Search results

This paper aims to associate two fields of research: circular economy and the restoration of water cycle through the implementation of rainwater catchment systems in urban zones.

This study considers the case of the metropolitan zone of Guadalajara, México. This urban concentration is the second largest in Mexico. It faces floods each year with a cost of over US$26m, while demand of water has a production cost over US$24m. At the same time, the aquifers are drying due to uncontrolled urbanization and increasing the impervious area over the recharge zones. In addition, rainwater is combined with wastewater, elevating the cost of the wastewater treatment because the amount and quality of water to treat exceeds the systems’ capacity. This situation causes floods and decreases the availability of ground water. These problems are reflected in the imbalance of parameters of water cycle and a new approach is needed. The circular economy model can help to preserve one of our most vital resources. Scarcity is already so pronounced that we cannot reach many of our desired economic, social and environmental goals. Technologies that help balance supply and demand can also help water (both stock and flow) to become part of a circular model. To prove this, the authors present a hypothetical scenario based on a pilot project and a basin modeling of Guadalajara, Mexico.

Through this paper, it is possible to demonstrate that rainwater harvesting can play an important role in circular economy. Using the rainwater catchment systems, the cost of damages caused by floods could be decreased, the demand of water could be reduced, cost of production can be reduced, the aquifers can be recharged and the wastewater treatments can be improved.

Few papers have been developed to associate two fields of research (circular economy and the restoration of water cycle), using rainwater catchment systems as the central element.

The purpose of this paper is to provide a review of the technology, design and application of rainwater harvesting (RWH) systems in a UK context and identify areas of research and development.

A comprehensive range of literature from 1978‐2010 is reviewed and divided into the following sections: history, application in developed countries, benefits of RWH, system categories and components, storage capacity, rainwater quality and factors influencing the use of RWH systems.

This paper provides a useful source of information relating to the potential benefits of RWH systems, different types of system and components used to supply non potable water. To ensure the potential of RWH systems in the UK is realized, an integrated approach to their application is required. This may improve the financial viability of these systems and sustainability credentials but requires further research.

It is not an exhaustive list of publications but attempts to draw on major sources of literature which catalogue the development and design of RWH systems. Current sources of literature are also identified which identify various factors influencing the future development and application of rainwater systems.

The paper provides practitioners with an initial basis for evaluating or undertaking the initial design of RWH systems.

The study provides historical context for the recent and ongoing development of RWH. In particular areas of further research and development are identified to ensure the potential of RWH systems are realized in the future.

The effects of population growth in the developing world and climate change have increased the stress on available water resources. The majority of Rajshahi city, Bangladesh, is facilitated with groundwater withdrawal. As Bangladesh is a country of monsoon climate, reserved rainwater can be contributed as an alternative to extracted groundwater. This study aims to develop a framework for rooftop rainwater harvesting (RRWH) for domestic purposes and estimate the appropriate size of the storage tanks and their costs required to fulfill the annual drinking and cooking water demands through RRWH in Rajshahi city of Bangladesh.

A total of 100 single-story residential dwellings with varying rooftop areas were surveyed for the projection of RRWH potential. The relationship between the size and cost of a water tank and the rooftop areas of different houses is expressed using a general mathematical equation. Cost estimates for the proposed RRWH system for all houses have been completed, and a cost model illustrating the relationship between rooftop or catchment area and associated cost of RRWH system has been developed.

This study reveals that a maximum of 110.75 m³/year rainwater can be collected from a 100 m² rooftop area of Rajshahi city. Moreover, this study finds that such harvesting of rainwater can reduce municipal water supply to the extent of almost 75%. Water samples collected from rooftops also revealed that if germs were removed through bacteria treatment, the collected rainwater potentially can be used for drinking and cooking purposes.

The novelty of this study is that it focused mainly on how significant RRWH can be to meet people’s daily required amount of water for household purpose and ascertain the cost reduction using the RWH method. This paper also is unique as it assessed the volume of the storage tank that is sufficient to distribute the necessary amount of water for drinking and cooking purpose as a sustainable alternative source in the dry season.

