Scarcity Of Potable Water Research Articles

IOT-Based Smart Irrigation System using DTMF and 8051 MCU

Abstract: In almost every facet of agriculture and gardening, irrigation is the cornerstone activity, with the regular watering of plants and crops paramount to their growth and well-being. However, this essential task often proves burdensome for individuals preoccupied with daily commitments. For farmers, the significance of water supply is further emphasized, as rainwater assumes a critical role in sustaining their crops. While relying on the unpredictability of monsoon rains, canals, and groundwater resources, farmers face the challenges of ensuring a consistent and appropriate water supply, as each crop type necessitates distinct watering regimens. Any insufficiency in providing water to crops can lead to devastating consequences, resulting in the potential destruction of crops and plants. Addressing these challenges and aiming to revolutionize irrigation practices, this paper proposes an IOT-based Smart Irrigation System using DTMF (Dual Tone Multi-Frequency) and 8051 MCU (Microcontroller Unit) as an innovative and transformative solution. This cutting-edge system combines the power of DTMF technology with the versatility of the 8051 microcontrollers, enabling remote control and monitoring of the irrigation process. By leveraging the interactive capabilities of mobile or landline phones, the system allows users, including farmers and gardeners, to conveniently manage irrigation operations from a distance, reducing the need for constant physical presence. This intelligent irrigation system exhibits applicability in automating the irrigation processes of various settings, including gardens, nurseries, and greenhouses. By carefully regulating the water supply to plants based on specific predefined conditions, the system ensures the provision of an optimal and essential amount of water. As a result, the system achieves energy conservation while effectively mitigating any potential water scarcity issues.

Hydratable Core-Shell Polymer Networks for Atmospheric Water Harvesting Powered by Sunlight.

The development of technologies to enable fresh water harvesting from atmospheric moisture could help overcome the problem of potable water scarcity. Here, an atmospheric water harvesting (AWH) device is assembled in a core-shell structure, with the core consisting of networks of alginate (Alg) and polyaniline (PANI) and the outer layer consisting of thermo-responsive poly(N-isopropylacrylamide) (PNIPAM) modified with sulfonic acid groups (SPNIPAM) to increase the water adsorption at low relative humidity. The resulting hydrogel, modified with lithium chloride (LiCl) for increased water storage capacity (SPNIPAM-Li-PANIAlg), displays a similar lower critical solution temperatureto pristine PNIPAM (32 °C) while affording a 15-fold higher water capture ratio, and releases water upon exposure to sunlight at intensities less than 1kW m-2 . The developed AWH system is capable of harvesting 6.5 L of water per kilogram in a single daily absorption/desorption cycle under sunlight and can operate at relative humiditylevels as low as 17% with no additional external energy input. The thermo-responsive hydrogel SPNIPAM-Li-PANIAlg exhibits excellent stability during natural sunlight-driven absorption/desorption cycles for at least 30 days, and allows sustainable harvesting of over 28.3 L kg-1 from a moisture-rich environment by means of multiple absorption/desorption cycles.

Carbon-based electrode materials with ion exchange membranes for enhanced membrane capacitive deionization

Potable clean water is in high demand for human life. Numerous technologies like reverse osmosis, flash distillation and electrodialysis are employed and explored to overcome the scarcity of potable water. Last decade has witnessed great attraction of researchers towards membrane capacitive deionization (MCDI) as an alternative technology for water desalination. MCDI holds ability to compete with benchmark desalination techniques as it involves adsorption of ions by porous carbon material on application of low voltage (<1.4 V). Ions are desorbed back into the stream on reversing the potential hence, regenerating the electrodes. Addition of ion exchange membranes enhances the desalination efficiency by reducing the effect of co-ions, which is not possible in traditional capacitive deionization (CDI). Present study aims to synthesize and explore the best fit carbon-based material for MCDI. SPEEK and QPPO polymers were used for CEM and AEM preparation over the porous carbon materials respectively. SEM, XRD and Raman spectroscopy were used to investigate the structural information about carbon materials. Nyquist plots were obtained to analyze diffusive behavior and formation of electrolyte double layer (EDL) on electrode-electrolyte interface. Capacitive behavior of the electrodes was analyzed through cyclic voltammetry (CV) and Galvanostatic charge discharge (GCD). Water desalination performance of membrane coated carbon materials was observed through batch-mode MCDI set-up. Important CDI parameters like salt adsorption capacity (SAC) and specific capacitance were also calculated to evaluate performance of the prepared MCDI electrodes. Among all four synthesized materials, CMGO (carbon spheres modified graphene oxide) reports highest SAC value i.e. 22.5 mg g−1 which suggest CMGO as a promising material for large scale MCDI application.

