Freshwater Research Articles

Productive Performance of Biomass Sorghum (Sorghum bicolor (L.) Moench) and Cowpea (Vigna unguiculata (L.) Walp) Cultivars in Different Cropping Systems and Planting Times

Global projections indicate that the demand for fresh water, energy, and food will increase significantly in the coming decades under the pressure of population growth, economic development, climate change, and other factors. Faced with this, technologies that promote sustainable development through the use of clean energy will be imperative. That way, this study aimed at evaluating the productive performance of biomass sorghum and cowpea cultivars in different cropping systems and planting seasons. The experiment was conducted at the Caatinga Experimental Field at Embrapa Semiarid, Petrolina—PE. Four cowpea (BRS Itaim, BRS Gurguéia, BRS Guariba, and BRS Carijó) and two biomass sorghum cultivars (BRS 716 and AGRI-002E) were used in intercropping and monoculture systems. The cultivars were sown during two different seasons: June (season 1—winter) and December (season 2—summer) of 2021. The biometric and productive parameters and land equivalent ratios (LERs) of sorghum and cowpea were evaluated. The data were subjected to multivariate analysis. The productive performance of biomass sorghum cultivars Agri-002E and BRS 716 was higher when planted in December, with an increase of 37% due to the planting season. Cowpea productivity was not influenced by sowing seasons or the cultivation system. Based on the calculation of efficient land use, the intercropping between biomass sorghum cultivar BRS 716 and cowpea cultivars BRS Gurguéia, BRS Guariba, and BRS Carijó was advantageous when compared to monocultures planted in the hottest season. This study showed the importance of cultivar selection, the planting time, and land use efficiency in intercropping systems.

Exergo-economic analyzes of a combined CPVT solar dish/Kalina Cycle/HDH desalination system; intelligent forecasting using artificial neural network (ANN) and improved particle swarm optimization (IPSO)

Power and freshwater are two energy-intensive products, which consume a huge amount of fossil fuels. It is important to supply the aforementioned products using renewable energy sources due to the depletion of fossil fuel resources and environmental issues. This paper investigates the exergy and exergy-economic analysis of water and power production using a small-scale combined cycle encompasses the concentrated photovoltaic thermal (CPVT) solar collectors, a Kalina cycle (KC), and a humidification-dehumidification (HDH) desalination unit. An exergo-economic parametric analysis was first investigated to determine the influence of some pertinent parameters on the exergy efficiency, and specific unit cost of the products. In the second stage, two intelligent forecasting approaches based on the artificial neural network (ANN) and improved particle swarm optimization (PSO) algorithms were utilized for predicting the performance metrics of the studied system. The system was supposed to work at half of the year's hour. The results demonstrated that the shares of CPVT, generator, humidifier, dehumidifier, and condenser in exergy destruction are 84 %, 6 %, 3 %, 2.5 %, and 2 %, respectively. Moreover, the exergy efficiency, and specific unit cost of the products, unit cost of electricity, and unit cost of the fresh water at the design condition were obtained as 23.23 %, 0.0806 $/kWh, 5.44 $/m3, and 31.15 $/GJ, respectively. Besides, the most effective parameter on the exergy efficiency and the specific unit cost of the products was the solar beam radiation, the increment in which from 300 W/m2 to 1000 W/m2 improved the exergy efficiency by 15.21 % and reduced the specific unit cost of the products by 63.16 %. In addition, the increase in the condenser pressure from 15 bar to 22 bar and the generator pinch point temperature difference from 5 °C to 15 °C reduced the exergy efficiency by 8.13 % and 4.03 %, respectively, leading to increasing the specific unit cost of the products by 1.30 % and 4.30 %. The results of modeling showed that hybrid ANN-IPSO models provide the most accurate prediction, highest tendency, and agreement to observation as compared to ANN in terms of (R2| exergy efficiency = 0.9903 and R2| specific unit cost of products = 0.9948) and (RMSE| exergy efficiency = 0.0010 and RMSE| specific unit cost of products = 0.9684).

