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Search Results (619)

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Keywords = alkaline reduced water

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23 pages, 3500 KB  
Proceeding Paper
Modelling Heat Recovery System for Efficiency Enhancement in Alkaline Electrolyser
by Mohamed Amin, Edward Antwi, Taimoor Khan, Romy Sommer, Qahtan Thabit and Johannes Gulden
Eng. Proc. 2026, 121(1), 19; https://doi.org/10.3390/engproc2025121019 - 16 Jan 2026
Abstract
The global energy landscape is transitioning towards cleaner solutions, with hydrogen emerging as a key energy source. To unlock hydrogen’s potential, it is crucial to prioritize the development of a more efficient, cost-effective, and environmentally friendly production process. Enhancing the efficiency and scalability [...] Read more.
The global energy landscape is transitioning towards cleaner solutions, with hydrogen emerging as a key energy source. To unlock hydrogen’s potential, it is crucial to prioritize the development of a more efficient, cost-effective, and environmentally friendly production process. Enhancing the efficiency and scalability of these technologies will not only reduce their environmental impact but also accelerate the adoption of hydrogen as a viable alternative energy solution, fostering a cleaner and more sustainable future. This paper presents a study on simulating a heat recovery system in an alkaline electrolyser consisting of 30 cells, which integrates a plate heat exchanger to preheat the water entering the system, and assessing how it affects efficiency. The study uses a thermal model, employing the concept of lumped thermal capacitance, to analyze the impact of the heat recovery system utilization on the overall performance of the electrolyser. MATLAB/Simulink was used to simulate and provide a detailed visualization of how recovery systems affect the electrolyser’s efficiency. The results of the simulations confirmed that incorporating a heat recovery system significantly improves the efficiency of alkaline electrolysers up to 8%. The study provides a promising outlook for the future of hydrogen production, emphasizing the potential of waste heat recovery systems to make green hydrogen production more viable and sustainable. Full article
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17 pages, 3706 KB  
Article
Carbonation of Calcined Clay Dolomite for the Removal of Co(II): Performance and Mechanism
by Can Wang, Jingxian Xu, Tingting Gao, Xiaomei Hong, Fakang Pan, Fuwei Sun, Kai Huang, Dejian Wang, Tianhu Chen and Ping Zhang
J. Xenobiot. 2026, 16(1), 13; https://doi.org/10.3390/jox16010013 - 13 Jan 2026
Viewed by 107
Abstract
The rising levels of Co(II) in aquatic environments present considerable risks, thereby necessitating the development of effective remediation strategies. This study introduces an innovative pre-hydration method for synthesizing carbonated calcined clay dolomite (CCCD) to efficiently remove Co(II) from contaminated water. This pre-hydration treatment [...] Read more.
The rising levels of Co(II) in aquatic environments present considerable risks, thereby necessitating the development of effective remediation strategies. This study introduces an innovative pre-hydration method for synthesizing carbonated calcined clay dolomite (CCCD) to efficiently remove Co(II) from contaminated water. This pre-hydration treatment successfully reduced the complete carbonation temperature of the material from 500 °C to 400 °C, significantly enhancing energy efficiency. The Co(II) removal performance was systematically investigated by varying key parameters such as contact time, initial Co(II) concentration, pH, and solid/liquid ratio. Optimal removal was achieved at 318 K with pH of 4 and a solid/liquid ratio of 0.5 g·L−1. Continuous flow column experiments confirmed the excellent long-term stability of CCCD, maintaining a consistent Co(II) removal efficiency of 99.0% and a stable effluent pH of 8.5 over one month. Isotherm and kinetic models were used to empirically describe concentration-dependent and time-dependent uptake behavior. The equilibrium data were best described by the Langmuir model, while kinetics followed a pseudo-second-order model. An apparent maximum removal capacity of 621.1 mg g−1 was obtained from Langmuir fitting of equilibrium uptake data. Mechanistic insights from Visual MINTEQ calculations and solid phase characterizations (XRD, XPS, and TEM) indicate that Co(II) removal is dominated by mineral water interface precipitation. The gradual hydration of periclase (MgO) forms Mg(OH)2, which creates localized alkaline microenvironments at particle surfaces and drives Co(OH)2 formation. Carbonate availability further favors CoCO3 formation and retention on CCCD. Importantly, this localized precipitation pathway maintains a stable, mildly alkaline effluent pH (around 8.5), reducing downstream pH adjustment demand and improving operational compatibility. Overall, CCCD combines high Co(II) immobilization efficiency, strong long-term stability, and an energy-efficient preparation route, supporting its potential for scalable remediation of Co(II) contaminated water. Full article
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17 pages, 3422 KB  
Article
Binder-Free Spinel Co2CuO4 Nanosheet Electrodes with Cu-Driven Kinetic Enhancement for Alkaline OER Applications
by Abu Talha Aqueel Ahmed, Momin M. Mujtaba, Abu Saad Ansari and Sangeun Cho
Materials 2026, 19(2), 301; https://doi.org/10.3390/ma19020301 - 12 Jan 2026
Viewed by 110
Abstract
Developing electrocatalysts that are efficient and durable for the oxygen evolution reaction (OER) is essential for improving the energy efficiency of alkaline water splitting. Spinel-type transition-metal oxides have emerged as promising non-noble alternatives; however, their catalytic performance is often limited by sluggish charge [...] Read more.
