Understanding the mechanisms governing Co(II) retention at mineral-water interfaces is critical for predicting its environmental mobility. Here, we investigate Co(II) sorption and surface-induced precipitation on palygorskite using batch experiments, scanning transmission electron microscopy-energy dispersive X-ray spectroscopy (STEM-EDS) mapping, extended X-ray absorption fine structure (EXAFS) spectroscopy, X-ray absorption near edge spectroscopy (XANES), and density functional theory (DFT) calculations. Co retention is strongly controlled by pH, ionic strength, and concentration. At pH 6.0, ionic strength effects indicate a shift from outer-sphere to inner-sphere surface complexation. In contrast, at pH 7.5, sorption is dominated by surface-induced precipitation and is associated with a substantially higher activation energy (102.6 kJ mol(-1)) relative to pH 6.0 (9.3 kJ mol(-1)), consistent with a nucleation-controlled process. Spectroscopic analyses reveal the formation of both Co-Al layered double hydroxide (LDH)-like and Co-phyllosilicate-like precipitates form on palygorskite across the concentration range 0.1-3 mM at pH 7.5. Their relative proportions vary with increasing concentrations: LDHlike phases predominate at low Co concentrations, whereas phyllosilicate-like phases increase and become dominant at higher concentrations. STEM-EDS mapping and DFT calculations confirm the nucleation of both LDH-like and phyllosilicate-like phases at palygorskite edge sites. Compared with reported systems such as kaolinite and gamma-Al2O3, palygorskite promotes precipitation at lower Co surface loadings, consistent with its Mgrich composition and fibrous structure. These results demonstrate that mineral composition, particularly Mg/Al ratio, influences the type and relative abundance of secondary Co precipitates, with implications for Co immobilization in both contaminated environments and lateritic weathering systems.

Coastal environments, particularly those adjacent to Superfund sites, are at increased risk of contaminant release during natural disasters, posing serious threats to nearby communities. To investigate this issue, we employed an advanced laboratory flood simulator to impose arsenic-contaminated sediments to turbulent flooding events. We further monitored changes in arsenic collocation and solid-phase speciation using advanced synchrotron radiation-based techniques to understand the impacts of flooding on arsenic mobility. Our results demonstrate that turbulent conditions significantly enhance the resuspension of arsenic-rich sediments, resulting in increased arsenic release into the water. This mobilization is driven by the erosion of the reduced sediments and the redox-mediated transformation and dissolution of Fe and Mn (oxyhydr) oxides, which promote the release of As(III). We found that arsenic speciation on resuspended particles is closely tied to shear stress, with As(V) prevailing at low stress and the more toxic As(III) dominating at higher stress levels. In the post-erosion phase, solid-phase As(III) decreased while dissolved As(III) increased, indicating ongoing desorption. The persistence of multiple arsenic species on resuspended particles marks them as potential long-range transport vectors. Thus, the environmental impact of flooding and sediment resuspension extends beyond the event itself, raising longer-term concerns for arsenic mobility. Our comprehensive geospatial analysis revealed substantial overlap between arsenic-contaminated soils and regions at high risk of flooding and hurricanes across the conterminous United States. This overlap disproportionately impacts economically disadvantaged and marginalized communities. Approximately 40 million Americans reside within 10 kilometers of these high-risk contaminated zones, with nearly 28 million exposed to hurricane threats and around 18 million vulnerable to flooding risks. Alarmingly, over 40% of those affected by hurricanes and 33% of those impacted by flooding belong to underrepresented minority and low-income populations. These findings highlight the urgent need for targeted mitigation strategies to protect public health and address environmental justice concerns.

