scholarly journals Adsorption Characteristics of Oxytetracycline by Different Fractions of the Organic Matter from Humus Soil: Insight from Internal Structure and Composition

2020 ◽  
Vol 17 (3) ◽  
pp. 914
Author(s):  
Mengya Luo ◽  
Shengke Yang ◽  
Siqi Shen ◽  
Yu Li
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Adsorption Capacity ◽  
Internal Structure ◽  
Batch Experiments ◽  
N2 Adsorption ◽  
Sem Images ◽  
Organic Fractions ◽  
Adsorption Desorption ◽  
Humus Soil

For minimizing the transport of antibiotics to groundwater, the migration of antibiotics in soils should be investigated. Soil organic matter can affect the migration of antibiotics. To date, the influence of aromatics and aliphatic content of organic matter on the adsorption of antibiotics has been controversial. To better understand the reaction mechanism of soil organic matter with antibiotics, this study investigated the adsorption of oxytetracycline (OTC) by humus soils (HOS) and their fractions. HOS were sequentially fractionated into four organic fractions, including the removal of dissolved organic matter (HRDOM), removal of minerals (HRM), removal of free fat (HRLF), and nonhydrolyzable organic carbon (HNHC). Moreover, batch experiments revealed that adsorption capacity was ordered by HNHC > HOS > HRDOM > HRLF > HRM. SEM images and N2 adsorption/desorption isotherms indicate that adsorption capacity is independent of the external structure. However, adsorption capacity is related to the internal structure and composition. Combination analysis with elemental composition and infrared spectroscopy showed that the adsorption capacity of HRM, HRLF, and HNHC had a good positive correlation with aromaticity, but a negative correlation with polarity and hydrophilicity. Additionally, the rule of binding affinity between OTC and functional groups with different properties was summarized as aromatic > polarity > hydrophilic.

Effect of L-Arginine on the Carbon Microsphere Forming under Hydrothermal Carbonization

2019 ◽  
Vol 41 (1) ◽  
pp. 72-72
Author(s):  
Jilei Liang Jilei Liang ◽  
Mengmeng Wu Mengmeng Wu ◽  
Hongmei Cai Hongmei Cai ◽  
Hao Wang Hao Wang ◽  
Hua Huang Hua Huang ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Adsorption Capacity ◽  
Surface Property ◽  
Condensation Reaction ◽  
Hydrothermal Carbonization ◽  
Carbon Microspheres ◽  
N2 Adsorption ◽  
Sem Images ◽  
Ft Ir ◽  
Adsorption Desorption

Carbon microspheres (CMs) with a diameter of 5-10 μm have been synthesized by hydrothermal carbonization of starch and L-arginine. The surface property and structure of CMs were examined by FT-IR spectra, N2 adsorption-desorption isotherms and SEM images. These characterizations indicated that the L-arginine does not connect into the CMs but it promotes the starch hydrolysis and polymerization-condensation reaction of intermediate, which accelerates the formation of CMs and improves the yield in shorter time. The surface property of CMs determines adsorption capacity for acetic acid. By contrast, the porosity resulted from the carbonization at 500 and#176;C dominates the adsorption capacity for acetic acid.

scholarly journals Fractionation of Soil Organic Matter into Labile and Stable Fractions

Agronomy ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 73
Author(s):  
Marek Kopecký ◽  
Ladislav Kolář ◽  
Kristýna Perná ◽  
Radka Váchalová ◽  
Petr Mráz ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Classical Method ◽  
Fulvic Acids ◽  
Exchange Capacity ◽  
Previous Method ◽  
New Method ◽  
Laboratory Equipment ◽  
Modified Method ◽  
Organic Fractions

The present study aims to test and evaluate the efficiency of a new modified method of organic matter evaluation. It allows the assessment of the quality and quantity of the primary soil organic matter and the stable organic fractions separately. The new method was tested in six soil samples of different localities in the Czech Republic. This method is based on observing reaction kinetics during the oxidation of soil organic matter and measuring the cation-exchange capacity of stable organic fractions. The results were compared with classical methods, which rely on the isolation of humic substances, determination of the content of humic acids and fulvic acids and their ratio CHA:CFA, quotient E4/6, and fractionation of soil organic matter according to resistance to oxidation. It turned out that the results of the new modified method are more sensitive in comparison with the results obtained by classical procedures. The linear regression demonstrated the dependence between the amounts of soil organic matter determined by the classical method compared with the modified method. Moreover, the new modified method was found to be faster and not demanding on laboratory equipment. The new method has been improved to be easily repeatable, and some shortcomings of the previous method were eliminated. Based on our results and other recent studies, the modified method may be recommended for the practical evaluation of soil organic matter conditions.