Developing electrocatalysts that are efficient and durable for the oxygen evolution reaction (OER) is essential for improving the energy efficiency of alkaline water splitting. Spinel-type transition-metal oxides have emerged as promising non-noble alternatives; however, their catalytic performance is often limited by sluggish charge transport and insufficient utilization of active sites. Herein, we present a systematic comparative study of electrodeposited Co3O4 (CO-300) and Cu-substituted Co2CuO4 (CCO-300) nanosheet films directly grown on Ni foam. Structural, morphological, and spectroscopic analyses reveal that Cu2+ integration into Co-oxide spinel lattice modifies the local electronic environment and produces a more open and interconnected nanosheet architecture, thereby enhancing conductivity and increasing the density of accessible redox-active sites. As a result, the optimized CCO-300 exhibits superior catalytic performance at higher current densities, along with a smaller Tafel slope (44 mV dec–1), a larger electrochemically active surface area (ECSA), and reduced charge-transfer resistance compared to CCO-300, indicating accelerated reaction kinetics and improved electron-ion transport. Furthermore, the multistep chronopotentiometry measurements and long-term stability tests over 100 h at current densities of 10 and 250 mA cm–2 highlight the excellent operational stability of the CCO-300 catalyst. Full article
(This article belongs to the Section Energy Materials)
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18 pages, 6750 KB  
Article
Impact of Different Extraction Methods on the Physicochemical Characteristics and Bioactivity of Polysaccharides from Baobab (Adansonia suarezensis) Fruit Pulp
by Huimin Cui, Shang Gao, Jiahui Shi, Yinghui Pan, Pengzhi Hong, Jiannong Lu and Chunxia Zhou
Foods 2026, 15(2), 273; https://doi.org/10.3390/foods15020273 - 12 Jan 2026
Viewed by 111
Abstract
Polysaccharides from baobab (Adansonia suarezensis) fruit pulp (ASPs) hold significant potential for pharmaceutical and functional food applications due to their bioactivities. This study systematically evaluated the effects of six extraction methods—hot water (ASP-HW), acid (ASP-AC), alkaline (ASP-AL), and their ultrasound-assisted counterparts [...] Read more.
Polysaccharides from baobab (Adansonia suarezensis) fruit pulp (ASPs) hold significant potential for pharmaceutical and functional food applications due to their bioactivities. This study systematically evaluated the effects of six extraction methods—hot water (ASP-HW), acid (ASP-AC), alkaline (ASP-AL), and their ultrasound-assisted counterparts (ASP-HWU, ASP-ACU, ASP-ALU)—on the yield, chemical composition, structural properties, and biological activities of ASPs. The results demonstrated that the extraction solvent critically influenced key properties: alkaline-based methods (ASP-AL, ASP-ALU) achieved the highest yields (up to 62.47%) and yielded polysaccharides with lower molecular weights (approximately 19,600–19,813 Da) and smaller particle sizes (around 140–147 nm). All ASPs were identified as acidic pectic polysaccharides, composed of galacturonic acid, xylose, galactose, and arabinose. Notably, ASP-AC, ASP-ACU, ASP-AL, and ASP-ALU exhibited a triple-helix conformation, which was absent in hot water-extracted polysaccharides. Bioactivity assessments revealed that ASP-AL and ASP-ALU possessed superior antioxidant capacities, demonstrating the lowest IC50 values for DPPH radical scavenging (113.67–116.67 μg/mL) and ABTS radical scavenging (79.33–79.67 μg/mL), as well as potent α-glucosidase inhibitory activity (IC50: 0.146–0.206 mg/mL), outperforming other extracts and the positive control acarbose. Correlation analysis indicated that enhanced bioactivity was associated with lower molecular weight and reduced uronic acid content. These findings underscore that alkaline extraction is an efficient strategy for obtaining highly bioactive polysaccharides from Adansonia suarezensis fruit pulp, providing a valuable theoretical foundation for their utilization in developing nutraceuticals and functional foods. Full article
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21 pages, 2856 KB  
Article
Influence of pH and Heat Treatment on the Physicochemical, Interfacial, and Emulsifying Properties of Hemp Seed Protein Dispersions
by Davide Odelli, Lingxin You, Jennyfer Fortuin, Jérôme Bour, Marcus Iken, Axel Archaimbault and Christos Soukoulis
Foods 2026, 15(2), 257; https://doi.org/10.3390/foods15020257 - 10 Jan 2026
Viewed by 156
Abstract
This study reports the effect of pH (2, 7, 10) and heat treatment (80 °C for 30 min) on the oil–water (o/w) interfacial behavior of hemp seed protein isolate (HPI) aqueous dispersions. The physicochemical, interfacial adsorption, rheology, and emulsifying properties of protein dispersions [...] Read more.
