CHEMICAL CHARACTERISTICS OF A NATURAL SOIL LEACHATE FROM A HUMIC PODZOL

1969 ◽  
Vol 49 (1) ◽  
pp. 151-158 ◽  
Author(s):  
M. Schnitzer ◽  
J. G. Desjardins

A leachate, collected in the field in a lysimeter placed between the Ae and Bhf horizon of a Humic Podzol in Newfoundland, was analyzed by chemical and spectroscopic methods.About 87% of the dry, ash-free weight of the leachate was fulvic acid, the remainder consisting mainly of polysaccharides and nitrogenous compounds. A comparison of the analytical characteristics of the purified leachate with those of extracted and purified Podzol Bh fulvic acid showed that the main structural features of the two materials were very similar. Judging from its high contents of oxygen-containing functional groups and from its water solubility, the organic matter in the leachate had all the characteristics of an efficient metal–complexing agent, capable of playing a significant role in metal–organic matter interactions in soils.An organic matter–silica sediment was isolated from the leachate, consisting of 47.6% organic matter and of 52.4% of almost pure SiO2∙nH2O. The organic matter in the sediment accounted for about 10% of the organic matter in the leachate. The isolation of the sediment suggests that investigations on interactions between compounds of silicon and humic substances deserve greater attention than they have so far received.

1970 ◽  
Vol 50 (2) ◽  
pp. 199-204 ◽  
Author(s):  
M. SCHNITZER

Organic matter was extracted from Podzol B horizons from nine different sites and analyzed by chemical and spectroscopic methods. The biological activity of each extract was also assessed. After purification, all extracts, which represented between 31 and 56% of the organic matter in the original soil samples, were soluble in base, acid and water, which classified them as fulvic acids. The chemical and spectroscopic data for the nine fulvic acids indicated great similarities in gross structural features and functional groups. As could be judged from the E4/E6 ratios, the acids contained few condensed ring structures. All fulvic acids contained stable free radicals and increased root initiation in bean stem segments. While the free radical content of the fulvic acids did not correlate statistically with their ability to increase root initiation, this aspect merits further investigation. The high acidity, the predominance of COOH groups and the water solubility exhibited by all fulvic acid preparations point to a significant role of these materials not only in soils and waters but also within plants.


1996 ◽  
Vol 34 (9) ◽  
pp. 157-164 ◽  
Author(s):  
Kim C.-H. ◽  
M. Hosomi ◽  
A. Murakami ◽  
M. Okada

Effects of clay on fouling due to organic substances and clay were evaluated by model fouling materials and kaolin. Model fouling materials selected were protein, polysaccharide, fulvic acid, humic acid and algogenic matter (EOM:ectracellular organic matter, microbial decomposition products) and kaolin was selected as the clay material. Polysulfone membrane (MWCO(Molecular Weight Cut-Off) 10,000, 50,000 and 200,000) was used as an ultrafiltration membrane. In particular, the flux measurement of solutions containing algogenic matter used an ultrafiltration membrane of MWCO 50,000. The flux of protein and polysaccharide with coexistence of kaolin increased in the case of the ratio of MW/MWCO being greater than one, but did not increase in the case of the MW/MWCO ratio being below one. In contrast, the flux of fulvic acid and humic acid with coextence of kaolin decreased regardless of the ratio of MW/MWCO. The addition of dispersion agent and coagulant in the organic substances and kaolin mixture solution changed the size distribution of kaolin, and resulted in a change of the flux. EOM and microbial decomposition products decreased with the increase of the fraction of organic matter having molecular weight more than MWCO of membrane. The flux of the algogenic organic matter with coexistence of kaolin decreased with the increase of the amount of kaolin. It was suggested that the decline of the flux with coexistence of kaolin was due to the change of the resistance of the kaolin cake layer corresponding to the change in kaolin size distribution with charge.


Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 779
Author(s):  
Václav Voltr ◽  
Ladislav Menšík ◽  
Lukáš Hlisnikovský ◽  
Martin Hruška ◽  
Eduard Pokorný ◽  
...  

