Organic Content Research Articles

Biological action of bleaching agents on tooth structure: A review.

The use of bleaching agents to remove stains is one of the main dental procedures to improve the aesthetics of teeth. This review presents the main agents used for tooth whitening, existing clinical protocols, and the structural changes that may occur through their use. The main bleaching agents consist of hydrogen peroxide and carbamide peroxide, which are used in bleaching techniques for vital teeth. These techniques can be performed in the office by a professional or by the individual in a home en-vironment under professional guidance. Bleaching agents come in a variety of concentrations and there are over-the-counter products available on the market with lower concentrations of hydrogen peroxide. Due to the chemical characteristics of the agents, changes in the organic and inorganic content of the tooth structure can be observed. These changes are related to morphological changes characterized by in-creased permeability and surface roughness, such changes compromise the mechanical resistance of the tooth. Furthermore, bleaching agents can promote molecular changes after reaching the dental pulp, resulting in oxidative stress of pulp cells and the release of pro-inflammatory mediators. Despite the bleaching effectiveness, tooth sensitivity is considered the main side effect of use. Therefore, among the heterogeneity of protocols, those that used the bleaching agent for a prolonged time and in lower con-centrations presented more harmful effects on the tooth structure.

The effect of adding Gracilaria on flavor and quality of low-salt fermented soy sauce

With the increasing awareness of health, there are higher expectations of customers for the unique flavor, umami, and nutritional value of soy sauce. To explore the potential application of edible seaweed in soy sauce, this study utilized high nutritional value seaweeds to ferment soy sauce and investigated the effects of the addition of Gracilaria on the physicochemical properties and flavor substances of soy sauce. The contents of amino acid nitrogen and total nitrogen in Gracilaria soy sauce were 0.8 g/100g and 1.4 g/100g, respectively, which were higher than those in traditional soy sauce. The free amino acid content of Gracilaria soy sauce (17.82 mg/g) was 1.35 times higher than that of traditional soy sauce, the organic acids content of Gracilaria soy sauce (15.78 mg/mL) was 1.12 times higher than that of traditional soy sauce. Compared with traditional soy sauce, the addition of Gracilaria promoted the accumulation of pyrazines and acids in soy sauce, which contributed to the seafood-like flavor. In general, the addition of Gracilaria to ferment soy sauce can improve the quality and give it a unique flavor. This study can provide a reference for improving the quality and flavor diversity of soy sauce by using seaweed as a fermentation substrate.

Study on ultrasound-assisted extraction of cold brew coffee using physicochemical, flavor, and sensory evaluation

Cold brew coffee is popular with consumers due to its simple preparation and unique taste. However, traditional cold brew coffee extraction is time consuming and inefficient, which can be improved by ultrasound-assisted extraction to enhance the product market potential. In this study, the flavor profiles and sensory differences of coffee prepared at three different ultrasonic temperatures, as well as traditional cold brew and hot brew coffee, were evaluated by consumer-based sensory evaluation, Rate-All-That-Apply, combined with the determination of the content of volatile and non-volatile components. The results showed that ultrasound assisted cold brew coffee prepared at 25 °C had a good extraction effect, with chlorogenic acid (CGA) and organic acid contents of 1.05 mg/mL and 0.97 mg/mL, respectively, which were higher than the traditional cold brew coffee obtained after 12 h of preparation, with contents of 0.53 mg/mL and 0.85 mg/mL, respectively. And the total content of volatile compounds can almost reach the results of traditional cold brew for 12 h, which were 1.25 mg/kg and 1.42 mg/kg, respectively. Sensory evaluation indicated that ultrasonic treatment enhanced the sensory attributes such as nutty and cocoa flavors in the coffee. Consumers preferred the cold brew coffee obtained via ultrasound-assisted extraction. These samples presented higher levels of sweetness, floral, and fruity flavors, which were associated with 2,5-Dimethyl-3-(2-methylpropyl)pyrazine, 2,3-Dimethyl-5-(3-methylbutyl)pyrazine, (S)-(+)-4-sec-Butylpyrazole, and styrene. In this study, we demonstrated that ultrasound-assisted extraction can help reduce the time to prepare cold brew coffee and make it possible to commercialize ultrasound-assisted cold brew coffee.

