Rainwater Harvesting Research Articles

Reticular Synthesis of Covalent Organic Frameworks with kgd-v Topology and Trirhombic Pores.

Two-dimensional (2D) covalent organic frameworks (COFs) with designable pore structures can be synthesized under the guidance of topology diagrams. Among the five existing edge-transitive topological nets, kgd topology is considered a fine candidate for constructing COFs with ultramicropores. However, all of the reported COFs with kgd topology need the use of C6-symmetric monomers, which are limited in compound type and difficult to synthesize. Here, we first develop a new approach to construct 2D COFs (clv-COFs) with a similar geometrical shape of kgd topology, named kgd-v topology, through the combination of C2v- and C3-symmetric monomers. The size of micropores in these clv-COFs is consistent with the rhombic pores in kgd topology and can be easily tuned by varying the length of C2v- and C3-symmetric monomers. These clv-COFs exhibit excellent atmospheric water harvesting (AWH) ability due to regular small micropores. An efficient water harvester based on clv-COF-1 can produce 1.73 L kg-1 day-1 at 45% relative humidity under solar illumination. Our approach enriches the reticular chemistry and can facilitate the research of COF-based AWH systems.

Environmental, Social & Governance (ESG) Implementation Strategy in Mining Companies with Design Thinking Method

The mining industry plays an important role in economic development, but its operations often have adverse environmental and social impacts and many companies are only concerned with profit. So it is important to apply ESG (Environmental, Social, Governance) principles to companies to create a sustainable business. This thesis examines the application of ESG in PT. X as a mining company. This research is qualitative research and uses descriptive analysis with the design thinking method. Observations and interviews were conducted at PT. X and using an informant from the management of PT. X. This research also aims to find effective strategies in the implementation of ESG in strengthening business sustainability in PT. X by using indicators from the ESG Reporting Guide that uses the Global Reporting Standard (GRI) in the mining sector. Based on the results of the analysis, it was found that the implementation of ESG in PT. X has achieved a percentage of 95% of the GRI Coal standard. There is one indicator that has not been implemented, namely the water and effluent indicators on the environmental aspect. Alternative strategies developed with design thinking methods are in the form of making rainwater catchment ponds, remote control waterfill, and automatic sprayer.

Commitment Competency and Growth of Aquaculture-Based Small Enterprises in Kenya

Purpose: This study evaluated the influence of commitment competency on growth of small enterprises in Kenya. Methodology: The study adopted descriptive research design using mixed methods approach. The target population was 600 fish farmers in Nyeri County, Kenya. The study utilized purposive sampling to select fish farmers within Nyeri County, then cluster sampling to identify fish farmers in their various sub-counties. Simple random sampling was then utilized to select respondents for the study. A self-administered questionnaire was used to collect data from the respondents. A pilot study was conducted to test validity and reliability of the questionnaire. Data analysis was done using Statistical package for Social Scientists (SPSS). Regression analysis and chi-square were used to test for significant associations between the dependent and independent variables. The findings were presented in frequency tables, pie charts, bar graphs and scatter diagrams in the final report. Findings: The findings indicated that commitment competency and growth had weak inverse linear statistical relationship. The study concluded that fish farmers are already aware of the many hurdles involved in fish farming but they remain resilient in doing what it takes to achieve the goals set for their fish farms. It is not the lack of commitment on their part that contributes to the stagnating or declining of their businesses. Instead, other challenges such as lack of crucial inputs such as reliable and quality feeds, quality fingerlings, adequate water, lack of business management knowledge, lack of market accessibility and capital contribute to the dismal performance of their businesses. Unique Contribution to Theory, Practice and Policy: The government and NGOs should provide subsidized inputs and promote cottage industries to enhance aquaculture value chains. In addition, extension officers should be equipped with resources like water testing kits, and water harvesting should be encouraged in water-scarce areas.

