INTRODUCTION It is an interesting research area using urease inhibitors to curb urease activity in soil,to decrease the rate of urea hydrolysis and to increase the recovery of urea nitrogen(Zhou,1984;Guan,1985).Few st...INTRODUCTION It is an interesting research area using urease inhibitors to curb urease activity in soil,to decrease the rate of urea hydrolysis and to increase the recovery of urea nitrogen(Zhou,1984;Guan,1985).Few studies have been conducted on the relationship betweenthe effectiveness of the inhibitors applied to rice and the environmental conditions and展开更多
The aim of the present study was to implant an efficient strategy for controlling the level of the effluent-oily foam interface in a DAF （dissolved air flotation） chamber of a pilot-scale prototype. DAF has been suc...The aim of the present study was to implant an efficient strategy for controlling the level of the effluent-oily foam interface in a DAF （dissolved air flotation） chamber of a pilot-scale prototype. DAF has been successfully used in the treatment of oily water, which is one of the main environmental problems in different industrial facilities. Along with important operational parameters, such as microbubble size and flow rate, the control strategy for the automation of a DAF chamber may be an important tool for increasing efficiency. Controlling the level was the strategy chosen to enhance the separation efficiency in a pilot-scale DAF prototype, with monitoring performed using a computational program in LabVIEW （laboratory virtual instrument engineering workbench）. The findings demonstrate that it is possible to maintain the level of the fluid at a reference value established by the operator using the software program through the application of classic proportional integral derivative controllers. Using this control tool, the efficiency of water-oil separation in the pilot flotation chamber prototype was increased to nearly 98%.展开更多
文摘INTRODUCTION It is an interesting research area using urease inhibitors to curb urease activity in soil,to decrease the rate of urea hydrolysis and to increase the recovery of urea nitrogen(Zhou,1984;Guan,1985).Few studies have been conducted on the relationship betweenthe effectiveness of the inhibitors applied to rice and the environmental conditions and
文摘The aim of the present study was to implant an efficient strategy for controlling the level of the effluent-oily foam interface in a DAF （dissolved air flotation） chamber of a pilot-scale prototype. DAF has been successfully used in the treatment of oily water, which is one of the main environmental problems in different industrial facilities. Along with important operational parameters, such as microbubble size and flow rate, the control strategy for the automation of a DAF chamber may be an important tool for increasing efficiency. Controlling the level was the strategy chosen to enhance the separation efficiency in a pilot-scale DAF prototype, with monitoring performed using a computational program in LabVIEW （laboratory virtual instrument engineering workbench）. The findings demonstrate that it is possible to maintain the level of the fluid at a reference value established by the operator using the software program through the application of classic proportional integral derivative controllers. Using this control tool, the efficiency of water-oil separation in the pilot flotation chamber prototype was increased to nearly 98%.
