Mathematical model of aerobic stabilization of old landfills

AbstractA short-term aerobic stabilization of digested waste in the final methane phase was studied. The effect of aeration rate on the reduction of leachate parameters and on the rate of CO2 production and O2 assimilation was investigated. Experimental simulation of aerobic landfill stabilization was carried out using lysimeters. When testing the effect of aeration rate on the reduction of leachate indices (BOD5, COD, N-NH4+), it was reported that the most significant reduction was obtained at the highest rate of aeration and the smallest reduction of leachate indices was attained not at the lowest but at medium aeration rates. Both the rate of CO2 production and the O2 assimilation reached their highest values in the lysimeters aerated at a high rate of aeration. The proposed mathematical model which consists of a system of five differential equations describing CO2 production, O2 assimilation and the changes of organic carbon content in the leachate correspond well with the experimental data.

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Short-Term Decomposition and Nutrient-Supplying Ability of Sewage Sludge Digestate, Digestate Compost, and Vermicompost on Acidic Sandy and Calcareous Loamy Soils

Agronomy ◽

10.3390/agronomy11112249 ◽

2021 ◽

Vol 11 (11) ◽

pp. 2249

Author(s):

Nikolett Uzinger ◽

Orsolya Szécsy ◽

Nóra Szűcs-Vásárhelyi ◽

István Padra ◽

Dániel Benjámin Sándor ◽

...

Keyword(s):

Organic Matter ◽

Sewage Sludge ◽

Organic Carbon ◽

Carbon Content ◽

Plant Biomass ◽

Test Plant ◽

Organic Carbon Content ◽

Short Term ◽

Mineral N ◽

Average Residual

Organic waste and the compost and vermicompost derived from it may have different agronomic values, but little work is available on this aspect of sewage sludge. A 75-day pot experiment with perennial ryegrass (Lolium perenne) as the test plant aimed to investigate the fertiliser value and organic matter replenishment capacity of digested sewage sludge (DS) and the compost (COM) and vermicompost (VC) made from it, applied in 1% and 3% doses on acidic sand and calcareous loam. The NPK content and availability, changes in organic carbon content and plant biomass, and the efficiency of the amendments as nitrogen fertilisers were investigated. The final average residual carbon content for DS, COM, and VC was 35 ± 34, 85 ± 46, and 55 ± 46%, respectively. The organic carbon mineralisation rate depended on the soil type. The additives induced significant N mineralisation in both soils: the average increment in mineral N content was 1.7 times the total added N on acidic sand and 4.2 times it on calcareous loam for the 1% dose. The agronomic efficiency of COM and VC as fertilisers was lower than that of DS. In the short term, DS proved to be the best fertiliser, while COM was the best for organic matter replenishment.

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Response of labile organic carbon content in surface soil aggregates to short-term nitrogen addition in artificial Pinus tabulaeformis forests

Acta Ecologica Sinica ◽

10.5846/stxb201608021590 ◽

2017 ◽

Vol 37 (20) ◽

Author(s):

姚旭 YAO Xu ◽

景航 JING Hang ◽

梁楚涛 LIANG Chutao ◽

谷利茶 GU Licha ◽

王国梁 WANG Guoliang ◽

...

Keyword(s):

Organic Carbon ◽

Carbon Content ◽

Surface Soil ◽

Soil Aggregates ◽

Nitrogen Addition ◽

Pinus Tabulaeformis ◽

Organic Carbon Content ◽

Short Term ◽

Labile Organic Carbon

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Interactions Between Nonionic Surfactant Monomers, Hydrophobic Organic Compounds and Soil

Water Science & Technology ◽

10.2166/wst.1992.0395 ◽

1992 ◽

Vol 26 (1-2) ◽

pp. 147-158 ◽

Cited By ~ 28

Author(s):

D. A. Edwards ◽

Z. Liu ◽

R. G. Luthy

Keyword(s):

Experimental Data ◽

Organic Carbon ◽

Nonionic Surfactant ◽

Organic Compounds ◽

Aqueous Phase ◽

Nonionic Surfactants ◽

Bulk Solution ◽

Organic Carbon Content ◽

Hydrophobic Organic Compounds ◽

Surfactant Sorption

Nonionic surfactant at aqueous-phase concentrations less than the CMC can affect the distribution of hydrophobic organic compounds (HOCs) in soil/aqueous systems. Sub-CMC levels of nonionic surfactant can enhance the apparent aqueous-phase HOC solubility, increase the soil organic carbon content due to surfactant sorption, and modify the value of the HOC soil/aqueous distribution coefficient. Experimental data quantifying these effects are presented for several HOCs and nonionic surfactants. A method is proposed for predicting the distribution of HOC between soil and bulk solution with sub-CMC aqueous-phase concentrations of nonionic surfactant.

