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.

scholarly journals An Analysis of the Effectiveness of Two Rainwater Harvesting Systems Located in Central Eastern Europe

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 458 ◽  
Author(s):  
Agnieszka Stec ◽  
Martina Zeleňáková
Keyword(s):  
Sensitivity Analysis ◽  
Net Present Value ◽  
Rainwater Harvesting ◽  
Payback Period ◽  
Practical Aspect ◽  
Financial Ratios ◽  
Present Value ◽  
Toilet Flushing ◽  
Harvesting Systems ◽  
The Impact

Decentralized water systems are perceived as solutions that not only save water, but also as a way to partially or completely become independent from centralized suppliers. Taking this into account, an analysis of the effectiveness of rainwater harvesting systems (RWHS) for toilet flushing in existing academic facilities located in Poland and in Slovakia was carried out. The tests took into account the different volumes of storage tanks collecting rainwater. On the basis of two financial ratios, namely Net Present Value and Discounted Payback Period, the profitability of these systems was also assessed. The research was extended by the sensitivity analysis, which allowed determination of the impact of changes in individual cost components on the financial effectiveness of the investments considered. The results obtained clearly showed that the implementation of RWHS in the dormitory in Rzeszów was unprofitable for all tank capacities tested, and the payback period significantly exceeded the period of 30 years accepted for the analysis. Completely different results were obtained for RWHS in a dormitory located in the city of Košice, for which the financial ratios NPV (Net Present Value) and DPP (Discounted Payback Period) were very favorable. It was also confirmed by the results of the sensitivity analysis. The use of rainwater for toilet flushing caused that it was possible to achieve water savings of an average of 29% and 18%, respectively, for facilities located in Slovakia and Poland. The results of the research have a practical aspect and can provide an indication for potential investors and managers of academic facilities, similar to those analyzed in the article. Taking into account that in many countries water and sewage rates are significantly higher than in Poland and Slovakia, the cost-effectiveness of using the analyzed installation options in these countries could be even higher.

scholarly journals A Hybrid Tool for Visual Pollution Assessment in Urban Environments

2019 ◽  
Vol 11 (8) ◽  
pp. 2211 ◽  
Author(s):  
Khydija Wakil ◽  
Malik Asghar Naeem ◽  
Ghulam Abbas Anjum ◽  
Abdul Waheed ◽  
Muhammad Jamaluddin Thaheem ◽  
...  
Keyword(s):  
Pollution Assessment ◽  
Observation Point ◽  
Urban Environments ◽  
Policy Makers ◽  
Complex Decision Making ◽  
Complex Decision ◽  
Developed World ◽  
The Impact ◽  
Reliable Methods

With increasing focus on more nuanced aspects of quality of life, the phenomenon of urban visual pollution has been progressively gaining attention from researchers and policy makers, especially in the developed world. However, the subjectivity and complexity of assessing visual pollution in urban settings remain a challenge, especially given the lack of robust and reliable methods for quantification of visual pollution. This paper presents a novel systematic approach for the development of a robust Visual Pollution Assessment (VPA) tool. A key feature of our methodology is explicit and systematic incorporation of expert and public opinion for listing and ranking Visual Pollution Objects (VPOs). Moreover, our methodology deploys established empirical complex decision-making techniques to address the challenge of subjectivity in weighting the impact of individual VPOs. The resultant VPA tool uses close-ended options to capture the presence and characteristics of various VPOs on a given node. Based on these inputs, it calculates a point based visual pollution scorecard for the observation point. The performance of the VPA tool has been extensively tested and verified at various locations in Pakistan. To the best of our knowledge, this is the first such tool, both in terms of quantitative robustness and broad coverage of VPOs. Our VPA tool will help regulators in assessing and charting visual pollution in a consistent and objective manner. It will also help policy makers by providing an empirical basis for gathering evidence; hence facilitating evidence-based and evidence-driven policy strategies, which are likely to have significant impact, especially in the developing countries.

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.

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

scholarly journals A Review of Roof and Pond Rainwater Harvesting Systems for Water Security: The Design, Performance and Way Forward

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3163
Author(s):  
Husnna Aishah Zabidi ◽  
Hui Weng Goh ◽  
Chun Kiat Chang ◽  
Ngai Weng Chan ◽  
Nor Azazi Zakaria
Keyword(s):  
Urban Areas ◽  
Rainwater Harvesting ◽  
Water Security ◽  
Small Scale ◽  
Rapid Urbanization ◽  
Harvesting Systems ◽  
Alternative Water ◽  
The Many ◽  
Equatorial Climate

Rapid urbanization, population explosion and climate change have threatened water security globally, regionally and locally. While there are many ways of addressing these problems, one of the innovative techniques is the recent employment of Sustainable Urban Drainage Systems (SUDS) which include rainwater harvesting systems (RWHS). Therefore, this paper reviews the design and component of two types of RWHS, the namely roof harvesting system (RHS) and the pond harvesting system (PHS). The performance in terms of quantity and quality of collected rainwater and energy consumption for RWHS with different capacities were evaluated, as well as the benefits and challenges particularly in environmental, economic and social aspects. Presently, the RHS is more commonly applied but its effectiveness is limited by its small scale. The PHS is of larger scale and has greater potentials and effectiveness as an alternative water supply system. Results also indicate the many advantages of the PHS especially in terms of economics, environmental aspects and volume of water harvested. While the RHS may be suited to individual or existing buildings, the PHS has greater potentials and should be applied in newly developed urban areas with wet equatorial climate.

Rainwater harvesting - an alternative for securing food production under climate variability

2004 ◽  
Vol 49 (7) ◽  
pp. 157-163 ◽  
Author(s):  
Q. Zhu ◽  
Y. Li
Keyword(s):  
Climate Variability ◽  
Food Production ◽  
Rainwater Harvesting ◽  
Farming Practices ◽  
Rainfed Agriculture ◽  
Harvesting Systems ◽  
Negative Impacts ◽  
Dry Farming ◽  
The Impact ◽  
Artificial Water

Food insecurity is still a challenge in some remote and mountainous areas in China. When studying the impact of climate variability on food production, we should pay even more attention to the rainfed area. This is because the larger part of agriculture is the rainfed one and climate variability has more negative impacts on the rainfed agriculture than on the irrigated one. The traditional dry farming practices based on the principle of storing as much rain in the soil as possible and making best use of soil water could not bridge the gap between the time that the crop needs water and the time that rain occurs, so its effects on enhancing food production under climate variability is limited. Combining artificial water supply from rainwater harvesting systems with the traditional dry farming practices is an innovation in water management in rainfed agriculture. Experiences in the recent two decades indicate that rainwater harvesting irrigation can well mitigate the drought caused by the climate variability and bring the rainfed agriculture to a new level.

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