ORGAN WEIGHT VARIATIONS IN CASES OF DROWNING IN FRESH WATER IN COMPARISION WITH NON-DROWNING DEATHS

Background: Diagnosis of drowning as a cause of death still remains a challenge in forensic pathology due to scanty pathognomic signs. Traditional diagnostic methods have shown limitations, prompting interest and pursuit on alternative approaches. One such approach involves analysing the weight of internal organs, particularly the lungs and spleen, to provide additional supportive evidence. Objectives: This study aimed to investigate the variations in organ weights in wet fresh water drowning cases compared to deaths due to other causes and assess the utility of the drowning index as a diagnostic tool. Methods: The study analyzed the findings in 245 cases,that were brought to the Department of Forensic Medicine, Government Medical College, Kozhikode for medico-legal autopsy. It included 83 cases of hanging, 71 cases of wet fresh water drowning and 91 cases of traumatic brain injury. Lung, spleen and other organ weights were measured using an electronic scale. The data obtained were subjected to statistical analysis using SPSS version 18 with focus on comparative analysis across the different types. Results: The results showed a significant increase in weight of lungs and a decrease in spleen weight in persons who had died of drowning when compared to other causes of death. However, the drowning index, though elevated in drowning cases, did not consistently surpass the established diagnostic threshold, suggesting variability and potential limitations in its application as a reliable diagnostic marker. Conclusion: Variations in weights of lungs and spleen can provide valuable clues in the diagnosis of drowning, but their diagnostic utility as a stand alone criteria is limited to a certain extent by case-to-case variability. The drowning index demonstrates potential as a supplementary diagnostic tool but requires further validation through more extensive studies to improve its reliability and accuracy.

Experimental analysis of tubular solar still with custard apple seeds a bio-waste material: An energy, exergy, economic, environmental and sustainability analysis

Solar desalination is emerging as a sustainable solution for addressing water scarcity and the lack of access to fresh drinking water in various regions worldwide. This experimental study has employed custard apple seeds (CAS) a biowaste substance in Tubular Solar Still (TSS) to attain maximum water yield, and improved energy and exergy efficiency, thereby addressing water scarcity issues. Furthermore, the research examines the economic feasibility, environmental impact, and sustainability of utilizing CAS biowaste medium in the TSS. Two separate TSS were used in the experimental work in which one TSS is provided with CAS, which is named as Enhanced Tubular Solar Still (ETSS). The other TSS is utilized without inclusion of biowaste substance and is named as Normal Tubular Solar Still (NTSS). The results indicated that ETSS system, using 600 g of CAS, has a water yield of 3.73 kg/m2/day while for NTSS without any biowaste materials, the yield is obtained as 2.45 kg/m2/day. The ETSS model demonstrates a significant improvement of 52.51 % compared to the NTSS model. Additionally, the thermal and exergy efficiencies of ETSS are achieved as 38.22 % and 1.96 %, respectively, whereas for NTSS, both are evaluated to be 23.78 % and 1.04 %, respectively. The energy and exergy efficiencies for ETSS show enhancements of 60.69 % and 87.37 % in comparison to the NTSS system. Moreover, economic investigation reveals that the Cost Per Liter (CPL) for NTSS and ETSS models is $0.024/L and $0.016/L, respectively, indicating a 33.33 % improvement in the ETSS model over the NTSS model. The Economic Payback Time (PBT) for NTSS and ETSS is 141.3 and 95.57 days, respectively. Environmental analysis indicates that the mitigation of CO2 in NTSS and ETSS is evaluated as 66.7 kg/year and 101.66 kg/year, respectively. Additionally, the Net Carbon Emission Mitigation (NCEM) for both models is 8 and 12.42 tons for the 10-year lifetime of both NTSS and ETSS, respectively. Carbon credits gained amount is $87.22 and $135.4 for NTSS and ETSS models, respectively.