Performance evaluation of pilot-scale reverse osmosis spiral wound membrane for water desalination systems

Abstract The increasing scarcity of potable water increases the demand for non-conventional potable water resources such as desalination. Experiments are carried out using a pilot-scale device of the desalination process for three configurations of membrane allocation inside the pressure vessel. Configuration (A) is one pressure vessel containing one spiral wound membrane (SWM), (B) is four pressure vessels each containing one SWM connected in parallel, and (C) is one pressure vessel containing four membranes connected in parallel. The effect of applied pressure, temperature, and water salinity is studied. Moreover, a mathematical model using ANSYS Fluent was developed and verified using the experimental data. The mathematical model is applied to an idealized case of an actual desalination plant. The main findings are (1) configurations (B) and (C) accomplished higher permeate discharge comparing to (A) by an average percentage of 60 and 50, respectively, while (C) has the lowest output salinity by 30% from configuration (A). (2) The mathematical model is found to reduce the operating pressure of the plant by 8%.

Use of condensed water from air conditioning equipment as a strategy to face the global scarcity of freshwater: a review

The increase in the world's demand for water has become one of the most relevant topics on environmental sustainability and the conservation of water resources. As a result of the scarcity of potable water, processes such as the use of water through practices, techniques, and technologies for its efficient use have become essential for future generations. Among the possibilities for using water, air conditioning systems stand out, due to the formation of condensed water during operation. The world's population is increasingly concerned about environmental issues, showing that it is necessary to seek alternatives to recycle water, whether for use in gardening, sewage systems, washing sidewalks, and cars, among others. The present study carried out a literature review to reflect on the theme of the reuse of condensation water from air conditioners as a strategy for the sustainable use of water resources and enhancing the future of planet Earth.

Natural way of treatment of domestic waste water by using anaerobic unit and engineered wetlands with phytoremediation

Population of world increase day by day and it may raise more than 9 billion upto 2040. Fresh potable water for drinking, domestic and agricultural use is life line of human, animals, plants. In present situation most of the countries fight with this scarcity of potable water. And in future situation will be very tuff. Construction of engineered wetlands is concept based on natural wetlands. Now days reduction of natural wetlands cause of water pollution, soil pollution and reduction of bio diversity. Processes of engineered wetlands surpass the problems of natural wetlands and will increase the capacity of waste water treatment process. Constructed wetland treated waste water on basis of natural process which is completely non-hazardous, eco-friendly and non-consumption of energy. At in present condition, land is costlier and most of the wetlands vanish due to effective use of lands, hence we found various hazardous changes like ground water depletion, increase of greenhouse gases (Methane, CO2), disturbance/vanishing of bio diversity lived into wetlands. Wetlands are also play a major role for flying animals, water animals for food chain and food web. Development of wetland is always cost effective, durable as compare to others conventional waste water treatments and engineered developed waste water treatment plants. Now a day’s, it very necessary to develop the techniques to reduce carbon foot prints and adopts those technology completely based on natural processes. Nature provides the techniques to humans but it need some scientific and engineered way to develop. Engineered developed wetlands have beautified locality/area and without any kind of odour, smell, nuisance of flying kits etc. Wetlands with pollution absorbent plants create bio diversity and beautified locality.

