A method for sizing first flush water diverters tanks in rainwater harvesting systems

2009 ◽  
pp. 311-314
Author(s):  
Gonzalo López-Patiño ◽  
F Martínez-Solano ◽  
P López-Jiménez ◽  
Vicente Fuertes-Miquel
Keyword(s):  
Rainwater Harvesting ◽  
First Flush ◽  
Harvesting Systems

Analysis of Fiber Filter Media after 6 Years of Use as a First Flush Filter

2011 ◽  
Vol 695 ◽  
pp. 93-96
Author(s):  
Ree Ho Kim ◽  
Jung Hun Lee ◽  
Sang Ho Lee ◽  
Hana Kim
Keyword(s):  
Water Quality ◽  
Ion Exchange ◽  
New Media ◽  
Rainwater Harvesting ◽  
Quality Parameters ◽  
First Flush ◽  
Filter Media ◽  
Harvesting Systems ◽  
Fiber Filter

Pollutants in rainwater often cause problems such as non-point source pollutant and deterioration of collected water quality in rainwater harvesting systems. Fiber filter media have been developed to resolve these problems by removing pollutants in rainwater by filtration and ion-exchange mechanisms. They have been also successfully applied for the treatment of first-flush rainwater. However, little information is available on the long-term efficiency and the lifetime of the fiber filter media. In this study, new and used fiber filter media were compared in terms of their filterability and ion-exchange capability. The used filter media samples were taken from a first flush filter in a rainwater harvesting system located in an elementary school in Kyonggi-Do. They were used from 2005 to 2010 without any replacement or cleaning. Water quality parameters of an inflow and outflow in the first flush filter were analyzed to quantify the on-site treatment efficiency of the used media. It was shown that the turbidity was removed by approximately 60% and COD was partly removed. The removal efficiency of particles by the used media was similar to that by the new media. Nevertheless, the removal efficiencies of nitrogen and phosphorous by the used media were substantially reduced when compared with the new media. This suggests that the fiber filter media should be periodically replaced to maintain high removals of nutrients. On the other hand, they can be used for more than 6 years if their primary purpose is to removal particles.

scholarly journals Knowledge of measures to safeguard harvested rainwater quality in rural domestic households

2009 ◽  
Vol 8 (2) ◽  
pp. 334-345 ◽  
Author(s):  
David Baguma ◽  
Willibald Loiskandl ◽  
Ika Darnhofer ◽  
Helmut Jung ◽  
Michael Hauser
Keyword(s):  
Rainwater Harvesting ◽  
Water Harvesting ◽  
First Flush ◽  
Waterborne Diseases ◽  
Subsequent Growth ◽  
Adequate Care ◽  
Harvesting Systems ◽  
Improve Water Quality ◽  
Rainwater Quality ◽  
Rainwater Tanks

Given the possibility of waterborne diseases caused by inappropriate rainwater harvesting systems, a survey was conducted in Uganda to assess existing knowledge of both physical and non-physical measures that safeguard harvested rainwater. Households who had received rainwater tanks were assessed on issues related to harvested rainwater quality. The study shows that 84% of respondents were aware of various sources of rainwater contamination, but only 5% were aware that they needed to adjust use of rainwater, depending on whether they cleaned the tank or not. Most of the respondents were not aware that gutter cleaning was necessary to improve water quality. Indeed, as the water from the collection surface is channelled through gutters, a number of measures need to be taken to control the entry of contaminations and subsequent growth of pathogens in the tank, e.g. first flush diverts, installation of filters, chemical use and mesh cleaning. The majority, however, did not take adequate care of the gutters and this impacts on health and social livelihood. Overall, the findings emphasize the need to provide more information to households when installing water harvesting tanks to ensure that the harvested rainwater is of high quality.

scholarly journals A Comparison of Methods to Address Anaerobic Conditions in Rainwater Harvesting Systems

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3419
Author(s):  
Kathy DeBusk Gee ◽  
Daniel Schimoler ◽  
Bree T. Charron ◽  
Mitch D. Woodward ◽  
William F. Hunt
Keyword(s):  
Arid Regions ◽  
Potable Water ◽  
Rainwater Harvesting ◽  
First Flush ◽  
Storage Tanks ◽  
Anaerobic Conditions ◽  
Rainfall Characteristics ◽  
Usage Patterns ◽  
Harvesting Systems ◽  
Semi Arid

Although historically used in semi-arid and arid regions, rainwater harvesting (RWH) systems have increasingly been used in non-arid and humid regions of the world to conserve potable water and mitigate stormwater runoff. Rainfall characteristics and usage patterns of stored rainwater are distinctly different in (semi-)arid and humid regions, thus presenting a unique set of challenges with respect to their utilization. Coupled with infrequent use, the addition of nitrogen and organic matter via pollen during the spring season can lead to anaerobic conditions within storage tanks, which hinders nitrogen removal, gives stored water an offensive odor, and ultimately discourages use of the water. This study evaluated three measures that can be implemented for new and existing RWH systems to prevent the development of anaerobic conditions within storage tanks: first flush diversion, simulated use, and the continuous circulation of stored water. Study findings indicate that preventing anaerobic conditions via simulated use and recirculation (1) does not necessarily remedy the issue of poor aesthetics within rainwater storage tanks, and (2) can decrease the water quality benefits provided by these systems. Rather, preventing the introduction of pollen and particulate matter to the storage tank via a first flush diverter and minimizing disturbance of settled material in the tank appear to be the most effective methods of addressing the poor aesthetics and odor problems associated with anaerobic conditions.

scholarly journals Dynamic Release of Solutes from Roof Bitumen Sheets Used for Rainwater Harvesting

Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3496
Author(s):  
Uri Nachshon ◽  
Meni Ben-Hur ◽  
Daniel Kurtzman ◽  
Roee Katzir ◽  
Lior Netzer ◽  
...  
Keyword(s):  
Electric Conductivity ◽  
Rainwater Harvesting ◽  
Urban Environments ◽  
First Flush ◽  
Degradation Processes ◽  
Harvesting Systems ◽  
Series Of Experiments ◽  
Inorganic Solutes ◽  
The Impact

Bitumen waterproof sheets are widely used to seal building roofs. Previous works have focused on the mechanical-physical properties of bitumen sheets, as well as their aging and degradation processes, and their impact on sealing properties of the buildings. Due to a growing need over recent years to use rooftops in urban environments for rainwater harvesting purposes, it is highly important to better characterize the quality of the harvested water from the bitumen covered roofs, and to shed more light on the impact of bitumen degradation processes on the release of various components to the harvested roof water. In the present study, the extracted organic and inorganic solutes from bitumen-covered roofs by water flow on the bitumen sheets were examined through a series of experiments, including measurements from the roofs of buildings in the center of Israel during the winter of 2019–2020. The results indicated high levels of organic and inorganic solute loads in the roof water during the first flush of the first rain of the winter, with maximal electric conductivity readings at the order of 4 dS/m. However, it was shown that following the first flush, a ~20 mm of cumulative rainfall was sufficient to wash off all the summers’ accumulated solutes from the roof. After this solute flushing of the roof, harvested rainwater along the winter was of good quality, with electric conductivity readings in the range of 0.04–0.85 dS/m. Moreover, it was shown that bitumen sheets which were exposed to direct sun radiation emitted greater loads of solutes, likely a result of elevated aging and degradation processes. The findings of the present research point to the need to find efficient ways to isolate roof bitumen sheets from direct sun radiation and to design rainwater harvesting systems that will not collect the water drained from the first flush.

Sign in / Sign up

Export Citation Format

Share Document