Important Environmental Processes Research Articles

Modification of clinoptilolite as a natural zeolite by copper oxide nanoparticles for efficient desulfurization of kerosene

In recent years, researchers are looking for ways to reduce the amount of sulfur in kerosene. Therefore, desulfurization of kerosene is considered an important commercial and environmental process. Among the hard and complicated methods available for the desulfurization process, natural zeolites can be a suitable alternative for the desulfurization of oil products due to their economic efficiency, biocompatibility, and natural abundance of oil reserves. In this research, natural zeolite (clinoptilolite) was modified with CuO nanoparticles and used as adsorbent for desulfurization of kerosene. The effect of important parameters such as adsorbent dose, pH of solution and initial adsorbate concentration were investigated. Results indicated the optimum conditions as follows: dose of adsorbent 2 g, pH 10 and the adsorbate dose 200 ppm. Results showed that the modified adsorbent is a suitable, low-cost and good efficiency for the desulfurization process of kerosene.

Periplasmic electron transfer network in Geobacter sulfurreducens revealed by biomolecular interaction studies

AbstractMultiheme cytochromes located in different compartments are crucial for extracellular electron transfer in the bacterium Geobacter sulfurreducens to drive important environmental processes and biotechnological applications. Recent studies have unveiled that for particular sets of electron terminal acceptors, discrete respiratory pathways selectively recruit specific cytochromes from both the inner and outer membranes. However, such specificity was not observed for the abundant periplasmic cytochromes, namely the triheme cytochrome family PpcA‐E. In this work, the distinctive NMR spectroscopic signatures of these proteins in different redox states were explored to monitor pairwise interactions and electron transfer reactions between each pair of cytochromes. The results showed that the five proteins interact transiently and can exchange electrons between each other revealing intra‐promiscuity within the members of this family. This discovery is discussed in the light of the establishment of an effective electron transfer network by this pool of cytochromes. This network is advantageous to the bacteria as it enables the maintenance of the functional working potential redox range within the cells.

Diffusivity of CO2 in H2O: A Review of Experimental Studies and Molecular Simulations in the Bulk and in Confinement.

An in-depth review of the available experimental and molecular simulation studies of CO2 diffusion in H2O, which is a central property in important industrial and environmental processes, such as carbon capture and storage, enhanced oil recovery, and in the food industry is presented. The cases of both bulk and confined systems are covered. The experimental and molecular simulation data gathered are analyzed, and simple and computationally efficient correlations are devised. These correlations are applicable to conditions from 273 K and 0.1 MPa up to 473 K and 45 MPa. The available experimental data for diffusion coefficients of CO2 in brines are also collected, and their dependency on temperature, pressure, and salinity is examined in detail. Other engineering models and correlations reported in literature are also presented. The review of the simulation studies focuses on the force field combinations, the data for diffusivities at low and high pressures, finite-size effects, and the correlations developed based on the Molecular Dynamics data. Regarding the confined systems, we review the main methods to measure and compute the diffusivity of confined CO2 and discuss the main natural and artificial confining media (i.e., smectites, calcites, silica, MOFs, and carbon materials). Detailed discussion is provided regarding the driving force for diffusion of CO2 and H2O under confinement, and on the role of effects such as H2O adsorption on hydrophilic confining media on the diffusivity of CO2. Finally, an outlook of future research paths for advancing the field of CO2 diffusivity in H2O at the bulk phase and in confinement is laid out.

Predicting Concentration- and Ionic-Strength-Dependent Air-Water Interfacial Partitioning Parameters of PFASs Using Quantitative Structure-Property Relationships (QSPRs).