This study reports the effect of pH (2, 7, 10) and heat treatment (80 °C for 30 min) on the oil–water (o/w) interfacial behavior of hemp seed protein isolate (HPI) aqueous dispersions. The physicochemical, interfacial adsorption, rheology, and emulsifying properties of protein dispersions were evaluated. HPI dispersions at pH 10 exhibited the highest water solubility (60%), the greatest net charge (−27 mV), and the lowest hydrophobicity (~5 a.u.), promoting o/w interfacial pressure (π) and interfacial viscoelasticity. Strong interfacial viscoelastic protein layers (E* = 25 mN/m) were also observed under acidic conditions (pH 2), where proteins exhibited high solubility (40%), a high positive net charge (21 mV), and increased hydrophobicity (46 a.u.). HPI dispersions in their neutral state (pH 7) were not able to form stable o/w emulsions due to their poor physicochemical properties such as low solubility (18%), low surface charge (−18 mV), and hydrophobicity (~5 a.u.). Heat treatment significantly increased the charge and hydrophobicity of both neutral and alkaline proteins (~30 mV and ~10 a.u., respectively), increasing their particle size distribution and ultimately reducing their interfacial protein layer elasticity (E* = 20 and 13 nM/m, respectively). While particles at acidic conditions showed high thermal resistance, heat treatment improved the emulsifying stability in alkaline conditions while further reducing it in the neutral state. Overall, HPI dispersions demonstrated the ability to form stable emulsions at both alkaline and acid pHs, with those formed at pH 2 exhibiting a lower droplet size and superior stability. Full article
(This article belongs to the Special Issue Research Trends in Plant-Based Foods)
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18 pages, 777 KB  
Article
Ecofriendly Biosurfactant-Containing Solid Shampoo Formulation for Pets
by Ana Paula B. Cavalcanti, Gleice P. de Araújo, Fabíola Carolina G. de Almeida, Káren Gercyane O. Bezerra, Maria da Glória C. da Silva, Alessandra Sarubbo, Rita de Cássia F. Soares da Silva and Leonie A. Sarubbo
Cosmetics 2026, 13(1), 11; https://doi.org/10.3390/cosmetics13010011 - 8 Jan 2026
Viewed by 245
Abstract
The growing demand for sustainable cosmetic products and the rapid expansion of the pet care market have driven the search for environmentally friendly, safe, and effective alternatives to conventional formulations. In this study, an ecofriendly solid shampoo for pets was developed using exclusively [...] Read more.
The growing demand for sustainable cosmetic products and the rapid expansion of the pet care market have driven the search for environmentally friendly, safe, and effective alternatives to conventional formulations. In this study, an ecofriendly solid shampoo for pets was developed using exclusively natural ingredients and a microbial biosurfactant produced by Starmerella bombicola ATCC 22214 as a surface-active component. The biosurfactant was combined with renewable anionic and nonionic surfactants, conditioning agents, natural oils and butters, and minimal water content to obtain a compact, solid formulation. The shampoo was produced through a controlled multi-phase process and subsequently characterized by physicochemical, microbiological, toxicological, and performance analyses. The formulation exhibited stable pH values suitable for pet skin, low moisture content, absence of free alkalinity, high solid content, and satisfactory foaming capacity. Cleaning efficiency tests demonstrated effective removal of artificial sebum from pet fur while preserving softness and shine. Microbiological assays confirmed the absence of bacterial and fungal contamination, and toxicological evaluations revealed no cytotoxicity and low eye irritation potential. In addition, the shampoo showed 100% biodegradability and maintained physicochemical and organoleptic stability over six months of storage. Overall, the results demonstrate that the developed solid shampoo represents an innovative, safe, and biodegradable alternative that reduces water consumption and plastic packaging, contributing to sustainable development in the pet cosmetics sector. Full article
(This article belongs to the Special Issue Feature Papers in Cosmetics in 2025)
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15 pages, 848 KB  
Article
Removal of Phenolic Compounds from Wastewater Through an Alternative Process with Zero-Valent Magnesium as Reactive Material
by Giulia Maria Curcio, Jose Luis Cayambe Guaman, Elvis Gribaldo Aucancela Rivera, Tiziana Andreoli, Rosaria Bruno, Carlo Limonti and Alessio Siciliano
Sustainability 2026, 18(2), 631; https://doi.org/10.3390/su18020631 - 8 Jan 2026
Viewed by 160
Abstract
Phenolic compounds are widespread environmental contaminants whose removal from water and wastewater is essential for ecosystem protection. Among the several purification technologies, the use of zero-valent metals has gained increasing interest in recent years. The identification of effective and environmentally friendly materials is [...] Read more.
