Photodegradation of Ciprofloxacin, Clarithromycin and Trimethoprim: Influence of pH and Humic Acids

In view of the rising relevance of emerging pollutants in the environment, this work studies the photodegradation of three antibiotics, evaluating the effects of the pH of the medium and the concentration of dissolved organic matter. Simulated light (with a spectrum similar to that of natural sunlight) was applied to the antibiotics Ciprofloxacin (Cip), Clarithromycin (Cla) and Trimethoprim (Tri), at three different pH, and in the presence of different concentrations of humic acids. The sensitivity to light followed the sequence: Cip > Cla > Tri, which was inverse for the half-life (Tri > Cla > Cip). As the pH increased, the half-life generally decreased, except for Cla. Regarding the kinetic constant k, in the case of Cip and Tri it increased with the rise of pH, while decreased for Cla. The results corresponding to total organic carbon (TOC) indicate that the complete mineralization of the antibiotics was not achieved. The effect of humic acids was not marked, slightly increasing the degradation of Cip, and slightly decreasing it for Tri, while no effect was detected for Cla. These results may be relevant in terms of understanding the evolution of these antibiotics, especially when they reach different environmental compartments and receive sunlight radiation.

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Properties of Humic Acids in Meadow Soils Irrigated With the Slope-And Flooding System

10.21203/rs.3.rs-535526/v1 ◽

2021 ◽

Author(s):

Magdalena Banach-Szott ◽

Andrzej Dziamski

Keyword(s):

Particle Size ◽

Organic Matter ◽

Organic Carbon ◽

Humic Acids ◽

Soil Samples ◽

Hydrophobic Properties ◽

Irrigation Ditch ◽

Ft Ir ◽

Degree Of Maturity

Abstract The aim of the research has been to determine the effect of many-year irrigation of unique grasslands on the properties of humic acids defining the quality of organic matter. The research was performed based on the soil (Albic Brunic Arenosol, the A, AE and Bsv horizons) sampled from Europe’s unique complex of permanent grasslands irrigated continuously for 150 years, applying the slope-and-flooding system; the Czerskie Meadows. The soil samples were assayed for the content of total organic carbon (TOC) and the particle size distribution. HAs were extracted with the Schnitzer method and analysed for the elemental composition, spectrometric parameters in the UV-VIS range, hydrophilic and hydrophobic properties and the infrared spectra were produced. The research results have shown that the HAs properties depended on the depth and the distance from the irrigation ditch. The HAs of the A horizon of the soils were identified with a lower “degree of maturity”, as reflected by the values of atomic ratios (H/C, O/C, O/H), absorbance coefficients, and the FT-IR spectra, as compared with the HAs of the Bsv horizon. The HAs molecules of the soils sampled furthest from the irrigation ditch were identified with a higher degree of humification, as compared with the HAs of the soils sampled within the closest distance. The results have demonstrated that many-year grassland irrigation affected the structure and the properties of humic acids.

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Solubilité de l'or dans les eaux interstitielles de la latérite coiffant le gîte aurifère de Misséni, au Mali

Canadian Journal of Earth Sciences ◽

10.1139/e93-134 ◽

1993 ◽

Vol 30 (8) ◽

pp. 1553-1565 ◽

Cited By ~ 3

Author(s):

Frédéric Séa ◽

Marc G. Tanguay ◽

Pierre Trudel ◽

Mario Bergeron

Keyword(s):