A series of biobased poly(ester-thioether) thermosets was developed from sugar-derived methacrylate monomers and characterized for their structure-property relationships. Xylose, glucose, and sucrose were functionalized via a one-step esterification with methacrylic anhydride to yield tetra-, penta-, and octa-methacrylated monomers, respectively. Thiol-ene photopolymerization with five dithiol cross-linkers produced 15 distinct thermoset networks. Fourier transform infrared spectroscopy (FTIR) confirmed successful cross-linking through the disappearance of the thiol peak at similar to 2560 cm-1. Thermal analysis revealed that temperatures at 5% weight loss (T 5%) and midpoint degradation temperatures (T mid) increased with cross-link density (nu c), with sucrose-based networks exhibiting the highest thermal stability. Dynamic mechanical analysis (DMA) showed glass transition temperatures (T g) between 73 and 96 degrees C and an inverse relationship between molecular weight between cross-links (M c) and the storage modulus (E '), indicating that network rigidity is governed by both nu c and monomer architecture. Alkaline degradation studies confirmed ester hydrolysis by mass loss over time, with degradation rates influenced by network structure. Soil degradation exhibited minimal yet detectable environmental degradation, suggesting a balance between durability and eco-responsiveness. These results highlight the potential of sugar-derived multifunctional monomers for designing degradable, high-performance thermosets for stereolithography (SLA) and digital-light processing (DLP) 3D-printing resins, transparent coatings, and recyclable adhesive systems.

In the coming decades, humanity will be faced with the challenge of feeding 10 billion people and managing large quantities of solid waste. These issues can be mitigated through the development of sustainable fertilizers derived from electrochemically treated waste activated sludge (EWAS) while promoting a nitrogen circular economy. This study investigates the chemistry of novel fertilizers to determine their soil chemistry dynamics. Untreated waste activated sludge (WAS) and EWAS were applied to agricultural soil and potting mix, and the resulting aqueous samples were analyzed to determine nitrogen, phosphorous, and carbon adsorption and release behaviors. Commercial inorganic and natural fertilizers were utilized for comparison. X-ray absorption near-edge structure (XANES) spectroscopy was performed to characterize phosphorus speciation in the solid phases of the novel fertilizers. Results indicated that EWAS and WAS samples released less total nitrogen into solution than other treatments due to organoclay complexation of biomolecules and differences in the solubility of the nitrogen species. Samples containing EWAS released a higher percentage of organic and total carbon into solution due to the deformation of the structure of the organic matter by the alkaline electrolysis process. The solubility of nitrogen and carbon in the sludge was increased by the electrochemical process. Solid-phase phosphorus in EWAS and WAS was characterized by XANES analysis as struvite, which is a novel finding with important implications for P management from waste-based fertilizers. These experimental findings suggest that fertilizing with EWAS could result in reduced runoff and improved soil health while facilitating domestic fertilizer production.

The objective of this study was to characterize the nutritional profile of plant-based meat alternatives (PBMA) and ground beef (GB). Beyond Beef (BEY); Impossible Burger (IMP), a third available product of plant-based protein, including SWEET EARTH, Incogmeato, Open Nature, and Good & Gather (GEN); and two lean levels of GB (regular [80%-85% lean, regular ground beef] and Lean [>93% lean, lean ground beef, LGB]) were purchased from retail stores across the United States. Proximate composition, mineral content, fatty acid profile, amino acid profile, and B-vitamin content were measured in raw products. Generally, PBMA had increased ash content which coincided with increased mineral concentration compared to GB, namely sodium, calcium, and zinc (p < 0.05). Similar trends were observed for B-vitamins. The fatty acid profile of IMP was primarily saturated due to lauric acid (12:0) and myristic acid (14:0) concentrations. Both BEY and GEN were highly unsaturated because of linoleic acid concentration (18:2n6). LGB possessed the greatest total amino acid concentration and total essential amino acid content (p < 0.05). Phenylalanine was increased in PBMA compared to GB (p < 0.05). Overall, these data show differences and similarities between the nutritional profile of PBMA and GB. However, the bioavailability of these nutrients and associated health outcomes, particularly in PBMA, require further investigation.

Agriculture in highly weathered tropical soils often requires considerable application of lime and fertilizers to ensure satisfactory plant nutrient levels. The consequences of these continue long-term applications is not well understood may induce changes in soil chemical properties, the abundance, and speciation of potentially toxic trace element and as well as of micronutrients in agriculture soils. In this study, we evaluated the adsorption (at pH 5) and speciation of Zn in tropical soils (both agricultural and native vegetation) as a function of fertilization and contact time using chemical fractionation analyses and X-ray absorption spectroscopy. The soils overall had high Zn adsorption capacities (similar to 700 mg kg (-1)), but the agricultural soil was approximately 30 % higher than of the soil under native vegetation, and the proportion of Zn in the mobile fraction was 35 % in native vegetation and 21 % in agricultural soils. Zn speciation via linear combination analysis showed a strong relationship with soil mineralogical composition and reveled that Zn associated with organic matter decreased while Zn associated with P increased after the conversion of soils from native vegetation to highly fertilized soil. Aluminosilicate soil minerals were identified as major sinks of soil Zn, accounting for 34 % of total Zn retention regardless of soil origin and land use. Association of Zn with phosphate (i.e., hopeite) was observed in the agricultural soil

