Amount Of Fresh Water Research Articles

Estimation of pressure drop in a demister for multi-stage flash desalination process based on stacked long short-term memory (LSTM) neural networks

The thermal desalination process such as a multi-stage flash desalination process (MSF) uses demisters as the separator between the flashed off vapor and the brine droplets in the flashing stage. The performance of the MSF plant depends on the quantity of fresh water produced. The separation efficiency depends on the pressure drops in the demister that influences the plant performance. This study proposes the application of Long Short-Term Memory (LSTM) neural networks for estimating pressure drop across demisters. The stacked LSTM algorithm is effective in estimating the pressure drop for experiment and real plant data. The superiority of stacked LSTM algorithm above reference benchmarks is evident. The Root Mean Square Error (RMSE) of the estimation from stacked LSTM algorithm is less than the estimation from the work of Al-Fulaij et al CFD model Al-Fulaij H, et al 2016, Desalination, 385: 148–157 by 40%.

Analysis of Conveyance Losses from Tertiary Irrigation Network

Irrigation canals are generally made through porous soil formations, since the soil is loose porous media – a huge amount of canal water is lost to conveyance losses. The situation becomes direr when these losses result in non-beneficial losses. The Sindh province of Pakistan has more than 70% saline groundwater, conveyance losses to such areas in the province not only become unusable but also creates water management problems. Perhaps the only cost-effective way to address these losses is canal lining. The present study was conducted in the command area of Belharo distributary, Sindh, Pakistan with an aim to determine the extent of losses from the tertiary irrigated network as these water channels are less considered in the literature with regards of conveyance losses. Using water balance method, conveyance efficiency and conveyance losses at 30% lined and 50 and 75% unlined length of the watercourses was observed. The results revealed that the tertiary irrigation channels face an average of 43% conveyance losses and major proportion of these losses is lost to non-beneficial losses from the study area. The study further suggests 75% lining of watercourses in order to minimize non-beneficial losses. This study also infers that with the use of geo-membrane lining, sizeable amount of fresh water can be saved. Doi: 10.28991/cej-2021-03091756 Full Text: PDF

Performance assessment of a desalination system integrated with ground heat exchanger for hydrogen and fresh water production

AbstractGround heat exchangers, which enable the utilization of shallow geothermal energy, have been widely used in recent years in order to improve the performance of systems. In the present study, theoretical performance of a humidification–dehumidification desalination system integrated with a ground heat exchanger in order to increase the productivity of the system was investigated. The system employed photovoltaic–thermal panels and polymer electrolyte membranes to meet the electrical and thermal energy requirement as well as producing hydrogen, respectively. The present study examined the impact of each parameter, namely solar radiation, soil temperature, and mass flow rate on the gained output rate, thermal efficiency of the photovoltaic‐thermal panel, the amount of fresh water, and hydrogen production. The results revealed that the solar radiation, soil temperature, and the mass flow rate ratio had a significant impact on the performance of the system, and that the capacity of hydrogen and fresh water production, and the gained output ratio of the system were in the range of 0.08–0.16 kg/h, 2–16 kg/h, and 0.1–0.5, respectively.

Decomposition Analysis of Global Water Supply-Demand Balances Focusing on Food Production and Consumption

Food production and consumption require large amounts of freshwater. There is no literature on the decomposition analysis of the intensities of water supply-demand balances (water balance intensities) for each country worldwide. The aim of this study is to evaluate the water balance intensities and elucidate the promoting factors and offset factors of water balance intensities for each country worldwide, focusing on food supply-demand balances and considering food trade balances on a global scale. The modified Laspeyres index method is applied to both a production-based water balance index (WBIPB) and a consumption-based water balance index (WBICB). The major promoting factor for the WBIPB is the renewable freshwater resources, whereas the major offset factor is the produced item preference. The major promoting factor for the WBICB is the consumed item preference, whereas the major offset factor is the producing area preference. Improving irrigation efficiencies of rice and cereals is effective because rice requires the largest blue water footprint intensities, considering irrigation efficiency on a calorie content basis in all of the items, whereas cereals are the largest share of calorie-based production quantities in all of the items worldwide. This study provides the foundation for decreasing water balance intensities regarding food production and consumption.