Organic Matter ◽

Humic Acid ◽

Organic Carbon ◽

Humic Acids ◽

Chloride Ion ◽

High Solubility ◽

Gold Solubility ◽

Mn Oxides ◽

Very High ◽

Interstitial Waters

Twenty samples of interstitial waters and pressed saprolite were collected within undisturbed saprolite blocks to determine the actual gold transporting mode in the auriferous laterites of Misséni, Mali. The results of the analyses indicate a very high solubility of gold in the interstitial waters of the Misséni laterites (from <2 to 16.7 ppb Au; Eh, 0.356–0.419 V; pH, 6.7–7.7). The calculated theoretical concentrations of auric chloride ion, [Formula: see text], (0.3 × 10−14 – 32.7 × 10−4 ppm) and thiosulphate ion, [Formula: see text], (2.5 × 10−212 – 6.7 × 10−180 ppm), which are generally inferred to be the ions transporting the gold in a supergene environment, are insignificant in the interstitial waters of the Misséni saprolite. Given the absence of significant concentrations of chloride or thiosulphate ions as measured in the interstitial waters of Misséni (Cl−, 1.5 × 10−4 – 1.2 × 10−2 mol L−1; [Formula: see text], 1.1 × 10−111 – 4.2 × 10−95 mol L−1), the gold monohydroxide, AuOH(H2O)0, could be responsible for the gold mobilization in the studied saprolite. However, its transport could be limited by the conspicuous (Fe, Mn) oxides in the Misséni saprolite, which can act as adsorbents. The calculated concentrtion of humic acid (0.004–0.03%), which can solubilize the gold contained in the analyzed interstitial waters, is 2 to 4 times lower than that of the measured organic matter in the samples of pressed saprolite (from <0.016 to 0.07% in organic carbon). These latter results could indicate that a part of the gold solubility in the Misséni superficial saprolite is linked to the humic acids. [Journal Translation]

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Soil organic matter in soils of the Russian Arctic: insights from 13C-NMR spectroscopy

10.5194/egusphere-egu2020-1058 ◽

2020 ◽

Author(s):

Ivan Alekseev ◽

Evgeny Abakumov

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Organic Carbon ◽

Humic Acids ◽

13C Nmr ◽

Cold Climate ◽

Molecular Organization ◽

Cold Temperatures ◽

Organic Matter Stabilization ◽

Global Carbon

<p>Polar soils play a key role in global carbon circulation and stabilization as they contain maximum stocks of soil organic matter (SOM) within the whole pedosphere. Cold climate and active layer dynamics result in the stabilization of essential amounts of organic matter in soils, biosediments, and grounds of the polar biome. Chemical composition of soil organic carbon (SOC) determines its decomposability and may affect soil organic matter stabilization (SOM) rate (Beyer, 1995). This is quite important for understanding variability in SOC pools and stabilization rate in context of changes in plant cover or climate (Rossi et al. 2016). <sup>13</sup>C nuclear magnetic resonance spectroscopy, which provides detailed information on diversity of structural composition of humic acids and SOM, may also be used to study the SOM dynamics under decomposition and humification proceses (Kogel-Knabner, 1997; Zech et al., 1997). This study aims to characterize molecular organization of the humic acids, isolated from various permafrost-affected soils of Yamal region and to assess the potential vulnerability of soils organic matter in context of possible mineralization processes. Organic carbon stocks for studied area were 7.85 &#177; 2.24 kg m-2 (for 0-10 cm layer), 14.97 &#177; 5.53 kg m-2 (for 0-30 cm), 23.99 &#177; 8.00 kg m-2 (for 0-100 cm). Results of solid-state 13C-NMR spectrometry showed low amounts of aromatic components in studied soils. All studied humic powders are characterized by predominance of aliphatic structures, and also carbohydrates, polysaccharides, ethers and amino acids. High content of aliphatic fragments in studied humic acids shows their similarity fulvic acids. Low level of aromaticity reflects the accumulation in soil of lowly decomposed organic matter due to cold temperatures. Our results provide further evidence of high vulnerability and sensitivity of permafrost-affected soils organic matter to Arctic warming. Consequently, these soils may play a crucial role in global carbon balance under effects of climate warming.</p>

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EFFECT OF LONG-TERM PIG SLURRY AND SOLID CATTLE MANURE APPLICATION ON SOIL CHEMICAL AND BIOLOGICAL PROPERTIES

Canadian Journal of Soil Science ◽

10.4141/cjss89-005 ◽

1989 ◽

Vol 69 (1) ◽

pp. 39-47 ◽

Cited By ~ 57

Author(s):