Air-water interfacial retention of poly- and perfluoroalkyl substances (PFASs) is increasingly recognized as an important environmental process. Herein, column transport experiments were used to measure air-water interfacial partitioning values for several perfluoroalkyl ethers and for PFASs derived from aqueous film-forming foam, while batch experiments were used to determine equilibrium Kia data for compounds exhibiting evidence of rate-limited partitioning. Experimental results suggest a Freundlich isotherm best describes PFAS air-water partitioning at environmentally relevant concentrations (101-106 ng/L). A multiparameter regression analysis for Kia prediction was performed for the 15 PFASs for which equilibrium Kia values were determined, assessing 246 possible combinations of 8 physicochemical and system properties. Quantitative structure-property relationships (QSPRs) based on three to four parameters provided predictions of high accuracy without model overparameterization. Two QSPRs (R2 values of 0.92 and 0.83) were developed using an assumed average Freundlich n value of 0.65 and validated across a range of relevant concentrations for perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), and hexafluoropropylene oxide-dimer acid (i.e., GenX). A mass action model was further modified to account for the changing ionic strength on PFAS air-water interfacial sorption. The final result was two distinct QSPRs for estimating PFAS air-water interfacial partitioning across a range of aqueous concentrations and ionic strengths.

An efficient chromatin immunoprecipitation (ChIP) protocol for studying histone modifications in peach reproductive tissues

BackgroundPerennial fruit trees display a growth behaviour characterized by annual cycling between growth and dormancy, with complex physiological features. Rosaceae fruit trees represent excellent models for studying not only the fruit growth/patterning but also the progression of the reproductive cycle depending upon the impact of climate conditions. Additionally, current developments in high‐throughput technologies have impacted Rosaceae tree research while investigating genome structure and function as well as (epi)genetic mechanisms involved in important developmental and environmental response processes during fruit tree growth. Among epigenetic mechanisms, chromatin remodelling mediated by histone modifications and other chromatin-related processes play a crucial role in gene modulation, controlling gene expression. Chromatin immunoprecipitation is an effective technique to investigate chromatin dynamics in plants. This technique is generally applied for studies on chromatin states and enrichment of post-transcriptional modifications (PTMs) in histone proteins.ResultsPeach is considered a model organism among climacteric fruits in the Rosaceae family for studies on bud formation, dormancy, and organ differentiation. In our work, we have primarily established specific protocols for chromatin extraction and immunoprecipitation in reproductive tissues of peach (Prunus persica). Subsequently, we focused our investigations on the role of two chromatin marks, namely the trimethylation of histone H3 at lysine in position 4 (H3K4me3) and trimethylation of histone H3 at lysine 27 (H3K27me3) in modulating specific gene expression. Bud dormancy and fruit growth were investigated in a nectarine genotype called Fantasia as our model system.ConclusionsWe present general strategies to optimize ChIP protocols for buds and mesocarp tissues of peach and analyze the correlation between gene expression and chromatin mark enrichment/depletion. The procedures proposed may be useful to evaluate any involvement of histone modifications in the regulation of gene expression during bud dormancy progression and core ripening in fruits.

Photoreductive Dissolution of Iron (Hydr)oxides and Its Geochemical Significance

Iron (hydr)oxides are the most abundant metal oxides, which are widespread on Earth’s surface in the major form of micro/nanoparticles. Dissolution of iron (hydr)oxides significantly controls their compositions on Earth’s surface and is a critical step for the global Fe cycling. Photoreductive dissolution of iron (hydr)oxides is recognized as one of the most important process for generating Fe2+ in surface water and is also a common pathway for transforming solar energy into chemical energy. This review article dissects the main characteristics of photoreductive dissolution of iron (hydr)oxides and discusses its geochemical and environmental significance. We categorize the mechanisms for photoreduction of iron (hydr)oxides into three types: reduction by intrinsic photogenerated electrons, reduction by ligand to metal electron transfer (LMCT), and reduction by direct injection of exogenous photoelectrons. The efficiency of photoreductive dissolution is constrained by both the structure of iron (hydr)oxides (e.g., crystal structure and particle size) and environmental conditions (e.g., light, pH, and concurrent chemicals). Therefore, different iron (hydr)oxides may exhibit quite distinctive photoreductive dissolution characteristics because of their unique crystal structures and physicochemical properties. Iron (hydr)oxides with low crystallinity (e.g., ferrihydrite, lepidocrocite) are subject to direct photoreductive dissolution, while those with high crystallinity (e.g., goethite, hematite) generally need ligands to proceed with photoreductive dissolution. The photoreductive dissolution of iron (hydr)oxides is involved in many important geochemical and environmental processes, such as the Fe availability to primary producers, the generation of reactive oxygen species, the transportation and fate of contaminants, and the phase transformation of iron (hydr)oxides. Given the ubiquitous occurrence of photoreductive dissolution of iron (hydr)oxides, this review will advance our understanding of the role of this process in Earth’s surface environments.