Environmental soil chemistry is a highly interdisciplinary field encompassing fundamental chemical processes that impact the mobility and fate of potentially toxic metals, metalloids, as well as plant nutrients. This chapter provides an overview of the major developments and concepts important to the discipline, including early leaders in the field and chemical processes. Solid, liquid, and gas phases of the soil are briefly discussed and an overview of the soil ecosystem services is provided in the chapter. A review of concepts and trends relevant to the periodic table prepares the reader for content throughout the book, and a description of elements found in each group is provided. Some key examples of units and unit conversions critical to the discipline are also presented.

Chromium (Cr) is a redox-sensitive element in contaminated coastal urban soils. Sea level rise (SLR) with subsequent soil inundation may facilitate Cr transformation and mobilization through alterations in local redox conditions and porewater ion composition. We investigated the impact of water salinity and redox conditions on Cr chemistry in these environments. Synchrotron-based X-ray spectroscopy and wet chemical analyses revealed that the soils contained very high levels of Cr (up to 4320 mg kg-1) and that chromite (∼52%) and Fe-Cr hydroxide coprecipitates (∼44%) were the predominant Cr species. The abundance of these two components resulted in low Cr mobility under non-flooded conditions. Chromium(II) was identified in the soils, potentially derived from the waste parent material. Seawater and anoxic conditions resulted in lower Cr release compared to freshwater and aerobic conditions. Up to three to eight times more Cr was released under aerobic conditions versus anaerobic conditions in the freshwater versus saltwater, respectively, with total dissolved Cr values remaining below 0.02 mg L-1. The decrease in Cr release was likely due to Cr reduction by Fe(II) and sulfide. This work provides important information on how salinity and redox fluctuations impact Cr cycling which is likely to occur during SLR.

The composition of the soil solution dictates important chemical reactions such as dissolution and precipitation, both of which impact ion mobility. Additionally, ions in the soil solution can form complexes, which impact their reactivity and transport in the soil. This chapter discusses the major constituent ions of the soil porewater and how they are impacted by different extraction techniques. A major focus is on the speciation of the ions in soil porewater utilizing thermodynamic and conditional equilibrium constants. A vast number of ion species occur in soil porewater, and computational methods, such as those employed by Visual MINTEQ, are introduced. These methods are used to predict ion species and conduct aqueous equilibrium speciation calculations. Ion activity coefficients and ionic strength are described. Dissolution and solubilization processes are linked to the creation of stability diagrams and the prediction of mineral precipitation.

In the United States, dangerously high arsenic (As) levels have been found in drinking water wells in more than 25 states, potentially exposing 2.1 million people to drinking water high in As; a known carcinogen. The anticipated sea-level rise (SLR) is expected to alter soil biogeochemical and hydrological conditions, potentially impacting their ability to sequester As. In our study of coastal Wilmington, DE, an area projected to experience a 1 -meter SLR by 2100, we examined the spatial distribution, speciation, and release possibilities of As due to SLR. To understand the complex dynamics at play, we employed a comprehensive approach, including bulk and micro X-ray absorption spectroscopy measurements, hydrological pattern evaluation, and macroscopic stirred-flow experiments. Our results suggest that introducing reducing and saline conditions can increase As release in both river water and seawater inundation scenarios, most likely due to ionic competition and the dissolution of As-bearing Fe/Mn oxides. Regardless of the salinity source, the released As concentrations consistently exceeded the EPA threshold for drinking water. Our results provide valuable insights for developing appropriate remedial and management strategies for this site and numerous others facing similar environmental challenges. Environmental Implication: With nearly two hundred million individuals living within coastal flood plains and with two million square kilometers of land and one trillion dollars' worth of assets lying less than 1 m above current sea level, sea-level rise (SLR) is one of the significant socio-economic threats associated with global warming. Arsenic is a prevalent contaminant in coastal areas impacted by industrial activities, many of which are susceptible to being impacted by SLR. This study examines SLR's impact on arsenic fate and speciation in a densely populated coastline in Wilmington, DE, expecting 1 meter of SLR by 2100.

