Calorimetry reveals the response of soil microbial metabolism to increasing temperature in soils with different thermal, chemical and biological properties |
Author : Nieves Barros, Sergio Feijóo, Ramón Balsa, José Antonio Rodríguez-Añón, Jorge Proupín, María Villanueva, Lee Hansen, Ander Arias, Nahia Gartzia, Verónica Piñeiro |
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Abstract :Understanding the connection between soil biodegradation and temperature is a matter of concern nowadays. Increasing temperature increases the rate at which soil is degraded by microbial action enhancing carbon losses with a negative impact on the atmosphere and water quality. The number of methods allowing these measurements is small, and additional options that contribute to improve our knowledge about this subject are welcome. Calorimetry is a new alternative to monitor directly and in real time the immediate response of soil microbial activity to changing temperature. This paper shows a methodological application of these calorimetric devices to soil samples with extreme different organic matter properties, to monitor the evolution of their biodegradation rates with increasing temperatures and the fitting of the most widely used models: Q10 and the Arrhenius equation. Results showed that calorimetry is sensitive enough to detect different responses of the soil samples to increasing temperature from 18 ºC to 35 ºC, that the range of temperatures at which the biodegradation rates fitted the existing models varied among soils and that Ea derived from Arrhenius equation was not sensitive in all cases to link soil sensitivity to temperature with the soil organic matter nature. |
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Bio-negative synergy of social and environmental situations for oil- and gas-field facilities in the Gulf of Guinea |
Author : Phyllis TETE, Anastasia M. MAKAROVA, Mikhail SLESAREV |
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Abstract :The cause of the emergence of bio-negative interaction of social and environmental situation in the oil- and gas-field facilities in the Gulf of Guinea (GoG) region has been studied. It has been established that the cause of the negative synergy of socio-ecological situations is due to the imbalance of equipment and building technology, along with increasing social and environmental load on the whole territory, related to the lack of relevant world-class technologies for collection, transportation and recycling of disposals and wastes from staff’s livelihood. It was found that the disorganized placement of oil and gas facilities in a typical area along the coast of the GoG, poor environmental protection, and inadequate organizational and financial mechanisms of the environmental safety are a part of the main factors, which affect the environment. From the analysis of the main factors determining the state of the socio-environmental structures, it follows that the further development of oil- and gas-field facilities cannot be based on pre-existing technologies. New technologies and design solutions for oil- and gas-field facilities that are safe for environment and integrated with nature should be developed and implemented. |
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Fertilizers with a delayed nutrient release |
Author : Krzysztof LUBKOWSKI |
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Abstract :The paper presents the most important issues relating to the research and application of materials with controlled-release properties that can increase the effectiveness of nutrient uptake, alleviate the negative influence of fertilizers on the environment and reduce labor and energy consumption associated with the use of conventional fertilizers. The article discusses predominantly commercially available controlled-release fertilizers manufactured with the use of sulfur, thermoplastics, polyurethane and alkyd resins. The multistep diffusion model was pointed out as the best tool for the qualitative description and quantitative prediction of the nutrient release. Attention was also paid to the fertilizers prepared with the use of other materials like superabsorbents and polysulfone-based materials. Bio-composites of starch, lignin, cellulose and other natural or synthetic biopolymers were depicted as the most promising materials for the future application. The article contains also the quantitative analysis of bibliographic data and information on the market situation of fertilizers with a delayed nutrient release. |
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Assessment of the compressive strength of weathered mine tailings matrices as a sustainable approach to road construction in cold regions |
Author : Ali A. MAHMOOD and Maria ELEKTOROWICZ |
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Abstract :New mine tailings matrices were formulated from two different mine tailings from Eastern Canada. The tailings were mixed with Portland cement, fly ash, slag and a new binder called Calsifrit. The study consisted of two phases where in the first phase 5 cm3 cubic tailings matrices were formulated to assess the change in curing period on the compressive strength of the matrices. In the second phase of these tests cylindrical specimens were formulated to assess the effect of weathering on the compressive strength of the tailings matrices. The cylindrical specimens were exposed to wetting/drying and freezing/ thawing durability tests before subjecting them to unconfined compression tests. To assess the suitability of such matrices to road construction, their layer coefficients were determined. It was found that the new mine tailings matrices were suitable structurally (even after weathering) for road construction as it was demonstrated by their layer coefficients. |
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Ma Jing, Jia Ying, Qin Zhang-Cheng, Song Jing-Tao |
Author : Ma Jing, Jia Ying, Qin Zhang-Cheng, Song Jing-Tao |
Abstract | Full Text |
Abstract :Manganese oxides supported on granular activated carbon (MnOx/GAC) for degradation of UDMH wastewater was prepared via facile in-situ reduction of permanganate by activated carbon. The growth and properties of MnOx/GAC were characterized by scanning electron microscopy, X-ray diffraction, Raman spectra and X-ray photoelectron spectroscopy. Test results showed that MnOx deposited on GAC surface was poorly crystallized layer birnessite-style MnOx and the sample of 30min synthesis time exhibited the best performance on UDMH degradation. Combined with vacuum ultraviolet (VUV), under the best optimal process conditions including 15g/L catalysis dosage, pH 9.0 and 50mg/L initial UDMH concentration, the UDMH and COD removal rate respectively reached 95% and 85% at room temperature. |
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