Membrane fouling seriously restricts applications of membrane technology. A novel strategy was applied in this study to retard membrane fouling by changing operating pressure with the pressure responsibility membrane....Membrane fouling seriously restricts applications of membrane technology. A novel strategy was applied in this study to retard membrane fouling by changing operating pressure with the pressure responsibility membrane. A polyurethane-based hollow fiber membrane was used to treat surface water for evaluating the effect of operating pressure on membrane fouling. Some bench-scale tests in dead-end mode were carried out. In the experiments without backwashing, as operating pressure increased, severe membrane fouling occurred on membrane surface, while the permeate quality was improved obviously, which is considered to be due to shrinkage deformation. The total resistance, irreversible resistance and reversible resistance under different backwash pressures were determined in filtration/backwashing test. With the increase of backwash pressure, the total resistance decreased, and more importantly, the irreversible resistance also decreased, which implies that small particles deposited inside membrane pores and cake layers on membrane surface are effectively removed. Similar results could be obtained in mass balance tests. The results of the present study indicate that the application of pressure responsibility membrane in surface water treatment may be an effective strategy for reducing membrane fouling.展开更多
This study focuses on such relevant factors that can influence employees＇ turnover decision in state-owned enterprise of China as the wages, work pressure, relevant industry working conditions, job duties related to ...This study focuses on such relevant factors that can influence employees＇ turnover decision in state-owned enterprise of China as the wages, work pressure, relevant industry working conditions, job duties related to moving to other industries, and management. This research shows that the employees correct their expectations to the current job and other jobs in the industry on the basis of their initial work experience, which finally affects their turnover decision. In addition, the study also reveals that the turnover caused by the difference of wages, and the management reasons can make the employees completely leave the state-owned enterprises.展开更多
基金Supported by the National Natural Science Foundation of China(51078264,51108314,51108315,51138008)
文摘Membrane fouling seriously restricts applications of membrane technology. A novel strategy was applied in this study to retard membrane fouling by changing operating pressure with the pressure responsibility membrane. A polyurethane-based hollow fiber membrane was used to treat surface water for evaluating the effect of operating pressure on membrane fouling. Some bench-scale tests in dead-end mode were carried out. In the experiments without backwashing, as operating pressure increased, severe membrane fouling occurred on membrane surface, while the permeate quality was improved obviously, which is considered to be due to shrinkage deformation. The total resistance, irreversible resistance and reversible resistance under different backwash pressures were determined in filtration/backwashing test. With the increase of backwash pressure, the total resistance decreased, and more importantly, the irreversible resistance also decreased, which implies that small particles deposited inside membrane pores and cake layers on membrane surface are effectively removed. Similar results could be obtained in mass balance tests. The results of the present study indicate that the application of pressure responsibility membrane in surface water treatment may be an effective strategy for reducing membrane fouling.
文摘This study focuses on such relevant factors that can influence employees＇ turnover decision in state-owned enterprise of China as the wages, work pressure, relevant industry working conditions, job duties related to moving to other industries, and management. This research shows that the employees correct their expectations to the current job and other jobs in the industry on the basis of their initial work experience, which finally affects their turnover decision. In addition, the study also reveals that the turnover caused by the difference of wages, and the management reasons can make the employees completely leave the state-owned enterprises.
