Air bubbles can disrupt conventional coagulation and sedimentation processes by floating
coagulant floc. This study explains the fundamental factors that lead to bubble
formation and corresponding floating floc during coagulation and sedimentation. Gas bubbles
(causing the floating floc) can form whenever the total dissolved gas (TDG) pressure exceeds the
local solution pressure, which can occur at localized minimum pressures during rapid mixing at
high fluid velocities. Very high rate rapid mixers can cause bubble formation and floating floc
even in waters undersaturated with dissolved gas. The formation and stability of floating floc are
dependent on many systems including water quality and plant operation, which can be optimized
to mitigate floating floc. A case study at a treatment plant afflicted by floating floc confirmed key
hypotheses. Includes 15 references, table, figures.
| Edition : | Vol. - No. |
| Number of Pages : | 18 |
| Published : | 06/17/2005 |