The content of organic matter in the soil, its labile (hot water extractable carbon–HWEC) and stable (soil organic carbon–SOC) form is a fundamental factor affecting soil productivity and health. The current research in soil organic matter (SOM) is focused on individual fragmented approaches and comprehensive evaluation of HWEC and SOC changes. The present state of the soil together with soil’s management practices are usually monitoring today but there has not been any common model for both that has been published. Our approach should help to assess the changes in HWEC and SOC content depending on the physico-chemical properties and soil´s management practices (e.g., digestate application, livestock and mineral fertilisers, post-harvest residues, etc.). The one- and multidimensional linear regressions were used. Data were obtained from the various soil´s climatic conditions (68 localities) of the Czech Republic. The Czech farms in operating conditions were observed during the period 2008–2018. The obtained results of ll monitored experimental sites showed increasing in the SOC content, while the HWEC content has decreased. Furthermore, a decline in pH and soil´s saturation was documented by regression modelling. Mainly digestate application was responsible for this negative consequence across all soils in studied climatic regions. The multivariate linear regression models (MLR) also showed that HWEC content is significantly affected by natural soil fertility (soil type), phosphorus content (−30%), digestate application (+29%), saturation of the soil sorption complex (SEBCT, 21%) and the dose of total nitrogen (N) applied into the soil (−20%). Here we report that the labile forms (HWEC) are affected by the application of digestate (15%), the soil saturation (37%), the application of mineral potassium (−7%), soil pH (−14%) and the overall condition of the soil (−27%). The stable components (SOM) are affected by the content of HWEC (17%), soil texture 0.01–0.001mm (10%), and input of organic matter and nutrients from animal production (10%). Results also showed that the mineral fertilization has a negative effect (−14%), together with the soil depth (−11%), and the soil texture 0.25–2 mm (−21%) on SOM. Using modern statistical procedures (MRLs) it was confirmed that SOM plays an important role in maintaining resp. improving soil physical, biochemical and biological properties, which is particularly important to ensure the productivity of agroecosystems (soil quality and health) and to future food security.


2020 ◽  
Vol 92 (7) ◽  
pp. 1093-1110 ◽  
Author(s):  
Aleksey A. Sidorov ◽  
Natalia V. Gogoleva ◽  
Evgeniya S. Bazhina ◽  
Stanislav A. Nikolaevskii ◽  
Maksim A. Shmelev ◽  
...  

AbstractHeterometallic carboxylate complexes are of paramount interest in pure and applied coordination chemistry. Despite that plurality of such type compounds have been published to date, synthetic aspects of their chemistry often remain in the shadow of intriguing physical properties manifesting by these species. Present review summarizes reliable data on direct synthesis of low nuclearity molecular compounds as well as coordination polymers on their base with carboxylate-bridged {M2Mg} (M = Co2+, Ni2+, Cd2+), {M2Li2} (M = Co2+, Ni2+, Zn2+, VO2+), {M2Ln2} and {M2Ln} (M = Cu2+, Zn2+, Co2+) metal cores. Structural features and stabilization factors are considered and principal outcomes are confirmed by quantum-chemical calculations. Particular attention is paid to consideration of ligand-exchange reactions that allow controllable modification of heterometallic metal core under mild conditions giving diverse molecular complexes with modified ligand environment or Metal-Organic Frameworks with permanent porosity.


Author(s):  
Zhenpeng Yao ◽  
Benjamin Sanchez-Lengeling ◽  
N. Scott Bobbitt ◽  
Benjamin J. Bucior ◽  
Sai Govind Hari Kumar ◽  
...  

Reticular frameworks are crystalline porous materials that form <i>via</i> the self-assembly of molecular building blocks (<i>i.e.</i>, nodes and linkers) in different topologies. Many of them have high internal surface areas and other desirable properties for gas storage, separation, and other applications. The notable variety of the possible building blocks and the diverse ways they can be assembled endow reticular frameworks with a near-infinite combinatorial design space, making reticular chemistry both promising and challenging for prospective materials design. Here, we propose an automated nanoporous materials discovery platform powered by a supramolecular variational autoencoder (SmVAE) for the generative design of reticular materials with desired functions. We demonstrate the automated design process with a class of metal-organic framework (MOF) structures and the goal of separating CO<sub>2</sub> from natural gas or flue gas. Our model exhibits high fidelity in capturing structural features and reconstructing MOF structures. We show that the autoencoder has a promising optimization capability when jointly trained with multiple top adsorbent candidates identified for superior gas separation. MOFs discovered here are strongly competitive against some of the best-performing MOFs/zeolites ever reported. This platform lays the groundwork for the design of reticular frameworks for desired applications.


2021 ◽  
Author(s):  
Parinaz Nezhadmokhtari ◽  
Nahideh Asadi ◽  
Marjan Ghorbani ◽  
Azizeh Rahmani Del Bakhshayesh ◽  
Morteza Milani ◽  
...  