Sustainable Land Use and Value Addition Practices to Combat Land Degradation and Enhance Food Security in Arid and Semi-Arids Regions

Combatting land degradation and desertification is crucial for protecting biodiversity, mitigating climate change impacts, and improving climate adaptation capacity. A cross-sectional study was conducted at the University of Namibia (UNAM) Ogongo campus to explore land use and value addition practices aimed at combating land degradation, building resilience to climate change, and enhancing food security. Data was collected through digital photography and face-to-face interviews using a standardized questionnaire. The data was analysed using content analysis and the Chi-Square (X2) test. Findings identified key land use practices, including the cultivation of drought-tolerant crops such as pearl millet and groundnuts, water management practices like rainwater harvesting using earth dams, and modern irrigation techniques such as drip irrigation and sprinklers for efficient water use. Soil management practices at the campus focus on enhancing fertility and conservation, with the use of organic matter from cattle and chicken manure to improve soil quality. Rice husk mulching reduces evaporation and maintains soil moisture during dry periods. Adaptive farming techniques, including agroforestry, crop rotation, and intercropping, were also employed to enhance biodiversity, improve soil quality, and increase resilience to climate change. The campus has installed solar panels to reduce reliance on non-renewable energy sources and reduce carbon emissions. Artificial waterholes in the Game Park provide water for wildlife during dry periods. Additionally, the campus adds value to agricultural products such as groundnuts, beans, rice, and fruits (e.g., guavas, lemons, mangoes) by processing them into flour, juices, dried snacks, omaere, fresh milk, butter, yogurt, and biltong. The findings suggest that campuses like UNAM Ogongo can serve as models for sustainable land management practices in arid and semi-arid regions, blending education, research, and practical implementation.

Functional flexible adsorbents and their potential utility.

Physisorbents are poised to address global challenges such as CO2 capture, mitigation of water scarcity and energy-efficient commodity gas storage and separation. Rigid physisorbents, i.e. those adsorbents that retain their structures upon gas or vapour exposure, are well studied in this context. Conversely, cooperatively flexible physisorbents undergo long-range structural transformations stimulated by guest exposure. Discovered serendipitously, flexible adsorbents have generally been regarded as scientific curiosities, which has contributed to misconceptions about their potential utility. Recently, increased scientific interest and insight into the properties of flexible adsorbents has afforded materials whose performance suggests that flexible adsorbents can compete with rigid adsorbents for both storage and separation applications. With respect to gas storage, adsorbents that undergo guest-induced phase transformations between low and high porosity phases in the right pressure range can offer improved working capacity and heat management, as exemplified by studies on adsorbed natural gas storage. For gas and vapour separations, the very nature of flexible adsorbents means that they can undergo induced fit mechanisms of guest binding, i.e. the adsorbent can adapt to a specific adsorbate. Such flexible adsorbents have set several new benchmarks for certain hydrocarbon separations in terms of selectivity and separation performance. This Feature Article reviews progress made by us and others towards the crystal engineering (design and control) of flexible adsorbents and addresses several of the myths that have emerged since their initial discovery, particularly with respect to those performance parameters of relevance to natural gas storage, water harvesting and hydrocarbon gas/vapour separation.

Integrating rainwater harvesting and organic soil amendment to enhance crop yield and soil nutrients in agroforestry

