Clay

The lack of extreme water level fluctuations in managed, non-peat forming wetland ecosystems can result in decreased productivity through the loss of heterogeneity of these ecosystems. Stochastic disruption, such as a water level drawdown, can effectively reverse this effect and return the wetland to a more productive state, associated with higher biodiversity through new vegetation development. Yet, aside from the effect on vegetation dynamics, little is known about longer-term effects (30 years) of a water level drawdown, hereafter referred to as legacy effects, and how this may impact future water level drawdowns...

Some antibiotics are used for the treatment of various bacterial crop diseases, and there is a concern that this practice may represent a selection pressure that increases the reservoir of antibiotic resistance carried by bacteria in crop production systems. Since the 1950s the aminoglycoside antibiotic streptomycin has been widely used for the treatment of some bacterial crop diseases such as fire blight in apples and pears. Following application, the time that bacteria will be exposed to the antibiotic, and therefore the pressure for selection of resistance, will vary according to the environmental persistence of the antibiotic...

Soil aggregates are crucial for reducing soil erosion and enhancing soil organic carbon sequestration. However, knowledge regarding influences of different slope positions on compositions and carbon content for different soil aggregates is limited. Soil samples were collected from various slope positions including dip slope, anti-dip slope and valley depression in the Longtan karst valley of Southwest China. Contents of macroaggregate (> 0.25 mm), microaggregate (0.053-0.25 mm) and silt and clay fraction (< 0...

The plastics derived from fossil fuels for food packaging results in serious environmental problems. Developing environment-friendly materials for food packaging is urgent and essential. In this study, polylactic acid (PLA) composite nanofibers membranes were prepared with good biocompatibility and antibacterial property. Cu2+ loaded in the natural halloysite nanotubes (HNTs) was used for the antibacterial agent. Cu2+ was loaded in the HNTs and was confirmed by the X-ray photoelectron spectroscopy (XPS). PLA nanofibers with different HNTs-Cu content were continuous nanofibers with the nanoscale range...

Palygorskite (Pal) is a naturally available one-dimensional clay mineral, featuring rod-shaped morphology, nanoporous structure, permanent negative charges as well as abundant surface hydroxyl groups, exhibiting promising potential as a natural hemostatic material. In this study, the hemostatic performance and mechanisms of Pal were systematically investigated based on the structural regulate induced by oxalic acid (OA) gradient leaching from perspectives of structure, surface attributes and ion release. In vitro and in vivo hemostasis evaluation showed that Pal with OA leaching for 1 h exhibited a superior blood procoagulant effect compared with the raw Pal as well as the others leached for prolonging time...

Clay-reinforced polyvinyl chloride (PVC) composites and nanocomposites are one of the newest and most important compounds studied and used in various applications, including the biomedical, automotive industry, water treatment, packaging, fire retarding, and construction. The most important clays used in the synthesis of these composites are Bentonite, Montmorillonite, Kaolinite, and Illite. The addition of these nanoclays to the PVC matrix improves mechanical properties, thermal stability, and yellowness index properties...

In this study, fast-growing poplar reclaimed from abandoned homestead in Xixian New District, Xi'an City, Shaanxi Province, was used as the research object to explore the multi-fractal characteristics of soil particle size distribution under different management modes of abandoned land (control), irrigation, fertilizer irrigation and mixed fertilizer irrigation. The results showed that the mean values of soil clay, silt and sand in abandoned land were 14.58%, 81.21% and 4.22% respectively, 14.08%, 79.92% and 5...

The objective of this study is to assess the effectiveness of different techniques employed in remediating contaminated soil and wastewater ecosystems to ensure the safety of tomato fruits (Solanum lycopersicum L. var. cerasiforme) cultivated in these environments. Three biochemical techniques T1-T3, besides two controls CCU and CCT, were used to remediate contaminated soil ecosystems using rock phosphate, elemental sulfur, bentonite, phosphate-dissolving bacteria, and Thiobacillus sp. The contaminated agricultural drainage water was remediated by a down-flow hanging sponge (DHS) system...

The reuse of treated wastewater (TWW) in agriculture for crop irrigation is desirable. Crop responses to irrigation with TWW depend on the characteristics of TWW and on intrinsic and extrinsic soil properties. The aim of this study was to assess the response of tomato (Solanum lycopersicum L.) cultivated in five different soils to irrigation with TWW, compared to tap water (TAP) and an inorganic NPK solution (IFW). In addition, since soil microbiota play many important roles in plant growth, a metataxonomic analysis was performed to reveal the prokaryotic community structures of TAP, TWW and IFW treated soil, respectively...

Drought is a global environmental problem, while the effect of drought-induced unsaturation on the fate of heavy metal ions is still poorly understood, particularly the lack of mechanistic information at the molecular level. This study used molecular dynamics simulations to investigate nanoscale interactions at the montmorillonite surface under different moisture conditions. Compared to the saturated condition, drought increased the amounts and strength of Cd2+ ions adsorbed on the montmorillonite (MMT) surface while decreased the diffusivity, which was especially obvious in extreme drought conditions (θv =21%-7%)...

