Water Reduction Research Articles

Influence of coexisting anions on the one-step electrochemical reduction and precipitation removal of Cr(VI): Implications for advanced wastewater treatment

Electroreduction of Cr(VI) coupled with in-situ precipitation of Cr(III) on the cathode is a promising method for removing Cr(VI) from wastewaters. However, the influence of coexisting anions in wastewaters on the electrochemical removal process remains unclear. This study investigated the impact of common inorganic anions, including nitrate (NO3−), chloride (Cl−), phosphate (PO43−) and sulfate (SO42−), on the electrochemical removal processes of Cr(VI). The results indicated that HCrO4− was directly electrochemically reduced to Cr3+, and the OH− generated through electro-mediated water reduction could complex with Cr3+, thereby transforming Cr3+ into chromium hydroxide (Cr(OH)3) coated at cathode. Coexisting anions would partially penetrate the alkaline Cr(III) complexes, inhibiting the formation of Cr(OH)3 passivation layer and promoting the electroreduction of Cr(VI), whose penetration ability followed the order of SO42− > PO43− > Cl− > NO3−. Both the inhibitory effect on Cr(III) precipitation and promoting effect on Cr(VI) reduction were intensified with increasing concentrations of these anions in the range of 1−100 mmol L−1. Accordingly, after electrolysis of 10 mg L−1 Cr(VI) at an initial pH of 3.0 and −0.2 V (vs. Ag/AgCl), the highest electrochemical reduction ratio of Cr(VI) (99.9%) was achieved in the presence of 100 mmol L−1 SO42−, while the total Cr removal ratio was minimal (3.3%). In contrast, the presence of NO3− at 1 mmol L−1 resulted in a nearly lowest reduction ratio of Cr(VI) (92.9%), with the maximum total Cr removal ratio (92.8%). These findings provide new insights into the electrochemical removal mechanisms of Cr(VI) in complex solution environments.

Molecular catalyst coordinatively bonded to organic semiconductors for selective light-driven CO2 reduction in water.

The selective photoreduction of CO2 in aqueous media based on earth-abundant elements only, is today a challenging topic. Here we present the anchoring of discrete molecular catalysts on organic polymeric semiconductors via covalent bonding, generating molecular hybrid materials with well-defined active sites for CO2 photoreduction, exclusively to CO in purely aqueous media. The molecular catalysts are based on aryl substituted Co phthalocyanines that can be coordinated by dangling pyridyl attached to a polymeric covalent triazine framework that acts as a light absorber. This generates a molecular hybrid material that efficiently and selectively achieves the photoreduction of CO2 to CO in KHCO3 aqueous buffer, giving high yields in the range of 22 mmol g-1 (458 μmol g-1 h-1) and turnover numbers above 550 in 48 h, with no deactivation and no detectable H2. The electron transfer mechanism for the activation of the catalyst is proposed based on the combined results from time-resolved fluorescence spectroscopy, in situ spectroscopies and quantum chemical calculations.

Deciphering Electrocatalytic Hydrogen Production in Water Through a Bioinspired Water-Stable Copper(II) Complex Adorned with (N2S2)-Donor Sites.

Electrocatalytic hydrogen production stands as a pivotal cornerstone in ushering the revolutionary era of the hydrogen economy. With a keen focus on emulating the significance of hydrogenase-like active sites in sustainable H2 generation, a meticulously designed and water-stable copper(II) complex, [Cl-Cu-LN2S2]ClO4, featuring the N,S-type ligand, LN2S2 (2,2'-((butane-2,3-diylbis(sulfanediyl))bis(methylene))dipyridine), has been crafted and assessed for its prowess in electrocatalytic H2 production in water, leveraging acetic acid as a proton source. The molecular catalyst, adopting a square pyramidal coordination geometry, undergoes -Cl substitution by H2O during electrochemical conditions yielding [H2O-Cu-LN2S2]2+ as the true catalyst, showcases outstanding activity in electrochemical proton reduction in acidic water, achieving an impressive rate of 241.75 s-1 for hydrogen generation. Controlled potential electrolysis at -1.2 V vs. Ag/AgCl for 1.6 h reveals a high turnover number of 73.06 with a commendable Faradic efficiency of 94.2 %. A comprehensive analysis encompassing electrochemical, spectroscopic, and analytical methods reveals an insignificant degradation of the molecular catalyst. However, the post-CPE electrocatalyst, present in the solution domain, signifies the coveted stability and effective activity under the specified electrochemical conditions. The synergy of electrochemical, spectroscopic, and computational studies endorses the proton-electron coupling mediated catalytic pathways, affirming the viability of sustainable hydrogen production.

