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1.
Harmful Algae ; 133: 102588, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38485443

RESUMO

To investigate the detrimental impacts of cyanobacterial bloom, specifically Microcystis aeruginosa, on brackish water ecosystems, the study used Moina mongolica, a cladoceran species, as the test organism. In a chronic toxicology experiment, the survival and reproductive rates of M. mongolica were assessed under M. aeruginosa stress. It was observed that the survival rate of M. mongolica fed with M. aeruginosa significantly decreased with time and their reproduction rate dropped to zero, while the control group remained maintained stable and normal reproduction. To further explore the underlying molecular mechanisms of the effects of M. aeruginosa on M. mongolica, we conducted a transcriptomic analysis on newly hatched M. mongolica cultured under different food conditions for 24 h. The results revealed significant expression differences in 572 genes, with 233 genes significantly up-regulated and 339 genes significantly down-regulated. Functional analysis of these differentially expressed genes identified six categories of physiological functional changes, including nutrition and metabolism, oxidative phosphorylation, neuroimmunology, cuticle and molting, reproduction, and programmed cell death. Based on these findings, we outlined the basic mechanisms of microcystin toxicity. The discovery provides critical insights into the mechanisms of Microcystis toxicity on organisms and explores the response mechanisms of cladocerans under the stress of Microcystis.


Assuntos
Cladóceros , Microcystis , Animais , Microcystis/fisiologia , Ecossistema , Perfilação da Expressão Gênica , Águas Salinas
2.
Mar Pollut Bull ; 200: 116135, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38359482

RESUMO

A twenty-four month long observational study conducted in an Asia's largest brackish water ecosystem, Chilika Lagoon, India, aimed to unravel dissolved organic matter (DOM) dynamics in this tropical brackish water ecosystem. The study assessed the interplay between allochthonous and autochthonous DOM sources during lean and active flow periods based on regional rainfall. Dissolved organic carbon (DOC), nitrogen (DON), and phosphorus (DOP) fluxes were analyzed, considering catchment runoff, phytoplankton production, benthic-pelagic interactions, and sea-lagoon exchanges as contributors. Contrary to conventional thinking, the study found autochthonous processes to be more significant than conservative mixing in shaping DOM dynamics. It introduced a novel conceptual model illustrating the multifaceted origins of DOM, encompassing catchment runoff, phytoplankton, benthic-pelagic interactions, bacterial activity, and sea-lagoon exchanges. These findings underscore the importance of holistic management strategies for Chilika Lagoon to preserve its ecological health, given its vital role in global carbon cycling, fisheries, and aquaculture.


Assuntos
Matéria Orgânica Dissolvida , Ecossistema , Fitoplâncton , Águas Salinas , Ásia
3.
Water Res ; 252: 121213, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38306752

RESUMO

The occurrence of large Microcystis biomass in brackish waters is primarily caused by its downward transportation from the upstream freshwater lakes and reservoirs through rivers rather than due to in situ bloom formation. Factors that determine the survival of freshwater cyanobacteria in brackish waters have not been well investigated. Here, we studied the spatiotemporal variability of inorganic nitrogen in an upstream lake and conducted laboratory and in-situ experiments to assess the role of nitrogen availability on the salt tolerance of Microcystis and the release of microcystins. A series of field experiments were carried out during bloom seasons to evaluate the salt tolerance of natural Microcystis colonies. The salt tolerance threshold varied from 7 to 17 and showed a positive relationship with intracellular carbohydrate content and a negative relationship with nitrogen availability in water. In August when upstream nitrogen availability was lower, the Microcystis colonies could maintain their biomass even after a sudden increase in salinity from 4 to 10. Laboratory-cultivated Microcystis that accumulated higher carbohydrate content at lower nitrogen availability showed better cell survival at higher salinity. The sharp release of microcystins into the surrounding water occurred when salinity exceeded the salt tolerance threshold of the Microcystis. Thus, Microcystis with higher salt tolerance can accumulate more toxins in cells. The obtained results suggest that the cell survival and toxin concentration in brackish waters depend on the physiological properties of Microcystis formed in the upstream waters. Thus, the life history of Microcystis in upstream waters could have a significant impact on its salt tolerance in downstream brackish waters, where the ecological risk of the salt-tolerant Microcystis requires special and careful management in summer at low nitrogen availability.