The new campus of Tianjin University was designed, built and now operates following a green and sustainable concept. The campus’ eco-friendly water environment was formed by establishing a water recycling system. The campus is divided into three drainage sections based on the masterplan. Each drainage section adopts different methods of collecting, utilizing and discharging water according to specific conditions, aimed at achieving both high drainage capability and the efficient utilisation of rainwater. The campus was designed so runoff pollution is reduced through the utilisation of low-impact development methods, ensuring the quality of the recharge water. Through studying the fundamentals of treatment measures and models for simulating water quality, water circulation, constructed wetlands and pollution control of rain runoff, parameters for efficient water recycling could be mathematically forecast, ensuring that stakeholders can be continuously engaged in improving and preserving the water quality of landscaped water on campus. The overall system integrates a variety of measures being implemented into one cohesive entity, which contributes to establishing the sustainable and healthy water cycling system of the green campus.

Rough estimations of water gain through greywater reuse and rainwater harvesting together with energy recovery from wastewater generated from a fictitious eco-city of population 100,000 located in Istanbul, Turkey form the main framework of the study. As such, the highly important concept of water–energy nexus will be emphasised and domestic wastewater will be partly considered for water recycling and the rest for energy recovery. The paper aims to discuss these issues.

Distribution of daily domestic water consumption among different household uses and the population in the residential area are the two governing parameters in the practical calculation of daily wastewater generated. Therefore, domestic wastewater will be initially estimated based on population, and in turn, the amount of greywater will be found from the per cent distribution of water use. After segregation of greywater, the energy equivalency of the rest of the wastewater, known as blackwater, will further be calculated. Besides, the long-term average precipitation data of the geographical location (Istanbul) are used in determining safe and sound rainwater harvesting. Harvesting is considered to be only from the roofs of the houses; therefore, surface area of the roofs is directly taken from an actual residential site in Turkey, housing the same population which is constructed in four stages. Similarly, the fictitious eco-city in Istanbul is assumed to be constructed in a stage-wise manner to resemble real conditions.

The water consumption of the fictitious eco-city ABC is considered as 15,000 m³/day by taking the unit water consumption 150 L/capita.day. Therefore, total water savings through on-site reuse and reuse as irrigation water (9,963 m³/day) will reduce water consumption by 64 per cent. Minimum 40 per cent water saving is shown to be possible by means of only greywater recycling and rainwater harvesting with a long-term average annual precipitation of 800 mm. The energy recovery from the rest of the wastewater after segregation of greywater is calculated as 15 MWh/day as electricity and heat that roughly correspond to electricity demand of 1,300 households each bearing four people.

A fictitious eco-city rather than an actual one located in Istanbul is considered as the pilot area in the study. So far, an eco-city with population around 100,000 in Turkey does not exist. An important implication relates to rainwater harvesting. The amount of safe water to be gained through precipitation is subject to fluctuations within years and, thus, the amount of collected rainwater will highly depend on the geographical location of such an eco-city.

The study covering rough calculations on water savings and energy recovery from domestic wastewater will act as a guide to practitioners working on efficient water management in the eco-cities, especially in those that are planned in a developing country.

Practising water–energy nexus in an eco-city of population 100,000 regarding water savings and energy recovery from wastewater forms the originality of the study. Sustainable water use and energy recovery from wastewater are among the emerging topics in environmental science and technology. However, safe and sound applications are lacking especially in the developing countries. Guiding these countries with practical calculations on both water gain and energy recovery from wastewater (blackwater) is the value of the work done. Moreover, Istanbul is deliberately selected as a case study area for various reasons: its annual rainfall represents the worlds’ average, it is one of the most crowded megacities of the world that supply water demand from the surface water reservoirs and the megacity has not yet significantly increased wastewater reuse and recycling practices.