Electrochemical Characteristics of Ambarella Peel Waste as Liquid Electrolyte for Zn-Cu Biobattery

This study focuses on the electrochemical characterization of Zn-Cu bio-battery cells utilizing electrolytes derived from ambarella peel waste. The primary objectives are to determine the half-cell and full-cell characteristics of these bio-batteries at various concentration ratios and to identify the optimal concentration ratio for maximum performance. Cyclic voltammetry analysis of the half-cells revealed an oxidation peak at 0.5 V vs Ag/AgCl, corresponding to the conversion of uronic acid to aldaric acid. Additionally, two reduction peaks were observed: hydrogen ion reduction to H2 at 0 V vs Ag/AgCl and water reduction at –0.42 V vs Ag/AgCl. The rate-determining step analysis indicated that the redox reactions in the ambarella peel electrolyte solution were surface reactions. The highest rate constant (ks) of 0.722 ± 0.05 s–1 was observed at a 1:2 concentration ratio. This ratio also resulted in the highest battery capacity of 0.0816 mAh and the maximum power density of 16.13 mW/m2. The study concluded that the 1:2 concentration ratio of ambarella peel waste electrolyte solution is optimal, outperforming the 1:1 and 1:3 ratios in terms of battery capacity and power density.

Conservation Agriculture and Crop Residue Management

India being a populous country the intensification of the cropping system is mandatory. However, this intensification of the cropping system results in the degradation of soil and other natural resources. Considering this situation, conservation agriculture is the most suitable alternative to achieving sustainable yield and productivity. Conservation agriculture is based on three major principles those are minimum disturbance of soil, crop rotation, and maintenance of crop residue. Crop residue management plays a major role in conservation agriculture as it helps in improving soil productivity, soil organic matter content, soil structure, soil water conservation, air quality, and reduction in soil erosion. India produces 273 Mt of crop residues annually which contain a total of 7.16 Mt of nutrients (N-1.28, P2O5-1.97, K2O-3.91). In modern agriculture, green manure crops like Sesbania and sunhemp increase the quantity and quality of the crop residues in the crop field. Among various residue management practices mulching has been practiced prominently in dry lands as it increases the resource use efficiency. The residue decomposition is affected by various factors like quality of crop residue, edaphic, management, and climatic factors. In modern scientific research crop residues are being used especially for site-specific nutrient management. It is observed in most studies that zero tillage or reduced tillage with crop residue gives comparatively higher net returns, water use efficiency, and resource use efficiency than conventional agriculture. In Indian context. The management of rice residue particularly in the Indo-Gangetic Plains of India is challenging, where the rice-wheat cropping system is intensively followed and the farmers are more anxious about timely seeding of wheat in combine harvested paddy fields (Sidhu et al., 2007; Singh et al., 2020).

Functional groups of leaf phenology are key to build climate-resilience in cocoa agroforestry systems

Agroforestry has the potential to enhance climate change adaptation. While benefits from agroforestry systems consisting of cash crops and shade trees are usually attributed to the (shade) trees, the trees can also have negative impacts due to resource competition with crops. Our hypothesis is that leaf phenology and height of shade trees determine their seasonal effect on crops. We test this hypothesis by categorizing shade tree species into functional groups based on leaf phenology, shade tree canopy height and shade tree light (wet and dry season) interception as well as the effects. To this end, leaf phenology and the effects on microclimate (temperature, air humidity, intercepted photoactive radiation (PAR)), soil water, stomatal conductance and cocoa yield were monitored monthly during wet and dry seasons over a two-year period on smallholder cocoa plantations in the northern cocoa belt of Ghana. Seven leaf phenological groups were identified. In the wet season, highest buffering effect of microclimate was recorded under the trees brevi-deciduous before dry season. During dry season, high PAR and lowest reduction in soil moisture were observed under the trees in the group of completely deciduous during dry season. The evergreen groups also showed less reduction in soil water than the brevi-deciduous groups. In the wet season, shade tree effects on cocoa tree yields in their sub canopy compared to the respective control of outer canopy with full sun ranged from positive (+10 %) to negative (-15 %) for the deciduous groups, while yield reductions for the evergreen groups ranged from −20 % to −33 %. While there were negative yield impacts for all phenological groups in the dry season, the trees in completely deciduous during dry season group recorded least penalties (-12 %) and the trees with evergreen upper canopy the highest (-35 %). The function of shade trees in enhancing climate resilience is therefore strongly dependent on their leaf phenological characteristics. Our study demonstrates how the key trait leaf phenology can be applied to successful design of climate-resilient agroforestry systems.