Assuntos
Microcystis , Microcystis/fisiologia , Microcistinas , Tolerância ao Sal , Nitrogênio , Lagos/microbiologia , Águas Salinas , Água , Carboidratos
4.
J Environ Manage ; 352: 120087, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38215592

RESUMO

Saline water has proven to be one of the alternative sources of freshwater for agricultural irrigation in water-scarce areas. However, the changes in farmland ecology caused by saline water irrigation remain unclear. In this study, six irrigation water salinities (CK: 1.3 dS m-1, S1: 3.4 dS m-1, S2: 7.1 dS m-1, S3: 10.6 dS m-1, S4: 14.1 dS m-1, S5: 17.7 dS m-1) were set in a three-year (2019, 2021-2022) experiment to investigate their effects on soil environment and greenhouse gas emissions in cotton fields under long-term saline water irrigation. Results show that soil salinity in the same layer increased as increasing water salinity. Soil moisture of S3-S5 increased significantly by 4.99-12.94%. There was no significant difference in soil organic matter content between CK and S1. Saline water irrigation increased soil ammonium nitrogen content by 0.57-49.26%, while decreasing nitrate nitrogen content by 1.43-32.03%. Soil CO2 and N2O emissions and CH4 uptake were lower in S1-S5 than in CK at different cotton growth stages. In addition, saline water irrigation reduced the global warming potential by 6.93-53.86%. A structural equation model was developed to show that soil salinity, moisture, and ammonium nitrogen content were negatively correlated with global warming potential, while organic matter and nitrate nitrogen had positive effects on global warming potential. Considering the comprehensive perspectives of gas emissions and cotton yield, irrigation water with salinity less than 10.6 dS m-1 could effectively reduce greenhouse gas emissions from cotton fields while maintaining stable cotton yields in the experimental area and similar region.


Assuntos
Compostos de Amônio , Gases de Efeito Estufa , Gases de Efeito Estufa/análise , Nitratos , Óxido Nitroso/análise , Solo/química , Irrigação Agrícola/métodos , China , Águas Salinas , Nitrogênio , Agricultura , Fertilizantes/análise , Metano/análise
5.
Environ Sci Pollut Res Int ; 31(9): 12995-13002, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38236570

RESUMO

Phytoremediation is an effective way to reduce heavy metal content in agricultural soil. The effects of brackish water irrigation on phytoremediation efficiency of plants have not yet been completely understood. In this study, the effects of brackish water irrigation on cadmium (Cd) uptake by maize as the phytoremediator were investigated. In a pot experiment, maize seedlings were grown in soil with exogenously added Cd (0, 5, 10, or 15 mg kg-1) and irrigated with deionized water (T1), natural brackish water (T2), or water with NaCl with salinity equal to that of natural brackish water (T3). Salt stress and cation antagonism caused by brackish water affected maize plant growth and Cd uptake. Under 5, 10, and 15 mg kg-1 Cd, Cd accumulation in maize shoots was 5.55, 7.08, and 5.71 µg plant-1; 4.08, 3.04, and 5.38 µg plant-1; and 2.48, 3.44, and 5.33 µg plant-1 under the T1, T2, and T3 treatments, respectively. Cd accumulation in the shoots was significantly lower under the T2 and T3 treatments than under the T1 treatment at 5 and 10 mg kg-1 Cd; however, no significant differences were observed among all treatments at 15 mg kg-1 Cd. These findings indicated that phytoremediation efficiency decreased in response to both salt stress and cation antagonism caused by brackish water under low soil-Cd concentrations; however, this effect was negligible under high soil-Cd concentration. Therefore, brackish water irrigation can be considered for the phytoremediation of soils contaminated with high Cd levels to save freshwater resources.