Optimal resource reallocation can achieve water conservation, emissions reduction, and improve irrigated agricultural systems

CONTEXTCrop production consumes large volumes of fresh water and is a key contributor to anthropogenic greenhouse gas (GHG) emissions. Increasing crop output to ensure adequate food supplies under water and land scarcity relies excessively on intensive agricultural inputs (e.g., fertilizers, pesticides, and agricultural films), leading to irreparable environmental consequences (water scarcity and degradation and GHG emissions). Therefore, research on a nexus approach and resource optimization model were carried out. OBJECTIVETo fill the gap of objectives priority and optimal allocation of water resources at irrigation area scale, this study constructed a model to achieve optimal water conservation, GHG emissions reduction, and economic benefit improvement, covering the cumulative environmental burden of agricultural inputs, production processes, trade and consumption related to agricultural activities. METHODSBased on a resource-environmental-economic framework, we took the blue water footprint (WFblue) as a decision variable and developed an integrated water resource optimization model, which was solved by the non-dominated Sorting Genetic Algorithm-II in Matlab. Minimizing crop water footprint (WFcrop), minimizing crop carbon emissions (CEcrop) and maximizing crop economic benefits (EBcrop) were the objectives of the model, and blue water resource, food security, electric energy consumption and land security were the constraint conditions. In addition, three scenarios were tested based on the priority of the objective functions. RESULTS AND CONCLUSIONSAnnually, WFcrop was 1234.29 × 106 m3 and CEcrop was 522.45 Gg CO2 eq for food production in Lianshui Irrigation District from 2005 to 2019. Grain crops exhibited a greater WFcrop and contributed significantly more to CEcrop than oilseed crops. Virtual water and carbon flows increased with food transfer. By adjusting the WFblue of crops compared to the baseline scenario (BS), the average WFcrop decreased by 10.0 %, CEcrop decreased by 4.0 %, and EBcrop increased by 6.4 % under Scenario 2 (minimizing WFcrop and maximizing EBcrop), respectively. Similarly, there were average reductions of 9.2 % in WFcrop, 6.2 % in CEcrop, and EBcrop increased by 5.6 % under Scenario 3 (minimizing CEcrop and maximizing EBcrop) compared to the BS. Therefore, the integrated model achieved the optimization objectives. SIGNIFICANCEThis research not only broadens the scope of traditional environmental impact assessments in agricultural production, but also underscores the positive impact of scientifically and rationally redistributing resources for water conservation, GHG emissions reduction, and economic benefit improvement.

Chemical composition of city wastewater and its effect on germination of some vegetable seeds

Due to increasing shortage of fresh water, the use of city wastewater in agricultural purpose has become more popular day by day. This experiment was conducted to analyze the physico-chemical parameters of the city wastewater and its effect on seed germination and seedling growth of Abelmoschus esculentus (Lady’s Finger), Vigna unguiculata (Yard Long Bean) and Cucumis sativus (Cucumber) plants during the period of January, March and May, 2023 with the application of five treatments i.e. T0 (control), T1 (3ml), T2 (5ml), T3 (7ml) and T4 (10ml). The experiment was laid out in a Completely Randomized Design (CRD) with three replications. Analyses included pH, EC, hardness, cations (Ca2+, Mg2+, Na+, K+, Zn2+, Cu2+, Mn2+ and Fe3+), anions (CO32-, HCO3-, SO42-, PO43- and Cl-) and TDS (total dissolved solids), SAR (sodium adsorption ratio). The pH (6.9 ~ 7.23) was neutral to alkaline and could be suitable for agricultural uses. According to TDS and SAR values, all samples of wastewater were classified as ‘Freshwater’ and ‘excellent’ categories. T0 (control) and T3 (7ml) were showed the highest germination percentage (100%) for every month and T4 (10ml) was showed the lowest germination percentage (80%). The speed of germination, relative germination ratio and germination index were also highest at T0 (control) and lowest was in T1 (3ml) condition and again the shoot and root length of the vegetables were gradually enhanced with increasing concentration and highest shoot and root length found in T4 (10 ml) treatment and lowest shoot and root length observed in T0 (control) treatment. Thus, the city wastewater, after proper dilutions can be used as a promising source of water in agricultural practice.

