrigation. The costs of materials, labour and maintenance were obtained to carry out the economic analysis; the indicators used were the net present value, internal rate of return and payback period. The investment feasibility analysis and the potential for potable water savings were obtained by means of computer simulation. The potential for potable water savings ranged from 26.70% to 64.70%. The net present value, internal rate of return and payback period for the best scenario were, respectively, R$132,801.47, 3.73% per month and 32 months. For the worst scenario the net present value was R$9,451.26, the internal rate of return was 0.91% per month and the payback period was 166 months. Thus, rainwater can be used as a sustainable alternative and be financially feasible.


Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2074 ◽  
Author(s):  
Custódio ◽  
Ghisi

The objective of this study is to evaluate the potential for potable water savings by using rainwater in the residential sector of Joinville, a city located in southern Brazil. Data on roof areas of residential buildings were obtained from the Joinville city council. By considering the roof areas and typologies of residential buildings, representative models were created. The following parameters were used to determine the rainwater tank capacity: the number of dwellers; the total daily water demand per capita; and the rainwater demand. To carry out the simulations for determining the optimal rainwater tank sizes and potential for potable water savings, the computer program Netuno was used to run 33,720 different scenarios. By considering the occurrence percentage for each representative building model (weighted average), the average potential for potable water savings by using rainwater was calculated. The average potential in the central region of Joinville was 18.5% when there is rainwater use only in toilets, and 40.8% when there is rainwater use in toilets and washing machines. The rainwater harvesting system showed a better performance for a rainwater demand equal to 20% of the total daily water demand. The results indicate the necessity to properly size rainwater tank capacities to meet water demands, thereby encouraging more people to adopt rainwater harvesting as an alternative source for non-potable water in buildings. The demand for rainwater should be carefully evaluated, especially in multi-story residential buildings, due to the low availability of roof areas.


Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 930
Author(s):  
Gustavo Rosa ◽  
Enedir Ghisi

This study aimed to evaluate the installation of a system that combines rainwater to wash clothes and greywater to flush toilets in a house located in Florianópolis, southern Brazil. The evaluation consisted of determining the potable water savings, performing a financial analysis, and verifying the possibility of using rainwater and reusing greywater according to the local legislation. The reduction in potable water consumption was determined by comparing the monthly water and sewage bill, before and after installing the system, combining rainwater and greywater. The financial analysis was performed considering the financial benefits, operational costs, costs for installing the system, and local water tariffs. After installing the system, there was a decrease of 38.0% in the monthly potable water consumption, which represents a decrease of 7.00 m3 in the monthly potable water consumption. The payback periods for the old and new water tariffs were equivalent to, respectively, ten years and seven months, and eight years and five months. Both rainwater and greywater had parameters with concentrations higher than the limits established by the legislation. Therefore, the rainwater had to go through a device for discarding the first flush and needed disinfection; and the greywater needed to go through a treatment process. The results indicated that the system combining rainwater and greywater shows significant potential for potable water savings, which can be a good alternative to the preservation of potable water resources. It is important to note that current studies on rainwater use and greywater reuse are mainly related to non-potable purposes, but it was shown herein that rainwater can be used for washing clothes.


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