The effectiveness of CO2 microsize bubbles for removal of Ca2＋ ions in the leaching water discharged from the final landfill site was evaluated using imitation water. For the important parameter in the Ca2＋ ion remo...The effectiveness of CO2 microsize bubbles for removal of Ca2＋ ions in the leaching water discharged from the final landfill site was evaluated using imitation water. For the important parameter in the Ca2＋ ion removal, it was found that the treatment in alkaline region above pH = 10 was optimum. The possibility of using CO2 microbubbles was examined by substitution of chemical Na2CO3, which is used in large quantifies today. In addition, the excellence of CO2 microbubbles was demonstrated by comparing with CO2 millimeter size bubbles. @ 2015 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.展开更多
The concentration of suspended solids in the secondary effluent often varies widely, leading to frequent adjustment of the UV dosage to meet the disinfection criterion. In addition, a desired disinfection rate is diff...The concentration of suspended solids in the secondary effluent often varies widely, leading to frequent adjustment of the UV dosage to meet the disinfection criterion. In addition, a desired disinfection rate is difficult to achieve sometimes. The authors studied the particle size distribution, contribution of particle-associated Fecal Coliform (F.C.), and their influences on UV disinfection. A combined disinfection process (chlorination with a subsequent UV disinfection) was tested to improve the disinfection effect. The results indicated that the content of suspended solids, especially that of large particles, has a strong impact on UV disinfection efficiency; D>10 μm particles associated F.C. are difficult to be disinfected and are the main part of the tailings of F.C. inactivation curves. Pre-chlorination could decrease the number of particles in the secondary effluent and transform the large particles into small ones, reducing the influence of particles on UV disinfection and enhancing the resistance ability of the combined process to particle loading.展开更多
The paper discussed a comprehensive numerical simulation and field work by the usage of waterjet slotting tech- nique to prevent the occurrence of outbursts in soft and outburst prone coal seams. This was based on the...The paper discussed a comprehensive numerical simulation and field work by the usage of waterjet slotting tech- nique to prevent the occurrence of outbursts in soft and outburst prone coal seams. This was based on the geological and ge- omechanical conditions of Jinjiachong Colliery, Guizhou Province, associated with varied waterjet slotting parameters such as slotting penetration, slotting thickness and slotting distance along the length of borehole. Also, to understand the variation of internal stress of coal seams after waterjet slotting application, the internal stress levels were compared with and without slot- ting application, and the results indicate that the internal effective stress levels can be reduced to 70% and 45% for the vertical and horizontal stresses, respectively, and the gas concentration can be increased up to 5 times when the waterjet slotting is ap- plied.展开更多
基金Supported by the National Natural Science Funds for Distinguished Young Scholars(21425625)the National Science Foundation for Excellent Young Scholars(21422607)
文摘The effectiveness of CO2 microsize bubbles for removal of Ca2＋ ions in the leaching water discharged from the final landfill site was evaluated using imitation water. For the important parameter in the Ca2＋ ion removal, it was found that the treatment in alkaline region above pH = 10 was optimum. The possibility of using CO2 microbubbles was examined by substitution of chemical Na2CO3, which is used in large quantifies today. In addition, the excellence of CO2 microbubbles was demonstrated by comparing with CO2 millimeter size bubbles. @ 2015 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.
文摘The concentration of suspended solids in the secondary effluent often varies widely, leading to frequent adjustment of the UV dosage to meet the disinfection criterion. In addition, a desired disinfection rate is difficult to achieve sometimes. The authors studied the particle size distribution, contribution of particle-associated Fecal Coliform (F.C.), and their influences on UV disinfection. A combined disinfection process (chlorination with a subsequent UV disinfection) was tested to improve the disinfection effect. The results indicated that the content of suspended solids, especially that of large particles, has a strong impact on UV disinfection efficiency; D>10 μm particles associated F.C. are difficult to be disinfected and are the main part of the tailings of F.C. inactivation curves. Pre-chlorination could decrease the number of particles in the secondary effluent and transform the large particles into small ones, reducing the influence of particles on UV disinfection and enhancing the resistance ability of the combined process to particle loading.
文摘The paper discussed a comprehensive numerical simulation and field work by the usage of waterjet slotting tech- nique to prevent the occurrence of outbursts in soft and outburst prone coal seams. This was based on the geological and ge- omechanical conditions of Jinjiachong Colliery, Guizhou Province, associated with varied waterjet slotting parameters such as slotting penetration, slotting thickness and slotting distance along the length of borehole. Also, to understand the variation of internal stress of coal seams after waterjet slotting application, the internal stress levels were compared with and without slot- ting application, and the results indicate that the internal effective stress levels can be reduced to 70% and 45% for the vertical and horizontal stresses, respectively, and the gas concentration can be increased up to 5 times when the waterjet slotting is ap- plied.