Host genotype and age shape the microbial community in the rhizosphere soils of Camellia forests.

Microbiota living in the rhizosphere influences plant growth and fitness, from the opposite perspective; whether host genotypes control its root microbiota is of great interest to forest breeders and microbiologists. To improve low-yield plantations and promote sustainable management of Camellia oleifera, high-throughput sequencing was used to study the chemical properties and microbiome in rhizosphere soil of Camellia forests under three genotypes (common C. oleifera, local C. gauchowensis, and C. chekiangoleosa) and three growth stages (sapling stage at 4-year-old, primary fruit stage at 7-year-old, and full fruiting stage at 11-year-old). The results showed that the rhizosphere soil organic matter (OM), nutrient concentrations, diversity, and community composition of the microbiome were significantly varied among different Camellia genotypes. The relative abundance of symbiotic and pathotrophic fungi in the rhizosphere soil of C. chekiangoleosa was significantly higher than that of C. gauchowensis. Concentrations of OM, available phosphorus (AP), and bacterial alpha diversity increased with tree age. Fungi of Saitozyma, Mortierella, and Glomeromycota and bacteria of Burkholderia-Caballeronia-Paraburkholderia and Vicinamibacterales had potential for fertilizer development for Camellia plantation. Camellia genotypes and growth stages were significantly correlated with the rhizosphere soil pH, OM, and available potassium (AK). Soil pH and OM were key factors that affected the microbiome in the Camellia rhizosphere soils. In conclusion, tree genotypes and growth stages shaped microbial communities in Camellia rhizosphere soils, and some plant growth-promoting rhizobacteria were identified as preliminary candidates for improving Camellia plantation growth.

Characterizing Wall Loss Effects of Intermediate-Volatility Hydrocarbons in a Smog Chamber with a Teflon Reactor

Intermediate-volatility organic compounds (IVOCs) serve as pivotal precursors to secondary organic aerosol (SOA). They are highly susceptible to substantial wall losses both in indoor environments and within smog chambers even with Teflon walls. Accurately characterizing the wall loss effects of IVOCs is thus essential for simulation studies aiming to replicate their atmospheric behaviors in smog chambers to ensure precise modeling of their physical and chemical processes, including SOA formation, yet a comprehensive understanding of the wall loss behavior of IVOCs remains elusive. In this study, we conducted a thorough characterization of wall losses for typical intermediate-volatility hydrocarbon compounds, including eight normal alkanes (n-alkanes) and eight polycyclic aromatic hydrocarbons (PAHs), using the smog chamber with a 30 m3 Teflon reactor. Changes in the concentrations of gaseous IVOCs with the chamber were observed under dark conditions, and the experimental data were fitted to the reversible gas–wall mass transfer theory to determine the key parameters such as the wall accommodation coefficient (αw) and the equivalent organic aerosol concentration (Cw) for different species. Our results reveal that Cw values for these hydrocarbon IVOCs range from 0.02 to 5.41 mg/m3, which increase with volatility for the PAHs but are relative stable for alkanes with an average of 3.82 ± 0.92 mg/m3. αw span from 1.24 × 10−7 to 1.01 × 10−6, with the values for n-alkanes initially showing an increase followed by a decrease as carbon numbers rise and volatility decreases. The average αw for n-alkanes and PAHs are 3.34 × 10−7 and 6.53 × 10−7, respectively. Our study shows that IVOCs exhibit different loss rates onto clean chamber walls under dry and dark conditions, with increasing rate as the volatility decreases. This study demonstrates how parameters can be acquired to address wall losses when conducting smog chamber simulation on atmospheric processes of IVOCs.