Assuntos
Cádmio , Poluentes do Solo , Cádmio/análise , Solo , Zea mays , Biodegradação Ambiental , Água , Águas Salinas , Cátions , Poluentes do Solo/análise
6.
Environ Sci Technol ; 58(2): 1131-1141, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38169368

RESUMO

Hydrogen gas evolution using an impure or saline water feed is a promising strategy to reduce overall energy consumption and investment costs for on-site, large-scale production using renewable energy sources. The chlorine evolution reaction is one of the biggest concerns in hydrogen evolution with impure water feeds. The "alkaline design criterion" in impure water electrolysis was examined here because water oxidation catalysts can exhibit a larger kinetic overpotential without interfering chlorine chemistry under alkaline conditions. Here, we demonstrated that relatively inexpensive thin-film composite (TFC) membranes, currently used for high-pressure reverse osmosis (RO) desalination applications, can have much higher rejection of Cl- (total crossover of 2.9 ± 0.9 mmol) than an anion-exchange membrane (AEM) (51.8 ± 2.3 mmol) with electrolytes of 0.5 M KOH for the anolyte and 0.5 M NaCl for the catholyte with a constant current (100 mA/cm2 for 20 h). The membrane resistances, which were similar for the TFC membrane and the AEM based on electrochemical impedance spectroscopy (EIS) and Ohm's law methods, could be further reduced by increasing the electrolyte concentration or removal of the structural polyester supporting layer (TFC-no PET). TFC membranes could enable pressurized gas production, as this membrane was demonstrated to be mechanically stable with no change in permeate flux at 35 bar. These results show that TFC membranes provide a novel pathway for producing green hydrogen with a saline water feed at elevated pressures compared to systems using AEMs or porous diaphragms.


Assuntos
Cloro , Hidrogênio , Metacrilatos , Osmose , Membranas Artificiais , Águas Salinas , Cloretos
7.
J Hazard Mater ; 465: 133512, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38232552

RESUMO

Parabens, a group of alkyl esters of p-hydroxybenzoic acid, have been found in aquatic systems in particular, leading to concerns about their potential impact on ecosystems. This study investigated the effects of three commonly used parabens, methylparaben (MeP), ethylparaben (EtP), and propylparaben (PrP), on the brackish water flea Diaphanosoma celebensis. The results showed that PrP had the most adverse impact on survival rates, followed by EtP and MeP, while MeP and EtP induced significant adverse effects on reproductive performance. A transcriptome analysis revealed significant differential gene expression patterns in response to paraben exposure, with MeP associated with the most significant effects. MeP and EtP exposure produced greater disruption in the microbiota of D. celebensis than did PrP compared with control groups, and we identified eight key microbiota, including Ruegeria and Roseovarius. Correlation analysis between transcriptome and microbiome data revealed key interactions between specific microbiota and host gene expression. Certain microbial taxa were associated with specific genes (e.g. cuticle related genes) and toxicological pathways, shedding light on the complex molecular response and in vivo toxicity effects of parabens. These findings contribute to a deeper understanding of the molecular mechanisms underlying paraben toxicity and highlight the importance of considering the ecological impact of chemical contaminants in aquatic ecosystems.


Assuntos
Cladóceros , Parabenos , Animais , Parabenos/análise , Transcriptoma , Ecossistema , Águas Salinas
8.
Water Environ Res ; 96(1): e10979, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38264925

RESUMO

This research focuses on boosting seawater pretreatment and desalination through electrocoagulation (EC)/ultrafiltration (UF) and electrocoagulation (EC)/nanofiltration (NF) processes. We first optimized the key parameters of the EC process using aluminum (Al) and iron (Fe) electrodes. Experimental results show EC process is efficient under optimal conditions. Second, membrane filtration using UF (ES10B), NF(UTC60) and NF(200) as post-processing steps to the EC process were experimented with. EC(Al)/NF(UTC60) combination resulted in the highest removal rate of organic matter (COD 98%, TOC 95%, fluorescence [humic and fulvic acids] 68%), optical density (OD600nm 75%, turbidity 70%, conductivity 64%). In terms of major ions removal, up to 55% was achieved as NF decreases conductivity, salinity, and hardness. EC(Al)/NF(UTC60) seawater permeate demonstrated the best results in terms of lowest flux decline (J/Jo = 0.9) and fouling, which was realized by resistance in series and recovery factor rate (%). Additionally, NF(UTC60) fouling reversibility led to a longer lifetime and higher recovery factor (93%). PRACTITIONER POINTS: Pretreatment by hybrid processes was experimented with to enhance the saline water treatment. Organic matter (COD 98%, TOC 95%, fluorescence [humic and fulvic acids] 68%) and turbidity were successfully removed. Salinity and hardness (conductivity 64%) were highly reduced by NF. Flux decline, retention rate, and membrane fouling were studied.