Interaction of Per- and Polyfluoroalkyl Substances with Estrogen Receptors in Rainbow Trout (Oncorhynchus mykiss): An In Silico Investigation.

Fresh water sources, including lakes, such as the Great Lakes, are some of the most important ecosystems in the world. Despite the importance of these lakes, there is increasing concern about the presence of per- and polyfluoroalkyl substances (PFAS)─among the most prevalent contaminants of our time─due to the ability of PFAS to bioaccumulate and persist in the environment, as well as to its linkages to detrimental human and animal health effects. In this study, PFAS exposure on rainbow trout (Oncorhynchus mykiss) is examined at the molecular level, focusing on the impact of PFAS binding on the alpha (α) and beta (β) estrogen receptors (ERs) using molecular dynamics simulations, binding free energy calculations, and structural analysis. ERs are involved in fundamental physiological processes, including reproductive system development, muscle regeneration, and immunity. This study shows that PFAS binds to both the estrogen α and estrogen β receptors, albeit via different binding modes, due to a modification of an amino acid in the binding site as a result of a reorientation of residues in the binding pocket. As ER overactivation can occur through environmental toxins and pollutants, this study provides insights into the influence of different types of PFAS on protein function.

The Effect of Adhatoda Vasica as A Herbal Supplement on The Performance, Nutrient Digestibility, and Blood Profile of Weaned Pigs

A 60-day trial was carried out to determine the impact of Adhatoda vasica as an herbal supplement on the performance, nutrient digestibility and blood profile of weaned pigs. 40 crossbred male pigs (Yorkshire × Landrace) with initial body weight of 10.21 ± 0.03 kg was distributed into 4 treatment consisting of 10 pigs each. On arrival, animals were quarantined for two weeks and fed basal diet which is adequate in all nutrients according to NRC (2012). Pigs in treatment 1 was fed basal diet without Adhatoda vasica leaf powder while those in treatment 2, 3 and 4 were fed same diet supplemented with Adhatoda vasica leaf powder at 200 g, 400 g and 600 g/kg respectively. A completely randomized design technique was adopted and the animals had unrestricted access to clean fresh water and feed. Quantification of phyto-constituents in Adhatoda vasica leaf powder showed that it contained higher concentration of flavonoids (102.1 mg/g) while steroids had the lowest concentration of 30.41 mg/g. Average daily weight gain was higher among pigs fed treatment 3 and 4, intermediate in treatment 2 and lowest in treatment 1. Average daily feed intake, feed conversion ratio and mortality were significantly (P<0.05) influenced by the treatment. Dry matter, ether extract, crude protein and crude fibre digestibility were influenced (P<0.05) by the treatment. Red blood cell, pack cell volume, mean platelet volume, mean corpuscular volume, mean corpuscular haemoglobin, white blood cell, total protein was significantly (P<0.05) different among the treatment except for aspartate amino transferase, alanine amino transferase and alkaline phosphatase (P>0.05). However, all values were within the established range for healthy pigs. In conclusion, Adhatoda vasica leaf powder can be supplemented in the diet of pigs without compromising their growth and health status.

Histological study of the development of the digestive system during larval feeding in the pike silverside Chirostoma estor.

