Preface: humic substances in the environment

Weber, Jerzy; Chen, Yona; Jamroz, Elżbieta; Miano, Teodoro

doi:10.1007/s11368-018-2052-x

Cited by 89 publications

(47 citation statements)

References 24 publications

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“…This ability depends on the structure of humic substances and the amount of functional groups containing oxygen 45,46 . Advanced phases of the composting process are characterized by the formation of stable humic substances with an abundance of aromatic carbon-and oxygen-containing functional groups which can easily interact with microelements 28,[47][48][49][50][51] . Hence the amount of WEMIE in more mature compost is much lower than that in the raw material.…”

Section: Change Of Wemiementioning

confidence: 99%

The contribution of water extractable forms of plant nutrients to evaluate MSW compost maturity: a case study

Jamroz

Bekier

Medyńska‐Juraszek

et al. 2020

Sci Rep

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were determined using FAAS; the N-NH 4 and N-NO 3 content was analysed using a SAN ++ SFA continuous flow colorimeter (Skalar Analytical B.V., Holland). The solubility index (I), presented as the percentage share of water-extractable forms of macro-and micronutrients in the total content, was calculated according to Eq. (1): p-macro-or microelement, pw-water-extractable form of element, pt-total content of the element. Statistical analysis. Results were statistically verified using Statistica 12.5. Means were compared by the Tukey test, at a confidence level of P < 0.05. Results and discussion pH and ec during composting. Changes in H + concentration were observed during composting of MSW, reflected by analysis of water solution pH (Table 1). The lowest pH values (6.9) were found for water extracts from raw material. During the composting process, the pH increased, with the highest values being observed at between 54 and 126 days. In the following phases of the composting process, a slight decrease in pH was observed (8.0-8.1), but the result was significantly higher than those observed in the first days of the composting process. The decomposition of organic matter, particularly its components like proteins, amino acids and peptides, causes the release of ammonium which contributes to an increase in pH 36. Changes in the EC of water extracts during the composting process were observed as well (Table 1). The values of this parameter depended on the length of the composting process, significantly decreasing with an increased in composting time. After about 54-70 days of composting, the EC value was about 2 mS/cm, and in the final phase it increased slightly to 2.15 mS/cm. From the 54th to 68th day of composting, we observed some stabilization of EC, and lower values with respect to that of the initial material, indicating a reduction in the amount of soluble salts in the matured compost. The results obtained, according to many authors 36,37 , suggest that the concentrations of soluble salts in the compost analysed here were in the range considered non-phytotoxic.

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Section: Change Of Wemiementioning

confidence: 99%

The contribution of water extractable forms of plant nutrients to evaluate MSW compost maturity: a case study

Jamroz

Bekier

Medyńska‐Juraszek

et al. 2020

Sci Rep

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“…Among all the surface water contamination, the most attention is paid to organic substances [1,2]. The main group of organic contamination in surface water are humic substances, whose structure is very diverse and has not yet been unambiguously determined [3,4]. They make up about 90% of all organic substances in surface waters and in general are made up of largemolecule substances, such as humic acid, fulvic acids and humines [3,5].…”

Section: Introductionmentioning

confidence: 99%

Effectiveness of humic substance removal during the coagulation process

2019

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This study concerns the utility of the coagulation process in removing humic substances and its dependence on the properties of these substances and their concentrations. The coagulation process was performed on model solutions of natural humic acids. Polyaluminum chloride (PAX XL3) and aluminum sulfate were used for this study, which allowed for a comparison of the effectiveness of pre-hydrolyzed and hydrolyzing coagulants. The coagulant dosages were determined as gram aluminum per gram carbon, thanks to which it was possible to compare the process effectiveness for different initial organic carbon concentrations, whose values were in the range of 5.51-21.23 gC/m 3. The obtained values of reductions in organic carbon concentrations point to a significant process effectiveness (37.2-59.4% and 20.0-41.5% for pre-hydrolyzed and hydrolyzing coagulants, respectively), which increased with increasing molecular mass of the humic substances present in water. These results are analogous to those found for coagulation of surface waters and point to a greater effectiveness of pre-hydrolyzed coagulant in removing humic substances (at the same coagulant dosage). The effectiveness in removing organic substances increased with coagulant dosage and the initial total organic carbon concentration. The coagulation process most effectively removed aromatic substances absorbing UV light. The content of substances absorbing UV light in raw and post-coagulation water was proportional to the dissolved organic carbon content.

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“…Over the last 3 years, the different suggestions of Lehmann and Kleber (2015) have caused quite a stir among soil scientists (e.g., Piccolo, 2016;Gerke, 2018;Hayes and Swift, 2018;Weber et al, 2018;Olt et al, in press). Defenses of entrenched habits against what is portrayed almost as a heresy have been extremely passionate, and the negative reactions to the proposals made have been very adamant.…”

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confidence: 99%

“…Defenses of entrenched habits against what is portrayed almost as a heresy have been extremely passionate, and the negative reactions to the proposals made have been very adamant. This is illustrated vividly by two special issues published recently by the Journal of Soils and Sediments, one celebrating Frank Stevenson's work on soil organic matter (Knicker et al, 2018) and the other devoted to humic substances (Weber et al, 2018). Both special issues contain many articles still dealing explicitly with alkali extracts and arguing the inherent merits of this approach.…”

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confidence: 99%

The (Bio)Chemistry of Soil Humus and Humic Substances: Why Is the “New View” Still Considered Novel After More Than 80 Years?

Baveye

Wander

2019

Front. Environ. Sci.

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Three years ago, a novel "soil continuum model" was proposed, in which soil organic matter was suggested to be of heterogeneous composition and to consist of a continuum of organic fragments of all sizes. A search of the literature reveals that this model is identical to several similar conceptualizations proposed about 15 years ago, and that it corresponds closely with the description of humic substances given in Waksman's (1936) remarkably thorough book on the topic, which also emphasized the intimate connections existing between humic substances and soil microorganisms. Several historical reasons, reviewed in this Perspective article, may explain why Waksman's viewpoint might still be considered novel more than 80 years later. Here we argue that the key reason for the agonizingly slow rate of progress in the field is linked to the extreme compartmentalization of research and education in soil science, which has been organized along distinct subdisciplines, with the result that interdisciplinary efforts that are desperately needed to understand the dynamics of soil humic substances are very hard to launch. To meet growing demands on soils we have to understand the mechanisms that underpin their many functions. To gain this understanding and finally make badly needed progress, we must reorganize funding and educational efforts to support exploration of "Waksman's frontier," which includes the microscale where the microbial, physical and biochemical processes governing organic matter turnover occur.

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Preface: humic substances in the environment

Cited by 89 publications

References 24 publications

The contribution of water extractable forms of plant nutrients to evaluate MSW compost maturity: a case study

The contribution of water extractable forms of plant nutrients to evaluate MSW compost maturity: a case study

Effectiveness of humic substance removal during the coagulation process

The (Bio)Chemistry of Soil Humus and Humic Substances: Why Is the “New View” Still Considered Novel After More Than 80 Years?

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