Assuntos
Águas Salinas , Água do Mar , Eletrocoagulação , Eletrodos , Ferro
9.
Environ Res ; 241: 117654, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-37980990

RESUMO

Water is a fundamental requirement for the survival of human beings. Although water is abundantly available across the globe, access to freshwater still remains a major concern. Most of the water available is saline or brackish, which is not fit for human consumption. Desalination is the optimum solution for production of potable water from saline water. A major shortcoming of conventional desalination technologies is their dependence on fossil fuel that results in environmental degradation, global warming, etc. Therefore, sustainable desalination technology has evolved as a need of hour. Among all renewable energy resources, solar energy is abundantly available and can be potentially harvested. Therefore, solar energy can be used to drive sustainable desalination technologies. A solar still converts saline water into freshwater in a single step using solar energy. But the major drawbacks of solar still are relatively lower efficiency and lower yield. Nanofluids are widely used to overcome these limitations due to their extraordinary and unique properties. This paper critically reviews the recent research performed on the application of nanofluids in solar desalination systems. Methods of nanofluid preparation, their types and properties are also discussed in detail. Application of nanofluids in solar desalination systems is discussed with special attention on performance enhancement of solar stills. Combinations of nanofluids with various other performance enhancement techniques are also considered. The effectiveness of nanofluids in solar stills is found to be dependent majorly on the nature and concentration of the nanofluid used.


Assuntos
Energia Solar , Humanos , Combustíveis Fósseis , Água Doce , Aquecimento Global , Águas Salinas
10.
Environ Sci Pollut Res Int ; 31(7): 10273-10295, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36645598

RESUMO

An experimental investigation was executed on the solar evacuated tube collector containing a collective condenser unit of heat pipe arrangement attached to a single slope solar desalination system. The brackish water preheating was done by the unique solar collector before entering the still. Performance analysis of the system was carried out with 0.001, 0.002 and 0.003 kg/s brackish water flow rate in the collector and 0.01, 0.02 and 0.03 m of brine water depth in a single-slope solar desalination system. The feasibility of the proposed system was evaluated by thermodynamic analysis, embodied energy, CO2 mitigation and economic analysis. Active desalination system with collective condenser heat pipe evacuated tube collector at 0.001 kg/s brackish water flow rate and 0.01 m water depth produced maximum freshwater yield, average daily thermal and exergy efficiency of 3.085 l/m2day, 30.25% and 3.17% respectively. An increase of maximum freshwater yield of 37.11% and average daily thermal efficiency of 43.5% respectively were achieved at a brackish water flow rate of 0.001 kg/s and 0.01 m of basin water depth in comparison with a traditional single slope solar desalination system. The embodied energy of the system was estimated as 630.77 kWh, and 0.001 kg/s and 0.01 m of water depth resulted in the highest earned carbon credit of 16,954.48 INR. The minimum payback period of 2.19 years was achieved at the lower brackish water flow rate and basin water depth of 0.001 kg/s and 0.01 m respectively.