Chirostoma estor (Jordan, 1879) is an endemic freshwater species with a high potential for aquaculture; however, as in many other fish, larviculture of this species is the most critical stage, in which the higher mortality rates. Therefore, it is necessary to fully describe the development of the digestive system to establish better feeding protocols in the larval culture of C. estor, both for aquaculture and restoration purposes. In the present study, larviculture was carried out from hatching to 20days after hatching (DAH). The organisms were fed with the rotifer Brachionus plicatilis from 2 to 14 DAH, and nauplii of Artemia sp. from 15 to 20 DAH. A total of 12 organisms (0, 3, 5, 10, 15, and 20 DAH) were taken for size and weight growth and histological and histochemical analysis. The histological analysis indicated that after 3 DAH, the opening of the mouth and anus was observed, coinciding with the beginning of exogenous feeding. In addition, the digestive system developed, with differentiation of the oropharyngeal sections, esophagus, and intestine, folding of the intestinal mucosa, as well as associated organs (liver and pancreas) that reach their maximum development at 20 DAH. Thus, C. estor at this stage of development can digest and absorb nutrients despite being an agastric fish. The results obtained in this study will facilitate a better understanding of the ontogenetic morphophysiological development processes, associated with the transition of larvae to exogenous feeding, which ensures a higher percentage of survival during larval development and of course, adds to the diversity ontogenetics of teleostean.

EDNAqua-Plan—Standardisation Overview for eDNA Sequencing of Aquatic Organisms and the Downstream Data Ecosystem

The eDNAqua-Plan project stands as a beacon of innovation in the biomonitoring of marine and freshwater ecosystems, propelled by the urgent need to integrate DNA-based approaches in aquatic bioassessment and monitoring frameworks. The broad utilisation of cutting-edge environmental DNA (eDNA) and DNA barcoding methodologies is dependent on complete, reliable, and accessible reference DNA sequence data (Rimet et al. 2021). Complete and interoperable metadata is crucial to allow a broad reuse of (e)DNA data and analysis outputs, and for a broader uptake of results by end users. The eDNAqua-Plan project aims to address key limitations to the routine implementation of eDNA-based monitoring methods in Europe by developing plans for federated DNA barcode reference libraries and eDNA data repositories to support DNA-based environmental monitoring. This will ensure a sustainable and reliable infrastructure to underpin its broad use, thereby paving the way for more effective conservation and management strategies. The project is working towards creating a comprehensive overview of standardisation efforts and data workflows, through collaborations with other projects, initiatives and infrastructures for aquatic monitoring across the European Union (EU) and associated countries. We are analysing existing archives (e.g., International Nucleotide Sequence Database Collaboration (INSDC), Barcode of Life Data System (BOLD), Global Biodiversity Information Facility (GBIF), Ocean Biodiversity Information System (OBIS)), portals, and papers to determine current and best practices through the use of questionnaires, manual evaluation of repositories, and machine learning methods (LLMs). This includes an overview of the usage of existing metadata and data standards (e.g., Minimum Information about any (X) Sequence Specifications from the Genomics Standards Consortium (GSC), Darwin Core standard). The results are being integrated by a team of experts in marine and freshwater biomonitoring. With a diverse consortium comprising 18 partner institutions from 11 countries and one international institute, eDNAqua-Plan brings together experts in marine and freshwater monitoring, eDNA analysis, and data science. The collective effort by this consortium will lay the groundwork for the creation of a digital ecosystem of eDNA repositories and an integrated reference library of marine and freshwater species, adhering to FAIR (Findable, Accessible, Interoperable, and Reusable) principles.

Description of a new freshwater mussel species of Pletholophus, Simpson, 1900 (Bivalvia, Unionidae) from Guangdong, China

The Pearl River Basin, China’s second-largest freshwater basin, hosts a significant diversity of species and a highly endemic freshwater mussel fauna. In this study, a new species from the Liuxi River in Guangzhou, Guangdong, China, Pletholophus guangzhouensissp. nov., is described based on morphological diagnostic features and molecular phylogenetics. The glochidia shells of the new species are subtriangular, medium-sized, and have a styliform hook on the ventral angle of each valve. Phylogenetic analyses based on the COI and 28S rRNA gene fragments indicated that Pletholophus guangzhouensissp. nov. is the sister to Pletholophus tenuis + Pletholophus reinianus. The pairwise uncorrected COI p-distance analysis demonstrated genetic distances ranging from 5.27% (between P. guangzhouensissp. nov. and P. tenuis) to 11.06% (between P. guangzhouensissp. nov. and P. honglinhensis). Our findings suggest a significant underestimation of the diversity of freshwater mussel species in Guangdong. Further field collections and systematic studies are necessary to fully explore the biodiversity of this region. Furthermore, integrative classification methods and genetic research are essential for informing the development of effective conservation strategies.