Abstract More than 90% of rainfed croplands in Sub-Saharan Africa (SSA) are severely affected by highly intermittent rainfall and frequent drought limiting crop productivity in the region. Besides, 27.1% of the population in SSA are currently food insecure and this is likely to increase with the current rapid population growth in the region. Soil erosion and water scarcity remain to be the core problem affecting agricultural productivity of smallholder farming. In the current study, we analysed rainwater harvesting assisted small-scale agroforestry system in order to mitigate both soil erosion and water scarcity issues simultaneously. The system included in-situ rainwater harvesting, soil organic amendment (raw poultry litter, poultry litter biochar, wood ash) and an agroforestry system (AFS) containing maize, barley- Eucalyptus globulus all intercropped in a holistic approach. The effect was evaluated on selected soil parameters and crop yield in a field experiment on a completely randomized design. The treatments were poultry litter (PWAFS), poultry litter biochar (BWAFS) wood ash (AWAFS) with supplementary irrigation (WAFS) and agroforestry system AFS (control). The first three treatments contained poultry litter, poultry litter biochar and wood ash along with rainwater harvesting respectively while the fourth treatment contained only rainwater harvesting. Besides, a control plot-AFS was assigned with neither rainwater harvesting nor soil organic resources. The result indicated that BWAFS increased the pH by 19.4% followed by AWAFS and PWAFS (9%). Maximum and minimum SOM (2.26%, 1.21%) were observed under BWAFS and the control (AFS) respectively. BWAFS significantly increased Av.P by 78.1% while WAFS increased by 40% compared to the control. Similarly, BWAFS and PWAFS had significant effect on maize yield with increase by 74% and 36% respectively. The study concluded that integrating rainwater harvesting and soil amendment with agroforestry systems can enhance crop yield and soil nutrient levels. Therefore, such agricultural practices should be adopted by smallholder farmers in areas with limited water and nutrients levels.

Integrating Fish Farming into Runoff Water Harvesting Ponds (RWHP) for Sustainable Agriculture and Food Security: Farmers’ Perceptions and Opportunities in Burkina Faso

Integrated aquaculture–agriculture systems are recognized as sustainable solutions to optimize resources, support livelihoods, and enhance food security in climate-sensitive Sahelian regions. In contexts like Burkina Faso, runoff water harvesting ponds (RWHPs) improve agricultural yields during the rainy season but remain underutilized for the rest of the year. This study assesses the feasibility of integrating fish farming into these ponds. Using the Waso-2 tool, structured perception interviews were conducted with 51 farmers across 17 localities. Welch ANOVA and Games–Howell tests revealed, on a scale of 20, that water insufficiency scored 16.01 among experienced farmers without additional water access as a key obstacle, while pond degradation scored 17.69 for those with water access. For motivations, income generation scored 16.24 among inexperienced farmers, whereas training opportunities scored 17.65 for experienced ones, highlighting varying priorities across strata. Farmers preferred fish farming effluents over NPK for vegetables, scoring 15.99. Some favored raw effluents for immediate use, scoring 13.91, while others preferred decanted water with dried sludge for gradual nutrient release, scoring 12.39. This study demonstrates strong farmer interest in integrated RWHP systems. Enhancing pond retention, supplementing groundwater, and providing tailored training in aquaculture practices, pond maintenance, and water management are recommended to encourage adoption.

Thermodynamic Analysis of Adsorption-Based Atmospheric Water Harvesting using Various Adsorbents in Iraqi Conditions

This study investigates the thermodynamic performance of various adsorbent materials used in adsorption-based atmospheric water harvesting (AWH), with a focus on their application in arid regions, such as Iraq. While significant advancements have been made in developing adsorbents capable of capturing water at low humidity levels, the lack of detailed thermodynamic analysis has hindered optimal operational conditions for these materials. The study evaluates the thermodynamic efficiencies of MOF-808, MCM-41, and COF-432, comparing their performance with other materials like MOF-801, MOF-803, and Ni2Cl2BTDD. Key findings indicate that source temperature and outlet relative humidity significantly influences system efficiency, with higher source temperatures generally improving thermal efficiency. However, lower outlet relative humidity, especially at higher temperatures, can further enhance system efficiency, emphasizing the importance of effective humidity control. Additionally, the study highlights that Iraq’s elevated ambient temperatures may exacerbate efficiency losses due to higher thermal sink temperatures, underscoring the need for adaptive design strategies. The performance of various adsorbents was found to be highly material-dependent, with certain adsorbents offering superior thermal and second-law efficiencies under specific conditions. This study offers crucial insights into optimizing adsorbent selection and system design for AWH systems, particularly in challenging climates.