The Role of Cation Exchange Membrane Characteristics in CO2 Electrolysis to CO Using Acid Anolyte

Cation exchange membranes are considered a suitable option for zero-gap CO2 electrolysis due to their potential to avoid carbonation and improve carbon efficiency. However, the use of acidic anolytes remains an issue due to high hydrogen production. This study investigates Nafion® membranes (111, 112, 115, 211, and 212) with different thicknesses produced by extrusion or solution-cast processes in a zero-gap cell with an acidic anolyte containing K2SO4. Faradaic efficiencies for CO production (FECO) are higher with thinner membranes, regardless of the manufacturing process, reaching FECO around 75% at 50 mA cm⁻². Additionally, membranes with similar thicknesses (∼50.8 µm) but produced in different ways displayed flow field carbonation after 3 hours of electrolysis at 30°C and 50 mA cm⁻². Linear sweep voltammetry (LSV) in full and half-cell configurations shows limiting diffusion current (iL) relative to proton transport for all the employed membranes, no matter the thickness. In contrast, the iL for Nafion® 115, the thicker membrane, is suppressed, indicating that proton depletion is fast and the electrode surface alkalinization primarily results from water reduction in this case. A mechanistic analysis was performed to explain the behavior of the limiting currents in the cell with Ar- and CO2-feed, indicating that CO2 reduction aids in the consumption of H+ provided by the membrane, increasing the local pH at less negative potentials. Overall, thinner membranes exhibited higher values of FECO and energy efficiency for CO (EE%CO). However, solution-cast membranes are more prone to provide K+, leading to better performance than those prepared by extrusion.

ZnFe-LDH synthesized by seed-induced method to simultaneous enhance arsenic removal, stabilization and sludge reduction

To simultaneously enhance arsenic removal, stabilization and sludge reduction, a seed-induced method was applied to in-stiu synthesize ZnFe-LDH containing arsenic (ZnFe-As-LDH). The optimal seed was determined to be ZnFe-LDH by analyzing the effects of the unseeded system and seed-induced system (FeⅡFeⅢ-LDH, ferrihydrite and ZnFe-LDH). In the ZnFe-LDH seed system, the arsenic removal efficiency increased and the arsenic leaching concentration were drastically reduced by 91.33% under the optimal conditions as the seeds dosage of 2.5g/L, pH 10 and Zn/Fe ratio of 1.5. The addition of seed crystals promoted crystal growth and aggregation and finally regulated the formation of dense bulk LDH with fewer pores and smaller pore sizes. The arsenic removal and stabilization were achieved by converting active arsenic into more stable crystalline bound arsenic through coprecipitation, ion exchange and complexation. The SV30 was reduced by 73.68% and it was due to reduction of unstable surface water and interspace and crystallinity enhancement. The formation pathway of ZnFe-As-LDH by seed-induced was elucidated. The seed-induced method promoted the formation of arsenic-containing ferrihydrite and Zn(OH)2 coprecipitations on the surface of ZnFe-LDH seed, and led to a structural rearrangement to generate ZnFe-As-LDH.