Irrigation increases and stabilizes mosquito populations and increases West Nile virus incidence

Humans have greatly altered earth’s terrestrial water cycle with the majority of fresh water being used for agriculture. Irrigation changes spatial and temporal water availability and alters mosquito abundance and phenology. Previous studies evaluating the effect of irrigation on mosquito abundance and mosquito-borne disease have shown inconsistent results and little is known about the effect of irrigation on variability in mosquito abundance. We examined the effect of irrigation, climate and land cover on mosquito abundance and human West Nile virus (WNV) disease cases across California. Irrigation made up nearly a third of total water inputs, and exceeded precipitation in some regions. Abundance of two key vectors of several arboviruses, including WNV, Culex tarsalis and the Culex pipiens complex, increased 17–21-fold with irrigation. Irrigation reduced seasonal variability in C. tarsalis abundance by 36.1%. Human WNV incidence increased with irrigation, which explained more than a third (34.2%) of the variation in WNV incidence among California counties. These results suggest that irrigation can increase and decouple mosquito populations from natural precipitation variability, resulting in sustained and increased disease burdens. Shifts in precipitation due to climate change are likely to result in increased irrigation in many arid regions which could increase mosquito populations and disease.

Fish diversity, assemblage pattern along with the environmental variables in tidal fresh water stretch in the Hooghly estuary of Gangetic delta, West Bengal, India

The greatest estuary created by the Gangetic delta in India is the Hooghly estuary. Despite their importance to the estuarine biodiversity, the tidal freshwater areas of this estuary have gained little interest from ecologists. Present study aims to explore the fish diversity with its assemblage pattern and their relationship with physico-chemical parameters from June 2020 to May 2021. There have been identified 118 fish species in total, from 14 orders and 47 families, with seven (7) being near threatened, fifteen (15) vulnerable, four (4) endangered, and eight (8) not evaluated. Perciformes (29.66 %), Cypriniformes (22.88 %), and Siluriformes (21.18 %) accounted for 73.72 % of the overall species count. Station-1 has significantly higher species richness, rarefied richness, and abundance. Station-3 and station-2 followed station-1 respectively. The composition of fish species changed significantly among the stations, as shown by cluster analysis, nMDS (nonmetric multidimensional scaling), ANOSIM (analysis of similarities), and SIMPER (similarity percentage analysis) (p <0.05). The canonical correspondence analysis revealed that alkalinity, conductivity, phosphate, and total carbon dioxide of the water were the key environmental parameters. In addition to defining a sustainable management method for the fish resources in the Hooghly estuary, this effort will act as a baseline study for further investigation.

Study on the prevalence of trematode cercariae infection in freshwater snails in Manipur, India.

Freshwater snails act as first intermediate carriers for numerous trematodes, which can induce sickness in both humans and animals. In Manipur, various species of freshwater snails have been discovered to harbor trematode infections. In this study, we aimed to assess the prevalence of different varieties of freshwater snail species serving as the primary, intermediate hosts for various trematodes in endemic areas of paragonimiasis, a disease caused by Paragonimus trematodes found in two separate regions, Luwangsangbam matai in the Imphal East district and Moreh in the Tengnoupal district of Manipur province. These areas are known to be endemic for human paragonimiasis. We examined 4074 snails, including Bortia costula, Filopaludina bengalensis, Paludomous pustulosa,Indoplanorbis exustus using the shedding and crushing method. Our findings revealed that 43(1.05%) snails were positive for different trematode cercariae. Specifically, Bortia costula was infected with Fasciola spp, and unidentified cercariae, while Filopaludina bengalensis and Paludomous pustulosa harboured Gymnacephalous and Echinostomous cercariae. Interestingly, Indoplanorbis exustus did not show any infection with trematode cercariae. A strong association was found between these types of snail species and cercarial infection. Furthermore, statistical analysis did not demonstrate a significant correlation between the geographical location and cercarial infection among snail species. Our study provides the current status of the prevalence of trematode cercarial infection in these snails, offering insights into disease transmission dynamics and the role of snails in paragonimiasis epidemiology.