Hydrolytic transformation mechanism of tetracycline antibiotics: Reaction kinetics, products identification and determination in WWTPs

Antibiotic residues and antibiotic resistance have been widely reported in aquatic environments. Hydrolysis of antibiotics is one of the important environmental processes. Here we investigated the hydrolytic transformation of four tetracycline antibiotics i.e. tetracycline (TC), chlortetracycline (CTC), oxytetracycline (OTC) and doxycycline (DC) under different environmental conditions, and determined their parents and transformation products in the wastewater treatment plants (WWTPs). The results showed that the hydrolysis of the four tetracyclines followed first-order reaction kinetics, and the acid-catalyzed hydrolysis rates were significantly lower than the base-catalyzed and neutral pH hydrolysis rates. The effect of temperature on tetracycline hydrolysis was quantified by Arrhenius equation, with Ea values ranged from 42.0 kJ mol−1 to 77.0 kJ mol−1 at pH 7.0. In total, nine, six, eight and nine transformation products at three different pH conditions were identified for TC, CTC, OTC and DC, respectively. The main hydrolysis pathways involved the epimerization/isomerization, and dehydration. According to the mass balance analysis, 4-epi-tetracycline and iso-chlortetracycline were the main hydrolytic products for TC and CTC, respectively. The 2 tetracyclines and 4 hydrolysis products were found in the sludge samples in two WWTPs, with concentrations from 15.8 ng/g to 1418 ng/g. Preliminary toxicity evaluation for the tetracyclines and their hydrolysis products showed that some hydrolysis products had higher predicted toxicity than their parent compounds. These results suggest that the hydrolysis products of tetracycline antibiotics should also be included in environmental monitoring and risk assessment.

Geochronology of sediment cores from the Vefsnfjord, Norway

The sedimentary environment is a repository and carrier for a variety of pollutants, and sediment transport from land to coastal areas is an important environmental process. In the present study, we use 210Pb/226Ra and 137Cs in sediment cores to assess sediment supply rates at four sites within the Vefsnfjord in Nordland county, Norway. This area was highly affected by fallout from the Chernobyl accident in 1986 and inventories of 137Cs in the fjord are much higher than in many other Norwegian fjords. Sedimentation rates between 0.042 and 0.25 g cm−2 y−1 (0.060 and 0.38 cm y−1) were determined using a combination of the Constant Rate of Supply (CRS) and Constant Flux:Constant Sedimentation rate (CF:CS) models. Well-defined 137Cs concentration peaks were used as a supplementary tool to the 210Pb dating methods.

Microbial co-occurrence network and its key microorganisms in soil with permanent application of composted tannery sludge