This study provides a performance analysis of using a rainwater harvesting system (RWHS) to supply water for toilet flushing and garden watering, with reference to a student accommodation hall in the University of Nottingham Malaysia in Semenyih, Selangor, Malaysia. Three different models were used in this analysis, in which the monthly analysis was based on the mass-balance approach, while the daily analysis was based on the yield before spillage and yield after spillage algorithms to define the tank release rule based on different sizes of storage tank (i.e. 3, 5, 7 and 10 m³). The performances of the various storage tanks were presented for water saving and reliability. The monthly analysis found promising results of collectable water on the demand, in which the average reliability is higher than 50%. Also, the daily water balance simulation verified the results from the monthly analysis. A cost analysis was performed that the best storage rainwater harvesting tank size was 10 m³ for the combined demand of toilet flushing and garden watering. Based on the findings, the proposed implementation of RWHS in the chosen campus university was reliable, not only environmentally beneficial but also economically viable.

The purpose of this paper is to develop a case study of niche governance to analyze the governance of rainwater systems in the Amazon.

A visualization of the interactions of stakeholders was made with the use of social network analysis, where data were collected through interviews to experts from the region. A framework based on niche management and the safe, resilient and sustainable (Safe and SuRe) principles were used to interpret the results.

The work identifies key players and issues influencing governance for the implementation of rainwater systems; and capture of decision-making powers by agents making evident redundancies in the management of rainwater in the region; highlighting issues of lack of inclusion in the decision-making process, planning and implementation; threatening the sustainability, resilience and governance of rainwater systems in Belem.

Methodologically, this work is the first of its kind for the amazon and contributes to the exploration of tools and frameworks to assess governance in the implementation of rainwater systems.

This study aims to provide and illustrate the application of a framework for conducting techno-economic analyses (TEA) of early-stage designs for net-zero water and energy, single-family homes that meet affordable housing criteria in diverse locations.

The framework is developed and applied in a case example of a TEA of four designs for achieving net zero-water and energy in an affordable home in Saint Lucie County, Florida.

Homes built and sold at current market prices, using combinations of well versus rainwater harvesting (RWH) systems and grid-tied versus hybrid solar photovoltaic (PV) systems, can meet affordable housing criteria for moderate-income families, when 30-year fixed-rate mortgages are at 2%–3%. As rates rise to 6%, unless battery costs drop by 40% and 60%, respectively, homes using hybrid solar PV systems combined with well versus RWH systems cease to meet affordable housing criteria. For studied water and electricity usage and 6% interest rates, only well and grid-tied solar PV systems provide water and electricity at costs below current public supply prices.

This article provides a highly adaptable framework for conducting TEAs in diverse locations for designs of individual net-zero water and energy affordable homes and whole subdivisions of such homes. The framework includes a new technique for sizing storage tanks for residential RWH systems and provides a foundation for future research at the intersection of affordable housing development and residential net-zero water and energy systems design.

Of all the natural disasters, drought is the most gradual and the most hard to predict. However, this insidious disaster continually affects the lives and livelihoods of farmers living in drought-affected areas. The northwestern part of Bangladesh is recognized as being more severely affected by drought than the rest of the country, as drought is a recurring event in this area. It has substantial impacts on agriculture and causes great suffering for farmers – in particular, poor and small farmers, who are more vulnerable to drought. Therefore, this study tries to illustrate farmers’ existing coping practices with regard to drought. It also addresses their prioritized adaptation practices, which are based on local context and available resources. This study not only focuses on the implementation of these adaptation practices from the national to the local level, but it also mentions various roles of stakeholders and a definite timeframe for each adaptation practice.

Groundwater resources are the primary source of meeting the water demand in Bangladesh. In rural areas, hand-pumped tube wells have been the primary source of drinking water. Though studies claim that Bangladesh has the potential to achieve universal safe drinking water supply coverage, the presence of excessive arsenic in the shallow groundwater sources, and the encroachment of salinity in the coastal aquifers in coastal regions (Satkhira, Khulna, Bagerhat, Patuakhali, Jhalakathi, Pirojpur, Barisal, Barguna etc.) hind the path. The concerned authorities of government and other non-government organizations assist the coastal people with alternative technologies like Desalination Plant, Arsenic-Iron Removal Plant, Pond Sand Filtration (PSF), Managed Aquifer Recharge, Rainwater Harvesting System, Installation of Shallow, and Deep Tube Wells. But based on case studies and surveys, this article shows how these existing technologies fail to ensure water safety within the coastal areas. The Singaporean water management policy is an example, this article advocates for necessary government intervention to ensure safe drinking water in coastal areas.