scholarly journals Biodegradation of Some Organic Materials in Soils and Soil Constructions: Experiments, Modeling and Prevention

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1889 ◽  
Author(s):  
Andrey Smagin ◽  
Nadezhda Sadovnikova ◽  
Vyacheslav Vasenev ◽  
Marina Smagina
Keyword(s):  
Carbon Dioxide Emission ◽  
Polymeric Materials ◽  
Emission Rates ◽  
Soil Environment ◽  
Decomposition Rates ◽  
Microbial Inhibitors ◽  
Incubation Experiments ◽  
Biodegradation Process ◽  
Thermodynamic Conditions

The decomposition of natural and synthetic polymeric materials (peat, humates, biochar, strongly swelling hydrogels and other soil conditioners) in a biologically and chemically active soil environment inevitably leads to a reduced ability to improve the structure, water-retention, absorptive capacity and fertility of artificial soil constructions in urbanized ecosystems and agro landscapes (constructozems). Quantitative assessment of the biodegradation process using field and laboratory incubation experiments, as well as mathematical modeling, showed the possibility of significant (up to 30–50% per year) losses of organic matter of constructozems and a corresponding deterioration of soil quality. Incubation experiments that track the carbon dioxide emission rates of polymeric materials under given thermodynamic conditions allow for the estimation of decomposition rates in addition to an exploration on the dependence of such rates on additions of microbial inhibitors. The use of nomographs provide an opportunity to optimize long-term amendment performance in soil constructions by identifying the most favorable depths to apply amendments to ensure stable functioning during desired in-service timelines in the built environment. The results of the study are useful for geo-engineers and landscaping practitioners.

scholarly journals Biodegradation of Materials in Soils and Soil Constructions: Experiments, Modeling and Prevention

2018 ◽  
Author(s):  
Andrey Smagin ◽  
Nadezhda Sadovnikova ◽  
Vyacheslav Vasenev ◽  
Marina Smagina
Keyword(s):  
Water Retention ◽  
Operating Time ◽  
Carbon Dioxide Emission ◽  
Polymeric Materials ◽  
Soil Environment ◽  
Incubation Experiments ◽  
Biodegradation Process ◽  
Thermodynamic Conditions ◽  
Optimum Depth ◽  
Urban Conditions

Decomposition of natural and synthetic polymeric materials (peat, humates, biochar, strongly swelling hydrogels and other soil conditioners) in a biologically- and chemically- active soil environment inevitably leads to their degradation and ability to improve the structure, water-retention, absorptive capacity and actual fertility of artificial soil constructions in urbanized ecosystems and agro landscapes (constructozems). Quantitative assessment of the biodegradation process using field and laboratory incubation experiments, as well as mathematical modeling, showed the possibility of significant (up to 30-50% per year) losses of organic matter of constructozems and a corresponding deterioration in their quality. Incubation experiments with the analysis of carbon dioxide emission for polymeric materials under given thermodynamic conditions allow to estimate the potential rates of their decomposition (half-life) and their dependence on the dose of inhibitors of microbial activity. Special nomographs provide an opportunity to determine the optimum depth of the arrangement of organic components in soil constructions to ensure their stable functioning during a fixed operating time in urban conditions. The results of the study are useful for geo-engineers and landscaping practitioners.

scholarly journals Study of the Ultraviolet Effect and Thermal Analysis on Polypropylene Nonwoven Geotextile

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1080
Author(s):  
Clever Aparecido Valentin ◽  
Marcelo Kobelnik ◽  
Yara Barbosa Franco ◽  
Fernando Luiz Lavoie ◽  
Jefferson Lins da Silva ◽  
...  
Keyword(s):  
Uv Light ◽  
Polymeric Materials ◽  
Tensile Tests ◽  
Thermomechanical Analysis ◽  
Material Stiffness ◽  
Before And After ◽  
Electron Microscopy Analysis ◽  
Physical Tests ◽  
Nonwoven Geotextile

The use of polymeric materials such as geosynthetics in infrastructure works has been increasing over the last decades, as they bring down costs and provide long-term benefits. However, the aging of polymers raises the question of its long-term durability and for this reason researchers have been studying a sort of techniques to search for the required renewal time. This paper examined a commercial polypropylene (PP) nonwoven geotextile before and after 500 h and 1000 h exposure to ultraviolet (UV) light by performing laboratory accelerated ultraviolet-aging tests. The state of the polymeric material after UV exposure was studied through a wide set of tests, including mechanical and physical tests and thermoanalytical tests and scanning electron microscopy analysis. The calorimetric evaluations (DSC) showed distinct behaviors in sample melting points, attributed to the UV radiation effect on the aged samples. Furthermore, after exposure, the samples presented low thermal stability in the thermomechanical analysis (TMA), with a continuing decrease in their thicknesses. The tensile tests showed an increase in material stiffness after exposition. This study demonstrates that UV aging has effects on the properties of the polypropylene polymer.

scholarly journals Changes in surface characteristics and adsorption properties of 2,4,6-trichlorophenol following Fenton-like aging of biochar

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Liqiang Cui ◽  
Qinya Fan ◽  
Jianxiong Sun ◽  
Guixiang Quan ◽  
Jinlong Yan ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Surface Properties ◽  
Aging Process ◽  
Surface Characteristics ◽  
Natural Soil ◽  
Peanut Shell ◽  
Soil Environment ◽  
Polluted Soils ◽  
Physico Chemical