Soil microbial communities act on important environmental processes, being sensitive to the application of wastes, mainly those potential contaminants, such as tannery sludge. Due to the microbiome complexity, graph-theoretical approaches have been applied to represent model microbial communities interactions and identify important taxa, mainly in contaminated soils. Herein, we performed network and statistical analyses into microbial 16S rRNA gene sequencing data from soil samples with the application of different levels of composted tannery sludge (CTS) to assess the most connected nodes and the nodes that act as bridges to identify key microbes within each community. The network analysis revealed hubs belonging to Proteobacteria in soil with lower CTS rates, while active degraders of recalcitrant and pollutant chemical hubs belonging to Proteobacteria and Actinobacteria were found in soils under the highest CTS rates. The majority of classified connectors belonged to Actinobacteria, but similarly to hubs taxa, they shifted from metabolic functional profile to taxa with abilities to degrade toxic compounds, revealing a soil perturbation with the CTS application on community organization, which also impacted the community modularity. Members of Actinobacteria and Acidobacteria were identified as both hub and connector suggesting their role as keystone groups. Thus, these results offered us interesting insights about crucial taxa, their response to environmental alterations, and possible implications for the ecosystem.

Recent Advances in 3D Printing of Structured Materials for Adsorption and Catalysis Applications.

Porous solids in the form of adsorbents and catalysts play a crucial role in various industrially important chemical, energy, and environmental processes. Formulating them into structured configurations is a key step toward their scale up and successful implementation at the industrial level. Additive manufacturing, also known as 3D printing, has emerged as an invaluable platform for shape engineering porous solids and fabricating scalable configurations for use in a wide variety of separation and reaction applications. However, formulating porous materials into self-standing configurations can dramatically affect their performance and consequently the efficiency of the process wherein they operate. Toward this end, various research groups around the world have investigated the formulation of porous adsorbents and catalysts into structured scaffolds with complex geometries that not only exhibit comparable or improved performance to that of their powder parents but also address the pressure drop and attrition issues of traditional configurations. In this comprehensive review, we summarize the recent advances and current challenges in the field of adsorption and catalysis to better guide the future directions in shape engineering solid materials with a better control on composition, structure, and properties of 3D-printed adsorbents and catalysts.

Effects of pH and Ca exchange on the structure and redox state of synthetic Na-birnessite

Abstract Birnessite-like minerals are among the most common Mn oxides in surficial soils and sediments, and they mediate important environmental processes (e.g., biogeochemical cycles, heavy metal confinement) and have novel technological applications (e.g., water oxidation catalysis). Ca is the dominant interlayer cation in both biotic and abiotic birnessites, especially when they form in association with carbonates. The current study investigated the structures of a series of synthetic Ca-birnessite analogs prepared by cation-exchange with synthetic Na-birnessite at pH values from 2 to 7.5. The resulting Ca-exchanged birnessite phases were characterized using powder X-ray diffraction and Rietveld refinement, Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning and transmission electron microscopy. All samples synthesized at pH values greater than 3 exhibited a similar triclinic structure with nearly identical unit-cell parameters. The samples exchanged at pH 2 and 3 yielded hexagonal structures, or mixtures of hexagonal and triclinic phases. Rietveld structure refinement and X-ray photoelectron spectroscopy showed that exchange of Na by Ca triggered reduction of some Mn3+, generating interlayer Mn2+ and vacancies in the octahedral layers. The triclinic and hexagonal Ca-birnessite structures described in this study were distinct from Na- and H-birnessite, respectively. Therefore, modeling X-ray absorption spectra of natural Ca-rich birnessites through mixing of Na- and H-birnessite end-members will not yield an accurate representation of the true structure.

Colony, morphological and biochemical characteristics of cotton phyllosphere bacteria and its antagonistic activity against the Alternaria leaf spot of cotton

