Water Harvesting Systems Research Articles

Localización óptima de zonas potenciales para cosecha de agua lluvia en la zona sur de Honduras, año 2016

En Honduras 137 de los 298 municipios son considerados vulnerables a la sequía según el Plan de Acción Nacional de Lucha contra la Desertificación y la Sequía (PANLCD) que es el instrumento técnico y estratégico elaborado en el año 2005. La captación de agua de lluvia, también denominada “cosecha de agua”, puede ser una de las soluciones para enfrentar el reto que plantea la baja disponibilidad del líquido en diversas regiones del país. Seis criterios en combinación lineal ponderada (WLC) fueron usados en esta investigación para seleccionar los sitios óptimos para la construcción de sistemas de cosecha y conservación de agua dentro del área de estudio. Se seleccionaron cinco municipios como área de estudio, todos en el departamento de Valle, y se encontró que las áreas óptimas para el establecimiento de cosechas de agua en la zona de estudio cubren un área de 7,116 Ha, lo cual representa un 10% del total del área, mientras que las áreas restantes se clasifican como No Adecuado (29%) y Menos Adecuado (61%).

Developments in water dams and water harvesting systems throughout history in different civilizations

The use of water for domestic and agricultural purpose is not a new phenomenon It has been used throughout centuries all over the world After food water is the basic component of human life and their settlement This paper considers developments in water dams and water harvesting systems throughout history in different civilisations The major component of this review consists of hydraulic dams during Pre Historical Time Bronze Ages Minoan Era Indus Valley Civilization Early Ancient Egyptian Era Hittites in Anatolia and Mycenaean Civilization Historical Period Pre Columbian Archaic Period Classical Greek and Hellenistic Civilizations Gandahara and Mauryan Empire Roman Period and early Chinese dynasties Medieval times Byzantine Period Sui Tang and Song Dynasties in China Venetian Period Aztec Civilization and Incas and Modern Time Ottoman Period and Present Time The main aim of the review is to present advances in design and construction of water dams and water harvesting systems of the past civilizations with reference to its use for domestic as well as agricultural purposes its impact on different civilizations and its comparison to the modern technological era In addition emerging trends and perspectives are discussed

Simplified Modeling and Analysis of the Fog Water Harvesting System in the Asir Region of the Kingdom of Saudi Arabia

Scarcity of fresh water is one of the greatest obstacles to achieve the sustainable development in the Kingdom of Saudi Arabia. About thirty desalination plants are built to satisfy the Kingdom needs. The Kingdom is in need of new unconventional water resources such as fog water harvesting system which will complement the existing water resources in the Asir region. This region is facing major challenges due to the flourishing tourism, irrigation in agriculture and rising living standards. Passive mesh type fog collector is analyzed in the current study to predict the rate of fog water collection by combining a physically based impaction and aerodynamic models. The results indicate that the greater volumes of water can be harvested from the fog associated with higher wind speeds, bigger sizes of fog droplet and higher liquid water content in the fog-laden winds with the threshold mesh shade coefficient of about 0.56. It is found that the aerodynamic efficiency has a significant impact on the overall fog collection efficiency compared to the impaction efficiency. The model shows that for the fog droplet size of 30 µm with the wind speed of 4 m s–1, it is possible to collect the fog water at the rate of 0.65 to 9.7 L m–2 per hour when the liquid water content (LWC) in the fog varies from 0.2 to 3 g m–3, respectively.

Modified Traditional Water Harvesting System for Irrigation in Malwa and Nimar Region

Modified Traditional Water Harvesting System for Irrigation in Malwa and Nimar Region

Hierarchical Superhydrophobic Surfaces with Micropatterned Nanowire Arrays for High-Efficiency Jumping Droplet Condensation.