Ecosystem services provision by Mediterranean forests will be compromised above 2℃ warming.

Forests provide a wide range of provisioning, regulating and cultural services of great value to societies across the Mediterranean basin. In this study, we reviewed the scientific literature of the last 30years to quantify the magnitude of projected changes in ecosystem services provision by Mediterranean forests under IPCC climate change scenarios. We classified the scenarios according to the temperature threshold of 2℃ set by the Paris Agreement (below or above). The review of 78studies shows that climate change will lead to a general reduction in the provision of regulating services (e.g. carbon storage, regulation of freshwater quantity and quality) and a general increase in the number of fires, burnt areas and generally, an increase in climate-related forest hazards (median+62% by 2100). Studies using scenarios above the 2℃ threshold projected significantly more negative changes in regulating services than studies using scenarios below this threshold. Main projected trend changes on material services (e.g. wood products), were less clear and depended on (i) whether or not the studies considered the interaction between the rise in temperatures and other drivers (e.g. forest management, CO2 fertilization) and (ii) differences in productivity responses across the tree species evaluated. Overall, the reviewed studies projected significant reductions in range extent and habitat suitability for the most drought-sensitive forest species (e.g. -88% Fagus sylvatica), while the amount of habitat available for more drought-tolerant species will remain stable or increase; however, the magnitude of projected change for these more xeric species was limited when high-end extreme climatic scenarios were considered (above Paris Agreement). Our review highlights the benefits that climate change mitigation (to keep global mean temperature increase <2℃) can bring in terms of service provision and conservation of Mediterranean forests.

Challenges and opportunities for sustaining coastal wetlands and oyster reefs in the southeastern United States

Formed at the confluence of marine and fresh waters, estuaries experience both the seaside pressures of rising sea levels and increasing storm severity, and watershed and precipitation changes that are shifting the quality and quantity of freshwater and sediments delivered from upstream sources. Boating, shoreline hardening, harvesting pressure, and other signatures of human activity are also increasing as populations swell in coastal regions. Given this shifting landscape of pressures, the factors most threatening to estuary health and stability are often uncertain. To identify the greatest contemporary threats to coastal wetlands and oyster reefs across the southeastern United States (Mississippi to North Carolina), we summarized recent population growth and land-cover change and surveyed estuarine management and science experts. From 1996 to 2019, human population growth in the region varied from a 17% decrease to a 171% increase (mean = +43%) with only 5 of the 72 SE US counties losing population, and nearly half growing by more than 40%. Individual counties experienced between 999 and 19,253 km2 of new development (mean: 5725 km2), with 1–5% (mean: 2.6%) of undeveloped lands undergoing development over this period across the region. Correspondingly, our survey of 169 coastal experts highlighted development, shoreline hardening, and upstream modifications to freshwater flow as the most important local threats facing coastal wetlands. Similarly, experts identified development, upstream modifications to freshwater flow, and overharvesting as the most important local threats to oyster reefs. With regards to global threats, experts categorized sea level rise as the most pressing to wetlands, and acidification and precipitation changes as the most pressing to oyster reefs. Survey respondents further identified that more research, driven by collaboration among scientists, engineers, industry professionals, and managers, is needed to assess how precipitation changes, shoreline hardening, and sea level rise are affecting coastal ecosystem stability and function. Due to the profound role of humans in shaping estuarine health, this work highlights that engaging property owners, recreators, and municipalities to implement strategies to improve estuarine health will be vital for sustaining coastal systems in the face of global change.