Influence of biofertilizers on potato (Solanum tuberosum L.) growth and physiological modulations for water and fertilizers managing

Biofertilizers constitute a safe way to alleviate the impacts of water shortage and the overload of chemical fertilizers. This work focuses on the effects of Arbuscular Mycorrhizal Fungi (AMF) and Plant Growth-Promoting Rhizobacteria (PGPR) on potato's agro-physiological response, beneath the reduction of water, nitrogen (N), phosphorous (P) and potassium (K) fertilizers. Five microbioal treatments (C: Control, AMF: Mycorhizae, B1: Bacillus halotolerans, B2: Bacillus amyloliquefaciens and B1B2: B.halotolerans+ B.amyloliquefaciens) were tested in arrangement with two nitrogen-phosphorous-potassium (NPK) rates (F1: Entire rate, F ½: Half rate) and three irrigation levels (100 % of crop water requirement: 100 % ETc; 75 % ETc; 50 % ETc) in a two year factorial split plot design. We studied vegetative growth, photosynthetic activity, chlorophyll fluorescence, water status, osmoticums, N, P, K and enzymatic antioxidants accumulation. Data obtained in 2019–2022 showed that AMF and B1B2 biofertilizers were beneficial to improve Root/Shoot, Dry Underground Part/Aerial Part, leaf area (LA), water saturation deficit (WSD), chlorophyll index (SPAD) and tuber yield under 75 % ETc. The photosynthetic promoter effect of biofertilizers under 75 % ETc, compared to 50 % ETc was observed in the following trend B1B2>AMF>B1. The efficacy of B1B2 and AMF were coupled to high catalase (CAT) activity. Potatoes treated with B1B2 were found to be efficient for 75 % ETc in terms of proline accumulation. The AMF was more effective in terms of soluble sugars (SS) accumulation and control of osmotic potential (Ψs). Taking together, the B1B2 and AMF could be regarded as efficient biofertilizers under 75 % ETc, alleviating the impacts of water stress and the problem of excessive fertilization in potatoes.

Novel Gel method MXene-Supported Dual-Site PtNi-NiO for Electrocatalytic Water Reduction and Urea Oxidation.

Compared to the traditional oxygen evolution reaction (OER), the urea oxidation reaction (UOR) generally exhibits a lower overpotential during the electrolytic process, which is conducive to the hydrogen evolution reaction (HER) at the cathode. The superior structure and abundant sites play a crucial role in promoting the adsorption and cleavage of urea molecules. Therefore, this paper introduces a simple metal cation-induced gelation method to prepare an electrocatalyst with PtNi alloy-NiO dual sites supported on Ti3C2Tx, which simultaneously exhibits excellent UOR and HER performance. PtNi-NiOx/Ti3C2Tx demonstrates good catalytic activity for the urea oxidation reaction, requiring only 1.364V (overpotential of 0.994V) to achieve a current density of 100mAcm-2 in UOR, and also exhibits remarkable catalytic activity in the hydrogen evolution reaction, with PtNi-NiOx/Ti3C2Tx achieving a current density of 10mAcm-2 in HER with only 24mV of overpotential. In the UOR//HER two-electrode electrolysis cell, it requires only 1.361 and 1.538V to reach current densities of 10 and 100mAcm-2, respectively. According to density functional theory (DFT) calculations, the dual active sites can intelligently adsorb the electron-donating/electron-withdrawing groups in urea molecules, activate chemical bonds, and thereby initiate urea decomposition.

Performance of an integrated household greywater treatment system for water optimization and reuse

This study evaluated the efficiency of an on-site household greywater treatment system for indirect human reuse and for domestic lawn irrigation. This helps in the reduction in the disparity between water demand and supply that is facing the rapidly increasing global populace. Natural household greywater was settled and then conventionally filtered by using two types of non-woven geotextile media; thermally bonded and needle punched. A third woven cotton textile media was also experimented and all the non-woven geotextile media were tested in single and double layers and combined with the woven cotton textile layer. The different filter media configurations were tested for a period of one year operation (six runs) with two filtration rates of 15.00 and 25.00 m3/m2/day for each run. For all runs, the final treated effluent was disinfected using calcium hypochlorite prior to reuse. The double layer needle punched non-woven geotextile media together with the woven cotton textile media gave the best removal efficiencies; 96.34 ± 1.85% for turbidity 81.87 ± 6.43% for BOD5, 97.49 ± 1.68% for TSS, 75.35 ± 3.99% for CODt, 99.59% for E.coli. The soluble CODs removal efficiencies were negligible (below 3%) in the first four runs with non-woven geotextile media and increased to 28.05 ± 4.29% when the woven cotton textile media was added. In general, the system was found to save about 63% of the daily water consumption reflecting a net 22.50% reduction in the daily water billing costs for the whole household.

