Preliminary sink-float experiments on high-sulfur coal was done in some mining areas and carried on elementary analysis, industrial analysis, and ashcontent analysis. Through the experiments, definite middlings, and g...Preliminary sink-float experiments on high-sulfur coal was done in some mining areas and carried on elementary analysis, industrial analysis, and ashcontent analysis. Through the experiments, definite middlings, and gangue, the phase analysis of sulfur was carried on, by which a good understanding of sulfur characters in raw coal was achieved.展开更多
Sulfur dioxide has been found to decrease the chemiluminescence of luminol-iodine system.A new determination method for sulfur dioxide in atmosphere is developed by applying this reaction to a flow injection gas diffu...Sulfur dioxide has been found to decrease the chemiluminescence of luminol-iodine system.A new determination method for sulfur dioxide in atmosphere is developed by applying this reaction to a flow injection gas diffusion separation system.This permits the determination of sulfur dioxide selectively and rapidly.展开更多
Combining a detailed catalytic surface reaction mechanism with noble metal and promoter elementary reactions, a new three-way catalytic converter(TWC) reaction mechanism is established. Based on the new mechanism, ste...Combining a detailed catalytic surface reaction mechanism with noble metal and promoter elementary reactions, a new three-way catalytic converter(TWC) reaction mechanism is established. Based on the new mechanism, steady condition numerical simulation is carried out, and the change of light-off temperatures and conversion efficiency with various SO2 contents is obtained. By grey relational analysis(GRA), the relational grade between conversion efficiency and SO2 content is obtained. And, the result shows that SO2 content has the most important influence on C3H6 and NOX conversion efficiency. This provides an important reference to the improvement of activity design of TWC, and may provide guidance for the condition design and optimization of TWC.展开更多
Sulfur flow for new generation steel manufacturing process is analyzed by the method of material flow analysis, and measures for SO2 emission reduction are put forward as assessment and target intervention of the resu...Sulfur flow for new generation steel manufacturing process is analyzed by the method of material flow analysis, and measures for SO2 emission reduction are put forward as assessment and target intervention of the results. The results of sulfur flow analysis indicate that 90 % of sulfur comes from fuels. Sulfur finally discharges from the steel manufacturing route in various steps, and the main point is BF and BOF slag desulfurization. In sintering process, the sulfur is removed by gasification, and sintering process is the main source of SO2 emission. The sulfur content of coke oven gas (COG) is an important factor affecting SO2 emission. Therefore, SO2 emission reduction should be started from the optimization and integration of steel manufacturing route, sulfur burden should be reduced through energy saving and consumption reduction, and the sulfur content of fuel should be controlled. At the same time, BF and BOF slag desulfurization should be optimized further and coke oven gas and sintering exhausted gas desulfurization should be adopted for SO2 emission reduction and reuse of resource, to achieve harmonic coordination of economic, social, and environmental effects for sustainable development.展开更多
In order to investigate the effects of carbonation on the microstructure of cement concrete,the carbonation depth and microstructure of cement paste with 0.3,0.4 and 0.5 water/cement ratio after 7,14,21 and 28 d accel...In order to investigate the effects of carbonation on the microstructure of cement concrete,the carbonation depth and microstructure of cement paste with 0.3,0.4 and 0.5 water/cement ratio after 7,14,21 and 28 d accelerated carbonation were studied respectively.The results showed that with the increase of waterto-cement ratio and carbonation age,the carbonation depth was deepened with faster early carbonation speed and slower later carbonation rate.Carbonation densified the structure of hardened cement stone with refinement of pore structure and reduced porosity.Then,during the carbonation process from the surface to the inside of carbonation area,it was prone to form micro-cracks extending to the interior specimen,resulting in cement paste carbonation depth uneven.It is further illustrated that the color reaction method using phenolphthalein solution combined with X-CT and X-ray diffraction analysis is much more reasonable to evaluate the cement concrete carbonation degree.Moreover,during carbonation process sulfur element in cement paste migrated to the area un-carbonated and the concentrated shape of sulfur element is consistent with the coloring region in carbonation interface.Finally it was identified that carbonation not only reduced the p H value in cement concrete but also made prone to crack in carbonation zone,which increased the probability of reinforcement corrosion.展开更多