Assuntos
Temperatura Alta , Energia Solar , Luz Solar , Água , Águas Salinas , Água Doce
11.
Water Res ; 250: 121009, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38118256

RESUMO

While electrodialysis (ED) demonstrates lower energy consumption than reverse osmosis (RO) in the desalination of low salinity waters, RO continues to be the predominant technology for brackish water desalination. In this study, we probe this skewed market share and project the potential for future disruption by ED through systematic assessment of the levelized cost of water (LCOW). Using rigorous process- and economic-models, we minimize the LCOW of RO and ED systems, highlighting important tradeoffs between capital and operating expenditure for each technology. With optimized current state-of-the-art systems, we find that ED is more economical than RO for feed salinities ≤ 3 g L-1, albeit to a minor extent. Considering that RO is a highly mature technology, we focus on predicting the future potential of ED by evaluating plausible avenues for capital and operating cost reduction. Specifically, we find that reduction in the price of ion-exchange membranes (i.e., < 60 USD m-2) can ensure competitiveness with RO for feed salinities up to 5 g L-1. For higher feed salinities (≥ 5 g L-1) we reveal that the LCOW of ED may effectively be reduced by decreasing ion-exchange membrane resistance, while preserving high current efficiency. Through extensive assessment of structure-property-performance relationships, we precisely identify target membrane charge densities and diffusion coefficients which optimize the LCOW of ED, thus providing novel guidance for future membrane material development. Overall, we emphasize that with a unified approach - whereby ion-exchange membrane price is reduced and performance is enhanced - ED can become the economically preferable technology compared to RO across the entire brackish water salinity range.


Assuntos
Purificação da Água , Análise Custo-Benefício , Osmose , Águas Salinas , Água , Membranas Artificiais
12.
Environ Sci Pollut Res Int ; 31(3): 4826-4847, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38110681

RESUMO

Saltwater intrusion is a prevalent global environmental issue that detrimentally impacts coastal groundwater aquifers. This problem is exacerbated by climate change and increased groundwater abstraction. Employing physical barriers proves effective in mitigating saline water intrusion. In this study, a validated numerical simulation model is utilized to assess the impact of aquifer stratification on the effectiveness of mixed physical barriers (MPBs) and their response to structural variations. Additionally, the performance of MPBs was compared with that of single physical barriers in a laboratory-scale aquifer. Three different configurations were replicated, comprising two stratified aquifers (HLH and LHL) and a homogenous reference aquifer (H). The results demonstrate that MPBs are efficient in decreasing the saltwater penetration length in the investigated cases. The reductions in penetration length were up to 65% in all cases. The removal efficacy of residual saline water for MPBs exceeded that of the subsurface dam by 2.1-3.3 times for H, 2.1-3.6 times for HLH, and 8.3 times for LHL conditions, while outperforming the cutoff wall by 38-100% for H, 39-44% for HLH, and 2.7-75% for LHL. These findings are of importance for decision-makers in choosing the most appropriate technique for mitigating saline water intrusion in heterogeneous coastal aquifers.


Assuntos
Água Subterrânea , Água do Mar , Água Subterrânea/química , Águas Salinas , Mudança Climática , Monitoramento Ambiental
13.
Water Res ; 250: 121016, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38134857

RESUMO

Nitrogen (N) compounds can occur in water resources from natural and anthropogenic activities. It is ideal that these contaminants be removed before water consumption. As water quality has been affected by increased salinity and pH variation, more advanced and robust technologies such as electrodialysis (ED) can be considered for simultaneous desalination and pollutant removal. In this context, the removal of N-species (NO3-, NO2-, NH4+, and CH4N2O) from brackish water by ED was investigated for different feed water quality, considering increased salinity (0 - 10g/L NaCl) and pH variation (3 - 11), under limit current density (LCD) at fixed electric potential condition. The applied electric potential (5 - 25V) under, at, and over the LCD at fixed electric potential and dynamic current density (DCD), as a percentage of LCD (0.4 - 1.2), were analyzed to improve the process. In addition, energy efficiency in the form of specific energy consumption (SEC) and current efficiency (CE) were assessed for ED at fixed electric potential and DCD. The results showed that, at extreme pH of the feed water, the removal of NO2- and NH4+ can be affected, while NO3-was the most stable compound with pH variation. An increase in feed water salinity just slightly impacted the removal of N-compounds, due to the similar characteristics of the ions in the water. The increase in electric potential at fixed electric potential or DCD increased the removal and molar flux of N-compounds. However, operating over the LCD increased the SEC of the ED process while changes in removal were not significant. DCD procedures resulted in higher CE and shorter run time of the experiments. Therefore, ED proved to be a suitable treatment technique to produce fresh water due to the selective removal of the studied ions, especially at 15V (fixed electrical potential) and 0.8 LCD (DCD) related to removal, molar flux, and run time to achieve guidelines.