Effects of dapagliflozin on body composition and its relation to hemodynamics in heart failure with preserved ejection fraction: the CAMEO-DAPA randomized clinical trial

Abstract Background Excess fat, particularly visceral fat, plays an important role in the development of heart failure with preserved ejection fraction (HFpEF). Sodium glucose cotransporter-2 inhibitors improve hemodynamics, reduce symptom severity, and decrease risk of hospitalization, but their impact on body composition, as well as potential relationships between changes in body composition and hemodynamic effects, are unknown in HFpEF. Purpose Evaluate the effect of dapagliflozin on body and blood composition and examined the potential correlation of such changes on cardiac hemodynamics. Methods The CAMEO-DAPA trial, a single-center, double-blind, randomized, placebo-controlled study, showed that 24 weeks of dapagliflozin reduced resting and exercise pulmonary capillary wedge pressures (PCWP) in patients with HFpEF. This prespecified secondary analysis reports the effects of dapagliflozin on body composition using dual energy x-ray absorptiometry (DEXA), blood composition (radiolabeled iodinated albumin), and cardiac hemodynamics using high-fidelity micromanometers. Analysis was performed based on the intention-to-treat. Relative change was calculated by dividing the absolute change on the baseline value. Results Overall, 37 patients (67 years, 65% women, 70% with obesity, 27% overweight) completed the trial. As compared with baseline, dapagliflozin decreased total body fat compared with placebo [mean (SD) absolute change: -2.29 (2.94) kg vs -0.32 (1.84) in placebo, p=0.03; relative change: -4.6% (5.4) vs -0.8% (4.3), p=0.02], Figure 1. This was primarily due to greater loss of upper body trunk fat [absolute change: -1.53 (1.70) kg vs +0.31 (0.99) in placebo, p<.001; relative change: -5.2% (5.6) vs +1.1% (4.1), p<.001], Figure 1. Reductions in trunk fat were correlated with decreases in PCWP (r=0.41, p=0.03), Figure 2. Total body fat-free mass (FFM) tended to decrease in the dapagliflozin group [absolute change: -0.63 (1.85) kg vs +0.34 (1.76), p=0.12]; reductions in leg, android, and gynoid FFM were all greater than placebo (p<0.05). Dapagliflozin reduced plasma volume [absolute change: -170 (343) ml vs +112 (346), p=0.02] compared with placebo, and the decrease in plasma volume was correlated with the reduction in FFM (r=0.47, p=0.006), Figure 2. Treatment with dapagliflozin had no effect on resting metabolic rate but was associated with modest reduction in bone mineral content [-16 (47) g vs +26 (61), p=0.03]. Conclusions In patients with HFpEF, dapagliflozin decreases body fat, particularly trunk fat, suggesting greater effect on visceral adipose, which is correlated with favorable hemodynamic effects. Dapagliflozin also tends to reduce FFM, which may relate to reduction in total body water with or without reduction is muscle mass, in tandem with modest decreases in bone mineral content.Figure 1:Relative change in fat massFigure 2

Electrochemical Growth of Copper Crystals on SPCE for Electrocatalysis Nitrate Reduction.

Copper is efficient, has a high conductivity (5.8 × 107 S/m), and is cost-effective. The use of copper-based catalysts is promising for the electrocatalytic reduction of nitrates. This work aims to grow and characterize copper micro-crystals on Screen-Printed Electrodes (SPEs) for NO3- reduction in water. Copper micro-crystals were grown by cyclic voltammetry. Different cycles (2, 5, 7, 10, 12, 15) of copper electrodeposition were investigated (potential ranges from -1.0 V to 0.0 V, scan rate of 0.1 V s-1). Electrodeposition generated different morphologies of copper crystals on the electrodes, as a function of the number of cycles, with various performances. The presence of numerous edges and defects in the copper micro-crystal structures creates highly reactive active sites, thus favoring nitrate reduction. The manufactured material can be successfully employed for environmental applications.

Insight into the Efficient Selective Reduction of Cr(VI) in Sulfite/UV Process under Near-Neutral Conditions: The Critical Role of In Situ-Generated Sulfite Radical.