Multistage interfacial thermal desalination system with metallic evaporators

Small scale and passive solar-thermal desalination system hold promise to be employed in decentralized and off-grid areas to address scarcity of potable water. Here, we present a compact multistage thermal desalination system based on interfacial evaporation and latent heat recovery. We develop a textured metallic evaporator substrate that serves as a wick and reduces the thermal resistance for interfacial evaporation. We demonstrate that the rate of evaporation can be increased by tuning the wettability of the condenser surface. Patterned wettability-contrast surfaces are shown to enhance the rate of condensation compared to an unpatterned substrate with spatially uniform wettability. In a single stage desalination system, with patterned condenser surfaces, the evaporation rate increases by ~11 % and the water collection increases by ~21 % compared to that using an unpatterned condenser substrate. The thermal to vapor efficiency of ~56 % in a single stage increases to ~185 % with the use of multistage system. We achieve a water collection of ~2.17 Lm−2 h−1 using a 5-stage system. A theoretical model based on heat and mass transport analysis is used to determine the influence of the system geometry and ambient conditions on the overall efficiency of the desalination system.

Use of condensed water from air conditioning equipment as a strategy to face the global scarcity of freshwater: a review

The increase in the world's demand for water has become one of the most relevant topics on environmental sustainability and the conservation of water resources. As a result of the scarcity of potable water, processes such as the use of water through practices, techniques, and technologies for its efficient use have become essential for future generations. Among the possibilities for using water, air conditioning systems stand out, due to the formation of condensed water during operation. The world's population is increasingly concerned about environmental issues, showing that it is necessary to seek alternatives to recycle water, whether for use in gardening, sewage systems, washing sidewalks, and cars, among others. The present study carried out a literature review to reflect on the theme of the reuse of condensation water from air conditioners as a strategy for the sustainable use of water resources and enhancing the future of planet Earth.

An integrated socio-economic agent-based modeling framework towards assessing farmers’ decision making under water scarcity and varying utility functions

A spatio-temporal Agent Based Modeling (ABM) framework is developed to probabilistically predict farmers' decisions concerning their future farming practices when faced with potential water scarcity induced by future climate change. The proposed framework forecasts farmers' behavior assuming varying utility functions. The functionality of the proposed ABM is illustrated in an agriculturally dominated plain along the Eastern Mediterranean coastline. The model results indicated that modelling farmers as agents, who were solely interested in optimizing their agro-business budget, was only able to reproduce 35% of the answers provided by the farmers through a administered field questionnaire. Model simulations highlighted the importance of representing the farmers' combined socio-economic attributes when assessing their future decisions on land tenure. This approach accounts for social factors, such as the farmers' attitudes, subjective norms, social influence, memories of previous civil unrest and farming traditions, in addition to their economic utility to model farmer decision making. Under this scenario, correspondence between model simulations and farmers' answers reached 95%. Additionally, the model results show that when faced with the negative impacts of climate change, the majority of farmers seek adaptive measures, such as changing their crops and/or seeking new water sources, only when future water shortages were predicted to be low to moderate. Most opt to cease farming and allow their lands to urbanize or go fallow, when future water shortages were predicted to be high. Meanwhile, incorporating and modeling the social influence structures within the ABM diminished farmers' willingness to adapt and doubled their propensity to sell or quit their land. The proposed framework is able to account for a variety of utility functions and to successfully capture the actions and interactions between farmers and their environment; thus, it represents an innovative modeling approach for assessing farmers’ behavior and decision-making in the face of future climate change. The nonspecific structure of the framework allows its application at any agriculturally dominated setting facing future water shortages promulgated by a changing climate.

An Empirical Investigation on Plastic Waste Issues and Plastic Disposal Strategies to Protect the Environment: A UAE Perspective

Due to the rise in waste, both developed and developing countries’ municipal solid waste (MSW) disposal systems are overburdened. The increased inflow of used plastic water bottles has rendered the situation difficult. Plastic usage in several forms is becoming indispensable in daily life, despite its harmful effects on humans and animals in general. Government bodies are eager to cut plastic usage in several forms, but the manufacturing costs and selling prices make it difficult to replace plastic with materials that are safe for living bodies. One such problem lies in the form of the water bottle. The use of plastic in water bottles is much more common in Gulf countries because of their geographical position and the scarcity of potable water. The large amount of plastic waste created by used water bottles is a very critical issue, as it has a severe environmental effect and is a hurdle in efforts to foster sustainable development and green initiatives. The present research undertook an empirical investigation on plastic waste issues, environmental concerns, and various mitigating initiatives. It further investigated the waste management system using closed-loop recycling for water bottles as an efficient means of managing MSW and protecting the environment in the UAE. A survey was initiated and distributed among the UAE population to study the feasibility of building such a system. The responses to the plastic waste issue and mitigating solutions were found to be encouraging. The statistical analysis showed a higher mean value of up to 4.47 on the 5-point Likert scale.