Simulation of Maize Growth Under the Applications of Brackish Water in Northwest China

The objective of this study is to assess the suitability of the AquaCrop model for growing maize using brackish water irrigation in Northwest China. Additionally, this study aims to examine how maize utilizes water in various soil layers when irrigated with varying water qualities. The AquaCrop model was calibrated and verified using experimental data from the years 2022 and 2023 in this research. (1) The findings indicated that the AquaCrop model effectively simulated the canopy cover, biomass, and yield of maize when irrigated with brackish water. The validation year’s R2, MAPE, and RMSE values for canopy cover, biomass, and yield of maize were 0.95, 5.36%, and 4.77%, respectively. For biomass, the R2, MAPE, and RMSE values were 0.91, 16.61%, and 2.12 t·hm−2, respectively. For yield, the R2, MAPE, and RMSE values were 0.84, 3.62%, and 0.42 t·hm−2, respectively. (2) Irrigation with water of high mineral content, measured at 1.6 ds/m, as well as with fresh water over the whole reproductive period, resulted in an increased reliance on groundwater for maize cultivation. There was no notable disparity in the usage of various soil layers between the irrigation with alternating freshwater and brackish water. (3) The AquaCrop model simulated the effects of seven different irrigation water quality treatments. It was shown that using water with mineralization levels of 0.5 and 0.8 ds/m resulted in decreased freshwater use without causing a substantial decrease in maize yield and biomass.

Renewable energy-driven desalination for sustainable water production in the Middle East

ABSTRACT Despite significant advancement in conventional desalination technologies, their widespread application is still constrained by high energy demands, high capital costs, and the associated greenhouse gas (GHG) emissions. The main objective of this study is to evaluate the potential and challenges of renewable energy desalination in the Middle East. The study also compared the production of energy and water, and emissions reductions of hypothetical 100 MW renewable energy plants in Kuwait, coupled with reverse osmosis (RO) desalination units. The wind-RO plant is estimated to produce 68 million cubic metres on an annual basis, while the CSP-RO and PV-RO plants produced 44 and 37 million cubic metres of fresh water, respectively. These estimates, however, only account for 5% to 9% of the annual fresh water demand in the reference case. Meeting 100% of the fresh water demand would require a 1000 MW to 2000 MW renewable energy capacity. Overall, the intermittent nature of renewable energy sources is a fundamental barrier to the large-scale transition to renewable energies for desalination. The results of this study indicate that the CSP’s relatively small footprint (compared to wind plants) and higher capacity factor make it an ideal compromise among the proposed plants.

The Isolation and Identification of Novel Arsenic-Resistant Bacteria from an Arsenic-Contaminated Region—A Study to Understand the Efficiency of Bacteria for Arsenic Removal from Aqueous Media

Drinking water sources with groundwater arsenic (As) contamination face multifaceted challenges in the removal and supply of fresh drinking water resources. To eradicate this problem, bioremediation has evolved to become more effective than other chemical and physical removal processes in its cost-effectiveness, high removal efficiency, and lesser production of secondary by-products or waste. Thus, this study aimed to treat As from aqueous media and to detoxify highly toxic forms of As by the isolated bacteria from As-affected areas. We isolated two new Gram-positive bacteria, which are reported here (Bacillus sp. and Bacillus cereus), with As5+ minimum inhibitory concentrations (MICs) of 4500 mg/L for the Bacillus sp. and 1000 mg/L for Bacillus cereus; meanwhile, for As3+, the MICs are 600 mg/L for both isolates. Bacillus sp. and Bacillus cereus can also effectively convert the highly toxic and easily mobile As3+ to As5+ in aqueous media. This study also demonstrates that these bacteria can remove a significant proportion of As3+ and As5+ (averaging 50% for both) from aqueous media. These As-resistant bacteria from the As-affected area can be used and upscaled for the treatment of As for a safer drinking water supply.