Efficient removal of contaminants in complex water matrices under mild conditions is highly desirable but still challenging. In this study, we unraveled the overlooked but crucial role of sulfite radical (SO3·-) in the efficient selective reduction of toxic Cr(VI) under near-neutral conditions. Fast removal of Cr(VI) at around pH 7 in sulfite/UV was found to be attributable to high reactivity of SO3·- toward HCrO4- (∼5.3 × 106 M-1 s-1). Furthermore, SO3·- was fast generated in situ via one-electron oxidation of S(IV) by transient reactive protonated Cr(V) and Cr(IV) intermediates. Therefore, the specific reactivity of SO3·- and its in situ generation together resulted in the surprisingly positive effect of nitrate and the efficient reduction of Cr(VI) in authentic surface water and industrial wastewater. A mathematical model was developed to simulate Cr(VI) removal in the process, and thus quantitatively demonstrated the roles of reactive species, i.e., SO3·- contributed to ∼93% of Cr(VI) reduction in surface water. Overall, this study provides an insight into the pivotal role of SO3·- in Cr(VI) reduction, and underscores its significance in selective reduction and detoxification of contaminants.

Cost-effective non-revenue water reduction: analysis through pilot activities in Kigali City, Rwanda

ABSTRACT Non-revenue water (NRW) is a major problem for water utilities, and its reduction has become an important challenge in ensuring a sustainable water supply. However, a lack of clarity regarding the cost–benefit analysis of investment in pilot activities to reduce NRW may hinder further investment in such projects. Thus, we attempted to identify strategies for effective NRW reduction and establish a method for estimating their cost-effectiveness. To this end, a project to strengthen the NRW management capacity and build a sustainable NRW reduction system was implemented in Kigali City, Rwanda, between 2016 and 2021. The project included four objectives: enhancement of the planning capacity for NRW reduction; acquisition of basic knowledge, skills, and techniques for NRW control; enhancement of staff capacity to execute NRW reduction measures; and establishment of a system to accurately measure NRW ratios. The project helped to formulate a 5-year plan for NRW reduction and 596 employees of Kigali City were trained for the same. The NRW ratios were reduced by 10 and 12% in the two pilot areas of the city. Cost–benefit analysis revealed the effectiveness of the investment in NRW reduction activities over time.

Metal Cocatalyst Engineering in Metal-Semiconductor Hybrid Photocatalysts Achieves a Fivefold Enhancement of Hydrogen Evolution.

This study explores the optimal morphology of photochemical hydrogen evolution catalysts in a one-dimensional system. Systematic engineering of metal tips on precisely defined CdSe@CdS dot-in-rods is conducted to exert control over morphology, composition, and both factors. The outcome yields an optimized configuration, a Au-Pt core-shell structure with a rough Pt surface (Au@r-Pt), which exhibits a remarkable fivefold increase in quantum efficiency, reaching 86 % at 455 nm and superior hydrogen evolution rates under visible and AM1.5 G irradiation conditions with prolonged stability. Kinetic investigations using photoelectrochemical and time-resolved measurements demonstrate a greater extent and extended lifetime of the charge-separated state on the tips as well as rapid water reduction kinetics on high-energy surfaces. This approach sheds light on the critical role of cocatalysts in hybrid photocatalytic systems for achieving high performance.

Effect of β-sitosterol+γ-oryzanol-based oleogels on protein conformation and gel properties of Nemiperus virgatus surimi.

The impact of β-sitosterol+γ-oryzanol-based oleogels or peanut oil on the protein conformation and gel quality of Nemiperus virgatus surimi was evaluated. A significant reduction in gel strength, texture parameters and water holding capacity (WHC) of surimi was found as oil concentration increased (P < 0.05). However, compared with peanut oil, the gel strength, hydrophobic interaction and disulfide bond content of surimi gel containing oleogels increased by 6.919%, 32.635% and 12.409%, respectively, when the oil concentration was 10 g kg-1. Both oleogels and peanut oil could enhance the whiteness of surimi gel. Oleogels induced the unfolding of surimi proteins, and promoted the conformational shift from α-helix to β-sheet structure. Furthermore, oleogels filled the gaps of protein networks to make the microstructure of surimi gel more compact and uniform, improving the WHC and reducing the cooking loss. γ-Oryzanol+β-sitosterol-based oleogel alleviated the adverse influences of direct addition of peanut oil on the gel and textural properties of surimi products. © 2024 Society of Chemical Industry.