Potable water generation from atmospheric moisture in coastal areas using the thermoelectric effect

Although water covers more than two-thirds of the globe’s area by a percentage of approximately 70 %, safe potable water is still scarce and therefore many countries where freshwater resources are scarce have directed to conduct many research and studies to find a suitable way to provide potable water, from this standpoint, many countries that possess coasts on the sea, including Egypt, have tended to desalinate seawater, but this method is very expensive and may be disrupted for various technical reasons such as lack of energy to operate or damage mechanical parts, and this is what happened recently in the Egyptian northern coast and the Red Sea islands. They depend on desalination plants or bottles of mineral water extracted from wells to meet their potable water needs. This article aims to solve the problem of potable water scarcity in the northern coast of Egypt, which is characterized by the high relative humidity of air in the atmosphere (60-80%) by designing a portable potable water capture device that depends on the (Peltier Effect) and takes the energy necessary to operate it from solar energy. This device can generate 2.86 L/h of fresh potable water at a temperature of 30 O C and Relative humidity of R.H = 60 %.

Three staged integrated community-based water filter system for potable water by effective removal of contaminants from ground water

Potable water scarcity is a dire problem faced worldwide due to contaminated ground water. Microbial contaminants, heavy metals chromium (Cr) and metalloid such as arsenic (As) are some of the major pollutants of ground water and pose serious health hazards. The present work is focused to design a multifunctional three compartment integrated water filtration system for community use and its validation at both lab and pilot scale. The top compartment is mainly for removal of flocculating contamination with improvement of taste and odor of drinking water. The second compartment consists of functionalized sand layers for removal of metal and microbial contaminants and the third compartment comprises of nanoparticle embedded ceramic candles to further eliminate any remaining contaminants. The developed integrated water filter containing various types of materials were characterized through flow rate, scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) before and after filtration. Moreover, the analysis of various physiological parameters such as pH, turbidity, total dissolved solids and hardness pre and post filtration elucidated stable and improved results. Micro-computed tomography (micro-CT) analysis of baked ceramic candle showed substantial increased porosity of ~83.11 ± 2.17 % in comparison to unbaked candle (26.09 ± 1.33 %). The inductively coupled plasma mass spectrometry (ICP-MS) analysis demonstrated significant reduction of As and Cr levels before and after filtration, which was further confirmed by EDS mapping. Microbial testing showed hierarchal decrease in microbial load after each stage at lab scale. This low-cost, multistage, gravity-based filtration system proved effective in removal of heavy metal and microbial contaminants in water and provides the potable filtrate for daily use. Thus, the integrated system with simple design without requiring major infrastructure and promising results may lead to its potential real-time application for supplying potable water to large populations, particularly in rural populations who cannot afford sophisticated water purification system.

Opportunities and Barriers Against Successive Implementation of Rainwater Harvesting Options to Ensure Water Security in Southwestern Coastal Region of Bangladesh