Assuntos
Compostos de Nitrogênio , Dióxido de Nitrogênio , Íons , Eletricidade , Nitrogênio , Águas Salinas
14.
Water Sci Technol ; 88(11): 2849-2861, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38096073

RESUMO

Capacitive deionization (CDI) is considered a promising technology for desalination of sea or brackish water. In this study, a ZnS/g-C3N4 composite was synthesized through a one-step high-temperature method and used as the main material to fabricate CDI electrodes. The results of SEM and TEM showed that spherical-like nanoparticles of ZnS were uniformly distributed on the g-C3N4 sheet. The g-C3N4 phase facilitates the ZnS particles precipitate and restrain their agglomeration, which contributes to a high specific surface area of ZnS. Furthermore, the electrochemical test results indicated that ZnS/g-C3N4 composite had a good capacitance characteristic, low resistance, and high electrochemical stability. Finally, the desalinization performance of the ZnS/g-C3N4 composite electrodes was tested in traditional mode and membrane capacitive deionization (MCDI) mode. The results showed that ZnS/g-C3N4//ZnS/g-C3N4 (MCDI) exhibited an optimal desalination capacity. The adsorption amount was 27.65, 50.26, and 65.34 mg/g for NaCl initial concentration of 200, 400, and 600 mg/L, respectively, with the voltage of 1.2 V and flow rate of 5 mL/min. Increasing initial concentration enhanced the conductivity and ion migration rate so as to increase the NaCl adsorption amount. ZnS/g-C3N4 composite can be used as potential electrode material for high performance of MCDI.


Assuntos
Cloreto de Sódio , Purificação da Água , Purificação da Água/métodos , Condutividade Elétrica , Águas Salinas , Eletrodos
15.
PLoS One ; 18(12): e0296222, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38127936

RESUMO

Invasive suckermouth armored catfish Pterygoplichthys spp. successfully spread during one decade into many river systems of Vietnam. Wide and rapid invasion of armored catfish might be associated with using brackish water in estuaries to spread from one river system to another. The first goal of our study was to assess the horizontal and vertical distribution of invasive fish in freshwater (Da Rang River) and in brackish water (Da Rang River estuary) associated with circadian rhythm. In the both sampling locations, fish were mainly caught at nighttime at the bottom and near the surface using the net traps and vertical nets. In estuary, fish were caught in the net traps with distance 2.0-7.5 m from the right or left banks where water was predominantly fresh. In freshwater of the Da Rang River, fish were often caught near the left bank with gravel and stone substrate. The second goal of our study was to experimentally evaluate the circadian (12 hours of the night and 12 hours of the day) rhythm of locomotor activity (LA) of fish. Fish from different freshwater locations (Am Chua canal and Da Rang River) had a similar diurnal dynamic of LA with mostly movements (77-83% of total diurnal LA) at nighttime (18:00-6:00, GMT+7) at the end of the wet season. Armored catfish from the brackish water location (Da Rang River estuary) also were mostly active (76% of total diurnal LA) overnight. However, fish from freshwater and brackish water had difference in the timing of behavioral activity. Fish LA from estuary was significantly lower than LA of fish from freshwater locations during 18:00 to 21:00 before low tide. The results of our field and experimental studies established that armored catfish in estuary moved in horizontal and vertical planes predominantly at nighttime. Tide level regulates locomotor activity of invasive fish and could influence on the possibility of their spreading through the estuary.