Global Influence of Organic Aerosol Volatility on Aerosol Microphysical Processes: Composition and Number

AbstractWe present MATRIX‐VBS, a new aerosol scheme that simulates organic partitioning in an aerosol microphysics model, as part of the NASA GISS ModelE Earth System Model. MATRIX‐VBS builds on its predecessor aerosol microphysics model MATRIX (Bauer et al., 2008, https://doi.org/10.5194/acp‐8‐6003‐2008) and was developed in the box model framework (Gao et al., 2017, https://doi.org/10.5194/gmd‐10‐751‐2017). The scheme features the inclusion of organic partitioning between the gas and particle phases and the photochemical aging process using the volatility‐basis set (Donahue et al., 2006, https://doi.org/10.1021/es052297c). To assess the performance of the new model, we compared its mass concentration, number concentration, and activated number concentration to the original scheme MATRIX, and evaluated its mass concentrations in four seasons against data from the NASA Atmospheric Tomography Mission (ATom) aircraft campaign. Results from MATRIX‐VBS show that organics are transported further away from their source, and their mass concentration increases aloft and decreases at the surface compared to those in MATRIX. The mass concentration of organics at the surface agrees well with measurements, and there are discrepancies for vertical profiles aloft. In the new scheme, the global mass load of organic aerosols increased by 50%, there is also an increased number of particles at the surface and fewer activated ones in most regions. The new scheme presents advanced and more comprehensive capability in simulating aerosol processes.

Investigating the Long-Term Effects of Anthropogenic Practices on Soil Features

Anthropogenic practices have been increasingly conducted on the rise in addressing the escalatingdemands for socioeconomic development, resulting in significant impacts on land ecosystems. This research seeks toevaluate the influence of anthropogenic activities on soil features in mountainous regions of Vietnam by focusing 84samples collected from 12 locations across Lam River Basin at seven soil profiles (0-10, 10-20, 20-30, 30-40, 40-60, 60-80 and 80-100 cm).The findings reveal notable differences in soil texture among land use types (LUTs). Forest cover lands (FCLs),showed the least amount of sand content, varying from 29.7% to 37.6%, while unplanted and bare lands (UBLs) had thehighest sand ratios, up to 53.9%. FCLs exhibited lowest bulk density (BD), soil porosity (SP) and soil electricalconductivity (EC) and C:N ratio with respective ranges of 0.93-1.29 g.cm-3, 32.7-36.5%, 0.526-0.743 mS.m-1 and6.74 -8.52, respectively.In contrast, crop cultivation lands (CCLs) demonstrated higher values for BD (1.17-1.25 g/cm3), SP (39.25-43.19%), EC (0.583-0.792 mS.m-1) and C:N ratio (11.27-15.77). UBLs, on the other hand, exhibited even highest valuesup to 1.23-1.36 g.cm-1, 43.19-49.62%, 0.437-0.619 mS.m-1 and 11.68-16.58% and displayed high levels of exchange ironsand soil organic content compared to FCLs. Other factors such as pH varied little in space between the sampled soillocations and along the soil profiles. Overall, the study indicates that anthropogenic practices have impacts on the soilfeatures across the study area.

Achieving more accurate microindentation hardness measurements of shale rocks – Insight into the effect of sink-in and pile-up

Shale rock has become a major source of oil and natural gas production. Hence, understanding the mechanical properties of shales is important for field applications, such as drilling and fracking. In this work, a workflow was developed for assessing the hardness of shale rocks, with the kerogen-rich and calcite-rich shales as the model systems, using Vickers microindentation coupled with confocal microscopy. The use of confocal microscopy facilitates the direct observation of indent impressions, overcoming the challenges posed by the complex contrasts of shales seen in traditional optical microscopy. Sink-in and substantial elastic recovery were observed in kerogen-rich shales due to the large amount of organic content. However, sink-in did not affect the hardness calculation. Apparent pile-up was observed in calcite-rich shales due to its granular nature, which could lead to overestimation of hardness if not accounted for. The hardness measurement in calcite-rich shale is further complicated by spallation. Therefore, only hardness ranges, instead of individual hardness values, can be obtained in calcite-rich shales. This research not only refines the methodology for determining the hardness of shales but also provides insight into indentation artifacts, such as sink-in and pile-up, to improve the accuracy in measuring and analyzing the microhardness of complex geological materials.