Sulfide dioxide(SO2) is often released during the combustion processes of fossil fuels. An integrated bioreactor with two sections, namely, a suspended zone(SZ) and immobilized zone(IZ), was applied to treat SO2...Sulfide dioxide(SO2) is often released during the combustion processes of fossil fuels. An integrated bioreactor with two sections, namely, a suspended zone(SZ) and immobilized zone(IZ), was applied to treat SO2 for 6 months. Sampling ports were set in both sections to investigate the performance and microbial characteristics of the integrated bioreactor. SO2 was effectively removed by the synergistic effect of the SZ and IZ, and more than 85%removal efficiency was achieved at steady state. The average elimination capacity of SO2 in the bioreactor was 2.80 g/(m3·hr) for the SZ and 1.50 g/(m3· hr) for the IZ. Most SO2 was eliminated in the SZ. The liquid level of the SZ and the water content ratio of the packing material in the IZ affected SO2 removal efficiency. The SZ served a key function not only in SO2 elimination, but also in moisture maintenance for the IZ. The desired water content in IZ could be feasibly maintained without any additional pre-humidification facilities. Clone libraries of 16 S r DNA directly amplified from the DNA of each sample were constructed and sequenced to analyze the community composition and diversity in the individual zones.The desulfurization bacteria dominated both zones. Paenibacillus sp. was present in both zones, whereas Ralstonia sp. existed only in the SZ. The transfer of SO2 to the SZ involved dissolution in the nutrient solution and biodegradation by the sulfur-oxidizing bacteria.This work presents a potential biological treatment method for waste gases containing hydrophilic compounds.展开更多
The performance of a biofilter relies on the activity of microorganisms during the gas contaminant treatment process. In this study, SO2 was treated using a laboratory-scale biofilter packed with polyurethane foam cu...The performance of a biofilter relies on the activity of microorganisms during the gas contaminant treatment process. In this study, SO2 was treated using a laboratory-scale biofilter packed with polyurethane foam cubes(PUFC), on which thermophilic desulfurization bacteria were attached. The thermophilic biofilter effectively reduced SO2 within 10 months of operation time, with a maximum elimination capacity of 48.29 g/m^3/hr.Temporal shifts in the microbial population in the thermophilic biofilter were determined through polymerase chain reaction-denaturing gradient gel electrophoresis and deoxyribonucleic acid(DNA) sequence analysis. The substrate species and environmental conditions in the biofilter influenced the microbial population. Oxygen distribution in the PUFC was analyzed using a microelectrode. When the water-containing rate in PUFC was over 98%, the oxygen distribution presented aerobic–anoxic–aerobic states along the test route on the PUFC. The appearance of sulfate-reducing bacteria was caused by the anaerobic conditions and sulfate formation after 4 months of operation.展开更多
文摘Preliminary sink-float experiments on high-sulfur coal was done in some mining areas and carried on elementary analysis, industrial analysis, and ashcontent analysis. Through the experiments, definite middlings, and gangue, the phase analysis of sulfur was carried on, by which a good understanding of sulfur characters in raw coal was achieved.
文摘Sulfur dioxide has been found to decrease the chemiluminescence of luminol-iodine system.A new determination method for sulfur dioxide in atmosphere is developed by applying this reaction to a flow injection gas diffusion separation system.This permits the determination of sulfur dioxide selectively and rapidly.
基金Project(2009CK2001) supported by the Science & Technology Development Key Program of Hunan Province STA of ChinaProject supported by the Young Teachers Program of Hunan University,China
文摘Combining a detailed catalytic surface reaction mechanism with noble metal and promoter elementary reactions, a new three-way catalytic converter(TWC) reaction mechanism is established. Based on the new mechanism, steady condition numerical simulation is carried out, and the change of light-off temperatures and conversion efficiency with various SO2 contents is obtained. By grey relational analysis(GRA), the relational grade between conversion efficiency and SO2 content is obtained. And, the result shows that SO2 content has the most important influence on C3H6 and NOX conversion efficiency. This provides an important reference to the improvement of activity design of TWC, and may provide guidance for the condition design and optimization of TWC.
基金Item Sponsored by National Natural Science Foundation of China(50334020)
文摘Sulfur flow for new generation steel manufacturing process is analyzed by the method of material flow analysis, and measures for SO2 emission reduction are put forward as assessment and target intervention of the results. The results of sulfur flow analysis indicate that 90 % of sulfur comes from fuels. Sulfur finally discharges from the steel manufacturing route in various steps, and the main point is BF and BOF slag desulfurization. In sintering process, the sulfur is removed by gasification, and sintering process is the main source of SO2 emission. The sulfur content of coke oven gas (COG) is an important factor affecting SO2 emission. Therefore, SO2 emission reduction should be started from the optimization and integration of steel manufacturing route, sulfur burden should be reduced through energy saving and consumption reduction, and the sulfur content of fuel should be controlled. At the same time, BF and BOF slag desulfurization should be optimized further and coke oven gas and sintering exhausted gas desulfurization should be adopted for SO2 emission reduction and reuse of resource, to achieve harmonic coordination of economic, social, and environmental effects for sustainable development.