Cotton crop is known to suffer from number of fungal, bacterial and viral diseases. Among them, Alternaria leaf spot caused by Alternaria spp. is predominant in causing economic losses to the cotton crop in the country. Phyllosphere inhabitants termed as epiphytes may consists of a variety of bacteria and filamentous fungi. They also play a key role in carbon and nitrogen cycling and help in important environmental processes such as methanol degradation and nitrification. So, bacterial phyllosphere cultures (P1 to P8) were isolated from the Bt and non Bt cotton by leaf imprint method and dilution method. The colony characters of isolates of bacteria pertaining to their shape, size, elevation, margin, texture, appearance and pigmentation were recorded. Gram’s staining and endospore staining revealed that P1, P2, P3, P5, P8 were Gram positive, P1, P2, P5 were showing endospore staining and P1, P4, P6, P7 were rod shaped. Biochemical tests revealed that the eight isolates Bt and non Bt cotton were differed in each test and showed positive for the catalase and oxidase test. The isolates P1, P5 and P6 showed positive results to Voges proskauer test. Isolates P2, P4 and P6 revealed positive results of phyllosphere bacteria to Indole test. Whereas, isolates P1, P2 and P8 showed negative reaction to methyl red test. The phyllosphere bacterial isolates P3, P5 and P7 recorded negative reaction to gelatin liquefaction. Screening of phyllosphere microflora against Alternaria macrospora was conducted following dual culture technique for all the isolates. Phyllosphere bacterial isolate P5 recorded maximum growth inhibition with 57.41 per cent followed by P4 isolate with 53.52 per cent growth inhibition over the test fungus Alternaria macrospora. Whereas least per cent growth inhibition was reported in isolate P6 with 45.63 per cent.

Stability of Ferrihydrite and Goethite Nanoparticles Under Different Environmental Conditions

Agglomeration and dispersion of nanoparticles control many important environmental processes. In this study, the particle size and zeta potential of ferrihydrite nanoparticles (FHNPs) and goethite nanoparticles (GTNPs) under different pH, ion, and organic matter conditions were measured. These data were used to calculate the Derjaguin-Landau-Verwey-Overbeek (DLVO) interaction energy between nanoparticles to further investigate the stability of two nanoparticles. The results showed that Na+ and Ca2+ promoted FHNPs and GTNPs agglomeration due to their ionic strength. The PO43- with low-concentration (2 mmol·L-1), humic acid and fulvic acid (2 mg·L-1 and 10 mg·L-1) loaded on iron mineral nanoparticles changed their surface charge and further improved the stability of FHNPs and GTNPs at medium and high pH. Although the PO43- with high concentration (10 mmol·L-1) also changed the electrical properties of iron mineral nanoparticles, it had little contribution to the GTNP stability due to its ionic strength. When the zeta potentials of FHNPs or GTNPs were close to 0, the primary barrier and secondary minima were nonexistent simultaneously. The two kinds of nanoparticles irreversibly agglomerated in primary minima. When the primary barrier and secondary minima coexisted, the proportion of reversible aggregation of FHNPs and GTNPs in secondary minima increased. The results provided support for further investigation of the environmental behavior of FHNPs and GTNPs, and iron mineral nanoparticle-facilitated transport of pollutants.

Sulfidation attenuates the adverse impacts of metallic nanoparticles on anammox from the perspective of chronic exposure

The risks of metallic nanoparticles (MNPs) in anammox have attracted increasing attention; however, how sulfidation, an important environmental transformation process, affects their toxicity potential is unclear.

Kinetics of Ni reaction with organic matter-ferrihydrite composites: Experiments and modeling

The interactions between organic matter (OM) and minerals are among the most important environmental processes, which significantly affect the fate of carbon and contaminants in the environment. How the interactions between OM and ferrihydrite (Fh), one of the most reactive iron oxides, affect the kinetic reactions of heavy metals with both OM and iron oxides, however, are still largely unknown. In this study, two typical OM, humic acids (HA) and fulvic acids (FA), were used to synthesize OM-Fh co-precipitation composites. We investigated the interactions between OM and ferrihydrite and their impact on kinetic reactions of nickel (Ni) with OM-Fh composites using spherical aberration corrected scanning transmission electron microscopy (Cs-STEM), batch and kinetic experiments, and X-ray adsorption spectroscopy (XAS). Cs-STEM results, at both nano and sub-nano scales, showed three typical distributions of OM on ferrihydrite, adsorbed on ferrihydrite surfaces, accumulated as OM nanoparticles, and being blocked in tiny pores in composites. Batch experiments and modeling quantified the effects of OM and ferrihydrite interactions, which was supported by XAS results. The kinetics model developed in this study integrated both WHAM 7 and CD-MUSIC models and successfully predicted the kinetics of Ni adsorption and desorption on OM-Fh composites under the impact of OM-Fh interactions. The model can quantitatively assess the dynamic changes of Ni speciation on different OM and Fh binding sites during the kinetic processes. Our results contribute to developing a comprehensive model for predicting the dynamic metal behavior in the environment when multiple adsorbents are present.