Phenolic compounds are widespread environmental contaminants whose removal from water and wastewater is essential for ecosystem protection. Among the several purification technologies, the use of zero-valent metals has gained increasing interest in recent years. The identification of effective and environmentally friendly materials is a key issue for the development of this technology. In this study, zero-valent magnesium (ZVMg), a highly reactive non-toxic material, was used for the first time for the degradation of gallic acid (GA), chosen as a model phenolic compound, in an aqueous system. Several tests were conducted in order to identify the effect of pH, ZVMg amount, and temperature on the process performance. Moreover, the reusability of the reactive material in subsequent treatment cycles was assessed. Optimal operational conditions were achieved with a ZVMg amount of 0.3 g, corresponding to a ratio of 0.33 gGA/gMg, reaching a removal efficiency of almost 90% in about 180 min. The performance was clearly favored by an alkaline environment, and yields close to the maximum values were reached under uncontrolled pH conditions. The increase in temperature significantly accelerated the reaction rate, which followed pseudo-first-order kinetic law, achieving high abatement percentages with a reduced quantity of ZVMg. Finally, Mg0 demonstrated good reusability, maintaining high efficiency, close to 78%, for up to four cycles, with the possibility of restoring the material’s activity through acid washing. The detected results confirm that ZVMg is a promising and sustainable reactive material for environmental remediation processes, offering an effective alternative for the treatment of water contaminated by phenolic compounds. Full article
(This article belongs to the Special Issue Sustainable Solutions for Wastewater Treatment and Recycling)
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23 pages, 5498 KB  
Article
The Effect of a Cactus-Based Natural Coagulant on the Physical–Chemical and Bacteriological Quality of Drinking Water: Batch and Continuous Mode Studies
by Abderrezzaq Benalia, Ouiem Baatache, Kerroum Derbal, Amel Khalfaoui, Loqmen Atime, Antonio Pizzi, Gennaro Trancone and Antonio Panico
Water 2026, 18(2), 138; https://doi.org/10.3390/w18020138 - 6 Jan 2026
Viewed by 347
Abstract
Cactus leaves from the Cactaceae family, particularly the Opuntia genus, have attracted increasing attention as natural coagulants for water treatment applications. In this work, Cactus-based extracts were investigated for drinking water treatment through the coagulation–flocculation process. Several extraction routes were examined, including [...] Read more.
Cactus leaves from the Cactaceae family, particularly the Opuntia genus, have attracted increasing attention as natural coagulants for water treatment applications. In this work, Cactus-based extracts were investigated for drinking water treatment through the coagulation–flocculation process. Several extraction routes were examined, including Ca-J, Ca-H2O, Ca-NaOH (0.05 M), Ca-NaCl (0.5 M), and Ca-HCl (0.05 M), and their performance was evaluated using jar test experiments. The removal efficiencies of total coliforms (TC), anaerobic sulfite-reducing bacteria (ASRB), total suspended solids (TSS), and turbidity were assessed, and the most effective extract was subsequently tested in a semi-industrial pilot-scale coagulation–flocculation–settling system. The physicochemical properties of the Cactus material were characterized using FTIR, SEM, XRD, and MALDI-TOF analyses. Results revealed bioactive components, including carbohydrates, proteins, tannins, flavonoids, and glucose, with functional groups (carboxyl, hydroxyl, carbonyl) responsible for coagulation. XRD and SEM analyses showed a semi-crystalline structure and a heterogeneous surface with fiber networks, while MALDI-TOF confirmed the presence of flavonoid and tannin compounds. These features collectively contribute to the effective removal of turbidity, suspended solids, and microbial contaminants. Among the tested extracts, Ca-NaOH (0.05 M) exhibited the highest removal efficiencies, achieving 100% removal of TC and ASRB, 94.15% removal of TSS, and 70.38% turbidity reduction under laboratory conditions. Pilot-scale application of this extract resulted in a turbidity reduction of 66.65%. Additional water quality parameters, including total alkalinity (TA), total dissolved solids (TDS), pH, and electrical conductivity (EC), were monitored to evaluate process performance. Overall, the results highlight the strong potential of Cactus leaves as an effective, cost-efficient, and environmentally friendly alternative to conventional chemical coagulants. However, further research is required to enhance their scalability and commercialization. Full article
(This article belongs to the Section Water Quality and Contamination)
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18 pages, 9445 KB  
Article
Integrated Electrochemical–Electrolytic Conversion of Oilfield-Produced Water into Hydrogen
by Pengjun Fan, Guangping Zha, Chao Zhang, Weikang Han, Fuli Wang, Bin Dong and Wenming Jiang
Processes 2026, 14(1), 173; https://doi.org/10.3390/pr14010173 - 5 Jan 2026
Viewed by 202
Abstract
This study tackles the challenge of treating high-oil (≥90 mg/L) and high-salinity (Cl ≥ 6900 mg/L) oilfield-produced water for green hydrogen production. An integrated technology combining electrochemical cascade purification (EDCF: electro-demulsification–coagulation–flotation) with alkaline water electrolysis is developed. The EDCF process effectively reduces [...] Read more.