A. NDAYEGAMIYE ◽

D. CÔTÉ

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Microbial Activity ◽

Humic Acids ◽

Organic Matter Content ◽

Biological Properties ◽

Matter Content ◽

Cattle Manure ◽

Pig Slurry

Chemical and biological properties were evaluated in 1987 on an acidic silty loam soil following a long-term field study established in 1978 and cultivated with silage corn. Treatments included a control, solid cattle manure (20, 40 and 60 Mg ha−1 FYM) and pig slurry (60, 120 m3 ha−1 SLU) applied every 2 yr and annually, respectively. No fertilizer was applied. The results of this study have shown that neither treatment significantly affected soil pH values, total-N contents and C:N ratios compared to the control. The cation exchange capacity (CEC) of the soil was significantly higher with FYM treatment than with control or SLU application. The highest rates of FYM and SLU have also increased (P < 0.05) soil organic carbon, microbial activity and potentially mineralizable nitrogen. The soil microflora populations (bacteria, fungi, actinomycetes, ammonifiers and nitrifiers) were greatly improved by both treatments. There were no significant differences in organic matter content or the relative amount of humic and fulvic acids between FYM and SLU plots. In spite of these results, FYM application (40 and 60 Mg ha−1) did affect more significantly the distribution of organic carbon in HA and the E4/E6 quotients than SLU additions. Humic acids extracted from SLU amended soils had a lower C content and lower E4/E6 ratios than humic acids from FYM soils. Long-term SLU application did not contribute to decreased organic matter content, CEC and humic acids yield, probably because of optimal organic residues returned to the soil by the corn crops. The FYM application generally improved soil chemical and biological properties. For a sustainable soil productivity, long-term SLU application should then be avoided in rotation in which small amounts of plant residues are returned, especially on soils with low organic matter contents. Key words: Organic matter, microbial activity, nitrogen mineralization potential, CEC, solid cattle manure, pig slurry

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Properties of Humic Acids in Meadow Soils Irrigated with the Slope-and-Flooding System

Agronomy ◽

10.3390/agronomy11122553 ◽

2021 ◽

Vol 11 (12) ◽

pp. 2553

Author(s):

Magdalena Banach-Szott ◽

Andrzej Dziamski ◽

Maciej Markiewicz

Keyword(s):

Organic Matter ◽

Carbon Sequestration ◽

Soil Organic Matter ◽

Organic Carbon ◽

Humic Acids ◽

Infrared Spectra ◽

Soil Protection ◽

Mean Values ◽

Irrigation Ditch ◽

The Mean

The still-advancing soil degradation and the related losses of soil organic carbon stocks due to the limited inflow of organic residues in agro-ecosystems encourage more and more soil protection. Establishing meadow ecosystems is one of the key methods of agricultural land use preventing losses of organic carbon in soils. Based on the research on the properties of humic acids, it is possible to determine the advancement of the processes of transformation and decomposition of soil organic matter. The obtained results may allow for the development of a soil protection strategy and more effective sequestration of organic carbon. Therefore, the aim of the research was to determine the properties of humic acids defining the quality of organic matter of meadow soils irrigated for 150 years with the slope-and-flooding system. The research was performed based on the soils (Albic Brunic Arenosol) sampled from Europe’s unique complex of permanent irrigated grasslands (the same irrigation management for 150 years), applying the slope-and-flooding system: the Czerskie Meadows. The soil samples were assayed for the content of total organic carbon (TOC) and the particle size distribution. HAs were extracted with the Schnitzer method and analysed for the elemental composition, spectrometric parameters in the UV-VIS (ultraviolet-visible) range, hydrophilic and hydrophobic properties and the infrared spectra. The research results showed that the HAs properties depend on the depth and the distance from the irrigation ditch. The HAs of soils sampled from the depth of 0–10 cm were identified with a lower “degree of maturity” as compared with the HAs of soils sampled from the depth of 20–30 cm, reflected by the values of atomic ratios (H/C, O/C, O/H), absorbance coefficients, and the FT-IR (Fourier transform infrared) spectra. The mean values of the H/C ratio in the HAs molecules of soils sampled from the depth of 20–30 cm were lower by 8.2% than those from the depth of 0–10 cm. The mean values of the absorbance coefficient A4/6 in the HAs molecules of soils sampled from the depth of 20–30 cm were lower by 9.6% than in the HAs molecules of soils sampled from the depth of 0–10 cm. The HAs molecules of the soils sampled 25 m from the irrigation ditch were identified with a higher degree of humification, as compared with the HAs of the soils sampled 5 m from the irrigation ditch. The results identified that humic acids produced in the many-year irrigated sandy soils were identified with a high degree of humification, which proves the relative stability of the soil’s organic matter. It confirms the importance of meadow soils for the carbon sequestration process. It should also be emphasized that the research area is interesting, although hardly described in terms of organic matter properties. Further and more detailed applicable research is planned, e.g., monitoring of total organic carbon content and comparing the properties of irrigated and non-irrigated meadow soils. Continuity of research is necessary to assess the direction of the soil organic matter transformation in such a unique ecosystem. The obtained results may allow for the development of, inter alia, models of agricultural practices that increase carbon sequestration in soils. In the long term, this will allow for greater environmental benefits and, thus, also increased financial benefits.