Au/CeO2-ZnO/Al2O3 as Versatile Catalysts for Oxidation Reactions: Application in Gas/Liquid Environmental Processes.

The present work showcases the versatility of nanogold systems supported on Zn-doped ceria when applied in two important environmental processes, the total CO oxidation, and the liquid phase oxidation of glucose to gluconic acid. In the CO oxidation the suitability of these materials is clearly demonstrated achieving full conversions even at sub-ambient conditions. Regarding the glucose oxidation our materials display high conversion values (always over 50%) and very importantly full or almost full selectivity toward gluconic acid—an added value platform chemical in the context of biomass upgrading routes. The key factors controlling the successful performance on both reactions are carefully discussed and compared to previous studies in literature. To our knowledge this is one of the very few works in catalysis by gold combining liquid and gas phase reactions and represents a step forward in the flexible behavior of nano gold catalysts.

Assessment of Total Amount of Surface Sediment in Urban Environment Using Data on Solid Matter Content in Snow-Dirt Sludge

The aim of the study is the development of a method of quantitative assessment of the total and size-fractionated amount of urban surface deposited sediment. The method utilises the feature of snow cover to accumulate the surface sediment. Snow-dirt sludge formed as a result of snow, and surface deposited sediment mixing on roads and other urban surfaces accumulates sediment over the winter period. In regions with long winter, the snow-dirt sludge lifecycle presents a delayed runoff event. Testing of the method was conducted in Ekaterinburg, Russia, a city situated in a cold region with long winter. Specimens of snow-dirt sludge and urban surface deposited sediment were collected in winter and summer 2017, respectively. Proportions of concentrations of dust, fine sand and coarse fractions in snow-dirt sludge were compared with the same proportion in surface deposited sediment sampled in the summer season. The average concentration of solid phase material in the snow-dirt sludge was 25 ± 9 g/L of melted water. The dust fraction <0.1 mm contributed 44% to the total concentration of the solid phase. The average mass concentrations of coarse fraction, fine sand and dust in summer samples of surface deposited sediment were in proportion 31%:31%:38%, respectively. A total amount of urban surface deposited sediment of approximately 320,000 tons (3.2 kg/m2 per unit residential area) was estimated in Ekaterinburg, of which about 120,000 tons was the dust fraction. Obtained quantitative assessments of sediment deposition on urban surfaces characterise the sedimentation as important environmental process in contemporary urban areas.

A putative novel Methylobacter member (KRF1) from the globally important Methylobacter clade 2: cultivation and salient draft genome features.