The Coastal Region of Bangladesh is surrounded by the acute crisis of safe drinking water. Potable water scarcity is an acute problem within the coastal regions of Bangladesh. Salinity intrusion in freshwater bodies, arsenic contamination, and low dry season rainfall are some of the reasons behind this deplorable condition. Such is the case in a southwestern district, Satkhira, where safe drinking water is a mirage for people. In this situation, adaptation and utilization of Rainwater Harvesting (RWH) can be considered as a globally sustainable solution among the various technologies to augment freshwater resources. RWH is becoming an integral part of the sustainable water management toolkit gradually. However, some issues are hindering the success of RWH. The absence of technical knowledge, unawareness of hygiene, economic constraints, and lack of training programs on the usage and maintenance of the technology are major reasons for reducing RWH technology's acceptability. This study assessed existing RWHs from several locations of Shyamnagar Upazila of Shatkhira district, incorporating social, economic, and institutional aspects along with policy and application gaps. A mixed-method approach was adopted for the assessment, which included 20 site inspections, questionnaire surveys among the consumers, focus groups discussions with concerning stakeholders, key informant interviews with local government officials. From the outcomes, Strength Weakness Opportunity Threat (SWOT) analysis was done to indicate opportunities and barriers which hinder the success of existing RWHs. We identified RWH as the most appropriate supplementary water source in this region. The substantial factors which enhanced the acceptance of RWH in the water-scarce area were the accessibility of water compared to other sources, improved livelihood potential, security against climate change, and provision from local government and Non-Government Organizations. Furthermore, there was enough quantity of water to support the total water need in household activities. However, a lack of knowledge and awareness was identified as a substantial social constrain of RWH use. High installation costs and the complex financial mechanism were found to be an economic obstruction to the acceptance of this system. There is a significant gap between policy and implementation at the field level. Identifying the opportunities, issues, and constraints of RWH in the study area allows stakeholders and policymakers to understand which programs, mechanisms, and strategies can be adopted for the sustainable implementation of RWH in Bangladesh. This assessment evaluates the socio-economic outcomes of an alternative water source in the coastal region, emphasizing the prominence of social awareness to sustainable development.

Experimental investigation and computational modelling of double slope solar still integrated with eutectic phase change material

The scarcity of potable water in many parts of the world is of primary concern and it is mainly due to the abrupt increase in population growth, environmental pollution and rapid social development. Solar desalination system associated with PCM can be one of the prominent solutions for conversion of saline water into fresh water. The main disadvantage of using the organic PCMs was that no single PCM possessed all of the favourable features required to operate the solar still in any environment. As a result, combining two or more different types of organic PCMs to create binary eutectic PCM increases the thermo-physical properties of PCM. The current research includes conduction of an experimental study to compare the energy efficiency and hourly yield of traditional and modified double slope single basin solar still integrated with binary eutectic PCM. The ANSYS FLUENT 19.2 workbench is used to create a multiphase three-dimensional CFD model of the solar still in order to compare experimental and simulation results in the atmospheric conditions of Bhopal (23.24° N, 77.40° E), India. The maximum experimental value of freshwater yield obtained at 3 PM is 0.31 kg/m2 h while the maximum yield in simulated result is 0.35 kg/m2 h with 11.4% difference in experimental and simulated results. Similarly, in case of conventional solar still there is maximum deviation of 10.3% in simulated result as compared to experimental values. The incorporation of PCM enhanced the average energy efficiency of modified solar still to 30.42%, which was greater than traditional solar still efficiency (22.21%). The experimental value of daily energy efficiency is 30.42%, whereas simulated result is 33.15%, with 9.06% difference in experimental and simulated results of modified still. The CFD analysis was carried out and the experimental results like basin temperature, glass cover temperature, water volume fraction and surface water temperature were also compared with simulation results for validation. It infers that the simulated and experimental findings are nearly identical, with negligible deviation.

Comparative study on stepped solar distillers internally loaded with different masses of phase change material