基金Funded by K.C.Wong Magna Fund in Ningbo Universitythe National Natural Science Foundation of China(Nos.51278255,51478227)Ningbo Municipal Science and Technology Project(Nos.2013C51006,2015A610300)
文摘In order to investigate the effects of carbonation on the microstructure of cement concrete,the carbonation depth and microstructure of cement paste with 0.3,0.4 and 0.5 water/cement ratio after 7,14,21 and 28 d accelerated carbonation were studied respectively.The results showed that with the increase of waterto-cement ratio and carbonation age,the carbonation depth was deepened with faster early carbonation speed and slower later carbonation rate.Carbonation densified the structure of hardened cement stone with refinement of pore structure and reduced porosity.Then,during the carbonation process from the surface to the inside of carbonation area,it was prone to form micro-cracks extending to the interior specimen,resulting in cement paste carbonation depth uneven.It is further illustrated that the color reaction method using phenolphthalein solution combined with X-CT and X-ray diffraction analysis is much more reasonable to evaluate the cement concrete carbonation degree.Moreover,during carbonation process sulfur element in cement paste migrated to the area un-carbonated and the concentrated shape of sulfur element is consistent with the coloring region in carbonation interface.Finally it was identified that carbonation not only reduced the p H value in cement concrete but also made prone to crack in carbonation zone,which increased the probability of reinforcement corrosion.
基金financially supported by the National Natural Science Foundation of China (No. 51221892)the Major Science and Technology Program for Water Pollution Control and Treatment (No. 2010ZX07319-001-03)
文摘Sulfide dioxide(SO2) is often released during the combustion processes of fossil fuels. An integrated bioreactor with two sections, namely, a suspended zone(SZ) and immobilized zone(IZ), was applied to treat SO2 for 6 months. Sampling ports were set in both sections to investigate the performance and microbial characteristics of the integrated bioreactor. SO2 was effectively removed by the synergistic effect of the SZ and IZ, and more than 85%removal efficiency was achieved at steady state. The average elimination capacity of SO2 in the bioreactor was 2.80 g/(m3·hr) for the SZ and 1.50 g/(m3· hr) for the IZ. Most SO2 was eliminated in the SZ. The liquid level of the SZ and the water content ratio of the packing material in the IZ affected SO2 removal efficiency. The SZ served a key function not only in SO2 elimination, but also in moisture maintenance for the IZ. The desired water content in IZ could be feasibly maintained without any additional pre-humidification facilities. Clone libraries of 16 S r DNA directly amplified from the DNA of each sample were constructed and sequenced to analyze the community composition and diversity in the individual zones.The desulfurization bacteria dominated both zones. Paenibacillus sp. was present in both zones, whereas Ralstonia sp. existed only in the SZ. The transfer of SO2 to the SZ involved dissolution in the nutrient solution and biodegradation by the sulfur-oxidizing bacteria.This work presents a potential biological treatment method for waste gases containing hydrophilic compounds.
基金supported by the Major Science and Technology Program for Water Pollution Control and Treatment (No.2010ZX07319-001-03)the National Natural Science Foundation of China (No.51221892)
文摘The performance of a biofilter relies on the activity of microorganisms during the gas contaminant treatment process. In this study, SO2 was treated using a laboratory-scale biofilter packed with polyurethane foam cubes(PUFC), on which thermophilic desulfurization bacteria were attached. The thermophilic biofilter effectively reduced SO2 within 10 months of operation time, with a maximum elimination capacity of 48.29 g/m^3/hr.Temporal shifts in the microbial population in the thermophilic biofilter were determined through polymerase chain reaction-denaturing gradient gel electrophoresis and deoxyribonucleic acid(DNA) sequence analysis. The substrate species and environmental conditions in the biofilter influenced the microbial population. Oxygen distribution in the PUFC was analyzed using a microelectrode. When the water-containing rate in PUFC was over 98%, the oxygen distribution presented aerobic–anoxic–aerobic states along the test route on the PUFC. The appearance of sulfate-reducing bacteria was caused by the anaerobic conditions and sulfate formation after 4 months of operation.