Optimization of anaerobic filter reactor with zeolite immobilization media for dairy sludge waste treatment for biogas production

Abstract Sludge from the dairy industry’s wastewater treatment contains a high organic content and a strong odor. It is proposed to treat the sludge by an anaerobic digestion process using a continuous anaerobic filter reactor (AFR) equipped with media immobilization support and a combination of ORP and pH sensors. Three immobilized media were put into different AFRs. The process took place in a cylindrical reactor with a column height of 150 cm and diameter of 63 cm with a total volume of 30 L. The total period of the anaerobic digestion process took place 17 days after the batch process. When the experiment was carried out using a flow-rate of 5 L/day, the highest sCOD removal of 90.44 % was using bioring media. Meanwhile, using flow-rate of 8L/day the highest sCOD removal up to 88.05 % was achieved by using zeolite media. The highest average methane production was obtained 8 mL/day and 24 mL/day of zeolite media by using flow-rate 5 L/day and 8 L/day respectively and reduced HRT up to 90 hours. To ensure the cellular activity on degradation of organic compounds is measured by Oxidation Reduction Potential (ORP) value. In the first stage, the ORP value is -60.23 mV to -472.82 mV for a flow-rate of 5 L/day subsequently the second stage is -471.9 mV to -477.75 mV for a flow-rate of 8 L/day. Anaerobic filter reactors using zeolite media can retain the effect of influent perturbation with a high range of alteration of sCOD and high recovery.

The Effect of Chicken Bones Powder Adsorbent Mass and its Contact Time on Reducing Color Concentration in Peat Water Treatment

Peat water is surface water or ground water which is found abundantly in tidal, swampy and lowland areas. It has a reddish-brown color, with an acerbic taste (high acidity), and has a high organic content. Peat water can be treated using the adsorption method. Adsorption is a physical phenomenon in which the molecules of the adsorbed material are attracted to a solid surface, which acts as an adsorbent. In this study, the authors used the adsorption method to reduce the color concentration of peat water using activated chicken bones powder as an adsorbent and observing the changes that occur when mass of powder to the amount of 0.1, 0.2, 0.3, 0.4, 0.5, 1.0, 1.5 and 2.0 grams were added to 50 ml of peat water with contact time that varied from 20, 30, 40, 50 and 60 minutes. From this study, we conclude that the optimum yield was obtained when the mass and contact time were at 0.5 grams and 40 minutes, which yield a percentage of reduction of 95.59%, wherein the initial color concentration of peat water at 337.816 was reduced to 14.89 Pt-Co, which is in line with the standard color for clean water as specified in a Regulation by the Minister of Health of the Republic of Indonesia No. 492/MENKES/PER/IV/2010, which state the standard color for clean water is 15 Pt-Co.

Relationship between the heterogeneity in mechanical properties, bone density and composition parameters of cortical bone to design and develop bone scaffolds and implants: Analysis of bone microstructure

Bone is heterogeneous and anisotropic because its mechanical characteristics vary by anatomic location and loading direction. Previous research established a correlation between bone density, mineral, organic content, and porosity and mechanical qualities. Medical and bioengineering researchers can learn about bone heterogeneity and anisotropy by analysing bone density and later composition parameters across the bone diaphysis in both longitudinal and transverse orientations. This research examines bone density and composition parameters in bovine femoral cortical bone from higher, middle, and lower diaphysis regions and longitudinal and transverse orientations. At three homogeneous diaphysis sites, these properties did not alter in longitudinal or transverse orientations. At the upper and lower diaphysis locations, mineral and organic content were statistically different in both longitudinal and transverse orientations, contributing to anisotropy. At the middle location, all measured parameters were not statistically different. Transverse bone density and water heterogeneity were greater, while longitudinal values were higher for the other metrics. Upper and lower sites had increased bone variability due to %water, although mineral content was more homogenous. The longitudinal and transverse organic content and apparent density heterogeneity was greater at the middle position. At the later site, bone density and mineral content were more homogenous longitudinally and transversely. Lamellar bone microstructure with canalicular/vascular network, cavities, and holes contributed to bone materials' %water content. Collagen fibres contributed to bone material's organic composition, whereas intrafibrillar and extra fibrillar minerals contributed to its mineral content.