The 6th International Conference On Climate Change (6th ICCC) Preface

Intro and Goal Covid-19 pandemic teaches us that climate change impact sometimes incredibly unpredictable. Not only the increase of heat exposure or natural hazard due to extreme weather, but the emergence of new species or the mutation of microorganism due to the changing ecology may harmful for human beings and another organism. This anthropological climate change phenomenon has negatively altered the most fundamental natural resources for living organism: air, water, and soil. Air has been polluted and warming due to human activities. The quantity of freshwater keeps on depleting, while the ground water recharge intervened with chemical and biological contamination. The sustainability of soil as the natural planting media is under threat due to land use conversion and soil quality degradation. Water acidification and temperature increase have been proved to change the salinity of seawater. Those climate change sensitive exposure may affect the immune system of the living things to survive. Those conditions grow the concern for the health status of humans, crops, farmed and wild animals.Understanding the mechanism whereby the climate change exposures affects the immunomodulation in living organisms may mitigate the negative health risks outcome. According to the circumstances, the 6th International Conference on Climate Change (ICCC) is focusing the discussion on climate change effects on immunomodulation as it is also the main topic of Sebelas Maret University of the 45th Dies Natalis’ anniversary address. Focusing and improving the climatic resilience strategies on immune system will be of considerably important to overcome the key climate-change sensitive pathways, as well as to support the achievements some global goals in the Sustainable Development Goals (SDGs). The goal of the 6th ICCC was to accommodate the new related inspiration and innovation about how to minimize the climate change impact at present. It formulated a comprehensive and efficient strategies on how to minimize the risk of outbreak and hazards caused by climate change.The 6th ICCC 2021 is organized by The Graduate School of Sebelas Maret University (Surakarta, Indonesia), collaborating with The United Graduate School of Agriculture Science (UGSAS), Gifu University (Japan) together and UNS Forestry Education and Training Center (UPT Pusat Pendidikan dan Pelatihan Kehutanan, UNS) (Karanganyar, Indonesia). The 6th ICCC is also part of Sebelas University 45th Dies Natalis Anniversary celebration activities, as can be seen in the e-poster of call for papers presented in Figure 1.List of titles Invited Speakers and Guest Editors, Virtual Conference Disclaimer, Date of conference, Location of organizer and Conference model, Location of participants and overall participant number, Committee List, The success of delivery of the conference are available in this Pdf.

Water Footprint and the Impact of Food Production Environmental Sustainability

Freshwater is a sparse source. It takes a significant amount of water to get food that we eat from the fields to the plates on our dining room tables. What we eat makes up a large number of our water footprints. A water footprint is used to indicate the amount of freshwater that any given process or activity uses. In addition to our diets, issues revolving around water footprint include water depletion and pollution. Water depletion, specifically freshwater depletion refers to the lack of sufficient available freshwater resources to meet water demand. Water pollution occurs when harmful substances such as microorganisms contaminate a source of fresh water such as a lake, stream, or river. The water footprint of food is significantly high and that is why it is important that we reduce food waste to preserve and protect the food available to us.

Water reuse and growth inhibition mechanisms for cultivation of microalga Euglena gracilis

BackgroundMicroalgae can contribute to more than 40% of global primary biomass production and are suitable candidates for various biotechnology applications such as food, feed products, drugs, fuels, and wastewater treatment. However, the primary limitation for large-scale algae production is the fact that algae requires large amounts of fresh water for cultivation. To address this issue, scientists around the world are working on ways to reuse the water to grow microalgae so that it can be grown in successive cycles without the need for fresh water.ResultsIn this study, we present the results when we cultivate microalgae with cultivation water that is purified and reused. Specifically, we purify the cultivation water using an ultrafiltration membrane (UFM) treatment and investigate how this treatment affects: the biomass and biochemical components of the microalgae; characteristics of microalgae growth inhibitors; the mechanism whereby potential growth inhibitors are secreted (followed using metabolomics analysis); the effect of activated carbon (AC) treatment and advanced oxidation processes (AOPs) on the removal of growth inhibitors of Euglena gracilis. Firstly, the results show that E. gracilis can be only cultivated through two growth cycles with water that has been filtered and reused, and the growth of E. gracilis is significantly inhibited when the water is used a third time. Secondly, as the number of reused water cycles increases, the Cl− concentration gradually increases in the cultivation water. When the Cl− concentration accumulates to a level of fivefold higher than that of the control, growth of E. gracilis is inhibited as the osmolality tolerance range is exceeded. Interestingly, the osmolality of the reused water can be reduced by replacing NH4Cl with urea as the source of nitrogen in the cultivation water. Thirdly, E. gracilis secretes humic acid (HA)—which is produced by the metabolic pathways for valine, leucine, and isoleucine biosynthesis and by linoleic acid metabolism—into the cultivation water. Because HA contains large fluorescent functional groups, specifically extended π(pi)-systems containing C=C and C=O groups and aromatic rings, we were able to observe a positive correlation between HA concentration and the rate of inhibition of E. gracilis growth using fluorescence spectroscopy. Moreover, photosynthetic efficiency is adversely interfered by HA, thereby reductions in the synthetic efficiency of paramylon and lipid in E. gracilis. In this way, we are able to confirm that HA is the main growth inhibitor of E. gracilis. Finally, we verify that all the HA is removed or converted into nutrients efficiently by AC or UV/H2O2/O3 treatments, respectively. As a result of these treatments, growth of E. gracilis is restored (AC treatment) and the amount of biomass is promoted (UV/H2O2/O3 treatment).ConclusionsThese studies have important practical and theoretical significance for the cyclic cultivation of E. gracilis and for saving water resources. Our work may also provide a useful reference for other microalgae cultivation.

