A new coordination polymer,Zn(bpy)L(BUC‐21),(H2L=cis‐1,3‐dibenzyl‐2‐imidazolidone‐4,5‐dicarboxylic acid,bpy=4,4′‐bipyridine),has been synthesized under hydrothermal conditions,and characterized by single‐cry...A new coordination polymer,Zn(bpy)L(BUC‐21),(H2L=cis‐1,3‐dibenzyl‐2‐imidazolidone‐4,5‐dicarboxylic acid,bpy=4,4′‐bipyridine),has been synthesized under hydrothermal conditions,and characterized by single‐crystal X‐ray analysis,Fourier transform infrared spectroscopy,thermogravimetric analyses,CNH elemental analysis and UV‐Vis diffuse reflectance spectroscopy.BUC‐21exhibited an excellent performance for photocatalytic Cr(VI)reduction with a conversion efficiency of96%,better than that of commercial P25(39%),under UV light irradiation for30min.BUC‐21could also be used to conduct photocatalytic degradation of organic dyes including methylene blue,rhodamine B,methyl orange and reactive red X‐3B.Also,the photocatalytic activity of BUC‐21remained high across a wide pH range from2.0to12.0.It is interesting to note,however,that BUC‐21was unable to achieve simultaneous reduction of Cr(VI)and degradation of an organic pollutant in a mixed matrix,which can be attributed to the competition between Cr(VI)and the organic dyes for access to the photo‐excited electrons.展开更多
A mathematical model is developed based on a simplified mechanism of anaerobic digestion. The main objective is to quantitatively analyze the digestion process to optimize operating conditions and maintenance of this ...A mathematical model is developed based on a simplified mechanism of anaerobic digestion. The main objective is to quantitatively analyze the digestion process to optimize operating conditions and maintenance of this equipment, which could be used to test different materials and be able to apply these results to the possible scaling to bio-digesters installed in the field. The experiments were carried out in a hybrid system bio-digester photovoltaic cells. The bio-digester is made of stainless steel with dimensions to treat an average of 10 kg of raw material and produce biogas from different organic materials. The reactor has been conditioned with temperature sensors, pressure and methane gas that allow monitoring the concentration of the gas and the conditions of operation during the time of digestion. The system has a photovoltaic array to provide the energy required to keep the temperature constant, The experiment was conducted using materials such as goat manure mixed with household waste, and various formulations of these materials were prepared. The experimental results were used to test the mathematical model.展开更多
Among fertilizer ingredients nitrogen is the one noted for biggest losses because its susceptibility to volatilize to the atmosphere and to be leached away from the soil. These losses depend on the level and mode of f...Among fertilizer ingredients nitrogen is the one noted for biggest losses because its susceptibility to volatilize to the atmosphere and to be leached away from the soil. These losses depend on the level and mode of fertilization. It appears that every year in Poland river waters transport to the Baltic Sea from the whole area about 180 thousand tons of the nutrient. The largest portion of this load is ascribed to agriculture. This study focused on the highland areas, which are commonly seen as a water supplying region owing to the fact that they cover about 35% of water need in the authors＇ country. Specificity of grassland fertilization in these lands is high contribution of natural fertilizers including dunging with fresh manure left by penned animals, particularly by sheep. Authors decided to assess the influence of dunging by folded sheep on meadow nitrogen balance and on its concentration in percolating water. It was demonstrated that a nitrogen balance was highly negative for each object, so the grassland plants supplied their needs in large part with nitrogen from mineralization of soil organic matter. Relatively high loads of nitrogen leached out of the folded objects indicate that nitrogen from mineral fertilizers is better utilized by grassland herbage and thus is much safer for soil and water environment.展开更多
基金supported by the National Natural Science Foundation of China(51578034)the Beijing Natural Science Foundation&Scientific Research Key Program of Beijing Municipal Commission of Education(KZ201410016018)+1 种基金Beijing Talent Project(2016023)Project of Construction of Innovative Teams and Teacher Career Development for Universities and Colleges Under Beijing Municipality(IDHT20170508)~~
文摘A new coordination polymer,Zn(bpy)L(BUC‐21),(H2L=cis‐1,3‐dibenzyl‐2‐imidazolidone‐4,5‐dicarboxylic acid,bpy=4,4′‐bipyridine),has been synthesized under hydrothermal conditions,and characterized by single‐crystal X‐ray analysis,Fourier transform infrared spectroscopy,thermogravimetric analyses,CNH elemental analysis and UV‐Vis diffuse reflectance spectroscopy.BUC‐21exhibited an excellent performance for photocatalytic Cr(VI)reduction with a conversion efficiency of96%,better than that of commercial P25(39%),under UV light irradiation for30min.BUC‐21could also be used to conduct photocatalytic degradation of organic dyes including methylene blue,rhodamine B,methyl orange and reactive red X‐3B.Also,the photocatalytic activity of BUC‐21remained high across a wide pH range from2.0to12.0.It is interesting to note,however,that BUC‐21was unable to achieve simultaneous reduction of Cr(VI)and degradation of an organic pollutant in a mixed matrix,which can be attributed to the competition between Cr(VI)and the organic dyes for access to the photo‐excited electrons.
文摘A mathematical model is developed based on a simplified mechanism of anaerobic digestion. The main objective is to quantitatively analyze the digestion process to optimize operating conditions and maintenance of this equipment, which could be used to test different materials and be able to apply these results to the possible scaling to bio-digesters installed in the field. The experiments were carried out in a hybrid system bio-digester photovoltaic cells. The bio-digester is made of stainless steel with dimensions to treat an average of 10 kg of raw material and produce biogas from different organic materials. The reactor has been conditioned with temperature sensors, pressure and methane gas that allow monitoring the concentration of the gas and the conditions of operation during the time of digestion. The system has a photovoltaic array to provide the energy required to keep the temperature constant, The experiment was conducted using materials such as goat manure mixed with household waste, and various formulations of these materials were prepared. The experimental results were used to test the mathematical model.
文摘Among fertilizer ingredients nitrogen is the one noted for biggest losses because its susceptibility to volatilize to the atmosphere and to be leached away from the soil. These losses depend on the level and mode of fertilization. It appears that every year in Poland river waters transport to the Baltic Sea from the whole area about 180 thousand tons of the nutrient. The largest portion of this load is ascribed to agriculture. This study focused on the highland areas, which are commonly seen as a water supplying region owing to the fact that they cover about 35% of water need in the authors＇ country. Specificity of grassland fertilization in these lands is high contribution of natural fertilizers including dunging with fresh manure left by penned animals, particularly by sheep. Authors decided to assess the influence of dunging by folded sheep on meadow nitrogen balance and on its concentration in percolating water. It was demonstrated that a nitrogen balance was highly negative for each object, so the grassland plants supplied their needs in large part with nitrogen from mineralization of soil organic matter. Relatively high loads of nitrogen leached out of the folded objects indicate that nitrogen from mineral fertilizers is better utilized by grassland herbage and thus is much safer for soil and water environment.