This study tackles the challenge of treating high-oil (≥90 mg/L) and high-salinity (Cl ≥ 6900 mg/L) oilfield-produced water for green hydrogen production. An integrated technology combining electrochemical cascade purification (EDCF: electro-demulsification–coagulation–flotation) with alkaline water electrolysis is developed. The EDCF process effectively reduces oil, suspended solids, and turbidity to <10 mg/L, <20 mg/L, and <20 NTU, respectively, meeting stringent feedwater criteria for electrolysis. An asymmetric electrolysis strategy employing a nickel felt anode/Raney nickel cathode system achieves a low cell voltage of 1.856 V at 1 A/cm2 in 6 M KOH at 85 °C, with 96.58% H2 purity. Crucially, separate anolyte/catholyte (0.5/6 M KOH) mitigates Cl corrosion, enabling stable 240 h operation (96.66% ± 0.5% H2 purity) in a duplex steel electrolyzer. The work establishes comprehensive boundary conditions for scalable hydrogen production from treated produced water. Full article
(This article belongs to the Section Chemical Processes and Systems)
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17 pages, 733 KB  
Article
Hydrogen Production Using MOF-Enhanced Electrolyzers Powered by Renewable Energy: Techno-Economic and Environmental Assessment Pathways for Uzbekistan
by Wagd Ajeeb
Hydrogen 2026, 7(1), 7; https://doi.org/10.3390/hydrogen7010007 - 4 Jan 2026
Viewed by 429
Abstract
Decarbonizing industry, improving urban sustainability, and expanding clean energy use are key global priorities. This study presents a techno-economic analysis (TEA) and life-cycle assessment (LCA) of green hydrogen (GH2) production via water electrolysis for low-carbon applications in the Central Asian region, [...] Read more.
Decarbonizing industry, improving urban sustainability, and expanding clean energy use are key global priorities. This study presents a techno-economic analysis (TEA) and life-cycle assessment (LCA) of green hydrogen (GH2) production via water electrolysis for low-carbon applications in the Central Asian region, with Uzbekistan considered as a representative case study. Solar PV and wind power are used as renewable electricity sources for a 44 MW electrolyzer. The assessment also incorporates recent advances in alkaline water electrolyzers (AWE) enhanced with metal–organic framework (MOF) materials, reflecting improvements in efficiency and hydrogen output. The LCA, performed using SimaPro, evaluates the global warming potential (GWP) across the full hydrogen production chain. Results show that the MOF-enhanced AWE system achieves a lower levelized cost of hydrogen (LCOH) at 5.18 $/kg H2, compared with 5.90 $/kg H2 for conventional AWE, with electricity procurement remaining the dominant cost driver. Environmentally, green hydrogen pathways reduce GWP by 80–83% relative to steam methane reforming (SMR), with AWE–MOF delivering the lowest footprint at 1.97 kg CO2/kg H2. In transport applications, fuel cell vehicles powered by hydrogen derived from AWE–MOF emit 89% less CO2 per 100 km than diesel vehicles and 83% less than using SMR-based hydrogen, demonstrating the substantial climate benefits of advanced electrolysis. Overall, the findings confirm that MOF-integrated AWE offers a strong balance of economic viability and environmental performance. The study highlights green hydrogen’s strategic role in the Central Asian region, represented by Uzbekistan’s energy transition, and provides evidence-based insights for guiding low-carbon hydrogen deployment. Full article
(This article belongs to the Special Issue Green and Low-Emission Hydrogen: Pathways to a Sustainable Future)
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14 pages, 6318 KB  
Article
Reverse Osmosis Membrane Cleaning Optimization from Textile Dyeing Wastewater Reuse Applications
by Zhengwei Wang, Rulu Ouyang, Guorui Zhang, Chunhai Wei, Shiming Ji, Qixuan Li, Chunyang Tao and Hongwei Rong
Membranes 2026, 16(1), 29; https://doi.org/10.3390/membranes16010029 - 4 Jan 2026
Viewed by 257
Abstract
Reverse osmosis (RO) is the key process for textile dyeing wastewater reuse applications. Membrane fouling reduces both permeability and rejection capability, negatively affecting the technological economy of RO process. Membrane cleaning is critical to recovery of the permeability of fouled RO membranes. Based [...] Read more.
