Dissolved air floatation

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

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). 

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. 

Flotation system this process is functioned by increased differences in specific gravity between the oil and water by blowing fine air bubbles through the oily wastewater. The most common floatation system is dissolved air flotation (DAE) process. 

Air-to-solid ratio is the ratio of mass of dissolved air delivered by the system to mass of solids in influent entering the floatation system. The suggested number is in the wide range from 0.005 to 0.07 mL air/mg solids, with 0.02 as a good design value. 

Vacuum-activated release of dissolved gases—In this system, the oily suspension is satnrated with air at atmospheric pressnre. Then the air is released from solntion when the snspension is subjected to vacuum conditions in a floatation nnit. The available amount of air is a limitation of this technique. 

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