Self-propelled droplet jumping on nanostructured superhydrophobic surfaces is of interest for a variety of industrial applications including self-cleaning, water harvesting, power generation, and thermal management systems. However, the uncontrolled nucleation-induced Wenzel state of condensed droplets at large surface subcooling (high heat flux) leads to the formation of unwanted large pinned droplets, which results in the flooding phenomenon and greatly degrades the heat transfer performance. In this work, we present a novel strategy to manipulate droplet behaviors during the process from the droplet nucleation to growth and departure through a combination of spatially controlling initial nucleation for mobile droplets by closely spaced nanowires and promoting the spontaneous outward movement of droplets for rapid removal using micropatterned nanowire arrays. Through the optical visualization experiments and heat transfer tests, we demonstrate greatly improved condensation heat transfer characteristics on the hierarchical superhydrophobic surface including the higher density of microdroplets, smaller droplet departure radius, 133% wider range of surface subcooling for droplet jumping, and 37% enhancement in critical heat flux for jumping droplet condensation, compared to the-state-of-art jumping droplet condensation on nanostructured superhydrophobic surfaces. The excellent water repellency of such hierarchical superhydrophobic surfaces can be promising for many potential applications, such as anti-icing, antifogging, water desalination, and phase-change heat transfer.

Water Saving and Cost Analysis of Large-Scale Implementation of Domestic Rain Water Harvesting in Minor Mediterranean Islands

This paper describes a novel methodology to evaluate the benefits of large-scale installation of domestic Rain Water Harvesting (RWH) systems in multi-story buildings. The methodology was specifically developed for application to small settlements of the minor Mediterranean islands characterized by sharp fluctuations in precipitation and water demands between winter and summer periods. The methodology is based on the combined use of regressive models for water saving evaluation and of geospatial analysis tools for semi-automatic collection of spatial information at the building/household level. An application to the old town of Lipari (Aeolian islands) showed potential for high yearly water savings (between 30% and 50%), with return on investment in less than 15 years for about 50% of the installed RWH systems.

Water Conservation: Traditional Rain Water Harvesting Systems in Rajasthan

Water Conservation: Traditional Rain Water Harvesting Systems in Rajasthan

Sustainable energy-water management for residential houses with optimal integrated grey and rain water recycling

South Africa is a semi-arid developing country facing water and energy insecurity. There are colossal challenges in reliably providing these resources amid growing population, increased urbanization and improved living standards causing increased demand for these resources. Development of new supply centralized systems comes at an exorbitant cost, whereas decentralized systems are touted as an attractive alternative. Grey water recycling and rain water harvesting at buildings level is such an alternative that can provide water for non-potable uses. However, there are technological challenges of optimally operating such systems while ensuring efficient use of associated energy. This paper introduces two control strategies; open loop optimal control and closed-loop model predictive control (MPC) strategies aimed at ensuring safe and reliable operation of the grey water recycling and rain water harvesting system while efficiently using associated energy. From the case study, the proposed system with either control strategy can save the cost of water and waste water by up to 32.3% and 29.5% respectively, while leading to 35.7% in energy cost savings and 31.5% in total operational cost savings in a month. Adoption of these systems would have a huge environmental effect in reducing demand for sewerage services, conservation of water hence reducing demand for potable water as well as increasing the energy efficiency. Furthermore, the system would increase the reliability and security of water supply. Despite the benefits, the system does not pay within its lifetime and therefore, government intervention is required so as to make it economically attractive. High cost of implementation coupled with low potable and waste water tariffs harbour adoption of these systems. Appropriate regulations, policies, incentives and public education are necessary to support such novel technologies in ensuring resource conservation, efficiency and security are achieved.

Nanoparticles Covered Surfaces for Post-functionalization with Aromatic Groups to Obtain Parahydrophobic Surface with High Water Adhesion (Petal Effect)

Numerous exceptional properties can be observed in nature. Among these properties, parahydrophobic feature is of interest. This property describes material with high adhesion with water such as rose petals or gecko foot. Such kind of surface presents a real potential for applications in the field of water harvesting systems. In this work, we report a new synthetic strategy to mimic this property. Here, we combine three strategies in one. First, a monomer is electropolymerized in order to form the starting structured surface. Then, nanoparticles are grafted on the surface to increase the structuration and consequently to create the reactive surface. Finally, the grafted surface is post-functionalized (Huisgen reaction) with various aryl alkynes to control the surface chemistry and energy. This strategy allows to reach surfaces with both very high hydrophobic properties (θ = 140°) and high water adhesion. This work also includes the surface wettability, roughness and morphology investigation in order to study the impact of the starting monomer structure and post-functionalization on the surface properties.