Ab Initio Predictions of Adsorption in Flexible Metal-Organic Frameworks for Water Harvesting Applications.

Metal-organic frameworks such as MOF-303 and MOF-LA2-1 have demonstrated exceptional performance for water harvesting applications. To enable a reticular design of such materials, an accurate prediction of the adsorption properties with chemical accuracy and fully accounting for the flexibility is crucial. The computational prediction of water adsorption properties in MOFs has become standard practice, but current methods lack the predictive power needed to design new materials. Limitations stem from the way the interatomic potential is described and the inadequate consideration of the framework flexibility. Herein, we showcase a methodology to obtain chemically accurate adsorption isotherms that fully account for framework flexibility. The method relies on very accurate and efficiently trained machine learning potentials and transition matrix Monte Carlo simulations to account for framework flexibility. For MOF-303, quantitatively accurate adsorption isotherms are obtained, provided an accurately benchmarked electronic structure method is used to train the machine learning potential, and local and global framework flexibility is accounted for. The broader applicability is shown through the study of MOF-333 and MOF-LA2-1. Analysis of the water density profiles in the MOFs gives insight into the factors governing the shape and origin of the isotherm. An optimal water harvester should have initial seeding sites with intermediate adsorption strength to prevent detrimental low-pressure water uptake. To increase the working capacity, linker extension strategies can be used while maintaining the initial seeding sites, as was done in MOF-LA2-1. The methodology can be applied to other guest molecules and MOFs, enabling the future design of MOFs with specific adsorption properties.

Rainwater Harvesting for Drought Disaster Prevention in Seraya Village, Karangasem Regency, Bali Province, Indonesia

Rainwater Harvesting for Drought Disaster Prevention in Seraya Village, Karangasem Regency, Bali Province, Indonesia

Metal-Organic Framework-Assisted Atmospheric Water Harvesting Enables Cheap Clean Water Available in an Arid Climate: A Perspective.

Extracting water directly from the atmosphere seems to be a perfect way to solve the water scarcity facing 2 billion people; however, traditional Atmospheric Water Harvesting (AWH) lacks the ability to adsorb water molecules in an arid climate. Porous materials are capable of assisting water adsorption; however, currently, only certain customizable Metal-Organic Frameworks (MOFs) are able to meet the standard of adsorbing water molecules at low humidity and releasing water at low temperatures at certain times that can realize assisted AWH's practical and energy-efficient use (Energy consumption < 5kWh/L-water). From this perspective, we offer a concise review of the advancements in enhanced AWH technologies, delve into the attributes of appropriate MOFs, and offer insights into the potential and future directions of MOFs-AWH. In conclusion, we underscore that that the development of designable MOFs holds the key to the widespread practical implementation of AWH, promising the availability of affordable clean water anywhere in the world.

Design of Combined Rainwater-Harvesting and Stormwater-Detention System with Passive Release for New Buildings in Taiwan

Taiwan experiences abundant rainfall, but faces significant water shortages, making rainwater harvesting (RWH) a potential alternative water source. Additionally, extreme rainfall events strain urban flood control systems, highlighting the need for integrated stormwater management. To address these challenges, Taiwan mandates stormwater detention (SWD) in new buildings. However, the current RWH and SWD systems are designed independently, with no combined design guidelines available. This study proposes three combined RWH and SWD systems, series, parallel, and enhanced parallel with a valve using a passive release mechanism. System performance was evaluated through short-term and long-term simulations. Short-term simulations were conducted to ensure the system’s compliance with the domestic flood control design standards. These simulations assessed the peak flow mitigation and lag times for 5-, 10-, and 25-year design storms under four scenarios. Long-term simulations used historical rainfall data to analyze the differences in the combined systems and operational plans for continuous rainfall events. Three performance indicators—volumetric reliability, the stormwater retention ratio, and the stormwater detention ratio—were employed to assess water supply and the stormwater detention performance. The short-term simulation results revealed that the system performance was sensitive to the initial conditions. The series and parallel systems performed well, while the enhanced parallel system outperformed the others under specific initial conditions and valve operations. In contrast, long-term simulations revealed that the series and parallel systems achieved higher stormwater retention and a more stable performance than the enhanced parallel system. Among the three systems, the parallel system offers reduced installation space, lower costs, and easier maintenance, making it the recommended option for Taiwan. This study provides valuable guidance for designing combined RWH and SWD systems.