scholarly journals Organic Matter Pore Characterization of the Wufeng-Longmaxi Shales from the Fuling Gas Field, Sichuan Basin: Evidence from Organic Matter Isolation and Low-Pressure CO2 and N2 Adsorption

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1207 ◽  
Author(s):  
Zhuo Li ◽  
Zhenxue Jiang ◽  
Hailong Yu ◽  
Zhikai Liang
Keyword(s):  
Organic Matter ◽  
Pore Volume ◽  
Sichuan Basin ◽  
Weight Ratio ◽  
Total Pore Volume ◽  
Low Pressure ◽  
N2 Adsorption ◽  
Sem Images ◽  
Gas Field ◽  
Flow Mechanisms

Organic matter (OM) pores are significant for shale gas accumulation and flow mechanisms. The pores of Wufeng-Longmaxi (W-L) shale in the Sichuan Basin, China have been extensively characterized, however, the proportion of OM pores in this shale have not been adequately discussed. In this study, the contribution of OM pores to the total pore volume of W-L shale was quantitatively studied through the analysis of OM isolation, field emission scanning electron microscopy (FE-SEM) and low-pressure CO2 and N2 adsorption (LPGA). FE-SEM images showed abundant OM pores, interparticle pores and intraparticle pores with various shapes and widths in the W-L shales. The pore size distribution (PSD) of the isolated OM from five shale samples showed a consistent, unimodal pattern. The pore volume of isolated OM was greater than that of the bulk shale samples, suggesting that OM is more porous than the inorganic compositions in shales. The average contribution of OM to the volumes of micropores, mesopores and macropores was 58.42%, 10.34% and 10.72%, respectively. Therefore, the pore volume of the W-L shale was dominantly related to inorganic minerals. This was probably due to the small weight ratio of OM in the shale samples (1.5 wt%–4.2 wt%). The findings of this study reveal the different effects of OM and minerals on pore development, and provide new insights into the quantitative contribution of OM pores to the total pore volume of the W-L shale.

Adsorption-desorption of parathion as affected by soil organic matter

1972 ◽  
Vol 20 (6) ◽  
pp. 1224-1226 ◽  
Author(s):  
Sarina Saltzman ◽  
Lilian Kliger ◽  
Bruno Yaron
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Adsorption Desorption

ADSORPTION AND DESORPTION OF UREA HERBICIDES ON SOILS

1975 ◽  
Vol 55 (2) ◽  
pp. 127-135 ◽  
Author(s):  
R. GROVER
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Matter Content ◽  
Matter Content ◽  
K Value ◽  
Soil Organic Matter Content ◽  
High Organic Matter Content ◽  
High Organic Matter ◽  
Adsorption Desorption ◽  
Relative Adsorption

The adsorption/desorption potential of several phenylurea herbicides was studied on representative prairie soils, using slurry-type adsorption experiments. The herbicides showed the following order of increasing tendency to be adsorbed: fenuron < monuron [Formula: see text] monolinuron < metobromuron < diuron [Formula: see text] linuron [Formula: see text] chlorbromuron. The relative adsorption of each herbicide on various soil types was significantly correlated with the soil organic matter content, but not with the clay content. The relationship between the k value and the soil organic matter content was found to be of the exponential type. The extent of adsorption was also inversely related to the order of their water solubilities. The urea herbicides were readily desorbed by water from the low to medium organic matter content sandy loam and heavy clay soils, but not from a loam with very high organic matter content. It is suggested that the relative adsorption/desorption potential of a herbicide may provide a mechanism by which soil applied herbicides can be biologically inactivated more readily in soils of high organic matter content.

scholarly journals Sorption and mobility of thiabendazole in a Brazilian Oxisol

2020 ◽  
Vol 42 ◽  
pp. e44
Author(s):  
Bianca Veloso Goulart ◽  
Wallace Nikolas dos Santos Nascimento ◽  
Ana Carolina Pinto ◽  
Patrícia Maralyne Lopes Lisboa Fagundes ◽  
Larissa Silva Maciel ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Adsorption Capacity ◽  
Clay Content ◽  
Soil Columns ◽  
Adsorption And Desorption ◽  
Adsorption Capacities ◽  
Study Results ◽  
Minas Gerais State ◽  
Ph Conditions

Thiabendazole is a benzimidazole class drug that is widely used due to its vermifugal and fungicidal properties. The present study investigates the behaviour of TBZ in the A and B horizons of a Red-Yellow Latosol typical of southern Minas Gerais State, Brazil. Adsorption and desorption assays were performed under different pH conditions (3.0, 4.2-5.1, and 8.5) and a leaching study was conducted using soil columns. The results demonstrated that the behaviour of TBZ in the soil was influenced by the pH, soil organic matter and clay content. The Freundlich constants  indicated that the adsorption capacities for horizons A and B were high (50-149 mg1-1/n.L1/n.kg-1) and low (0-24 mg1-1/n.L1/n.kg-1), respectively. The leaching study results indicated that for both horizons, TBZ presented higher sorption in the initial fractions of the column (0-2 cm), and that the B horizon had a lower adsorption capacity, compared to the A horizon.