Methane oxidation by methanotrophs is a very important environmental process in the mitigation of methane. Methylobacter (Mtb.) clade 2 members have been reported as dominant methane oxidisers in soils and sediments worldwide. We enriched and purified a methanotroph from a tropical rice field soil sample from India. The highly enriched culture showed the presence of motile, long and thick rods (3-5µm × 0.9-1.2µm) and minor presence of short, thin rods. The culture was purified on agarose medium and formed yellow colonies which showed the presence of only thick and long rods, henceforth termed as strain KRF1. Based on 16S rRNA gene sequence analysis, strain KRF1 shows close phylogenetic affiliation to Methylobacter tundripaludum SV96T (98.6% similarity). Due to the taxonomic novelty, and being the first member of Mtb. related to Mtb. tundripaludum from the tropics, the draft genome was sequenced. From the blastx analysis of the contigs, it was clear that the culture still had contamination of another organism, a Methylophilus species. The data binned in two clear bins: Mtb. related contigs and Methylophilus-related contigs. The binned draft genome of KRF1 shows features including the typical pathways for methane metabolism, denitrification and the presence of molybdenum iron and vanadium-iron nitrogenase genes. KRF1 is phylogenetically distinct from the five strains of Mtb. tundripaludum including SV96T, Lake Washington strains and OWC strains, showing ~ 26% DDH and ~ 81% ANIb values and a unique position in a phylogenomic tree. Subsequently, KRF1 has been completely purified from its methylotrophic partner and a pure culture has been established and maintained in a WDCM approved culture collection, the MACS Collection of Microorganisms (as MCM 1471). KRF1 is thus the first cultured member of a putative novel species of Methylobacter clade 2 isolated from the tropics.

In Situ Liquid Secondary Ion Mass Spectrometry: A Surprisingly Soft Ionization Process for Investigation of Halide Ion Hydration.

The understanding of ion solvation phenomena is of significance due to their influences on many important chemical, biological, and environmental processes. Mass spectrometry (MS)-based methods have been used to investigate this topic with molecular insights. As ion-solvent interactions are weak, ionization processes should be as soft as possible in order to retain solvation structures. An in situ liquid secondary ion MS (SIMS) approach developed in our group has been recently utilized in investigations of Li ion solvation in nonaqueous solution, and it detected a series of solvated Li ions. As traditionally SIMS has long been recognized as a hard ionization process with strong damage occurring at the sputtering interface, it is very interesting to study further how soft in situ liquid SIMS can be. In this work, we used halide ion hydration as an example to compare the ionization performance of the in situ liquid SIMS approach with regular electrospray ionization MS (ESI-MS). Results show that, although ESI has been recognized as a soft ionization method, nearly no solvated halide ions were detected by ESI-MS analysis, which acquired only strong signals of salt ion clusters. In contrast, in liquid SIMS spectra, a series of obvious hydrated halide ion compositions could be observed. We further evaluated the hydration numbers of halide ions and revealed the effects of the ion size, charge density, and polarizability on the hydration phenomenon. Our findings demonstrated that the in situ liquid SIMS approach is surprisingly soft, and it is expected to have very broad applications on investigation of various ion-solvent interactions and many other interesting chemical processes (e.g., the initial nucleation of nanoparticle formation) in liquid environment.

Long‐term water balance partitioning explained by physical and ecological characteristics in world river basins

AbstractFor decades, scientists have debated the relation between physical attributes and vegetation and the partitioning of rainfall (P) into evaporation (E) and run‐off (R) in basins. Physical and ecological processes explain the long‐term behaviour of E via water or energy limitations. Needed are similar globally applicable frameworks for describing the production of streamflow and its interaction with factors influencing E, to produce long‐term patterns of E–R partitioning. Here, we analyse 131 independent river basins that flow naturally (or with minimum intervention to their flow) in three major world regions (tropical, temperate, and boreal). We relate water balance partitioning to physical and ecological attributes in these basins to show how P partitioning into E and R is significantly related to the amount of forest and Shrub‐Grass‐Savannas cover in tropical and temperate basins and mostly influenced by slope and Shrub‐Grass‐Savannas cover in boreal basins. Our results highlight that in tropical and temperate basins, if not limited by water, partitioning tends to be equally distributed between E and R as forest cover increases. When Shrub‐Grass‐Savannas cover increases, E dominates, indicating water limitations. In boreal basins, the partitioning does not respond to forest cover, potentially due to the effects of snowmelt and geomorphology. According to normalized difference vegetation index observations, the dominance of E is more related to land cover and seasonality than to vegetation activity. Current processes including deforestation in the tropics, forest die‐off in temperate regions, and afforestation in boreal regions can influence other societally important environmental processes, such as the production of river flow regimes.