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Degradation and sorption of the herbicides 2,4-D and quizalofop-P-ethyl and their metabolites in soils from railway tracks

Environmental Sciences Europe ◽

10.1186/s12302-020-00422-6 ◽

2020 ◽

Vol 32 (1) ◽

Author(s):

Ignaz J. Buerge ◽

Pavlina Pavlova ◽

Irene Hanke ◽

Astrid Bächli ◽

Thomas Poiger

Keyword(s):

Experimental Data ◽

Organic Carbon ◽

Agricultural Soils ◽

Organic Carbon Content ◽

Primary Metabolite ◽

Railway Tracks ◽

Groundwater Assessment ◽

Active Substances ◽

Construction Works ◽

Herbicide Glyphosate

Abstract Background Broad spectrum of activity and low potential for leaching to groundwater are important arguments for the application of the herbicide glyphosate on railway tracks. Nevertheless, certain weeds are insufficiently controlled or develop resistance, and there is also an ongoing controversial discussion about possible carcinogenicity of glyphosate. Alternatives are thus strongly desired. 2,4-D and quizalofop-P-ethyl (QE) are two selective herbicides with a complementary spectrum of activity. When used in agriculture, the compounds and their metabolites exhibit low groundwater contamination potential. Uses on railway tracks may, however, be more critical, since degradation likely is slower and mobility higher than in agricultural soils. In this study, we investigated degradation and sorption of the two active substances as well as five metabolites in three soils collected from railway tracks and in a crushed sand, used for construction works. Results In these railway materials, the compounds were indeed degraded slower than in agricultural soils (mean half-lives differed by a factor of 1.4–26, depending on the substance) and mobility was higher (mean sorption coefficients differed by a factor of 3–19). Half-lives and sorption coefficients were also estimated by extrapolation of data from agricultural soils, considering the organic carbon content of railway soils and agricultural soils. Estimated values were more conservative than measured values. Conclusions Based on our experimental data, possible leaching to groundwater is predicted to be highest for 2,4-D and quizalofop-acid, the primary metabolite of QE, moderate for 2,4-dichlorophenol, the primary metabolite of 2,4-D, but low for QE. Secondary and tertiary metabolites were formed in only low quantities. For herbicides, for which no measured parameters are available for railway soils, estimated values may also be a viable alternative for a first tier groundwater assessment.

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Degradation and sorption of the herbicides 2,4-D and quizalofop-P-ethyl and their metabolites in soils from railway tracks

10.21203/rs.3.rs-48499/v2 ◽

2020 ◽

Author(s):

Ignaz J Buerge ◽

Pavlina Pavlova ◽

Irene Hanke ◽

Astrid Bächli ◽

Thomas Poiger

Keyword(s):

Experimental Data ◽

Organic Carbon ◽

Agricultural Soils ◽

Organic Carbon Content ◽

Primary Metabolite ◽

Railway Tracks ◽

Groundwater Assessment ◽

Active Substances ◽

Construction Works ◽

Herbicide Glyphosate

Abstract Background Broad spectrum of activity and low potential for leaching to groundwater are important arguments for the application of the herbicide glyphosate on railway tracks. Nevertheless, certain weeds are insufficiently controlled or develop resistance, and there is also an ongoing controversial discussion about possible carcinogenicity of glyphosate. Alternatives are thus strongly desired. 2,4-D and quizalofop-P-ethyl (QE) are two selective herbicides with a complementary spectrum of activity. When used in agriculture, the compounds and their metabolites exhibit low groundwater contamination potential. Uses on railway tracks may, however, be more critical since degradation likely is slower and mobility higher than in agricultural soils. In this study, we investigated degradation and sorption of the two active substances as well as five metabolites in three soils collected from railway tracks and in a crushed sand, used for construction works.Results In these railway materials, the compounds were indeed degraded slower than in agricultural soils (mean half-lives differed by a factor of 1.4-26, depending on the substance) and mobility was higher (mean sorption coefficients differed by a factor of 3-19). Half-lives and sorption coefficients were also estimated by extrapolation of data from agricultural soils, considering the organic carbon content of railway soils and agricultural soils. Estimated values were more conservative than measured values. Conclusions Based on our experimental data, possible leaching to groundwater is predicted to be highest for 2,4-D and quizalofop-acid, the primary metabolite of QE, moderate for 2,4-dichlorophenol, the primary metabolite of 2,4-D, but low for QE. Secondary and tertiary metabolites were formed in only low quantities. For herbicides, for which no measured parameters are available for railway soils, estimated values may also be a viable alternative for a first tier groundwater assessment.