scholarly journals Shale Heterogeneity in Western Hunan and Hubei: A Case Study from the Lower Silurian Longmaxi Formation in Well Laidi 1 in the Laifeng-Xianfeng Block, Hubei Province

Geofluids ◽  
2022 ◽  
Vol 2022 ◽  
pp. 1-15
Author(s):  
Peng Zhang ◽  
Junwei Yang ◽  
Yuqi Huang ◽  
Jinchuan Zhang ◽  
Xuan Tang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Fractal Dimension ◽  
Low Temperature ◽  
Mineral Composition ◽  
Relative Pressure ◽  
N2 Adsorption ◽  
Longmaxi Formation ◽  
Western Hunan ◽  
Adsorption Desorption ◽  
Organic Matter Abundance

Shale heterogeneity directly determines the alteration ability and gas content of shale reservoirs, and its study is a core research topic in shale gas exploitation and development. In this study, the shale from the Longmaxi Formation from well Ld1 located in western Hunan and Hubei is investigated. The shale’s heterogeneity is analyzed based on shale mineral rocks, microslices, geochemistry, and low-temperature N2 adsorption-desorption. It is found that the shales of the Longmaxi Formation from well Ld1 are mainly composed of siliceous shale, mixed shale, and clayey shale. The three types of shale facies exhibit strong heterogeneity in terms of the occurrence state of organic matter, organic content, mineral composition, microstructure and structure, brittleness, and micropore type. Sedimentation, late diagenesis, and terrigenous input are the main factors influencing the shale’s heterogeneity. With a total organic carbon (TOC) of 0.41%-4.18% and an organic matter maturity ( R o ) of 3.09%-3.42%, the shales of the Longmaxi Formation from well Ld1 are in an overmature stage, and their mineral composition is mainly quartz (5%-66%) and clay minerals (17.8%-73.8%). The main pore types are intergranular pores, intragranular pores, microfractures, and organic pores. The results of the low-temperature N2 adsorption-desorption experiment show that the shale pores are mainly composed of micropores and mesopores with narrow throats and complex structures, and their main morphology is of a thin-necked and wide-body ink-bottle pore. Based on the Frenkel-Halsey-Hill (FHH) model, the pore fractal dimension is studied to obtain the fractal dimension D 1 (2.73-2.76, mean 2.74) under low relative pressure ( P / P 0 ≤ 0.5 ) and D 2 (2.80-2.89, mean 2.85) under high relative pressure ( P / P 0 > 0.5 ). The shales of the Longmaxi Formation in the study area have a strong adsorption and gas storage capacity; however, the pore structure is complex and the connectivity is poor, which, in turn, imposes high requirements on reservoir reformation measures during exploitation. Moreover, the fractal dimension has a positive correlation with organic matter abundance, TOC, clay mineral content, and pyrite content and a negative correlation with quartz content. Since the organic matter contained in the shales of the Longmaxi Formation in the study area is in the overmature stage, the adsorption capacity of the shales is reduced, and the controlling effect of organic matter abundance on the same is not apparent.

Fluometuron Adsorption-Desorption Equilibria in Soil

Weed Science ◽  
1974 ◽  
Vol 22 (2) ◽  
pp. 106-110 ◽  
Author(s):  
K. E. Savage ◽  
R. D. Wauchope
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Sandy Loam ◽  
Equilibrium Constants ◽  
Organic Matter Content ◽  
Clay Content ◽  
Matter Content ◽  
Adsorbed State ◽  
Significant Linear Correlation ◽  
Adsorption Desorption

The adsorption-desorption equilibria of fluometuron [1,1-dimethyl-3-(α,α,α-trifluoro-m-tolyl)urea] were studied; a slurry technique with soil at 0-bar moisture tension was used. The equilibria established with Bosket very fine sandy loam (VFSL) were evaluated by three equations. The equation best describing the adsorption isotherm was x/m = K1Ce+ K2Ce2. Successive equilibrations resulted in a shift in the equilibria toward the adsorbed state, most likeiy due to a physical change in the adsorption capacity of the soil with repeated agitation. Desorption studies with seven additional soils indicated the importance of soil organic matter content in the adsorption-desorption equilibria of fluometuron. The relationship between soil organic matter contents and the adsorption-desorption equilibrium constants was characterized by a highly significant linear correlation (r = 0.93) and the resulting regression equation: K1= 0.46 + 0.45(O.M.%). Clay content of these soils was not significantly correlated with fluometuron equilibrium constants.

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