An innovative formulation to improve spent coffee characteristics as soil fertilizer: Nutrient, chemical characterization and effects on plant germination

Spent coffee grounds (SCG) possess high organic content and various essential nutrients. However, their direct use as a fertilizer is limited due to high acidity, phenolic content, and C/N ratio. Therefore, in this study, SCG-based fertilizer (SCGf) was developed by mixing the raw SCG (SCGr) and zein through a granulation process and was compared with the SCGr. According to the obtained results, in SCGf, a reduction in the C/N ratio from 22.9 to 10.9, improved flowability from fair to good, an increase in the concentration of elements (N, C, S), nutrients (ash, fats, proteins), macrominerals (Ca, Mg, P, K, Na), microminerals (Cu, Fe, Mn, Zn), total polyphenolic content (TPC), total flavonoid content (TFC), and antioxidant activities (AOA) was noted. Additionally, a decrease in total organic acids, total chlorogenic acids, and was also observed in SCGf. Regarding phytotoxicity test results obtained by using Sinapis alba, Sorghum saccharatum, and Lepidium sativum and treating them with 2.5%, 5%, and 10% of SCGf and SCGr, better germination was observed for SCGf in S. alba (5%, 10%), L. sativum (2.5%, 5%). However, in L. sativum, 5% of SCGr and 10% of both SCGr and SCGf completely inhibited seed germination. For S. saccharatum, higher germination rates were observed for SCGf (2.5%, 10%), and at 5%, a comparable effect of both SCGf and SCGr was noted. SCGf gave the longest root length at all concentrations in all plants except for 2.5% in S. alba. In conclusion, this study addresses the effective use of SCG for sustainable agriculture while mitigating environmental impacts.

Effect of culture history and carbon sources on polyhydroxyalkanoates production in activated sludge systems

ABSTRACT Polyhydroxyalkanoates (PHAs) are important and completely biodegradable alternatives to regular plastics, and they can be produced by activated sludge systems during wastewater treatment. Wastewaters with high organic content are being used for PHA production, which is an important resource recovery option. In this context, the effect of sludge retention time and different carbon sources, such as acetate, peptone-mixture and industrial wastewater (containing acetic acid (AA), lactic acid (LA) and propionic acid (PA)), on PHA storage was investigated. Oxygen utilisation rate (OUR) profiles were generated in respirometric tests and were evaluated by activated sludge modelling. Results showed that high storage (AA: 70%; LA: 49%; PA: 60% and industrial wastewater: 52%) was achievable in the feast phase even when the biomass was fed with a high organic acid content substrate to which it is not acclimated.

Sediment properties control riverine methane emissions: A case study of the Liao River in northern China

River and stream sediments act as biogeochemical reactors for greenhouse gases, particularly methane. However, understanding how riverbed sediment properties influence river carbon emissions remains relatively unclear. The Liao River in northern China is a typical watershed with heterogeneous water and sediment sources, characterized by varying sediment properties. In this study, we surveyed CH4 and CO2 emissions from its mainstem and tributaries during flood and dry seasons. We found consistent seasonal patterns in CH4 and CO2 emissions, with peaks occurring during the flood season. The average CH4 and CO2 fluxes were 1.64 ± 1.80 mmol·m−2·d−1 and 59.66 ± 44.60 mmol·m−2·d−1, respectively. Notably, the percentage of sediment silt was significantly correlated with CH4 concentration and flux (R2 = 0.12−0.30, p < 0.05). Fine particles dominated the availability of sediment organic matter and redox conditions, which were related to riverine CH4 production and emissions. Structural equation modeling revealed that both grain size and the percentage of TOC (total organic carbon) directly influenced riverine CH4 and CO2 emissions. The organic content and redox conditions of the riverbed sediment collectively explained 65% of riverine CH4 emissions, while grain size composition indirectly controlled CH4 emissions by altering sediment substrate quality and redox conditions. In contrast, river CO2 emissions were only weakly dependent on anaerobic metabolism in riverbed sediments. These findings enhance our understanding of the sources and metabolic mechanisms of riverine CH4 and CO2 emissions and offer potential improvements for estimating carbon fluxes in regional or global riverine networks by considering riverbed sediment properties.