Assuntos
Peixes-Gato , Animais , Água Doce , Rios , Águas Salinas , Estuários , Locomoção
16.
Braz J Biol ; 83: e274991, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37909589

RESUMO

The objective of this study was to evaluate the water status, photosynthetic pigments, and photochemical efficiency of mini watermelon plants under salt stress and phosphate fertilization. The experiment was conducted in pots under greenhouse conditions in Pombal, PB, Brazil. The experimental design used was randomized blocks in a 5 × 4 factorial scheme, with five levels of electrical conductivity of irrigation water - ECw (0.3, 1.3, 2.3, 3.3, and 4.3 dS m-1) and four doses of phosphorus (60, 80, 100, and 120% of the recommendation), with three replicates. The relative water content in the tissues decreased with the increase in ECw levels in all phosphorus doses, with decreases of 7.05, 7.81 and 8.83% per unit increase in ECw, in plants fertilized with 80, 100 and 120% P2O5. On the other hand, ECw levels increased electrolyte leakage, regardless of phosphorus doses of the recommendation. The synthesis of photosynthetic pigments and the quantum efficiency of photosystem II were inhibited by increasing water salinity from 0.3 dS m-1 in plants grown under phosphorus doses above 60% of the recommendation. Water salinity from 0.3 dS m-1 reduced chlorophyll b contents, initial, maximum, and variable fluorescence of mini watermelon plants, with a decrease of 11.86, 4.51, 4.53, and 4.54% per unit increment of ECw, respectively.


Assuntos
Citrullus , Fosfatos , Fotossíntese , Águas Salinas , Fósforo
17.
Environ Sci Pollut Res Int ; 30(57): 120564-120575, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37940830

RESUMO

Solar still is the easiest method to purifying the saline water for domestic usage, but this method needs much improvement for better performance since it has lower productivity. In this paper, an experimental investigation is completed to analyse the semi cylindrical solar productivity still. The semi-cylindrical still is incorporated with direct atomizer and scrap used as an energy storage medium. Experiments are carried out during March 2020 in Kovilpatti, the southern part of India, with a depth of 2 and 4 cm saline water. Comparative performance analysis is made for conventional semi-cylindrical still, semi-cylindrical still with an atomizer, and semi-cylindrical still with atomizer and storage materials. The experimental study shows that the productivity of still increases while decreasing the water depth. Compared with 2-cm and 4-cm depth, solar still with 2-cm depth gives promising distillate productivity. The solar productivity still having 4-cm depth of water without atomizer gives only 2670 ml; on the other side, 2-cm water depth without atomizer gives 3100-ml productivity. The maximum productivity of solar still is found on a semi-cylindrical solar still combined with atomizer and energy storage medium having 2-cm water depth. Results revealed a higher freshwater production rate of 3610 ml found while incorporating atomizer and energy storage with the solar still. The system efficiency improved up to 35.20% compared to conventional semi-cylindrical still with 4 cm of saline water depth.


Assuntos
Energia Solar , Purificação da Água , Água Doce , Índia , Nebulizadores e Vaporizadores , Águas Salinas
18.
Water Res ; 245: 120625, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37820474

RESUMO

Capacitive electrodialysis (CED) is an emerging and promising desalination technology for decentralized drinking water production. Brackish water, often used as a drinking water source, may contain organic micropollutants (OMPs), thus raising environmental and health concerns. This study investigated the transport of OMPs in a fully-functional decentralized CED system for drinking water production under realistic operational conditions. Eighteen environmentally-relevant OMPs (20 µg L-1) with different physicochemical properties (charge, size, hydrophobicity) were selected and added to the feed water. The removal of OMPs was significantly lower than that of salts (∼94%), mainly due to their lower electrical mobility and higher steric hindrance. The removal of negatively-charged OMPs reached 50% and was generally higher than that of positively-charged OMPs (31%), whereas non-charged OMPs were barely transported. Marginal adsorption of OMPs was found under moderate water recovery (50%), in contrast to significant adsorption of charged OMPs under high water recovery (80%). The five-month operation demonstrated that the CED system could reliably produce water with low salt ions and TOC concentrations, meeting the respective WHO requirements. The specific energy consumption of the CED stack under 80% water recovery was 0.54 kWh m-3, which is competitive to state-of-the-art RO, ED, and emerging MCDI in brackish water desalination. Under this condition, the total OPEX was 2.43 € m-3, of which the cost of membrane replacement contributed significantly. Although the CED system proved to be a robust, highly adaptive, and fully automated technology for decentralized drinking water production, it was not highly efficient in removing OMPs, especially non-charged OMPs.