To understand phosphorus (P) mobility in agricultural soils and its potential environmental risk, it is essential to directly measure solid phase P speciation. Often, bulk P K-edge X-ray absorption near edge structure (XANES) spectroscopy followed by linear combination fitting (LCF) is utilized to determine the solid P phases in soil. However, this method may limit results to only a few major phases. Additionally, XANES spectra for different P species may have very similar features, leading to an over- or underestimate of their contribution to LCF. Here, an improved P speciation by pairing multimodal microbeam-X-ray fluorescence (mu -XRF) mapping coupled with mu -XANES (microbeam-X-ray absorption near edge structure) analysis to directly speciate major and minor P phases on the micron scale is provided. We combined maps of both tender (P, sulfur, aluminum, and silicon) and hard energy (calcium, iron [Fe], and manganese) elements to evaluate the elemental co-locations with P. To better account for uncertainty assigning XANES peaks to individual compounds, a more quantitative fingerprinting by "spectral feature analysis" was completed. With this analysis, an R-factor is reported for the fit. These results were compared to traditional LCF. Pre-edge fitting results revealed the presence of a two-component pre-edge feature for phosphate adsorbed to ferrihydrite. Additionally, phytate co-precipitated with ferrihydrite (Phytate-Fe-Cop) had a pre-edge feature, indicating direct association with Fe. Lastly, a unique P species associated with manganese oxide was identified in the soil via multimodal mapping and mu -XANES. These results allow for better prediction of P dissolution and mobility. Coupling multimodal microbeam-X-ray fluorescence maps with mu -XANES (microbeam-X-ray absorption near edge structure) spectra aids in phosphorus species identification in soils. Fingerprinting by spectral feature analysis overcomes common problems of self-absorption in LCF of P mu -XANES. Phosphate adsorbed to ferrihydrite has a two-component pre-edge feature determined via spectral feature analysis. Phytate co-precipitated with ferrihydrite has a pre-edge feature and a peak shift to higher energy. A unique species of phosphorus associated with manganese oxide was identified via multimodal mapping and mu -XANES.

Bioavailability, uptake, and spatial distribution of essential and toxic mineral elements are pivotal factors that govern crop growth, development, and productivity. Soybean is a major leguminous crop globally, and yield losses are commonly attributed to various abiotic factors, including nutrient deficiencies or the influence of toxic minerals in the soil. Therefore, understanding the molecular basis of differential mineral element uptake, translocation, and accumulation in soybean is vital for developing improved cultivars. Here, we used portable X-ray fluorescence (p-XRF) for rapid and high-throughput mineral element profiling of a diverse set of soybean germplasm using leaves, stem, root, and seed tissues. Genome-wide association (GWAS) was performed on the element profiles of 219 soybean accessions, revealing lines with notable two to tenfold difference in various mineral nutrient uptake. These identified lines represent valuable genetic resources for germplasm development and gene discovery. The GWAS analysis pinpointed significant genomic loci and haplotypes associated with accumulation of aluminum (Al), silicon (Si), iron (Fe), and manganese (Mn). Remarkably, genes associated with the transport of solutes, metals, and ions have been pinpointed, indicating their potential involvement in the nutrient uptake and soybean improvement. To gain functional insights, Si deposition, allelic variants and expression of three Si transporter genes was studied in greater details. The high Si accumulating line PI548452 showed 12-fold increase in leaf Si content compared to low Si lines. Expression of HiSil2b and HiSil2c effluxer genes showed root and leaf specific expression, respectively, providing evidence for tissue specific Si transport and the basis for precise management of Si uptake to improve abiotic and biotic stresses. In summary, this study uncovered the novel accessions, haplotypes, allelic diversity, and the potential candidate genes underpinning the mineral nutrient accumulation in soybean.