Effective drug delivery for is the foremost requirement for the complete recovery of the disease. Nanomedicine and nanoengineering has provided so many spaces and ideas for the drug delivery design, whether controlled, targeted, or sustained. Different types of nanocarriers or nanoparticles are aggressively designed for the drug delivery applications. Clay minerals are identified as a one of the potential nanocarrier for the drug delivery. Owing to their biocompatibility and very low cytotoxicity, clay minerals showing effective therapeutic applications...

The application of biomarkers to study the molecular composition of soil organic matter (SOM) can be used to analyze the source and degradation of SOM and reveal the stability mechanism of soil organic carbon (SOC) at the molecular level. In order to further clarify the effects of different land use patterns (farmland, grassland, and forest) on the molecular composition of SOM, the changes in molecular composition of organic matter (free lipids, cutin, suberin, and lignin) on a global scale were studied using a meta-analysis method...

Investigating the relationship of soil aggregate stability with the organic carbon in the aggregate and its response to land use change is conducive to the estimation of soil carbon sink potential, improvement of rocky desertification, and rational land use in karst areas of Southwest China. In order to explore the effects of land use change on the composition and stability of soil aggregate stability as well as the content of aggregate organic carbon, the soil (0-30 cm) of five land use types (secondary forest, pomelo forest, paddy field, pepper forest, and dry land) was selected as the research object...

Sarcoidosis, a multifaceted systemic disorder characterized histologically by the presence of non-caseating granulomas, has a wide array of cutaneous manifestations. We describe a case of a 74-year-old woman with a complex medical history, who presented with asymptomatic hyperpigmented papules on her lower extremities. Histological examination of a punch biopsy specimen showed nodular and angiocentric patterns of granulomatous inflammation consistent with sarcoidosis, and chest radiography demonstrated bilateral hilar opacities, supporting the diagnosis...

Electroosmosis has been proposed as a technique to reduce moisture and thus increase the stability of soft clay. However, its high energy consumption and uneven reinforcement effect has limited its popularization and application in practical engineering. This paper presents the results of some electrokinetic tests performed on clayey specimens with different electrification time and anode boundary conditions. The results indicate that the timing of the formation of electroosmotic flow (EF) by the water originally contained in different soil cross sections, from the anode to the cathode, varies...

The European Green Deal encourages the use of non-productive activities in agriculture. One of the measures is the cultivation of melliferous floral plants at the field margins. Their influence on soil compaction and other deterioration is due to heavy machinery, its inappropriate use and frequent driving on field margins, is little studied. Plants of a high environmental value though rarely grown by farmers were selected for melliferous plant strips: perennial grass swards (PGS), perennial legume swards (PLS), annual floral plats mixture (AEP) and natural grassland swards (NGS)...

This study is to understand the fate and ecological consequences of pyroxasulfone in aridisols of Punjab, a detailed dissipation study in soil, its influence on soil enzymes, microbial count and succeeding crops was evaluated. Half-lives (DT50 ) increased with an increase in the application rate of pyroxasulfone. Dissipation of pyroxasulfone decreased with increase in organic matter content of soil and was slower in clay loam soil (DT50 12.50 to 24.89) followed by sandy loam (DT50 8.91 to 17.78) and loamy sand soil (DT50 6...

BACKGROUND: A major impact of the invasive Myocastor coypus in the introduction range is the collapse of riverbanks and nearby infrastructure, such as railway lines, due to the species' burrowing activities. As the ubiquitous implementation of preventive measures along watercourses is unfeasible, identifying susceptible areas is key to guide targeted management actions. This study used species-habitat models to (i) identify the local environmental features of the railway line/watercourse intersections (RLWIs) that make them particularly susceptible to coypu damage, and (ii) predict species occurrence probability in a wide lowland-hilly area of northern Italy (Lombardy) to identify priority areas for monitoring...

The link between biodiversity and ecosystem multi-functionality is an ongoing concern in ecological studies. Ecologists have focused on soil quality (SQ) as an ecosystem function and its relationship to biodiversity. Developing an appropriate and sensitive soil quality index (SQI) is critical, but it is severely restricted particularly in the forests. This study determined the most appropriate SQI for both protected and unprotected areas of Arasbaran biosphere reserve forests (Northwest Iran), as well as its relationship to the diversity of three layers of forest plant species (tree, tree regeneration, and forest floor plant cover), NDVI index, and litter amount...

The presence of dissolved organic nitrogen (DON) in stormwater treatment processes is a continuous challenge because of the intertwined nature of its decomposition, bioavailability, and biodegradability and its unclear molecular characteristics. In this paper, 21 tesla Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) in combination with quantitative polymerase chain reaction was applied to elucidate the molecular change of DON and microbial population dynamics in a field-scale water filtration system filled with two specialty adsorbents for comparison in South Florida where the dry and wet seasons are distinctive annually...