Reverse osmosis (RO) is the key process for textile dyeing wastewater reuse applications. Membrane fouling reduces both permeability and rejection capability, negatively affecting the technological economy of RO process. Membrane cleaning is critical to recovery of the permeability of fouled RO membranes. Based on multi-batch filtration and cleaning experiments, this study systematically evaluated the RO membrane fouling potential of pre-treated textile dyeing wastewater by a membrane bioreactor and the recovery performance of fouled RO membranes after different cleaning methods. A significant decline (more than 15%) in RO membrane permeability occurred after RO membrane permeate production of 625 L/m2 at a water recovery ratio of 60%. Protein-like substances and soluble microbial products were identified as the primary organic foulants via three-dimensional fluorescence excitation-emission matrix spectrometry (3D-FEEM). The single forward flushing with either pure water, acid, alkaline, or sodium hypochlorite solutions with a low active chlorine concentration showed very limited recovery of fouled RO membrane permeability. The combined forward flushing with acid followed by alkaline solutions restored fouled membrane permeability by up to 87% of a new RO membrane. The addition of pure water backwashing at a transmembrane pressure (TMP) of 0.5 MPa after both acid and alkaline solutions combined forward flushing restored fouled membrane permeability by up to 97% of a new RO membrane but deteriorated the rejection capability of the RO membrane. The backwashing parameters were further optimized at a TMP of 0.125 MPa and crossflow velocity (CFV) of 0.5 m/s, achieving fouled RO membrane permeability by up to 96% of a new RO membrane, and there were no negative effects on the rejection capability of the RO membrane. Alkaline forward flushing followed by pure water backwashing was the dominant contributor for fouled RO membrane permeability recovery. A preliminary economic analysis showed that the total chemical cost per RO production was 0.763 CNY/m3 and could be further reduced via removing acid cleaning and replacing combined alkaline flushing and pure water backwashing with alkaline backwashing. Full article
(This article belongs to the Section Membrane Applications for Water Treatment)
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18 pages, 7161 KB  
Article
Assessment of the Impact of the Irrigation Regime and the Application of Fermented Organic Fertilizers on Soil Salinity Dynamics and Alfalfa Growth in Coastal Saline–Alkaline Land
by Qian Yang, Shanshan Shen, Qiu Jin and Jingnan Chen
Agronomy 2026, 16(1), 117; https://doi.org/10.3390/agronomy16010117 - 1 Jan 2026
Viewed by 418
Abstract
Alfalfa cultivation is an effective way to achieve soil improvement while utilizing saline soils. Irrigation and drainage, as physical measures to leach salts, can effectively reduce the soil salt content, while application of organic fertilizer fermented with an effective microorganism (EM) may further [...] Read more.
Alfalfa cultivation is an effective way to achieve soil improvement while utilizing saline soils. Irrigation and drainage, as physical measures to leach salts, can effectively reduce the soil salt content, while application of organic fertilizer fermented with an effective microorganism (EM) may further enhance the improvement effect of saline–alkaline soil by improving soil fertility and microbial community structure. However, there is still a lack of systematic assessment on the effects of applying these three measures on the saline soil–plant system. In this study, we used alfalfa as the plant material and set three water depths of 8 mm (IR1), 16 mm (IR2), and 24 mm (IR3) under the condition of irrigating every 10 days with remote-controlled timed and quantitative irrigation, which is the most acceptable to farmers in the era of smart agriculture. EM organic fertilizer dosage was designed as 0 kg/ha (CK), 1500 kg/ha (OF1), 3000 kg/ha (OF2), 4500 kg/ha (OF3), and 6000 kg/ha (OF4). The multiple-crop alfalfa yield, quality (crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF)), and soil electrical conductivity (EC) were observed. The results showed that after the application of EM organic fertilizer, the soil’s EC value of fertilized treatments was higher than that of CK, but this difference became smaller with the prolongation of alfalfa’s growing period, implying that EM organic fertilizer could absorb more soil salts by promoting alfalfa’s growth; the water depth was obviously negatively correlated with the soil’s EC value, demonstrating that the increase in the water depth had a stronger ability to reduce the soil salts. By the end of the experiment, the soil’s EC values were reduced by 21.4–43.7% for the treatments. The alfalfa yield was significantly increased by EM organic fertilizer