Sustainable Urban Water Resource Management in China: Challenges and Innovations

Rapid urbanization in China has led to severe challenges in urban water resource management, including water scarcity, pollution, and the impacts of climate change. This study examines innovative technologies such as water recycling, rainwater harvesting, and urban green infrastructure, focusing on their implementation in major cities like Beijing, Shenzhen, and Guangzhou. Through case studies and data analysis, the research evaluates the effectiveness of these solutions in addressing the pressing water management issues. The findings suggest that integrated water management strategies, supported by strong policy frameworks and public involvement, are critical for achieving sustainable urban water systems. The study concludes with recommendations for improving urban resilience to water-related challenges in the face of ongoing climate and demographic pressures.

Superfast nanodroplet propulsion in 2D nanochannels tuned by strain gradients.

Directional transport of droplets is crucial for industrial applications and chemical engineering processes, with significant potential demonstrated in water harvesting, microfluidics, and heat transfer. In this work, we present a novel approach to induce self-driving behavior in nanodroplets within a two-dimensional (2D) nanochannel using a strain gradient, as demonstrated through molecular dynamics simulations. Our findings reveal that a small strain gradient imposed along a nanochannel constructed by parallel surfaces can induce water transport at ultrafast velocities (O(102 m s-1)), far exceeding macroscale predictions. Certainly, a larger strain gradient further enhances droplet transport velocity. Additionally, combining a strain gradient with nonparallel surfaces results in up to a 150% increase in transport efficiency. Furthermore, we show that this spontaneous transport mechanism is applicable to nanochannels composed of various 2D materials and successfully establish a reliable theoretical model. These simulation results provide new insights into the directional transport of nanodroplets in 2D nanochannels, opening avenues for advanced applications in nanotechnology and fluid dynamics.

Evaluation of Green Building Parameters to Improve the Green Rating System of Existing Non-Rating Building.

There are various activities which are creating adverse impact on environment construction is one of them. Construction industries are having potential to reduce the environmental impact by constructing green building, net zero energy building etc. The various rating agencies have developed different tools for designing and development of green building. The present study consists of study of various green building parameters of non-rated building to convert into rated building. Total 21 parameters were studied out of these rainwater harvesting, use low flow fixture for efficient use of water and energy saving were studied in detail and discounted payback period method was used. The discounted payback period was calculated. Research reveals it is worth investment of Rs 4.58 lacs to upgrade the infrastructure and within 1.97 years the invested amount will get recovered and which will safeguard the environment.

Traditional Dual Tank Water Management: A Study of Kolakanatham in Perambalur District, Tamil Nadu

Societies make rainwater harvesting structures to collect and store rain water to cater for their immediate and future needs. In a remote village in the Perambalur district, the people use the dual temple tank, nearly 350 years old, for their drinking purposes. This study tries to understand the traditional knowledge embedded in the dual pond structures, cascade aerators, and an open well connected with the ground aquifer inside the tank. This study delves into projected rainfall trends using NASA POWER data for 2050, revealing a noticeable increase and an assessment of pond water quality parameters demonstrating adherence to acceptable limits set by the Bureau of Indian Standards (BIS). However, despite meeting these standards, the water quality index deems the water unsuitable for direct human consumption, though it remains suitable for domestic household use. Moreover, analysis of land cover and land use changes by Sentinel2A data over the past 22 years underscores significant growth in settlement areas, indicative of a rising demand for water resources. The study proposes the restoration and utilization of the dual tank system as a potential solution to address this burgeoning water demand, offering a reliable water source and preserving traditional practices within the local community.