Assessment of Climate Change Awareness in the Kakamega-Nandi Forest Complex in the Western Region

Aims: This study assessed the level of climate change awareness among the forest-adjacent communities in the Kakamega-Nandi forest ecosystem complex. Four locations were chosen for the study, Buyangu and Isecheno in the Kakamega forest, Kaptumo in Nandi South and Kipsamoite in Nandi North forest ecosystems.&#x0D; Study Design: A cross-sectional survey design was used to collect data from primary sources. Structured questionnaires were administered to the residents aged 25years and older within the study area.&#x0D; Place and Duration of Study: The Kakamega, north and south Nandi forest ecosystems in western Kenya between June -December 2019.&#x0D; Methodology: A total of 280 questionnaires were randomly administered to the forest-adjacent respondents with, Kakamega forest 163 respondents, South Nandi forest 60, while North Nandi had 57respondents. A total of 217 questionnaires were filled and returned and the information wherein used in data analysis. Focused Group Discussion and key informants were used to supplement data collects by the questionnaires.&#x0D; Results: Majority of the residents (54%) were less concerned about climate change. In addition, 85% of the respondents had very little knowledge on coping and adapting to the adverse impacts of climate change. Some 40 % and 45% of the respondents got information about climate through televisions and radios, respectively. Further analysis of the results revealed that climate change was responsible for fourteen key impacts. These included an increase in rainfall, prolonged drought, decrease in the quality and quantity of fresh water, decrease in food security, an increase in temperature, a decrease in agricultural resources, an increase in sickness and disease, a decrease in quality of life, flooding, decrease in forest cover, loss of homes, reduction in biodiversity, and rise in storm surge. A Chi test revealed a significant relationship between forest cover decline and changes in rainfall patterns (X2 = 111.86, df =12, p&lt;0.001), increasing temperature (X2 = 80.492, df =12, p&lt;0.001);, drought( (X2 = 204.84, df =16, p&lt;0.001) and storm surges (X2 = 74.34, df =8, p&lt;0.001)]. The respondents' level of education was significantly different from their level of climate change awareness (X2=44.88, df=4, p&lt;0.001).&#x0D; Conclusion: Forest-adjacent communities in the Kakamega-Nandi forest ecosystem complex are vulnerable to climate change as a result of insufficient knowledge about climate change and its impacts. The Kakamega-Nandi forest ecosystem is already experiencing climate change effects such as erratic rainfall and increasing food insecurity.

Does Nitrate Enrichment Accelerate Organic Matter Turnover in Subterranean Estuaries?