A travel in the Echeveria genus wettability's world

Nature is a constant source of inspiration for researchers and engineers. In this work, we study the wettability of various species from the genus Echeveria. All species studied present very strong hydrophobic properties with various water adhesions. Echeveria ‘Perle von Nürnberg' has properties very close to superhydrophobicity with low water adhesion (sliding angle α=15° and contact angle hysteresis H=9°) while Echeveria pallida and Echeveria runyonii are completely sticky (parahydrophobic) and water droplets do not move even if the surface is inclined to 90°. This work shows that most of the differences in the hydrophobic properties depend on the amount of wax crystallization. However, Echeveria pulvinata shows special wettability results. Their leaves possess long hairs. When a water droplet is placed on the surface, the water droplet is completely sticky. When the size of the droplets becomes critical, the water droplets spread across the leaf surface displaying superhydrophilic properties. More investigations reveal that the hairs are highly hydrophobic and rough due to the presence of wax crystals while the bottom of the surface is smooth and hydrophilic. Such materials are excellent candidates for water harvesting systems and oil/water separation membranes.

Modeling humid air condensation in waste natural gas-powered atmospheric water harvesting systems

4% of the natural gas produced globally is flared at oilfields due to the absence of gas handling infrastructure and unfavorable economics. Recent work has proposed the utilization of this excess gas for atmospheric water harvesting (AWH) for oilfield operations, wherein gas-powered refrigeration cycles generate the cooling capacity for large scale dehumidification, via condensation. This work develops an indepth, comprehensive, analytical modeling framework to predict the water condensation in waste gas-powered AWH systems. Firstly, gas powered refrigeration systems are analyzed to identify key system parameters and considerations. Secondly, an analytical model is developed to capture the complex heat and mass transfer phenomena associated with condensation of humid air in a fin and tube heat exchanger. This involves using heat and mass transfer relations to estimate the dehumidification process line. The model can predict the water condensation rate as a function of the gas flow rate, ambient weather and the refrigeration system utilized. The model is used to predict flared gas-based water harvests in the Eagle Ford (Texas) and Bakken (North Dakota) Shale oilfields, which account for the majority of US flaring. Results indicate that 1 cubic meter of natural gas can condense 2.3 and 0.65gallons water (on an annual average basis) in Texas and North Dakota, respectively. The weather-dependent condensation rates range from 3 to 10 (Texas) and 0 to 0.8 (North Dakota) gallons/day/square meter of condenser area. Overall, flared gas-based AWH can utilize 77% and 40% of the excess gas in Texas and North Dakota, respectively. This work analyzes various aspects of humid air condensation and evaluates the sensitivity of the condensation rate to key engineering parameters. Overall, this work develops the foundational modeling tool to predict the performance of all types of humid air condensation systems.

A dimensionless approach for the urban-scale evaluation of domestic rainwater harvesting systems for toilet flushing and garden irrigation

A dimensionless methodology to evaluate the water saving obtainable from large-scale implementation of domestic rain water harvesting (RWH) systems in urban areas is presented. The methodology combines the use of regressive relationships for water saving evaluation based on the results of the dimensionless rainwater tank water balance and of catchment-wide information obtained from geospatial databases. The adopted RWH scheme included internal use of rainwater for toilet flushing and external use for garden irrigation. An application to a portion of the city of Rome, Italy showed the methodology to allow systematic and accurate evaluation of RWH system performance at the selected urban scale. Results pointed out high water saving potential for toilet flushing ranging between 38–65% for tank sizes within 1–50 m3. Furthermore, more than one third of the systems provided water saving benefit for irrigation larger than 20% by using a 50 m3 tank.