A dual-biomimetic surface with leaf-skeleton-based hierarchical structures for efficient atmospheric water harvesting

A dual-biomimetic surface with leaf-skeleton-based hierarchical structures for efficient atmospheric water harvesting

Revisiting water resources management in the Mandara Mountains.

This article evaluates the prospects for rainwater harvesting (RWH) as a means of optimizing water management in the Mandara Mountains. RWH is a small-scale water conservation approach for locally intercepting and storing rainfall before it enters the usual hydrologic cycle. This ancient practice has recently sustained lives in semiarid areas of the world (e.g. Brazil, China), but is not yet really used in the Mandara Mountains of Cameroon where people are still lacking safe drinking water. Recently, RWH was also demonstrated as the missing puzzle in integrated water resources management (IWRM) not only in areas facing water scarcity. The present article aims to prepare large scale RWH in the Mandara Mountains. Water harvesting yields are estimated for residential roofs, administrative and confessional buildings, and agricultural areas (e.g. farm scale). The results show that RWH is an affordable, applicable, and attractive tool for both rural and urban communities to sustainably solve the long-lasting problem of lack of safe drinking water in the Mandara Mountains. Moreover, despite the short rainy season, RWH may provide enough irrigation water to mitigate dry spells and increase agricultural and livestock productivity. This study is regarded as a blueprint for planning sustainable water management in the Mandara Mountains.

Water quality assessment of rooftop harvested rainwater across different roof types in a semi-arid region of South Africa.

Uneven distribution of precipitation and climate change have led to water shortages, adversely impacting numerous countries worldwide. Rooftop rainwater harvesting (RWH) has emerged as a crucial method for providing water for domestic uses. However, there are concerns about the quality of rainwater collected from roofs, as it may be contaminated with pollutants such as metals and microbiological pathogens. This study investigates the common roof types used as catchments for rainwater harvesting with the aim of establishing the quality and usefulness of the harvested water resource. Compliant levels of major and trace metals were recorded across various roof types in the three study areas. Metals of concern, such as lead (below detection limit to 0.69 μg/l), arsenic (0.06-0.13 μg/l), and cadmium (0.02-0.13 μg/l), were also within acceptable limits at all study sites. However, the average levels of E. coli detected ranged from 4.32 to 27.97 cfu/100 ml, exceeding the recommended limits set by both the World Health Organization and the South African National Standards. The trace metal levels in water collected from slate roofs were slightly higher than those from other roof types for most of the metals studied. The quality of the water obtained from various roof types indicates it is suitable for all domestic purposes, including drinking after disinfection. No significant differences were observed in the water quality across the different rooftops in the study areas. PRACTITIONER POINTS: Different roofing materials did not significantly affect the quality of the harvested rainwater. Water quality of the harvested rainwater complied with regulatory standards except for microbial water quality parameters. Rainwater can be used for several domestic purposes without treatment except for drinking purposes where it should be treated with a simple point-of-use water treatment system. First flush should be discarded as it impacts greatly on the water quality parameters determined. Rainwater harvesting offers an alternative and supplementary form of water supply in the semi-arid region of South Africa.

Recent advances in atmospheric water harvesting technology and its development.

Water scarcity is a pressing issue worldwide. Given the ample atmospheric water sources, water harvesting from the atmosphere presents a promising solution to this challenge. In recent years, the solar-driven atmospheric water harvesting technology utilizing an adsorption-desorption process has garnered considerable interest. This is attributed to the abundant availability of solar energy, advanced adsorbents, improved photothermal materials, sophisticated interface heating system designs, and efficient thermal management techniques, all of which collectively enhance conversion efficiency. This article provides an overview of the advancements in atmospheric water collection, specifically focusing on hygroscopic water harvesting driven by solar energy. The discussion also encompasses the roles of materials, surfaces, equipment, and systems in enhancing water collection efficiency. By outlining both the advantages and challenges of atmospheric water collection, this study aims to shed light on future research directions in this research field.