Toward sustainable energy resource: Integrated concentrated photovoltaic and membrane distillation systems for fresh water and electricity production

This study introduces and evaluates a novel Concentrated Photovoltaic (CPV)-assisted Direct Contact Membrane Distillation (DCMD) system, examining its efficiency and energy output under varying operational conditions. A Computational Fluid Dynamics (CFD) model, validated with experimental data, assesses the system's performance at different concentration ratios ranging from 1x to 10x and 25x to 100x, flow patterns (counterflow and parallel flow) at different Reynolds numbers (30–1200). This study investigates the seasonal performance of the CPV-DCMD system, providing valuable insights into its reliability and sustainability throughout the year. Results show increased mass flux and electric power with higher concentration ratios, especially at lower Reynolds numbers. In the counter-flow arrangement, the mass flux increases notably under specific conditions, while seasonal analysis reveals peak flux during summer and autumn afternoons. Electric power output follows a consistent trend across seasons, with high output observed during noon hours. The study demonstrates the system's energy efficiency, with notable energy gain compared to consumption across diverse operational conditions. Overall, the findings provide insights into optimizing the performance of CPV-assisted DCMD systems for sustainable energy generation and water desalination applications.

Economics of Fresh Water Cultured Fish Production in Odisha and Bihar, India: A Comparative Analysis

Fisheries and aquaculture are important sectors that provide nutritional security, contribute to agricultural exports, and provide livelihoods to about 28 million fishermen, fish farmers, and other value-chain actors. The study was conducted in two states of Eastern India, i.e. Odisha and Bihar, to estimate the comparative economics of freshwater fish production and its profitability. The results showed that the cost of fish production was estimated to be Rs. 346943.45/ha of pond, constituting Rs. 208582.74 as a variable cost and Rs.138360.71 as a fixed cost in Odisha. In Bihar, the per hectare fish production for an average pond size was estimated to be Rs. 318445.47, comprising variable cost as Rs 188061.82 and fixed cost as Rs. 130383.64. On average, per hectare, fish production in Odisha from all ponds was estimated to be 45.69 quintals, while in Bihar, it was 35.67 quintals. The profitability analysis revealed that in Odisha, per hectare gross income, on average, for all ponds was Rs. 717763.06. In the case of Bihar, the gross income for all the ponds was calculated to be Rs. 540352.02/ha. It was concluded that returns on investments in all pond categories were comparatively higher in Odisha than in different pond size groups of Bihar.

S2−-modified hetero MOF-on-MOF of Ni-MOF/Fe-MOF with efficient seawater oxidation performance

Direct seawater electrolysis offers a viable solution to the excessive consumption of fresh water resources in existing industrial electrolytic water processes. However, electrolysis efficiency and material stability are affected by electrode material corrosion caused by chlorine evolution reactions (CER) at the anode positions. In this study, the prepared S-Ni-MOF/Fe-MOF material exhibits an exceptional performance in the oxygen evolution reaction (OER) both in alkaline solution and seawater. Specifically, the material achieves low overpotentials of 281 and 279 mV in 1.0 M KOH and alkaline seawater at 100 mA cm−2 current density, and maintains stability for at least 100 h in both electrolyte solutions. The electronic structure of MOF-on-MOF was modulated through the introduction of S2−, which induced a large number of vacancies. Furthermore, the reconstruction process on the material surface was accelerated by the formation of NiOOH and FeOOH, that served as protective layers and prevented the corrosion of the electrode material by Cl−, thereby enhancing its stability in seawater. Furthermore, computational studies have indicated that the Fe-Ni active sites at the heterointerface exhibit a synergistic effect, which has been confirmed by density functional theory (DFT) calculations. These results prove that this combination significantly reduces the energy barrier associated with the OER. Consequently, the reaction process is accelerated.