Assuntos
Água Potável , Purificação da Água , Cloreto de Sódio , Íons , Adsorção , Águas Salinas
19.
Environ Pollut ; 337: 122554, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37717895

RESUMO

The brackish water clam (Corbicula japonica) is constantly exposed to stressful salinity gradients and high levels of heavy metals in the freshwater-saltwater interface of estuary environments, which are introduced from upstream regions and land. To identify the key molecular pathways involved in the response to salinity changes and heavy metal bioaccumulation, we obtained the transcriptomes of C. japonica inhabiting different salinities and heavy metal distributions in Gwangyang Bay (Korea) using RNA sequencing. Among a total of 404,486 assembled unigenes, 5534 differentially expressed genes were identified in C. japonica inhabiting different conditions, 1549 of which were significantly upregulated and 1355 were significantly downregulated. Correlation analyses revealed distinct gene expression patterns between the low and high conditions of salinity and heavy metal bioaccumulation. Functional annotation revealed significant downregulation of genes involved in "ubiquitin-dependent protein catabolic process," "tricarboxylic acid cycle," and "intracellular protein transport" in C. japonica from the high condition compared to the low condition. Transcription and translation pathways were significantly enriched in the high condition. Additionally, upon comparison of the low and high conditions by qRT-PCR and proteasome enzyme activity analyses, our findings demonstrated that environmental stress could suppress the ubiquitin-proteasome complex (UPC). Additionally, transcriptomic changes under high salinity stress conditions may be related to an increase in cellular protection by defense enzymes, which leads to more energy being required and a disruption of energy homeostasis. Ultimately, this could cause growth retardation in the clam C. japonica. In summary, this study provides the first evidence of UPC suppression induced by a combination of high salinity and heavy metal bioaccumulation stress in C. japonica, which could compromise the survival and growth of estuarine bivalves.


Assuntos
Corbicula , Metais Pesados , Animais , Corbicula/metabolismo , Bioacumulação , Salinidade , Complexo de Endopeptidases do Proteassoma/metabolismo , Águas Salinas , Metais Pesados/análise , Transtornos do Crescimento , Ubiquitinas/metabolismo
20.
Water Res ; 243: 120428, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37536247

RESUMO

Although the autopsies of reverse osmosis (RO) membranes from full-scale, brackish water desalination plants identify the co-presence of silica and Ca-based minerals in scaling layers, minimal research exists on their formation process and mechanisms. Therefore, combined scaling by silica and either gypsum (non-alkaline) or amorphous calcium phosphate (ACP, alkaline) was investigated in this study for their distinctive impacts on membrane performance. The obtained results demonstrate that the coexistence of silica and Ca-based mineral salts in feedwaters significantly reduced water flux decline as compared to single type of Ca-based mineral salts. This antagonistic effect was primarily attributed to the silica-mediated alleviation of Ca-based mineral scaling. In the presence of silica, silica skins were immediately established around Ca-based mineral precipitates once they emerged. Sheathing by the siliceous skins hindered the aggregation and thus the morphological evolution of Ca-based mineral species. Unlike sulfate precipitates, ACP precipitates can induce the formation of dense and thick silica skins via an additional condensation reaction. Such a phenomenon rationalized the notion concerning a stronger mitigating effect of silica on ACP scaling than gypsum scaling. Meanwhile, coating by silica skins altered the surface chemistries of Ca-based mineral precipitates, which should be fully considered in regulating membrane surface properties for combined scaling control. Our findings advance the mechanistic understanding on combined mineral scaling of RO membranes, and may guide the appropriate design of membrane surface properties for scaling-resistant membrane tailored to brackish water desalination.


Assuntos
Dióxido de Silício , Purificação da Água , Cálcio , Sulfato de Cálcio , Sais , Purificação da Água/métodos , Osmose , Minerais , Águas Salinas , Membranas Artificiais
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