Due to the widespread pollution of coastal groundwaters with fertilizers, submarine groundwater discharge (SGD) is often thought to be a large dissolved inorganic nitrogen (DIN) source to the ocean. Whether this N is autochthonous or allochthonous to the subterranean estuary (STE), the availability of large quantities of DIN can nevertheless interact with the cycling of other elements, such as carbon (C). In previous studies, we documented the discharge of large quantities of freshwater and NO3– from the mouth of an STE into the Ria Formosa lagoon (SW Iberian Peninsula). For the period covered in this study (2009–2011), the same STE site was dominated by recirculating seawater due to a prolonged fall in piezometric head in the coupled coastal aquifers. Total SGD rates remained similarly high, peaking at 144 cm day–1 at the lower intertidal during fall. We observed a progressive increase of NO3– availability within the STE associated with the recovery of piezometric head inland. Interestingly, during this period, the highest SGD-derived dissolved organic C and DIN fluxes (112 ± 53 and 10 ± 3 mmol m–2 day–1, respectively) originated in the lower intertidal. NO3– enrichment in the STE influences the benthic reactivity of fluorescent dissolved organic matter (FDOM): when seawater recirculation drives STE dynamics, only small changes in the benthic distribution of recalcitrant humic-like FDOM are observed (from −2.57 ± 1.14 to 1.24 ± 0.19 10–3 R.U. “bulk” sediment h–1) in the absence of DIN. However, when DIN is available, these recalcitrant fractions of FDOM are actively generated (from 1.32 ± 0.15 to 11.56 ± 3.39 10–3 R.U. “bulk” sediment h–1), accompanied by the production of labile protein-like FDOM. The results agree with previous studies conducted with flow-through reactor experiments at the same site and suggest that DIN enrichment in the STE enhances the metabolic turnover of sedimentary organic matter up to the point of discharge to surface waters. DIN pollution of coastal aquifers may therefore promote a contraction of the residence time of particulate organic C within the STE, driving carbon from continental storage into the sea.

Use of efficient water saving techniques for production of rice in India under climate change scenario: A critical review

Rice uses 34 to 43 per cent of the global irrigation water and is responsible for the withdrawal of 24–30 per cent of the of World's total freshwater. In Asia, irrigation consumes greater than 80% of the freshwater resources available and among that rice irrigation accounts for more than 50%. The amount of water applied to produce 1 kg of rice ranges from 800 to 5000 L, with an average value of about 2500 L. Earlier studies indicated that seasonal water requirement for rice ranged from 660 to 5280 mm depending on the climatic features, growing season, hydrological framework and type of soil conditions, with the average value range from 1000 to 2000 mm as a mean value in most cases. Several approaches of water saving techniques such as, AWD- Alternate Wetting and Drying, SSC- Saturated Soil Culture, aerobic rice, ground-cover systems, SRI- System of Rice Intensification, raised beds, etc. are discussed in lieu of frequent occurrence of extreme weather events and depleting water resources globally. Climate change and variability alters the water requirement, a simulation study by CROPWAT for temperature increase from 0.5 to 3.0 °C resulted in an increase in the irrigation water requirement from 0.6 to 3.7%, respectively. Future climate models showed that the rice growing area and yield of paddy tends to have a minor increase (1.55%) in some of the RCPs. Adopting innovative water saving techniques are absolutely essential for maintaining the food security (future rice production) due to increasing water scarcity under the changing climate scenario. Water savings in rice farming through different approaches are discussed and even adoption of any of these practices will transform into saving of larger quantity of water, since huge quantities of fresh water is used for rice cultivation. Because of the continuously depleting water table due to natural and anthropogenic factors, here we have explored to exploit the potentials of various water-saving approaches and the strategies for improving the water productivity along with the improved yield of rice in this review.

Variasi Diameter Nozzle Terhadap Lamanya Proses Vakum Pada Fresh Water Generator di Laboratorium Polimarin

Ejector is a static pump which is worked by a vacuum principal. A vacuum which is happened in the ejector affect the performance and the ability of suction on the secondary mass flow section. A vacuum ejector in the fresh water generator affects the amount of fresh water which is generated. The objective of this research is to know the affection of variation in the outlet diameter of the nozzle towards secondary mass flow, especially on the air suction section (vacuum). In this research, an analysis has been done in a fresh water generator (FWG) with three alternative design of the outlet diameter of the nozzle using Computer Fluid Dynamics (CFD) method to get the optimal performance. The inlet pressure of primary flow is regulated to be steady at 3 bars. The variations of the diameter outlet of the nozzle are 4, 6, and 8 mm. The distance between the edge of the nozzle with outlet flow of the pipe is made at a settled position. The edge of the nozzle is at 3 mm inside the outlet flow of the pipe measured from the inside edge of the pipe. The result of CFD method is shown that on the variation of the outlet diameter of the nozzle 8 mm has the biggest mass flow (4.6838048 kg/s) between 4 and 6 mm. The implication of this research is that the outlet diameter of the nozzle 8 mm has the maximum value of a vacuum.

