TCEQ Class B Surface Water |Exam-Questions with Correct
Answers|Verified
Filtration rate for rapid sand filters?
2-6 gpm/ sq ft
List the characteristics of the coagulation process?
Type of reaction ( physical-chemical)
Time required ( reaction complete in seconds)
Mixing intensity ( high intensity mixing is required for proper coagulation)
Name the advantages of dual and mixed media filters over plain rapid sand filters??
Higher filtration rate and longer filter runs
Proper way to re fill rapid sand filter that was been out of service
Slowly fill the filter through the backwash valve
List the characteristics of polymers?
Cationic ( net positive charge )
Anionic ( net negative charge )
Non-ionic ( no net charge )
Name the characteristics of the flocculation process??
Type of reaction ( physical )
Time required ( 20-30 min )
Mixing intensity ( Controlled slow mixing )
, Coagulants typically used in the water treatment industry
Alum or aluminum sulfate Al2(SO4)3
Iron salts: Ferric Chloride (FeCl3), Ferrous Sulfate (FeSO4)
Low molecular weight cationic polymer
What is the optimum pH for coagulation
Alum: pH 5-7
Iron salt: pH 4-11
Cationic polymer: effective over a wide pH range.
Alum or aluminum Sulfate
Al2(SO4)3 : pH 5-7
Ferric chloride
FeCl3 : ph 4-11
Ferrous sulfate
FeSO4 : pH 4-11
Typical rapid sand filter rate??
15 gpm/ sq ft or 24 inch rise/ minute
The overall change on a colloidal particle is determined by measuring what??
Zeta Potential
What may develop as a result of inadequate backwash of rapid sand filter??
Mudball formation
Answers|Verified
Filtration rate for rapid sand filters?
2-6 gpm/ sq ft
List the characteristics of the coagulation process?
Type of reaction ( physical-chemical)
Time required ( reaction complete in seconds)
Mixing intensity ( high intensity mixing is required for proper coagulation)
Name the advantages of dual and mixed media filters over plain rapid sand filters??
Higher filtration rate and longer filter runs
Proper way to re fill rapid sand filter that was been out of service
Slowly fill the filter through the backwash valve
List the characteristics of polymers?
Cationic ( net positive charge )
Anionic ( net negative charge )
Non-ionic ( no net charge )
Name the characteristics of the flocculation process??
Type of reaction ( physical )
Time required ( 20-30 min )
Mixing intensity ( Controlled slow mixing )
, Coagulants typically used in the water treatment industry
Alum or aluminum sulfate Al2(SO4)3
Iron salts: Ferric Chloride (FeCl3), Ferrous Sulfate (FeSO4)
Low molecular weight cationic polymer
What is the optimum pH for coagulation
Alum: pH 5-7
Iron salt: pH 4-11
Cationic polymer: effective over a wide pH range.
Alum or aluminum Sulfate
Al2(SO4)3 : pH 5-7
Ferric chloride
FeCl3 : ph 4-11
Ferrous sulfate
FeSO4 : pH 4-11
Typical rapid sand filter rate??
15 gpm/ sq ft or 24 inch rise/ minute
The overall change on a colloidal particle is determined by measuring what??
Zeta Potential
What may develop as a result of inadequate backwash of rapid sand filter??
Mudball formation