Accurate measurement of metal concentrations in soil and water is vital for healthy crop production and decision making for environmental surveys. While there are a multitude of laboratory-based soil analysis methods, such as inductively coupled plasma-optical emission spectroscopy (ICP-OES), flame emission spectrometry, and atomic absorption spectroscopy, most are time and resource intensive. Additionally, there is a lack of information for rapid analysis of elements for aqueous soil extractions. The goal of this research is to establish elemental correlations between portable X-ray fluorescence (pXRF) measurements of Mehlich III soil extractions and traditional elemental measurements via ICP-OES. We hypothesize that certain metals can be accurately measured in aqueous soil extraction solutions by pXRF to the same degree as they are measured by ICP-OES. To test this hypothesis, Mehlich III and 2% nitric acid solutions with known elemental concentrations were analyzed via ICP-OES and pXRF. Soil samples extracted using Mehlich III were compared between ICP-OES and pXRF to verify correlations. High correlations were found for As, Ca, Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, V, and Zn in both the Mehlich III and 2% nitric acid solutions at concentrations between 5 and 85 mg L-1. P, S, and Si did not show high correlations at concentrations <100 mg L-1. These results indicate that between 5 and 85 mg L-1, pXRF analysis of aqueous solutions and soil extractions is a reliable technique; however, at low concentrations (i.e., <5 mg L-1 for metals and <100 mg L-1 for P and S), pXRF is not well suited.

Mesoamerican nephropathy (MeN) is a non-traditional chronic kidney disease in some areas of Mesoamerica. The health risk from nephrotoxic metals, such as arsenic (As), lead (Pb), mercury (Hg), vanadium (V), cadmium (Cd), rubidium (Rb), chromium (Cr), and nickel (Ni), was assessed in drinking water and soils. These metals, even at low concentrations, have the capacity to induce epigenetic damage and a nephrotoxic effect. The quantification of metals in soils was made through X-ray fluorescence spectrometry (XRF) and inductively coupled plasma optical emission spectrophotometry (ICP-OES), while the quantification of metals in water was carried out through inductively coupled plasma mass spectrometry (ICPMS) and atomic absorption (AA) spectrometry. The levels of As, Hg, Cd, and V in water were within the permissible limits, whereas Pb was found to be double and triple the value recommended by the World Health Organization. The non-carcinogenic risk from As in soil was evaluated using the Hazard Index (HI), and the route of ingestion was found to be the most important route. The results indicate that consuming water or ingesting soil particles with Pb and As poses a health risk to humans. Therefore, these findings identify the presence of toxicants in an exposure scenario and justify further research into these metals in people and the analysis of exposure routes.

Green rusts (GR) are important drivers for trace metal and nutrient cycling in suboxic environments. We investigated whether green rusts would incorporate aluminum (Al) or other elements from naturally-formed clay minerals containing easily-weatherable clay minerals (e.g. mica, interlayered clays). We isolated the clay min-erals from a Matapeake silt loam soil by removal of silt and sand, organic matter, and reducible oxides to study mechanisms of interaction between Fe(II) and soil-sourced clay minerals. We conducted batch Fe(II) sorption experiments at multiple near-neutral pHs (6.5-7.5) and reaction times (2 h-365 days). Mineral transformations were characterized by selective extractions, X-ray diffraction (XRD), and Fe X-ray absorption spectroscopy (XAS) analyzed by shell-fitting and linear combination fitting (LCF) with natural and synthetic standards.Clay mineral fraction contained a mixture of quartz, kaolinite, interlayered vermiculite, mica, and chlorite with significant structural Fe (2.6% wt). Uptake of Fe(II) increased with pH and kinetics were rapid until 5 days, followed by slow continuous Fe(II) uptake. Citrate-bicarbonate desorption kinetics from Fe(II) sorbed clay released more Al and silicon (Si) compared with unreacted soil clay fraction whereas magnesium (Mg) and potassium (K) were unaffected. Citrate-bicarbonate extracted Fe contained more Fe(II) than an ideal GR with an Fe(II)/Fe(III) molar ratio of 5.50. Analysis of the Fe EXAFS by both LCF and shell fitting was best modeled as a combination of Fe(III)-clay reduction to Fe(II) and precipitation of GR and Fe(II)-Al LDH. After 7 days of Fe(II) sorption, LCF identified 55.2% total Fe in clay, 33.4% GR(Cl) and 11.4% Fe(II)-Al LDH. These results provide novel evidence of Fe(II)-Al LDHs precipitating on naturally-formed soil clay minerals as a minor phase to GR. The geochemical implications are that GRs formed in soils and sediments should be considered to have Al and Si as well as Mg substitutions affecting their structure and reactivity.