Designing a biochar-based pretreatment method for distillery effluents entering constructed wetlands

Spent lees is an important distillation waste by-product created during whisky production, characterised by low pH and high dissolved copper (dissCu) content. Constructed wetland systems (CWs) are used in some Scotch whisky distilleries to treat spent lees prior to surface water discharge to prevent substantial environmental risks of spent lees in aquatic ecosystems, by buffering the acidic nature and decreasing the dissCu and organics content. However, as these wetland systems are biological communities (containing bacteria, fungi, plants, etc.), direct disposal of spent lees into CW ecosystems presents a challenge given its nature. This study investigates the efficacy of modified biochar (waste) sourced from whisky cask cooperage operations, as an effluent pretreatment method. The aim is to transform this raw biochar into NaOH-modified biochar, which will be capable of buffering the effluent pH and removing dissCu from spent lees before it enters CWs. To enhance raw biochar, NaOH modification and additional heat treatment were utilised which increased the alkalinity, heavy metal removal capacity and pH buffering potential. Experiments with 0.2% and 2% NaOH treated biochar demonstrated its treatment performance using a diverse range of spent lees samples with varying characteristics, including pH (4.1–4.4), dissCu concentrations (33.8–59.5 mg/L), and total organic carbon (685–754 mg/L). Column studies further supported the efficacy of the modified biochars, showing significant pH elevation and efficient dissCu removal (of 5.72 mg of Cu per g of biochar) when treating spent lees. This dissCu removal capacity compares favorably with other wood-derived biochars studied in the literature, which have reported between 2.75 and 7.44 mg/g. Surface characterisation techniques (EDX, XPS, FTIR, XRD) showed how the Cu ions microprecipitated on the modified biochar surface, validating its remediation potential. This study highlights the potential of biochar as a sustainable pretreatment solution for distillery effluents, paving the way for enhanced and more circular waste management practices within the Scotch whisky industry.

Carbon Stock and Chemical Fractionation of Organic Matter in Different Soil Management Systems in the Bahian Cerrado

ABSTRACT Determining total organic carbon and its stock and quantifying the chemical fractions of soil organic matter can be used as indicators of the quality of the soil management used in a cropping area. This study aimed to quantify soil organic matter’s carbon stock and chemical fractions in different soil management systems used in the western Bahian Cerrado, Brazil, and compare them to a native Cerrado area. Ten microregions (Alto Horizonte, Anel da Soja, Bela Vista, Cascudeiro, Coaceral, Novo Paraná, Panambi, Placas, Roda Velha, Roda Velha de Baixo), three soil management systems [tillage system (TS), no-tillage systems (nTS), native Cerrado (NC)], and two soil layers (0–0.1 and 0.1–0.2 m) were studied. Soil bulk density (Sd), soil organic matter (SOM), total organic carbon (TOC), SOM quantification (qSOM), equivalent carbon stock (EqCs), humin (HF), humic acid (HAF) and fulvic acid (FAF) fractions from SOM were evaluated. The results indicated that Sd in all evaluated microregions was below the critical upper limit that would restrict plant root development. SOM, TOC, EqCs, and qSOM revealed increasing results following the TS, nTS, and NC order. The NC area presented the highest soil organic fraction contents (HF, HAF, and FAF). The microregions with better soil quality for all evaluated parameters were Coaceral and Cascudeiro; the lowest soil quality was observed in Alto Horizonte. The present study indicates that conservation agricultural management, such as the no-tillage system, improves the structure and composition of SOM parameters over time.

Exploring the physicochemical and microbiological properties of glutinous rice (Tapai pulut) fermented using Lactobacillus plantarum: A comprehensive characterization using 1H NMR

This study aimed to investigate the potential of producing lacto-fermented glutinous rice (Tapai pulut) to improve its physicochemical properties, metabolite compounds, and antibacterial activity of the end product. Glutinous rice was fermented with Amylomyces rouxii, and Lactobacillus plantarum 1 at 30 °C for 48 h. Lacto-fermented glutinous rice had significantly lower pH values and higher total lactic acid, soluble solid, glucose, and organic acid contents. The 1H NMR metabolomics profile revealed the presence of alcohols (7.67 mmol/L), sugars (208.16 mmol/L), organic acids (0.91 mmol/L) and amino acids (15.74 mmol/L), contributing to its antimicrobial activities and flavor profile. The lacto-fermented glutinous rice exhibited strong antibacterial activity against Bacillus cereus (18.20 mm), Staphylococcus aureus (18.92 mm), Listeria monocytogenes (15.42 mm), Escherichia coli (15.85 mm), and Salmonella typhimurium (12.23 mm). Meanwhile, the viable count of lactic acid bacteria (LAB) in the lacto-fermented glutinous rice was 9.49 log10 CFU/g. Based on sensory evaluation and positive feedback from panelists, lacto-fermented glutinous rice emerges as a promising probiotic food with potential health benefits for consumers.