application, and the three alfalfa yields were increased by 63.3–69.1%, 65.4–83.6%, and 52.6–56.2%, respectively, when fertilizer application was elevated from CK to OF4. The highest alfalfa yields were all found at IR2OF4, reaching 1164.7, 2637.3 and 2519.7 t/ha, corresponding to the first, second, and third alfalfa crops, respectively. The analysis of alfalfa quality indexes revealed that higher CP values were found in the IR2 treatments, and increasing fertilizer application from OF1–OF4 resulted in an increase in CP values by 2.4–9.1%, 1.5–7.4%, and 0.8–6.7% for the three alfalfa crops. Relatively low NDF and ADF values were observed for alfalfa under IR2 conditions; however, the application of EM organic fertilizer reduced the NDF and ADF values within a certain range. According to the results of the entropy weight evaluation model, IR3OF4, IR3OF2, and IR3OF3 were the top three treatments with the best overall benefits, respectively, with relative closeness values of 0.71, 0.70, and 0.68, in that order, which suggests that the appropriate water depth is 24 mm, while the appropriate EM organic fertilizer dosage is in the range of 3000–6000 kg/ha. There was a pattern observed in our study, in which the treatments with better overall benefits were better distributed at high water depths, which emphasizes the critical role of the irrigation volume in ameliorating saline soils. The conclusions of the study are intended to provide a practical basis for the comprehensive utilization and sustainable development of saline soils. Full article
(This article belongs to the Special Issue Impact of Irrigation or Drainage on Soil Environment and Crop Growth)
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18 pages, 10160 KB  
Article
Hydrogeochemistry of Thermal Water from Lindian Geothermal Field, Songliao Basin, NE China: Implications for Water–Rock Interactions
by Yujuan Su, Fengtian Yang, Xuejun Zhou, Junling Dong, Ling Liu, Yongfa Ma, Minghua Chen and Chaoyu Zhang
Water 2026, 18(1), 90; https://doi.org/10.3390/w18010090 - 30 Dec 2025
Viewed by 401
Abstract
To explore the hydrogeochemical characteristics and dominant water–rock interaction processes of thermal water in Lindian geothermal field (northern Songliao Basin, NE China), this study analyzed 16 thermal water samples (1900–3000 m depth) and 3 shallow groundwater samples using hydrochemical indices, water isotopes, and [...] Read more.
To explore the hydrogeochemical characteristics and dominant water–rock interaction processes of thermal water in Lindian geothermal field (northern Songliao Basin, NE China), this study analyzed 16 thermal water samples (1900–3000 m depth) and 3 shallow groundwater samples using hydrochemical indices, water isotopes, and statistical methods (Pearson Correlation and Principle Component Analysis). Results show that the thermal water originates from precipitation and exhibits an “oxygen shift” indicating a long-time water–rock interaction under low to medium reservoir temperature. The thermal water is alkaline with a high TDS and dominated by Na+, Cl, and HCO3, and its hydrochemical facies changes from HCO3·Cl–Na to Cl·HCO3–Na and Cl–Na along the groundwater flow path. Leaching of halite, silicates, and carbonates is the primary process controlling solute accumulation. The geothermal reservoir is in a relatively closed, strong reducing environment, and thermal water reached water–rock equilibrium with respect to Na-, K-, Ca-, and Mg-alumino silicates. Principle Component Analysis identifies three key controlling factors, including mineral leaching, organic matter degradation, and sulfate reduction/mineral precipitation. This study establishes a hydrogeochemical baseline for the initial exploitation stage, providing a scientific basis for predicting long-term water quality changes and formulating differentiated sustainable development strategies for the Lindian geothermal field. Full article
(This article belongs to the Special Issue Groundwater Environment Evolution and Early Risk-Warning)
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22 pages, 5812 KB  
Article
Acute CO2 Toxicity and the Effects of Seawater Acidification on Health Status, Histopathology, Immunity and Disease Resistance in Asian Seabass (Lates calcarifer)
by Phattarapan Mongconpattarasuk, Thanasin Sumngern, Phutana Kongwatananonda, Anurak Uchuwittayakul, Chalermchai Ruangchainikom and Prapansak Srisapoome
Environments 2026, 13(1), 16; https://doi.org/10.3390/environments13010016 - 29 Dec 2025
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Abstract
Carbon dioxide capture and storage (CCS) is a technology that can be used to reduce carbon dioxide (CO2) emissions generated by both natural and anthropogenic industrial processes, particularly petroleum production. To mimic and investigate the effects of CO2 leakage that [...] Read more.
