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 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.

The purpose of this paper is to use rainwater quality parameters as indicators of pollution to assess the level of aerial pollution for sustainable environmental development.

Rainwaters were collected in open spaces within commercial, industrial and residential areas in Ibadan metropolis, Nigeria during onset, peak and late rainy season. Values of NO₃⁻, NH₄⁺, Cl⁻, SO₄²⁻, pH, electrical conductivity, total dissolved solid, total acidity and total alkalinity were determined using certified wet chemistry procedures, whereas those of Ca²⁺, Na⁺, K⁺ and Mg²⁺ were measured using atomic absorption spectrophotometry.

Overall results showed that the concentrations of the physical parameters, anions and cations, were comparatively higher at the onset of the rainy period than the latter periods, indicating washout of the pollutants as the rainy season progressed. Results of Pearson correlation matrix and Cluster analysis results showed that many of the parameters have similar source(s). Analysis of variance and t-test results indicated significant difference between the concentrations of the analyzed parameters at different rainy periods, whereas ratio values of sea salt fraction were higher than non-sea salt fraction for all species, depicting anthropogenic influences.

From the findings, the study concluded that the quality of the rainwaters was substandard due elevated levels of most of the analyzed quality parameters; this method proved to be economical, effective and simple compared to the conventional methods; it also proved rainwater quality to be a reliable pointer of aerial pollution and the concept can be used to assess the pollution level of areas of similar settings.

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 purpose of this paper is to focus on the structural integrity of the rainwater propeller pumps installed in the municipal wastewater treatment plant (WTP).

A numerical analysis is performed to determine the maximum shear stress on the fasten bolts. The rainwater propeller pump is examined in operation at normal conditions and when one blade is progressively blocked.

The failure mechanism of the rainwater pump impeller is determined.

The fibbers and wastes are discharged together with rainwater during storms with these types of pumps to avoid the flood of the WTP. Several catastrophic events have occurred in service due to the fibbers clog the gap between the impeller blades and the pump casing. The clogging process is partially understood so actual technical solutions deal with effects rather the main causes.

The operation time of all seven rainwater pumps installed in Timisoara’s WTP is investigated. Climate changes in Banat region and new waste properties found in the wastewater require appropriate technical solutions. A technical solution is proposed based on these investigations to extend the operation time and to diminish the operation and maintenance costs.

These large pumps are installed in the urban sewage centralised system implemented in the most cities. The access to the sewerage network is a requirement of any community, regardless of the social status.

The fracture surfaces of both fastening bolts of the rainwater pump impellers produced in service are examined. As a result, it has been identified that the catastrophic events are due to the brittle fracture of both fasten bolts between the impeller blades and the pump hub, respectively. The catastrophic events of the rainwater propeller pumps are directly correlated to the clog level of the impeller. The numerical simulation is performed to determine the maximum shear stress on the fasten bolts. The case with pump operating at normal conditions is performed identifying its vulnerabilities to clog conditions. Next, one impeller blade is progressively blocked considering three time stop scenarios associated with different clog levels. Conclusively, the operating time of the rainwater pump up to the catastrophic failure is correlated to the clog level of the impeller.

Examines rainwater chemistry as it relates to atmospheric pollution in Southern Nigeria. Rainwater samples were collected and analysed for major cations and anions in Lagos, Ibadan and Port Harcourt, these sites reflecting industrial, residential and oil flaring regions respectively. In general, water samples from Ibadan were about neutral. Correlation studies revealed that HCl and H₂SO₄ dominated the slightly acidic rainwater in the Lagos and Port Harcourt areas respectively. The effect of marine spray from the Gulf of Benin was observed with trace of NaCl. The reaction of the much emitted NH₃ with the available SO₄^2– in the atmosphere produced (NH₄)₂SO₄ which acted as a neutralizer for samples from the Lagos area. The findings suggest that rainwater from most industrial cities of Nigeria are tending towards acidity and if oil flaring activities are not checked, there is a tendency of increasing acidic rainwater in the delta regions. The observation and findings are useful for preliminary assessments of the influence of rapid industrial and urban development on atmospheric pollution and indirectly rainwater constituents.

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.

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.

Flood season in our country is characterized by frequent heavy rains, and flood problems are becoming increasingly serious. The uneven distribution of water resources causes conflicts in the occurrence of floods and droughts. Implementing effective flood control planning and solving drought and flood disasters are the research highlights of relevant institutions both domestic and abroad. This study develops a multiscale method of urban flood control planning based on microcirculation. A microcirculation water ecosystem, which consists of six elements, namely, collecting, interacting, precipitating, reserving, storing, and purifying, is introduced. This study investigates precipitation; peak shaving; recycle mode of filtration at the macro level in different regions; “hierarchy” in rainwater ecosystems in rain parks, heavy rain garden parks, and wetland parks at the meso level; and the concept of zero-emission rain in residential areas and roads at the micro level. Finally, this study analyzes a rain garden and its domestic application. A conclusion is drawn that the flood control planning model based on microcirculation can effectively reduce rain runoff. Empirical measurement proves that the proposed multiscale model for city flood control planning based on microcirculation promotes flood control and effectively reduces the occurrence of droughts and floods.

This study aims to examine determinants of farmers’ use of climate-smart agricultural practices, specifically improved crop varieties, intercropping, improved livestock breeds and rainwater harvesting in Wadla district, northeast Ethiopia.

A cross-sectional household survey was used. A structured interview schedule for respondent households and checklists for key informants and focus group discussants were used. This study used both descriptive statistics and a multivariate probit econometric model to analyze the collected data. The model was used to compute factors influencing the use of climate-smart agricultural practices in the study area.

The results revealed that households adopted selected practices. The likelihood of farmers’ decisions to use improved crop varieties, intercropping, improved livestock breeds and rainwater harvesting was 85%, 52%, 69% and 59%, respectively. The joint probability of using these climate-smart agricultural practices was 23.7%. The model results confirmed that sex, level of education, livestock holding, access to credit, farm distance, market distance and training were significant factors that affected the use of climate-smart agricultural practices in the study area.

The present study used the most selected locally practiced interventions for climate-smart agriculture.