Intensive leaf cooling promotes tree survival during a record heatwave

Increasing heatwaves are threatening forest ecosystems globally. Leaf thermal regulation and tolerance are important for plant survival during heatwaves, though the interaction between these processes and water availability is unclear. Genotypes of the widely distributed foundation tree species Populus fremontii were studied in a controlled common garden during a record summer heatwave-where air temperature exceeded 48 °C. When water was not limiting, all genotypes cooled leaves 2 to 5 °C below air temperatures. Homeothermic cooling was disrupted for weeks following a 72-h reduction in soil water, resulting in leaf temperatures rising 3 °C above air temperature and 1.3 °C above leaf thresholds for physiological damage, despite the water stress having little effect on leaf water potentials. Tradeoffs between leaf thermal safety and hydraulic safety emerged but, regardless of water use strategy, all genotypes experienced significant leaf mortality following water stress. Genotypes from warmer climates showed greater leaf cooling and less leaf mortality after water stress in comparison with genotypes from cooler climates. These results illustrate how brief soil water limitation disrupts leaf thermal regulation and potentially compromises plant survival during extreme heatwaves, thus providing insight into future scenarios in which ecosystems will be challenged with extreme heat and unreliable soil water access.

Development of a water resources utilization model and optimization of the patterns of rice genotypes with system dynamics approach

The system dynamics approach was conducted to optimize genotype patterns in various climatic and water availability scenarios, to address the water productivity improvement of the Sefidrood irrigation network. The studied cropping pattern scenarios were SD1 (the continuation of current trends), SD2 (the reduction in the cultivated area), SD3 (replacing modified crops on an annual basis), and SD4 (increasing the annual cultivated area of Hashemi type rice). Moreover, the impacts of irrigation efficiency improvements and water resources management strategies on the physical and economic water productivity indices were studied. The results indicated that the SD3 scenario has the most positive impact on water productivity with 0.45 kg/m3 increases. However, a questionnaire survey revealed that this scenario that belongs to the increase in the modified genotype area cannot be recommended due to cooking quality and low prices. The Hashemi genotype was the favorite rice among farmers and experts. Also, analyzing the irrigation efficiency improvement scenario showed that this strategy has a limited impact on the physical and economic water productivity. Increasing the capacity of local rainwater storage pools, Ab-bandans, and increasing the drainage water reuse had the highest water productivity in the condition of river water reduction and uncertain water availability.

Engineering hierarchical TiO2/ZnIn2S4 hybrid heterostructure with synergistic interfaces: A dual-functional S-scheme photocatalyst for efficient CO2 reduction and norfloxacin degradation

The development of multifunctional photocatalysts that can harness solar energy for both environmental remediation and energy generation is a considerable challenge in achieving sustainable development. This study introduces a dual-functional S-scheme hybrid catalyst comprising hierarchical 3D flower-like ZnIn2S4 (ZIS) microspheres embedded with TiO2 (TO) nanoparticles, synthesized via a facile in situ hydrothermal process. The unique structural and compositional synergy between ZIS and TO leverages their complementary photocatalytic properties, facilitating efficient solar energy utilization, increasing specific surface area, and enhancing CO2 adsorption capabilities. The S-scheme mechanism, confirmed by in situ-irradiated X-ray photoelectron spectroscopy and electron spin resonance spectroscopy, underlying this system promotes effective separation of photoexcited charge carriers while preserving the intrinsic strong reducibility of ZIS and high oxidizability of TO. These beneficial properties of the TO/ZIS hybrid provide a robust platform for CH4 production (75.6 μmol h−1 g−1) through selective (99.6 %) CO2 reduction over competing water reduction and achieve exceptional degradation and mineralization of the persistent antibiotic norfloxacin in water, addressing both energy and environmental challenges. Furthermore, the hybrid catalyst exhibits significant stability and recyclability, maintaining high catalytic performance across multiple cycles, thereby underscoring its practical viability. This work offers a promising blueprint for developing multifunctional photocatalysts capable of addressing critical global challenges, demonstrating the potential of hierarchical nanostructures and S-scheme charge transfer mechanisms.