A robust definition of energy effectiveness for humidification dehumidification desalination systems

Humidification-dehumidification (HDH) is a cost-effective thermal desalination system that utilizes low-grade energy to extract freshwater from high salinity seawater with minimum maintenance. A robust method is presented using an innovative definition for energy effectiveness to facilitate the practical utilization of HDH modeling in the design process. This definition is mainly based on representing the flow stream on the temperature-enthalpy diagram to locate the pinch point and overcome the terminal-based definition limitation accordingly. The possible violation of the Second Law of Thermodynamics is the main drawback of the previous definitions due to the temperature-cross inside the humidifier, which defeats the purpose of air heating and humidification. The closed-air open-water HDH model is examined thermodynamically, and its design characteristics are explored at different operating conditions. The proposed definition is compared with analogous data from the literature. It showed an excellent agreement with a maximum discrepancy of 2.30%. Furthermore, a direct and straightforward design scheme is provided to estimate the dehumidifier and humidifier sizes based on the location and amount of freshwater needed. A case study for a system that produces 5 kg h−1 of freshwater in Dhahran is presented. The optimal energy effectiveness is found to be 78%, where the average minimum and maximum temperature of seawater in the system are assumed to be 25 and 70 °C, respectively.

Solar-powered desalination, a novel solar still directly connected to solar parabolic trough

Technologies that utilize natural renewable resources and rely on no fuels are more sustainable and could, in part, solve the world’s current water and energy problems. The aim of this study is to fabricate and develop a single solar still that is directly connected with a solar parabolic trough and does not utilize any heat exchanger. An innovative feeding water tank was installed with the parabolic unit. Fieldworks and manufacturing, laboratory experiments, and water quality analysis were the tools used in this study. The results of the field experiments demonstrated that the overall water productivity of the modified solar still increased by 177% compared to the conventional still. The average hourly quantity of freshwater obtained from the modified and unmodified models of the solar still were 0.67 L/m2/hr and 0.38 L/m2/hr, respectively. Building on these results, this study also proposed the future investigation of a step-shaped conical unit for the same device, which appears more promising and easier to handle, install, and maintain. This study showed feasible and viable results and verifies the importance of technologies that rely on renewable resources to achieve secure and sustainable management of the world’s water and energy needs.

Optimal Design of Hybrid Renewable Energy System for a Reverse Osmosis Desalination System in Arar, Saudi Arabia

Saudi Arabia tries to build local desalination water stations to supply water to remote areas. Due to the low cost and energy requirements of reverse osmosis (RO) desalination technology, it has been used to supply fresh water to Arar City in the northeast of Saudi Arabia. In this paper, it is proposed to provide an average of 1000 cubic meters of water per day by using autonomous hybrid renewable energy system (RES). This proposed system contains wind turbines (WTs), photovoltaic (PV), battery, and it is designed to feed the RO system with the energy adequate to produce the required amount of fresh water for the minimum cost and minimum loss of supply probability. The proposed system was designed to generate 2440 kW power to produce this amount of water. Matching study between the site and the best WT among 10 market-available WTs is introduced. Three optimization strategies were used and compared for the design of the proposed system to ensure that no premature convergence can occur. These strategies consisted of two well-known techniques, particle swarm optimization and bat algorithm (BA), and a relatively new technique: social mimic optimization. The simulation results obtained from the proposed system showed the superiority of using a RES for feeding a RO desalination power plant in Arar City, and they also showed that the BA is the fastest and most accurate optimization technique to perform this design problem compared with the other two optimization techniques. This detailed analysis shows that the cost of production of fresh water is $0.745/m3.