This experimental work discusses the thermo-enviro-economic analyses for effect of mass of paraffin wax as phase change material (PCM) on solar distillation in inclined stepped solar still (SSS). Three identically designed SSS units, namely, S1, S2, and S3 respectively, laden with 0.45, 0.90, and 1.35 kg of PCM filled in copper tubes are fabricated and tested at 25 mL/min flow rate. The findings of the experimental study manifested that the performance of SSS unit is significantly improved as the mass of the PCM is increased. The amount of distillate produced by units S1, S2, and S3 are respectively, 1.99, 2.12, and 2.18 kg. The distillate obtained from S3 unit is 8.4% and 2.6% more than S1 and S2 units, respectively. The average values of energy and exergy efficiencies of this unit are evaluated as 31.53% and 2.15%, respectively. This unit is capable to mitigate 8.28 t of CO2 per year which is 7.6% and 2.1% higher than that of units S1 and S2, respectively. Carbon credit earned by units S1, S2 and S3 are respectively, $114.78, $121.58, and $124.23. The carbon credit earned from S3 unit is the highest among tested units which inferred that unit S3 is environmentally friendlier. The total productive cost of environmentally and thermally supreme unit S3 is evaluated as $0.30 which is 6.67% and 3.34% higher than that of S1 and S2 units, respectively. The study shows that the use of PCM in solar distillation has the potential to improve its productivity which helps to eradicate the scarcity of potable water. Highlights The effect of mass of paraffin wax loading on the performance of stepped solar still is presented. Thermo-enviro-economic performance of system is observed to improve with increase in mass of paraffin wax loading. The system loaded with 1.35 kg paraffin wax is found best in environmental conservation and can mitigate 8.28 t CO2 per year. The total productive cost per day of the unit having maximum mass of paraffin wax is $0.30.

Erosion-control interventions associated with pond-catchment rehabilitation on the Borana plateaus, Southern Ethiopia

Among the major problems of Borana pastoralists are scarcity of potable water inside dry season and gully erosion in a widespread on the Borana plateau. Gullies are the main pathway for sediment accumulation in community ponds, which reduces pond capacity. Ponds are therefore a critical source of water during dry seasons the Borana rangelands. However, most ponds rapidly fill with sediment from eroding catchments after rainfall events and hence, their water holding capacity gradually get reduced. Much work is then required each year from the communities to remove sediment manually. Erosion of pond catchments is the consequence of uncontrolled grazing that causes heavy grazing and trampling by livestock. Sediment movement in gullies can be substantially reduced by installation of sieve structures that slow down water flows and allow sediment to settle out of suspension. Sieves can be easily constructed from trees by community labour at low cost. Yabello researchers have demonstrated that a series of sieve structures down a secondary gully in Bunaka and Liban Jatani pond that effectively trap sediment. When gully head treatments are accompanied by a series of sieves in the main channel, gully erosion can be arrested, gully floor and walls re vegetated and sediment captured. Overall, protection of grazing land from livestock reach for only one year led to a 55.45% increase in ground cover. Similarly, increases in cover tended to be greater (118.1 % more) at Liban Jatani pond that had less cover at the beginning when compared to Bunaka pond. Protection from livestock grazing led to substantial increases in ground cover. Within the Liban Jatani pond enclosure, ground cover steadily increased at each sampling period by 7.1% in June 2019, 11.13% in November 2019.

Water Management Issues in Indian Cities: Case Study of Gwalior, Madhya Pradesh, India

Abstract: Urban development has a substantial role for depleting and polluting surface water sources along with contamination of ground water sources. It creates several uncertain circumstances due to reduction in quantity of water and this land become barren on surfaces. As a result, people started to encroach it, which further impact on water bodies in undesirable way. These water bodies are anguish due to continuous pollution and change the way of treatment of urban water bodies, even government also converted these water bodies and rivers in to drain and area for dumping garbage. These are also miss used by local communities for many purposes like open defecations, occasionally these are used for immersion of idol due to lack of facilities and other reasons too. Besides all of these Industrial effluents, run off from nearest agricultural fields, refuse from sewage and other domestic wastes provide a nice platform for eutrophication. (http://spaenvis.nic.in/index1.aspx?) Now everyone is worried about the potential water scarcity in the face of increasing, mainly population-driven, water demands, and its consequences on our energy and food production. The Over 900 recognized professionals conducted a survey for under the heading “Global Risk Perception Survey”, it is directed by the World Economic Forum. They found that reports that the highest level of common impact over the next 10 years will be from water crises. (http://www3.weforum.org/docs/WEF_Global_Risks_2015_Report15). So, this paper is an attempt to see challenges in Indian fast-growing cities and how we can manage water resource those are engulfed by rapid urbanization. Principally focused on the depleted source and characterize their conditions. Keywords: Urban Water Bodies, Water management, Water Crisis, Urbanization, Globalization, Indian Cities, Gwalior.

