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Practical implications of bubble formation IN CONVENTIONAL TREATMENT
Author(s) -
Scardina Paolo,
Edwards Marc
Publication year - 2002
Publication title -
journal ‐ american water works association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.466
H-Index - 74
eISSN - 1551-8833
pISSN - 0003-150X
DOI - 10.1002/j.1551-8833.2002.tb09528.x
Subject(s) - supersaturation , flocculation , bubble , turbidity , coagulation , chemistry , filtration (mathematics) , dissolved air flotation , entrainment (biomusicology) , liquid bubble , sedimentation , particle (ecology) , environmental engineering , chemical engineering , environmental science , mechanics , sewage treatment , geology , physics , mathematics , psychiatry , engineering , psychology , paleontology , rhythm , statistics , organic chemistry , sediment , acoustics , oceanography
Air entrainment and ozonation are the key causes of dissolved gas supersaturation and eventual bubble formation in water treatment plants. Total dissolved gas probes directly measure supersaturation and have many advantages over conventional gas measurement techniques. Experiments conducted during this study found that bubble formation during coagulation/flocculation hindered particle sedimentation—producing settled turbidity levels double those of solutions without dissolved gases. In a filtration experiment, the run time to one half of initial flow was decreased by 54% when the source water was increased from 0.1 to 0.2 atm supersaturation. Even at only 0.05 atm supersaturation, run length decreased to only 21 h in solutions without added particulate matter. A case study at a utility confirmed that bubble formation from supersaturated gases can interfere with coagulation and filtration processes at conventional water treatment plants.