Austenitic Stainless-Steel Reinforcement for Seawater Sea Sand Concrete: Investigation of Stress Corrosion Cracking

Seawater and sea sand concrete (SWSSC) is a highly attractive alternative to normal concrete (NC) that requires huge amounts of fresh water and river sand. However, reinforcements of stainless steel (instead of mild steel that is used in NC) may be required for SWSSC. This article reports investigation of stress corrosion cracking (SCC) of AISI 316 stainless steel (SS) in simulated SWSSC and NC environments, with and without addition of silica to SWSSC and NC, employing slow strain rate testing (SSRT) at 25 and 60 °C. For the purpose of comparison, SCC of SS was also investigated in simulated seawater (SW) solution. SS showed no SCC at 25 °C in any of the test solutions. Indications of SCC were seen in SW at 60 °C, but no features of SCC in SWSSC and NC at 60 °C, as suggested by scanning electron microscopy (SEM) fractographs. While the absence of SCC in SWSSC and NC is attributed to the highly passivating alkaline condition, its absence in SWSSC also indicates the role of alkalinity to predominate the deleterious role of chloride content of SWSSC. However, the addition of silicate to SWSSC or NC triggers transgranular SCC to SS at 60 °C, as evidenced by the fractography.

Low environmental impact in cotton knit processing with reuse of raw wastewater

Textile chemical processing involves the use of a vast quantity of water, which necessitates water management using reduce, reuse, and recycle (3R's) techniques. Reuse of water is an attractive option and needs a detailed investigation to make it feasible commercially. In the present work, the direct reuse of wastewater in the pretreatment of cotton fabric was studied. The treated fabrics were characterized, tested for efficacy of pretreatments, and analyzed for dyeability towards reactive dyes. The novel process’s ecological aspects were studied to find out the benefits compared with the existing process. The fabrics were characterized using SEM, FTIR, and XRD techniques, demonstrating the reuse process without harming the substrate. This novel process showed a great promise to save a substantial quantity of freshwater, i.e. 33% of the total freshwater used, thus achieving economy and ecology in cotton pretreatments.

Modelling impacts of water diversion on water quality in an urban artificial lake.

As an important form of urban water resource, urban artificial lakes are severely affected by rapid urbanization and interference from human activities. These small lakes are characterized by their unique irregular shape, fragile ecosystem, and relatively closed, stagnant waterbodies. However, few studies have focused on their hydrodynamics and water quality, in particular the restoration methods and mechanisms remaining unclear. The present study applied the MIKE 21 FM model to investigate the effects of water diversion on water quality in a typical urban artificial lake. By considering different flow arrangements, several model scenarios were set up to predict the impacts of water diversion on selected water quality parameter. The results showed that the effectiveness of water diversion was directly related to flow velocity, the relative position to the fresh water inlet, the amount and quality of fresh water and water remaining to be diluted, and the circulation direction of flow field. The inflow-outflow arrangement was the primary factor determining the flow field and NH3-N variation trends across the lake, and an increased discharge exhibited unequal effects in individual zones. Wind was also important for the formation of flow circulation and pollutant variation. Methods were proposed for enhancing water quality in urban small-scale lakes, including changing the way diversion projects are managed, improving the quality of diverted flow, enhancing flow fluidity, or utilizing wind effects and local topography.

Air-cooled adsorption-based device for harvesting water from island air

Adsorption-based, atmospheric water harvesting is a promising method for addressing water scarcity, which is a common issue in island areas, which often contain a large amount of fresh water in the air. Most existing adsorption-based atmospheric water harvesting systems usually require an additional cooling source, e.g., water-cooling, to cool the released humid high-temperature air below its dew point to harvest liquid water. To date, large-scale atmospheric water harvesting devices that use air cooling in such conditions have not yet been developed. Herein, we report a forced air-cooled proof-of-concept device for harvesting water from island air. Fabricated using 21 kg activated carbon fibre felt (ACFF)–silica sol–LiCl30, this device generated up to 7.7 kg of water (adsorption at 31 °C with 63% relative humidity) per day-and-night cycle, with a thermal efficiency (ratio of thermal energy to water conversion) of 0.37, using air cooling alone in laboratory-simulated island conditions. This study verifies the possibility of using air cooling to condense released humid air. It provides a flexible water generation solution for island regions with limited supplies of fresh water and power.