Potential application of nanotechnology in wastewater management: A paradigm shift

Water contamination adversely affects the environment and human health and has significant socioeconomic implications. Scarcity of potable water requires effective strategies for wastewater treatment. Conventional strategies release disinfection byproducts (DBPs), consume time and are expensive. Nanotechnology uses molecules or atoms to develop new devices with enhanced optical, conductive, magnetic, mechanical, and electronic characteristics. It is an emerging viable technique for wastewater purification, but its implementation needs to be explored. In this review, we specify nanotechniques for wastewater treatment, formulated on processes of adsorption, biosorption, photocatalysis, nanofiltration, sensing and monitoring technologies. Additionally, we also interpret the future of wastewater treatment through nanotechnology and the risks associated.

Equal Access to Primary Education In Environmentally Challenged Area Of Bangladesh: A Study Into the Tanguar Haor Of Sunamganj District

The Tanguar Haor is overwhelmed with huge problems such as flash floods, poverty, extreme dependency on natural resources, lack of alternative sources of income, inadequate health facilities and sanitary latrines, scarcity of potable water, poor road connectivity, the insufficient and flimsy infrastructure of educational institutions. The main objective of this research is to find out the core causes of these problems and to examine how these problems make hindrances to ensure equal access to primary education in Tanguar Haor. Simultaneously, this study has analysed the existing scenario of primary education in this area. Both qualitative and quantitative approaches have been incorporated in this fieldwork-based study. The survey, FGD, and KII methods have been applied in this research to collect primary data from sixty (60) respondents of purposively selected villages and primary schools. The researcher has identified major drawbacks such as poverty, dropout, high repetition, absenteeism in school, shortage of enough teachers that create serious obstacles towards ensuring equal access to primary education in the Tanguar Haor of Sunamganj District. Finally, this study concludes that climate change-induced threats and environmental vulnerabilities are mainly responsible for producing these snags. Social Science Review, Vol. 38(1), June 2021 Page 175-202

A comparative study of various fatty acids as phase change material to enhance the freshwater productivity of solar still

The scarcity of potable water due to rapid growth in population, industrialization, and the continuous extraction of groundwater has led to an impending crisis. Researchers have invented numerous techniques to obtain freshwater in order to fulfill the increased requirements, and solar desalination using a solar still is one of the low-cost methods to generate freshwater. In a solar still, the usage of PCM (Phase Change Material) storage under the absorber plate enhances the productivity during the nighttime so that the still continues to generate freshwater even in the absence of solar energy. The present study undertakes the experimental, energy, exergy and economic analysis for a conventional solar still and solar stills using different types of fatty acids as PCM storage along with pin fins for enhanced heat transfer. For a comparative study of different organic fatty acids as PCM storage materials- lauric acid, palmitic acid and stearic acid were used along with high-conductive aluminum pin fins which were inserted in the PCM storage to enhance the rate of heat conduction. The results obtained using the PCM along with pin fins were compared with the output from the conventional solar still (CSS). Thus, four different cases were considered for the current study, namely: the conventional solar still (CSS); the solar still with lauric acid and pin fins (SSLA); the solar still with palmitic acid and pin fins (SSPA), and, the solar still with stearic acid and pin fins (SSSA). The experiments were performed in the months of January (representing the winter season) and May (representing the summer season), at the location Gandhinagar, Gujarat (23.22°N 72.650°E), India, with variation in the depth of water (1 cm, 2 cm and 3 cm) in the basin of solar still. The accumulated productivity, energy efficiency, and exergy efficiency were observed as 4.43 L/m2, 47.9% and 2.23% for SSLA in January, which was the maximum amongst all cases in January. The accumulated productivity, energy efficiency and exergy efficiency were 5.74 L/m2, 56.2% and 2.96% for the case of SSSA in the month of May, which was the maximum amongst all the cases. The SSSA was the economical solar still amongst all cases; the payback period and cost per liter of SSSA were 72 days and 0.016 $/L/m2, respectively.