Carbon dioxide capture and storage (CCS) is a technology that can be used to reduce carbon dioxide (CO2) emissions generated by both natural and anthropogenic industrial processes, particularly petroleum production. To mimic and investigate the effects of CO2 leakage that may result from CCS, the acute toxicity of seawater acidification induced by continuous CO2 injection was studied in Asian seabass (Lates calcarifer) fry under static bioassay conditions. Fry (0.828 ± 0.22 g) were exposed to seawater with different pH levels (5.5, 6.0, 6.5, 7.5, and 8.3). Rapid and 100% mortality within 15 min was observed in the pH 5.5 exposure group, while mortality rates ranging from 10.00–41.67% were recorded at 6–96 h in the pH 6.0 exposure group; no mortality was noted in the other pH exposure groups. According to these mortality data, the median lethal concentration at 96 h (96 h LC50) was determined to be a pH of 5.884. Interestingly, after exposure to seawater with pH levels of 5.5 and 6.0, histopathological alterations in the skin, gills, trunk kidney and liver were evident. Additionally, some water quality parameters, especially dissolved oxygen (DO) levels, alkalinity, ammonia levels, and nitrite levels, vary depending on the pH. To further investigate the effects of seawater with pH levels of 8.3 and 5.884 (96 h LC50) and 6.5 (10% safety level) on health status, immune responses and disease susceptibility, fingerling fish (21.25 ± 3.89 g) were studied. Unexpectedly, fish exposed to seawater with a pH of 5.884 rapidly lost muscle control and gradually died, reaching 100% mortality within 24 h, and all response analyses were aborted. Interestingly, with the exception of hematocrit and some immune parameters, various serum innate immune indices, blood biochemistry parameters and immune-related gene expression patterns were similar in fish exposed to seawater with pH levels of 8.3 and 6.5. Additionally, fish were challenged with 0 (control), 1 × 107 and 1 × 109 CFU/mL Vibrio vulnificus, and fish in seawater with a pH level of 6.5 showed a higher sensitivity to 1 × 109 CFU/mL Vibrio vulnificus than fish in seawater with a pH level of 8.3, with mortality rates of 71.24% and 25.44%, respectively (p < 0.05). These findings enhance the understanding of the toxicity effects of seawater acidification caused by CO2, which will be useful for further assessing the site-specific effects of CCS projects. Full article
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Article
Resource-Efficient Nutrient Dosing for Sustainable Aquaponics: Analysis System for Nutrient Requirements in Hydroponics (ASNRH) Using Aquaculture Byproducts and Neural Networks
by Surak Son and Yina Jeong
Sustainability 2026, 18(1), 247; https://doi.org/10.3390/su18010247 - 25 Dec 2025
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Abstract
Aquaponics is a water-reusing, circular form of controlled-environment agriculture, but its sustainability benefits depend on reliable, constraint-aware nutrient dosing under delayed inflow effects. Aquaponics involves coupling hydroponics with aquaculture but is difficult to control because the greenhouse/crop state at the current time step [...] Read more.
Aquaponics is a water-reusing, circular form of controlled-environment agriculture, but its sustainability benefits depend on reliable, constraint-aware nutrient dosing under delayed inflow effects. Aquaponics involves coupling hydroponics with aquaculture but is difficult to control because the greenhouse/crop state at the current time step (t) must anticipate water-quality changes that arrive at the next time step (t+1), under hard EC–pH and dose constraints. We propose the Analysis System for Nutrient Requirements in Hydroponics (ASNRH), a two-module, constraint-aware framework that directly regresses next-step elemental supplementation (N, P, K; mg·L−1). First, the Fish-farm By-product Prediction Module (FBPM) uses a lightweight GRU forecaster to predict inflow chemistry at t+1 (e.g., NH4+/NO2/NO3, alkalinity) from standard aquaculture sensors. Second, the Nutrient Requirement Prediction Module (NRPM) encodes the current hydroponic and crop state at t in parallel with the FBPM inflow at t+1 via a dual-branch architecture and fuses both representations to produce non-negative dose recommendations while penalizing forecasted EC/pH violations and excessive actuation volatility. The data pipeline assumes low-cost greenhouse and aquaculture sensors with chronological, leakage-free splits. A protocol-first simulation evaluates ASNRH against time-series and rule-based baselines using accuracy metrics (MAE/RMSE/R2), EC/pH violation rates, and robustness under missingness/noise; ablations isolate the contributions of the inflow branch, constraint-aware losses, and lightweight physics priors. The framework targets deployability in decoupled or coupled aquaponics by structurally resolving t vs. t+1 asynchrony and internalizing domain constraints during learning; procedures are specified to support reproducibility and subsequent field trials. By operationalizing anticipatory dosing from reused aquaculture byproducts under EC/pH feasibility constraints, ASNRH is designed to support sustainability goals such as reduced nutrient wastage and fewer corrective water exchanges in coupled or decoupled aquaponics. Full article
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