The Brookside Farm Wetland Ecosystem Treatment (WET) System: A Low-Energy Methodology for Sewage Purification, Biomass Production (Yield), Flood Resilience and Biodiversity Enhancement

Wastewater from domestic developments, farms and agro-industrial processing can be sources of pollution in the environment; current wastewater management methods are usually machine-based, and thus energy consuming. When Permaculture Principles are used in the creation of water purification and harvesting systems, there can be multiple environmental and economic benefits. In the context of energy descent, it may be considered desirable to treat wastewater using minimal energy. The constructed wetland design presented here is a low-entropy system in which wastewater is harvested and transformed into lush and productive wetland, eliminating the requirement for non-renewable energy in water purification, and also maximising benefits: biodiversity, flood resilience and yield. In permaculture design, the high concentrations of nitrogen and phosphorous compounds in sewage are viewed as valuable nutrients, resources to be harvested by a constructed wetland ecosystem and converted into useful yield. Similarly, rainwater runoff is not viewed as a problem which can cause flooding, but as a potential resource to be harvested to provide a yield. This paper presents a case study, with both water quality and productivity data, from Brookside Farm UK, where the use of Permaculture Design Principles has created a combined wastewater management and purification system, accepting all site water.

USES OF NON-CONVENTIONAL ENERGY SOURCES IN DEVELOPMENT OF RURAL AREA: A CASE STUDY OF GURAVAWADI VILLAGE

In the initial phase of planned rural development the concentration was on sector of agriculture industry, communication, education and health. The ministry of rural development places importance now on health, education, drinking water; housing and road so that the quality of life in rural areas Improves and fruit of economic reform are shared by section of society. The basic objective of all rural development endeavors program has been welfare of the millions. In order to achieve this, planned attempts have been made to eliminate poverty, ignorance and inequality of opportunities. As we discuss about the development of village without disturbing the environment, we can develop “Guravwadi village” by using non-conventional energy sources like bio-gas plant, rain water harvesting system and solar power energy plant and wind turbine. By such a way we can make the Guravwadi village independent, clean, eco-friendly and free from chemical and dust etc. This project is totally economical for Guravwadi village in all aspects, like solving the problem of electricity in the development of Guravwadi village. By the setup of biogas plant expenditure on cooking has been decreased which also helped in cleanliness of Guravwadi village. By using the technique of rain water harvesting & percolation tank the ground water table of Guravwadi village will increase which help in solving all waters related to water scarcity

Evaluating the financial efficiency of energy and water saving installations in passive house

The article contains the outcomes of the Life Cycle Cost analysis for alternative energy and water sources utilized in passive buildings. The solutions taken into account included: heat pumps, solar collectors, photovoltaic panels, Drain Water Heat Recovery units, Rain Water Harvesting Systems and Greywater Recycling Systems. In addition, air pollution emission reduction was also calculated for all the installation variants analyzed. The analysis have shown that the systems under consideration could serve as alternatives for traditional installations. Their use has resulted in reductions in the consumption of fossil fuels and natural water resources, thus contributing to environmental improvements.

Small Structures, Big Droplets: The Role of Nanoscience in Fog Harvesting.

Designing materials for water harvesting has gained much attention in recent years as water scarcity continues to be one of the biggest problems facing mankind. In this issue of ACS Nano, Xu et al. propose a new device for harvesting water from fog. They use conically shaped copper wires with periodic roughness to enhance condensation and transport of water drops. While the periodic roughness enhances drop coalescence and motion, the conical shape of the wires guides the drops in a specific direction. Together, a self-sustained water-harvesting system is described which does not require additional external stimulus but makes use of a smart design and economic production.

Evaluating the SWMM LID Editor rain barrel option for the estimation of retention potential of rainwater harvesting systems

The low-impact development (LID) Editor rain barrel option of release 5.5 of the EPA storm water management model (SWMM) software does not allow the consideration of demand-driven behaviour of domestic rain water harvesting (RWH) systems to evaluate their runoff retention potential. This paper compares the results of the LID Editor with those obtained by a detailed demand-driven tank model scheme – used as a benchmark – and developed using basic functions of SWMM. The comparison showed the LID Editor-based model to generally overestimate the benchmark model in the evaluation of both volumetric and peak retention efficiency. The high variability of the results of the comparison suggests the use of the LID Editor rain barrel option for long-term simulation but not for single event analysis. A sensitivity analysis revealed that the overestimation provided by the rain barrel option is significant for tanks smaller than 2 m3, tank sizes of major diffusion for domestic RWH.