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Capillary electrophoresis characterisation of humic acids: application to diverse forest soil samples

Environmental Chemistry ◽

10.1071/en11054 ◽

2011 ◽

Vol 8 (6) ◽

pp. 589 ◽

Cited By ~ 7

Author(s):

Michael Tatzber ◽

Franz Mutsch ◽

Axel Mentler ◽

Ernst Leitgeb ◽

Michael Englisch ◽

...

Keyword(s):

Organic Matter ◽

Capillary Electrophoresis ◽

Soil Organic Matter ◽

Organic Carbon ◽

Humic Acids ◽

Soil Characteristics ◽

Soil Samples ◽

The Other ◽

Total Carbon ◽

Soil Layers

Environmental contextAnalysis of soil organic matter is important for understanding turnover and stabilisation processes of organic carbon in soils. Capillary electrophoresis is used here to investigate humic acids from soils of diverse forest sites, and show that the patterns of signals are indicative of soil characteristics. The method provides useful information of soil types and complements the existing set of methods for humic acid characterisation. AbstractAnalyses of humic substances provide very useful information about turnover characteristics and stabilisation processes of soil organic matter in environmental soil samples. The present study investigates 113 samples of forest soils from three different layers (undecomposed litter (L), if present, mixed samples of F (intermediate decomposed) and H (highly decomposed) organic matter (FH) and upper mineral soil layers (Ah horizon) from 0 to 5 cm) by extracting humic acids (HAs) and recording electropherograms. Five signals of these electropherograms were evaluated and correlated with basic parameters from soil (organic carbon, Corg, and total nitrogen, Nt, and extraction yields of HAs) and HAs (total carbon, Ct, and Nt), and with signals from photometry, mid-infrared and fluorescence spectroscopy. The developed method was able to separate HAs from different soil layers by calculating a discriminant function based on the five evaluated electrophoretic signals. The dataset of this work opened the opportunity to correlate the observed electrophoretic signals with the other determined soil parameters and spectroscopic signals. This can be seen as a very important step in the direction to assignments of the obtained electrophoretic signals. Soil characteristics were reflected quite well by this method and, combined with the other approaches, it is suitable for applications in further studies.

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Assessments of Organic Carbon Stabilization Using the Spectroscopic Characteristics of Humic Acids Separated from Soils of the Lena River Delta

Separations ◽

10.3390/separations8060087 ◽

2021 ◽

Vol 8 (6) ◽

pp. 87

Author(s):

Vyacheslav Polyakov ◽

Evgeny Abakumov

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Organic Carbon ◽

Humic Acids ◽

Terrestrial Ecosystems ◽

River Delta ◽

The Arctic ◽

Lena River ◽

Organic Matter Stabilization ◽

Lena River Delta

In the Arctic zone, where up to 1024 × 1013 kg of organic matter is stored in permafrost-affected soils, soil organic matter consists of about 50% humic substances. Based on the analysis of the molecular composition of humic acids, we assessed the processes of accumulation of the key structural fragments, their transformations and the stabilization rates of carbon pools in soils in general. The landscape of the Lena River delta is the largest storage of stabilized organic matter in the Arctic. There is active accumulation and deposition of a significant amount of soil organic carbon from terrestrial ecosystems in a permafrost state. Under ongoing climate change, carbon emission fluxes into the atmosphere are estimated to be higher than the sequestration and storing of carbon compounds. Thus, investigation of soil organic matter stabilization mechanisms and rates is quite an urgent topic regarding polar soils. For study of molecular elemental composition, humic acids were separated from the soils of the Lena River delta. Key structural fragments of humic matter were identified and quantified by CP/MAS 13C NMR spectroscopy: carboxyl (–COOR); carbonyl (–C=O); CH3–; CH2–; CH-aliphatic; –C-OR alcohols, esters and carbohydrates; and the phenolic (Ar-OH), quinone (Ar = O) and aromatic (Ar–) groups as benchmark Cryosols of the Lena delta river terrestrial ecosystem. Under the conditions of thermodynamic evolutionary selection, during the change between the dry and wet seasons, up to 41% of aromatic and carboxyl fragments accumulated in humic acids. Data obtained showed that three main groups of carbon played the most important role in soil organic matter stabilization, namely C, H-alkyls ((CH2)n/CH/C and CH3), aromatic compounds (C-C/C-H, C-O) and an OCH group (OCH/OCq). The variations of these carbon species’ content in separated humics, with special reference to soil–permafrost organic profiles’ recalcitrance in the current environment, is discussed.