AbstractFenton-like system formed in a natural soil environment deemed to be significant in the aging process of biochar. Aged biochars have distinct physico-chemical and surface properties compared to non-aged biochar. The aged biochar proved to be useful soil amendment due to its improved elements contents and surface properties. The biochar aging process resulted in increased surface area and pore volume, as well as carbon and oxygen-containing functional groups (such as C=O, –COOH, O–C=O etc.) on its surface, which were also associated with the adsorption behavior of 2,4,6-trichlorophenol (2,4,6-TCP). The biochar aging increased the adsorption capacity of 2,4,6-TCP, which was maximum at pH 3.0. The 2,4,6-TCP adsorption capacity of aged-bush biochar (ABB) and aged-peanut shell biochar (APB) was increased by 1.0–11.0% and 7.4–38.8%, respectively compared with bush biochar (BB) and peanut shell biochar (PB) at the same initial concentration of 2,4,6-TCP. All biochars had similar 2,4,6-TCP desorption rates ranging from 33.2 to 73.3% at different sorption temperatures and times. The desorbed components were mainly 2,4,6-TCP and other degraded components, which were low in concentration with small molecule substance. The results indicated that the aged-biochar could be effective for the long-term remediation of naturally organic polluted soils.

One Step Chip Attach Materials (OSCA) for Conventional Mass Reflow Processing

2014 ◽  
Vol 2014 (1) ◽  
pp. 000262-000267
Author(s):  
Daniel J. Duffy ◽  
Lin Xin ◽  
Jean Liu ◽  
Bruno Tolla
Keyword(s):  
Flip Chip ◽  
Polymeric Materials ◽  
Cure Kinetics ◽  
Filler Loading ◽  
Single Step ◽  
Seamless Integration ◽  
Device Reliability ◽  
One Step ◽  
Traditional Processing

One step chip attach (OSCA) materials are dispensable polymeric materials for flip chip assembly, which are designed to flux metallic interconnections and subsequently turn into an underfill upon curing. OSCA materials enable a drastic simplification of the assembly process by combining the reflow (fluxing/soldering), defluxing and capillary underfilling steps used in traditional processing into a single step. One key challenge for the design of OSCA materials is timing the cure kinetics with fluxing activity and solder reflow during processing. A second key challenge is to factor a process-friendly rheological design into the formulation. The OSCA material rheology must allow for high filler loading levels, seamless integration with standard dispensing equipment, flow control during and after dispense (avoid keep out zones), flow during die placement (elimination of voids), after placement (fillet formation) and during reflow. The final key requirements for a functional device are defect-free interconnections combined with optimal thermo-mechanical and water resistant properties of the final underfill to guarantee the long-term reliability of the assembly in various environmental conditions. This paper presents the properties of materials designed by Kester for use in mass reflow processing (OSCA-R). The rheological design principles behind a seamless integration into customer-friendly processes will be presented In addition results illustrating the timing of cure kinetics with fluxing and soldering events during processing will be discussed. Preliminary device reliability results will also be presented for several types of test vehicles including; Si-Si and Si-FR4.

scholarly journals Long-Term Evaluation of Mesophilic Semi-Continuous Anaerobic Digestion of Olive Mill Solid Waste Pretreated with Steam-Explosion

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2222 ◽  
Author(s):  
Antonio Serrano ◽  
Fernando G. Fermoso ◽  
Bernabé Alonso-Fariñas ◽  
Guillermo Rodríguez-Gutiérrez ◽  
Sergio López ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Phenolic Compounds ◽  
Solid Waste ◽  
Steam Explosion ◽  
Loading Rates ◽  
Microbial Inhibitors ◽  
Olive Mill Solid Waste ◽  
Term Evaluation ◽  
Olive Mill

Steam-explosion is a promising technology for recovering phenolic compounds from olive mill solid waste (OMSW) due to its high impact on the structure of the fibre. Moreover, the recovery of the phenols, which are well-known microbial inhibitors, could improve the subsequent biomethanization of the dephenolized OMSW to produce energy. However, there is a considerable lack of knowledge about how the remaining phenolic compounds could affect a long-term biomethanization process of steam-exploded OMSW. This work evaluated a semi-continuous mesophilic anaerobic digestion of dephenolized steam-exploited OMSW during a long operational period (275 days), assessing different organic loading rates (OLRs). The process was stable at an OLR of 1 gVS/(L·d), with a specific production rate of 163 ± 28 mL CH4/(gVS·d). However, the increment of the OLR up to 2 gVS/(L·d) resulted in total exhaust of the methane production. The increment in the propionic acid concentration up to 1486 mg/L could be the main responsible factor for the inhibition. Regardless of the OLR, the concentration of phenolic compounds was always lower than the inhibition limits. Therefore, steam-exploited OMSW could be a suitable substrate for anaerobic digestion at a suitable OLR.

Applications of Chemiluminescence in Rubber Research

1992 ◽  
Vol 65 (4) ◽  
pp. 736-743 ◽  
Author(s):  
Dan Forsström ◽  
Anna Kron ◽  
Bengt Mattson ◽  
Torbjörn Reitberger ◽  
Bengt Stenberg ◽  
...  
Keyword(s):  
Service Life ◽  
Natural Rubber ◽  
Organic Materials ◽  
Photon Counting ◽  
Cellulose Fiber ◽  
Polymeric Materials ◽  
Sensitive Technique ◽  
Weak Light ◽  
Counting Equipment

Abstract The oxidation of most organic materials is accompanied by the emission of weak light, so called chemiluminescence (CL). This emission has previously often been designated oxyluminescence. CL has been known for several years, but it is not until recently that the development of photon counting equipment has allowed detection of levels down to a few photons per second. This development makes CL a promising nondestructive and extremely sensitive technique to provide data which may be useful to estimate the service life of polymeric materials. Various applications of the CL-method for the detection of oxidation of elastomers are reported: such as, stabilization of hydroxyl-terminated polybutadiene; degradation of latex coating of paper; long-term thermo-oxidation of natural rubber; indication of ultrathin coating of cellulose fiber with polybutadiene.

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