Brownfield Topsoil Vertical Heterogeneity: Implications for Germination and Soil Microbial Functioning.

Soil vertical heterogeneity refers to the variation in soil properties and composition with depth. In uncontaminated soils, properties including the organic matter content and nutrient concentrations typically change gradually with depth due to natural processes such as weathering, leaching, and organic matter decomposition. In contaminated soils, heavy metals and organic contaminants can migrate vertically through leaching or root uptake and translocation by plants and macrobiota, if present, leading to vertical heterogeneity in contaminant concentrations at different depths. Contaminants can alter soil properties, and we investigated the implications of soil vertical heterogeneity for germination and microbial functioning. We collected soil from an urban brownfield and created two conditions: structured soil samples collected with the soil core intact and mixed (unstructured) samples. When planted, the germination rate was significantly lower in the structured conditions (3.1 ± 1.7%) compared to mixed soils (17 ± 4.6%), suggesting that the vertical heterogeneity of contaminated soil influenced plant germination. To map the vertical distribution of contaminants and nutrient cycling rates in the structured soil samples, we collected 10 cm-deep soil cores from the barren site and a neighboring vegetated reference site and measured heavy metal concentrations, soil enzyme activities, and organic matter content in five 2 cm vertical layers. In the barren soil cores, metals were found concentrated in the top 2 cm layer, while in the vegetated soil cores, metals were uniformly distributed. No significant differences were observed for the organic matter content or moisture along depth. Published studies on vertical distribution of enzyme activities and metal concentrations have treated the top 10-20 cm as a single layer and thus would have not revealed the thin (<2 cm thick) metal cap on the surface of the barren soil core. Despite the metal cap, enzyme activities in the top layer were similar to those in the lower layers of the barren soil core, suggesting that high metal concentrations do not limit soil enzyme activity under all circumstances. Investigating vertical heterogeneity in postindustrial soils can inform efforts to convert industrial barrens to vegetated environments.

Evaluation of Heavy Metal Concentration in Different Organs of Labeo rohita in Water and Sediment of Marala Ravi Link Canal (MRL) and Upper Chenab Canal (UCC) of Chenab River, Pakistan, and Their Health Implications

Evaluation of Heavy Metal Concentration in Different Organs of Labeo rohita in Water and Sediment of Marala Ravi Link Canal (MRL) and Upper Chenab Canal (UCC) of Chenab River, Pakistan, and Their Health Implications

Organic Heterophase Composites Induced Sulfur Vacancies and Internal Electric Field Enhancement for Advanced Magnesium Storage of Copper Sulfide Cathodes

AbstractRechargeable magnesium‐ion batteries (MIBs) hold significant promise for safe and efficient large‐scale energy storage, but the lack of high‐performance cathodes hinders their development for practical applications. In this work, a series of nanocomposites consisting of π‐conjugated perylene‐3,4,9,10‐tetracarboxylic dianhydride annealed at 450 °C and copper sulfide (CuSP) are synthesized solvothermally to explore their utility as a host for Mg2+ storage in MIBs. The carbonyl organics in the hybrid materials modify the predominant CuS phase, expanding interlayer spacing and enriching sulfur vacancies through modifications of the internal electric field. This synergistic interaction enhances magnesium storage performance and accelerates reaction kinetics. Using chlorine‐free Mg[B(hfip)4]2/DME electrolytes, the CuSP91 cathode containing an appropriate organic content displays a remarkably high reversible capacity of 285 mAh g−1 at 50 mA g−1, and demonstrates a stable capacity of 220 mAh g−1 at 100 mA g−1, surpassing pure CuS cathode in terms of shorter activation time. The CuSP91 cathode maintains a discharge capacity of 55 mAh g−1 over 1000 cycles at 500 mA g−1. A co‐redox mechanism is revealed through in/ex situ investigations and analyses. Overall, this research contributes valuable insights targeting the development of advanced organic–inorganic hybrid composite cathode materials in next‐generation energy storage systems.