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Influence of Tillage and Crop Rotations in Organic and Conventional Farming Systems on Soil Organic Matter, Bulk Density and Enzymatic Activities in a Short-Term Field Experiment

Agronomy ◽

10.3390/agronomy11040724 ◽

2021 ◽

Vol 11 (4) ◽

pp. 724

Author(s):

Marco Pittarello ◽

Nicola Dal Ferro ◽

Francesca Chiarini ◽

Francesco Morari ◽

Paolo Carletti

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Organic Farming ◽

Cover Crops ◽

Management Practices ◽

Aggregate Stability ◽

Enzymatic Activities ◽

Crop Rotations ◽

Organic Carbon Content ◽

Short Term

Intensive agricultural practices are leading to loss of soil fertility and overexploitation of natural resources which cause nutrients imbalance and further impair ecosystem services. Organic farming (OF), also coupled with minimum tillage and crop rotations, represents one of the strategies to limit this process and maintain soil functions. In a two-year field trial, organic farming practices, including a set of fertilizations combined with crop rotations and association with nitrogen fixing cover crops, were compared. The aim of this research was to assess in the short-term the effects on soil organic carbon, aggregate stability, and soil enzymes activities of using a combination of promising management practices in the delta region of the Po river. Results did not show improvements in organic carbon content and soil aggregate stability. Conversely, enzymatic activities were always significantly higher in OF treatments than the conventional one. Crop rotation and associated legumes were effective in enhancing β-glucosidase and P fixation through phosphatases activities. The present work suggests that an effective choice of crop species coupled with legumes can enhance biological activity re-starting main mechanisms of microbial development even without a contemporary increase of organic matter.

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Saltwater intrusion into tidal freshwater marshes alters the biogeochemical processing of organic carbon

Biogeosciences ◽

10.5194/bg-10-8171-2013 ◽

2013 ◽

Vol 10 (12) ◽

pp. 8171-8183 ◽

Cited By ~ 86

Author(s):

S. C. Neubauer ◽

R. B. Franklin ◽

D. J. Berrier

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Saltwater Intrusion ◽

Carbon Mineralization ◽

Tidal Freshwater ◽

Co2 Production ◽

Soil Co2 ◽

Short Term ◽

Ch4 Production

Abstract. Environmental perturbations in wetlands affect the integrated plant-microbial-soil system, causing biogeochemical responses that can manifest at local to global scales. The objective of this study was to determine how saltwater intrusion affects carbon mineralization and greenhouse gas production in coastal wetlands. Working with tidal freshwater marsh soils that had experienced ~ 3.5 yr of in situ saltwater additions, we quantified changes in soil properties, measured extracellular enzyme activity associated with organic matter breakdown, and determined potential rates of anaerobic carbon dioxide (CO2) and methane (CH4) production. Soils from the field plots treated with brackish water had lower carbon content and higher C : N ratios than soils from freshwater plots, indicating that saltwater intrusion reduced carbon availability and increased organic matter recalcitrance. This was reflected in reduced activities of enzymes associated with the hydrolysis of cellulose and the oxidation of lignin, leading to reduced rates of soil CO2 and CH4 production. The effects of long-term saltwater additions contrasted with the effects of short-term exposure to brackish water during three-day laboratory incubations, which increased rates of CO2 production but lowered rates of CH4 production. Collectively, our data suggest that the long-term effect of saltwater intrusion on soil CO2 production is indirect, mediated through the effects of elevated salinity on the quantity and quality of autochthonous organic matter inputs to the soil. In contrast, salinity, organic matter content, and enzyme activities directly influence CH4 production. Our analyses demonstrate that saltwater intrusion into tidal freshwater marshes affects the entire process of carbon mineralization, from the availability of organic carbon through its terminal metabolism to CO2 and/or CH4, and illustrate that long-term shifts in biogeochemical functioning are not necessarily consistent with short-term disturbance-type responses.

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Saltwater intrusion into tidal freshwater marshes alters the biogeochemical processing of organic carbon

Biogeosciences Discussions ◽

10.5194/bgd-10-10685-2013 ◽

2013 ◽

Vol 10 (7) ◽

pp. 10685-10720 ◽

Cited By ~ 6

Author(s):