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Influence of pH, Aluminum, and Organic Matter on Stream Invertebrates

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f86-159 ◽

1986 ◽

Vol 43 (6) ◽

pp. 1285-1289 ◽

Cited By ~ 44

Author(s):

Thomas M. Burton ◽

Jon W. Allan

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Dissolved Organic Carbon ◽

Stream Water ◽

Organic Ligand ◽

Low Ph ◽

Interactive Effects ◽

Stream Invertebrates ◽

Natural Stream ◽

Influence Of Ph

The interactive effects of low pH, aluminum, and organic matter on five species of invertebrates collected from low-alkalinity (160–300 μeq/L) Michigan streams were measured using five 28-d experiments during 1982 and 1983. Such interactive effects had not been tested previously for these species. Each experiment consisted of a control channel (pH 7.0), a pH modified (4.0 or 5.0), and pH plus Al (250 or 500 μg Al/L) modified channel. Three experiments were conducted using natural stream water (dissolved organic carbon of 42–47 mg C/L), while two were conducted using simulated stream water with no dissolved organic carbon added. The invertebrates included Asellus intermedius Forbes, Pycnopsyche guttifer (Walker), Lepidostoma liba (Ross), Nemoura sp., and Physella heterostropha (Say). Survival of all species was significantly decreased at pH 4 compared with controls but not at pH 5 except for Asellus (15–20% mortality). Adding 500 μg Al/L caused significant additional mortality under some conditions for all species except Physella. Removal of organic matter from the water caused complete mortality at pH 4 for Nemoura and Asellus when 500 μg Al/L was added and decreased survival for Pycnopsyche to less than 20%. Addition of citrate as an organic ligand reduced susceptibility to Al in the low-organic streamwater treatment.

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CHARACTERISTICS OF ORGANIC MATTER IN DEGRADING CHERNOZEMIC SURFACE SOILS

Canadian Journal of Soil Science ◽

10.4141/cjss63-034 ◽

1963 ◽

Vol 43 (2) ◽

pp. 275-286 ◽

Cited By ~ 5

Author(s):

C. D. Sawyer ◽

S. Pawluk

Keyword(s):

Organic Matter ◽

Humic Acid ◽

Organic Carbon ◽

Humic Acids ◽

Acid Content ◽

Organic Carbon Content ◽

Total Acidity ◽

Organic Fraction ◽

Organic Debris ◽

Organic Fractions

Humic acids, polysaccharides, and polyuronides were extracted from samples representative of the organic and mineral A horizons of two Dark Grey Wooded soils. These organic fractions were characterized in order to determine the alterations, if any, which may be evident in some of the organic constituents present at varying depths in the organic and mineral A horizons as a result of progressive podzolic degradation.Humic acid content in the organic fraction was found to decrease with depth in the mineral A horizon. Methoxyl content of the purified humic acids averaged 0.26 me./g. and decreased with depth while the total acidity (phenolic and carboxyl acidity) averaged 7.6 me./g. and increased with depth. Nitrogen content of the purified humic acids averaged 2.6 per cent and was relatively constant throughout the organic and mineral A horizons. The humic acid content of the undecomposed and semi-decomposed organic debris was found to be only slightly lower than that of the Ah horizon. This was probably at least partially due to hydrolyses of organic matter during the harsh extraction of humic acids with warm 1.0 N NaOH.Total polysaccharide and polyuronide content of these soils decreased rapidly with depth; however, this decrease paralleled the decrease in total organic carbon content.

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