High tunnel (HT) vegetable cultivation stands out as a superior choice when compared to open field (OF) production due to its numerous production benefits. However, intensive cultivation practices involving excessive use of inorganic fertilizer (IF) in HT production systems may lead to degradation of soil health, and ultimately poor crop yields. Therefore, this study investigated the effect of liquid organic fertilizer (LOF) and IF on growth and yield of eggplant (Solanum melongena L.) cultivars in HT and OF production systems. Two experiments were conducted in a split-split plot design with production systems (HT and OF) as main plot, fertilizers (LOF and IF) as sub-plot, and cultivars (‘Angela’ and ‘Jaylo’) as sub-sub plot factors. Throughout the growing season, daily average temperature and relative humidity were greater by 2 to 4 ​°C and 2 to 4%, respectively, under HT compared to OF conditions. In contrast, average daily light integral of HT decreased 18 to 24% compared to OF. Results from pooled growth and yield data of both experiments indicate HT produced 61% taller plants with 62% thicker stem diameter compared to OF. However, eggplant height and stem diameter did not differ significantly between fertilizer treatments or between cultivars. Due to a greater fruit count for each plant (63%) and average fruit weight (9%), total yield was 84% greater in HT compared to OF. Eggplant cultivar ‘Jaylo’ yielded 33% greater fruit count for each plant and 38% greater fruit yield compared to ‘Angela’ cultivar. However, no differences in fruit count, fruit weight, and the total yield were observed between LOF and IF. Results indicate that HT production offered a favorable microclimate which encouraged plant growth and greater fruit yield of eggplant compared to OF conditions. LOF and ‘Jaylo’ could be successfully used in organic eggplant production in HT and OF systems.

Chronic kidney disease of non-traditional origin (CKDnt) in Central America, also known as Mesoamerican Nephropathy (MeN), is of particular concern in agricultural populations. The member states of the Central American Integration System (SICA) determined in 2013 that there was an imperative need to address the situation in a comprehensive manner and defined policies for the intervention of the disease. A situation that currently worries health authorities is that cases are on the rise—without distinguishing or implementing effective actions to achieve a decrease in disease prevalence. The incidence of heat and strenuous activities on renal health is undeniable; however, labeling these variables as the only responsible causes for MeN has not catalyzed the implementation of health measures to lead to a preventive approach to solve the epidemic or to achieve a decrease in the number of new cases. This review addresses the role nephrotoxic metals present in the environment, mainly in soils and water, may have as part of a scenario of exposure to environmental toxins in which environmental, occupational, geographic and population variables interact. An integral approach was used to encompass the multicausality that is attributed to MeN and based on the multidisciplinary concept of the re-emerging discipline called medical geology.

Corn performance is often unchanged by modifying the potassium fertilizer application timing, especially when soil K is not a limiting factor. Consequently, there is no literature reporting K timing on K-fertilizer contribution (or use) in high-yielding corn fields. We evaluated corn performance and K-fertilizer use based on timings of K-fertilizer application in the oat-corn sequence at subtropical environment with highly weathered soils. Additionally, we propose a timing strategy to ensure high corn use of fertilizer. The crop sequence study was conducted in two field experiments to investigate corn performance with respect to K-leaf, K uptake, and yield. Additionally, we evaluated K-fertilizer use by rubidium as potassium derived from fertilizer and potassium use efficiency. Application timings were two before and three during corn growth and development. Timings did not change corn performance even for late K application, and this was attributed mainly to soil K sufficiency levels. Corn K-fertilizer use, on the other hand, was different and higher for timings before (versus during) corn growth and development. Importantly, timing of K application similar to 22 days before corn sowing improved corn K-fertilizer use approximately 2-fold versus the two late timings. Timings in oat or during corn sowing were identical for corn K-fertilizer use. We link our rainfall data with literature K-fertilizer movement (positional aspect), and the corn ability to acquire it. Application of K at 3-weeks before corn sowing constituted the optimal timing for fertilizer supply. This finding will assist farmers in large-scale areas to manage K-fertilizer application to promote higher efficiency.