Air floatation

Sewage Treatment (Air floatation units and Biological Oxidation units)... 

Oil-Water Separation Gravity separation Dissolved air floatation... 

The skimmed oil Is collected and transferred to wet crude tank. Water from the SPI separator is discharged to induced air floatator. This unit is composed of four floatation cells. Each cell is equipped with a motor driven self-aerating rotor meonanistn. As the rotor spins, minute bubbles are generated ar.d oil and suspended solid particles attach to the gas bubbles as tney rise to the surface. Tne oil and suspended solids gather in a dense froth on the surface and are removed from the cell by skimmer paddles and collected in a scum tank. Then skum is pumped out of scum tank to the inlet of SPI separator by skum return pump. 

To enhance the effect of air induced air floatation, a chemical called coagulant is injected prior to entering the floatator. The treated water with oil content less than 10 ppm Is pumped to the disposal pit. 

C. Upgrade Process Water Treatment Plant Replace the API Separator with a covered gravity separator and air floatation system. Capture hydrocarbon vapors from both units. 

V. C. Gopalratnam, G. F. Bennett, and R. W. Peters, The simultaneous removal of oil and heavy metals from industrial wastewater by joint precipitation and air floatation. Environ. Prog. 7, 84-92 (1988). 

The floor of a cylindrical water tank was distorted into 7-m. bulges due to the settling of improperly stablized soil under the tank floor. However, several consulting engineers restored the damaged tank to use by placing plastic skirts around the bottom of the tank wall and devising an air floatation stem to move it to an adjacent location. The tank was 30.5 m in diameter and 13.1 m deep. The top, bottom, and sides of the tank were made of 9.35-mm-thick welded steel sheets. The density of the steel is 7.86 g/cm. ... 

Dissolved air floatation and sequential batch reactors can also be considered. Considerations for these important units for the treatment of liquid effluent ... 

To dissolve the stabilizing agent, the use of cosolvents such as carbon disulfide, carbon tetrachloride, acetone and ether is in current practice. For specific examples of oil/water separations and for further details about the use of dissolved air floatation, deep bed filtration, and the selection and sizing of various equipment, the interested reader is referred to ref. (46). 

Kaolin deposits are cored and analyzed before mining to determine quality. Mined clays are then either wet or dry processed by air floatation or water fractionation. Surface-modified clays can be made by treating standard, delaminated, and calcinated grades with surface modifiers. The treatment can be performed by either the supplier or the end user. These surface modifiers include silane, titanate, polyester, and metal hydroxide. The objective of these surface treatments is to increase filler loadings and/or improve physical properties such as melt viscosity, thermal stability, and modulus without loss of physical characteristics. Electrical applications represent the largest use of surface-modified kaolin in plastics. 

A small fraction of the clean treated effluent is recycled and again saturated with air, mixed with the wastewater influent and irrjected into the dissolved air floatation (DAF) separation chamber. 

Figure 1. Schematic of the bio-contact oxidation system for air pollution control. (1) buffer poor (2) air floatation (3) bio-contact oxidation reactor 1 (4) bio-contact oxidation reactor 2 (5) gravity sedimentation (6) peristaltic pump (7) Air pump.

Oil concentration was in the range of 135-594mg L, the undulation of wastewater quality was comparatively large. Fig. 2 show that oil concentration was in 40-60 mg L after gravity sedimentation, while the oil concentration of wastewater was still high for bio-contact oxidation process. Then the wastewater is treated by air floatation, most of floating oil was separated from... 

When the kaolin clay is mined, there are two common ways of providing rubber-quality kaolin clay fdlers by air floatation or by water sedimentation as shown in Figure 8.11. 

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