S. C. Neubauer ◽

R. B. Franklin ◽

D. J. Berrier

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Saltwater Intrusion ◽

Carbon Mineralization ◽

Tidal Freshwater ◽

Co2 Production ◽

Soil Co2 ◽

Short Term ◽

Ch4 Production

Abstract. Environmental perturbations in wetlands affect the integrated plant-microbial-soil system, causing biogeochemical responses that can manifest at local to global scales. The objective of this study was to determine how saltwater intrusion affects carbon mineralization and greenhouse gas production in coastal wetlands. Working with tidal freshwater marsh soils that had experienced roughly 3.5 yr of in situ saltwater additions, we quantified changes in soil properties, measured extracellular enzyme activity associated with organic matter breakdown, and determined potential rates of anaerobic carbon dioxide (CO2) and methane (CH4) production. Soils from the field plots treated with brackish water had lower carbon content and higher C : N ratios than soils from freshwater plots, indicating that saltwater intrusion reduced carbon availability and increased organic matter recalcitrance. This was reflected in reduced activities of enzymes associated with the hydrolysis of cellulose and the oxidation of lignin, leading to reduced rates of soil CO2 and CH4 production. The effects of long-term saltwater additions contrasted with the effects of short-term exposure to brackish water during three-day laboratory incubations, which increased rates of CO2 production but lowered rates of CH4 production. Collectively, our data suggest that the long-term effect of saltwater intrusion on soil CO2 production is indirect, mediated through the effects of elevated salinity on the quantity and quality of autochthonous organic matter inputs to the soil. In contrast, salinity, organic matter content, and enzyme activities directly influence CH4 production. Our analyses demonstrate that saltwater intrusion into tidal freshwater marshes affects the entire process of carbon mineralization, from the availability of organic carbon through its terminal metabolism to CO2 and/or CH4, and illustrate that long-term shifts in biogeochemical functioning are not necessarily consistent with short-term disturbance-type responses.

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On the available evidence for the temperature dependence of soil organic carbon

Biogeosciences Discussions ◽

10.5194/bgd-2-749-2005 ◽

2005 ◽

Vol 2 (4) ◽

pp. 749-755 ◽

Cited By ~ 10

Author(s):

W. Knorr ◽

I. C. Prentice ◽

I. J. House ◽

E. A. Holland

Keyword(s):

Experimental Data ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Model Fitting ◽

Selection Criterion ◽

Short Term ◽

Temperature Changes ◽

Original Analysis ◽

Pool Model ◽

The One

Abstract. Two recent papers by Knorr et al. (2005) and Fang et al. (2005) provide variations of model fitting conducted in the former study. Knorr et al. (2005) suggested that more recalcitrant fractions of soil organic carbon (SOC) could be more sensitive to temperature. Fang et al. (2005) argue that this is an implication of the choice of model used. Further, Reichstein et al. (2005) point out that the evidence for a stronger temperature sensitivity of recalcitrant soil carbon mainly rests on an analysis of data provided by Kätterer et al. (1998) and argue for a different selection criterion to exclude short-term incubations. Here, we explain why the model used by Knorr et al. (2005) is the simplest multi-pool model that can fit the available data and is at the same time fully consistent with the concept of "pools", as opposed to some of the model formulations proposed by Fang et al. (2005). It is also pointed out that the criterion proposed by Reichstein et al. (2005) uses posterior information to determine inclusion of experimental data, a practice that should be avoided. We conclude that the original analysis of Knorr et al. (2005) as well as the one added by Fang et al. (2005) indicate that there is a serious possibility that recalcitrant SOC reacts more to temperature changes than labile SOC.

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EXPERIMENTAL STUDIES OF CAR PROPERTIES ON A PHYSICAL MODEL

Avtoshliakhovyk Ukrayiny ◽

10.33868/0365-8392-2019-4-260-10-16 ◽

2019 ◽

pp. 10-16

Author(s):

Oleksii Timkov ◽

Dmytro Yashchenko ◽

Volodymyr Bosenko

Keyword(s):

Mathematical Model ◽

Remote Control ◽

Physical Model ◽

Model Experiment ◽

Experimental Studies ◽

Electrical Energy ◽

Short Term ◽

Motor Current ◽

Memory Card ◽

The Mathematical Model

The article deals with the development of a physical model of a car equipped with measuring, recording and remote control equipment for experimental study of car properties. A detailed description of the design of the physical model and of the electronic modules used is given, links to application libraries and the code of the first part of the program for remote control of the model are given. Atmega microcontroller on the Arduino Uno platform was used to manage the model and register the parameters. When moving the car on the memory card saved such parameters as speed, voltage on the motor, current on the motor, the angle of the steered wheel, acceleration along three coordinate axes are recorded. Use of more powerful microcontrollers will allow to expand the list of the registered parameters of movement of the car. It is possible to measure the forces acting on the elements of the car and other parameters. In the future, it is planned to develop a mathematical model of motion of the car and check its adequacy in conducting experimental studies on maneuverability on the physical model. In addition, it is possible to conduct studies of stability and consumption of electrical energy. The physical model allows to quickly change geometric dimensions and mass parameters. In the study of highway trains, this approach will allow to investigate the various layout schemes of highway trains in the short term. It is possible to make two-axle road trains and saddle towed trains, three-way hitched trains of different layout. The results obtained will allow us to improve not only the mathematical model, but also the experimental physical model, and move on to further study the properties of hybrid road trains with an active trailer link. This approach allows to reduce material and time costs when researching the properties of cars and road trains. Keywords: car, physical model, experiment, road trains, sensor, remote control, maneuverability, stability.

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