Abstract Bacterial nanocellulose (BNC) is a type of 3-dimensionally structured polymer gel produced by Acetobacter that has recently attracted increased interest in wound healing concerns. To produce an effective antibacterial wound dressing, researchers investigated the manufacturing and structural features of honey-infused BNC reinforced gelatin/aldehyde-modified Guar gum films (H/BNC/Ge/AD-GG). Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), mechanical characteristics, water solubility, and degradability were all used to assess the produced films. In addition, the influence of honey addition on the produced films' various properties has been examined. Antibacterial activity, better degradation capability, improved mechanical qualities, and excellent cell adhesion and proliferation by NIH-3T3 fibroblast cells were among the outcomes. The cytotoxicity assay in vitro revealed good cytocompatibility. As a result of the findings, the produced H/BNC/Ge/AD-GG films appear to have a high potential for antibacterial wound dressing applications.


2010 ◽  
Vol 2 (5) ◽  
pp. 1-11
Author(s):  
Atreyee Sahana

Soil is the foundation of all life activities in terrestrial ecosystems. Soil micro arthropod groups (less than 2 mm in size) like Acari and Collembola comprise more than 90% of arthropod fauna in most soil types. They majorly help in soil formation by breaking up the organic matter and mixing it up with inorganic mineral components. Among them, various species of Collembola have been proved to be effective bioindicator tool to measure soil health either it is polluted or not by its several characteristics in temperate countries. Therefore, in today’s world where pollution in soil by various agents is a baffling issue like other environmental pollutions, these natural soil inhabitants can make a hope to measure the natural health of soil.


Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3661
Author(s):  
Kimio Fukami ◽  
Tatsuro Oogi ◽  
Kohtaro Motomura ◽  
Tomoka Morita ◽  
Masaoki Sakamoto ◽  
...  

Beverage industries often discharge large amounts of organic matter with their wastewater. Purification of the effluent is their obligation, but it is nontrivial. Among wastewater components, removal of dissolved organic matter often requires much effort. Therefore, a special effective technique must be considered. Microbubbles (1–100 μm) have several special properties of relevance to wastewater treatment. In this study, the effectiveness of microbubbles for treating and purifying beverage wastewater was evaluated. Orange juice, lactic acid drink, and milk were used as model substrates of dissolved organic matter, and degradation experiments were carried out. Rates of air supply by microbubbles were 0.05% (air/wastewater) min−1. Results indicated that the total organic carbon (TOC) in an experimental vessel containing milk (high nitrogen content) decreased by 93.1% from 11.0 to 0.76 g during a 10-day incubation. The TOC of lactic acid drink (least nitrogen content) decreased by 66.3%, from 15.6 to 5.26 g, and the TOC of orange juice (medium nitrogen content) decreased by 82.7%, from 14.8 to 2.55 g. Large amounts of particulate organic matter floated on the water surface in the milk with microbubbles and were removed easily, while almost no floating materials were observed in the orange juice and lactic acid drink. In contrast, in the macrobubble treatment (diameter 0.1 to 2 mm), only 37.0% of TOC in the milk was removed. Whereas the macrobubble treatments were anaerobic throughout the incubations, the microbubble treatments returned to aerobic conditions quickly, and brought 10 times greater bacterial abundances (>108 cells mL−1). These results suggest that microbubbles are much superior to macrobubbles in supplying oxygen and accelerating the growth of aerobic bacteria, and that wastewater containing more nitrogenous compounds was purified more effectively than that with less nitrogen by microbial degradation and floating separation.


2020 ◽  
Author(s):  
Zhenpeng Yao ◽  
Benjamin Sanchez-Lengeling ◽  
N. Scott Bobbitt ◽  
Benjamin J. Bucior ◽  
Sai Govind Hari Kumar ◽  
...  

Reticular frameworks are crystalline porous materials that form <i>via</i> the self-assembly of molecular building blocks (<i>i.e.</i>, nodes and linkers) in different topologies. Many of them have high internal surface areas and other desirable properties for gas storage, separation, and other applications. The notable variety of the possible building blocks and the diverse ways they can be assembled endow reticular frameworks with a near-infinite combinatorial design space, making reticular chemistry both promising and challenging for prospective materials design. Here, we propose an automated nanoporous materials discovery platform powered by a supramolecular variational autoencoder (SmVAE) for the generative design of reticular materials with desired functions. We demonstrate the automated design process with a class of metal-organic framework (MOF) structures and the goal of separating CO<sub>2</sub> from natural gas or flue gas. Our model exhibits high fidelity in capturing structural features and reconstructing MOF structures. We show that the autoencoder has a promising optimization capability when jointly trained with multiple top adsorbent candidates identified for superior gas separation. MOFs discovered here are strongly competitive against some of the best-performing MOFs/zeolites ever reported. This platform lays the groundwork for the design of reticular frameworks for desired applications.


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