Deforestation Effects on Soil Erosion in the Lake Kivu Basin, D.R. Congo-Rwanda

Deforestation and natural grassland conversion to agricultural land use constitute a major threat to soil and water conservation. This study aimed at assessing the status of land cover and land use (LCLU) in the Lake Kivu basin, and its related impacts in terms of soil erosion by water using the Universal Soil Erosion Equation (USLE) model. The results indicated that the Lake Kivu basin is exposed to soil erosion risk with a mean annual rate of 30 t·ha−1, and only 33% of the total non-water area is associated with a tolerable soil loss (≤10 t·ha−1·year−1). Due to both natural factors (abundant tropical precipitation and steep slopes) and anthropogenic activities without prior appropriate conservation practices, all land-use types—namely settlement, cropland, forestland, and grassland—are exposed to a severe mean erosion rate of 41 t·ha−1·year−1, 31 t·ha−1·year−1, 28 t·ha−1·year−1, and 20 t·ha−1·year−1, respectively. The cropland that occupied 74% of the non-water area in 2015 was the major contributor (75%) to the total annual soil loss in the Lake Kivu basin. This study showed that conservation practices in the cropland cells would result in a mean erosion rate of 7 t·ha−1·year−1, 18 t·ha−1·year−1, and 35 t·ha−1·year−1 for terracing, strip-cropping, and contouring, respectively. The adoption of terracing would be the best conservation practice, among others, that could reduce soil erosion in cropland areas up to about 23%. The erosion risk minimization in forests and grasslands implies an increase in overstorey canopy and understorey vegetation, and control of human activities such as fires, mining, soil compaction from domestic animals grazing, and so on. Soil erosion control in settled areas suggests, among other things, the revegetation of construction sites, establishment of outlet channels, rainfall water harvesting systems, and pervious paving block with grass.

Combating water scarcity through roof water harvesting: planning and design with stakeholders' perception in Sikkim (India)

Sikkim is one of the constituent states of India, endowed with huge water resources. However, due to steep terrain and non availability of a groundwater aquifer, water conservation is a challenge. The water received as rainfall drains away through the steep terrain in the deep valleys, thereby creating a water stress after withdrawal of the monsoon. To overcome such a situation, a study was undertaken to design a suitable rain water harvesting system for the state. To design a suitable water harvesting system, we estimated the water demand of the end users, assessed the water availability during the non-rainy period, and designed the volume of storage structure. The study revealed that more than 80% of the respondents experienced water stress during the period from December to March. The average daily water demand of individual households was observed to be around 400 litres. The rainfall pattern indicated that 90% of the rainfall is concentrated during 6 rainy months. On average, 24 consecutive dry days were observed in the state. The volume of storage structure obtained, based on water availability and demand, was 5 m3 per household. It is felt that this volume can take care of the domestic water demand.

Optimization of a residential district with special consideration on energy and water reliability

Many cities around the world have reached a critical situation when it comes to energy and water supply, threatening the urban sustainable development. From an engineering and architecture perspective it is mandatory to design cities taking into account energy and water issues to achieve high living and sustainability standards. The aim of this paper is to develop an optimization model for the planning of residential urban districts with special consideration of renewables and water harvesting integration. The optimization model is multi-objective which uses a genetic algorithm to minimize the system life cycle costs, and maximize renewables and water harvesting reliability through dynamic simulations. The developed model can be used for spatial optimization design of new urban districts. It can also be employed for analyzing the performances of existing urban districts under an energy-water-economic viewpoint.The optimization results show that the reliability of the hybrid renewables based power system can vary between 40 and 95% depending on the scenarios considered regarding the built environment area and on the cases concerning the overall electric load. The levelized cost of electricity vary between 0.096 and 0.212$/kWh. The maximum water harvesting system reliability vary between 30% and 100% depending on the built environment area distribution. For reliabilities below 20% the levelized cost of water is kept below 1$/m3 making competitive with the network water tariff.