WEF/ABC Lab Analyst Grade 1
Certification Exam – EXAM STUDY
GUIDE 2026/2027 COMPLETE
QUESTIONS WITH VERIFIED CORRECT
ANSWERS || 100% GUARANTEED PASS
MLVSS - ANSWER Mixed Liquor Volatile Suspended Solids
Only organic portion of sludge
MnO4 - ANSWER permanganate
MnSO4 - ANSWER manganous sulfate
mol - ANSWER mole
(6.022 x 10²³ elementary entities (atoms, molecules, etc.), a number known as Avogadro's
number)
MPN - ANSWER most probable number
MW - ANSWER molecular weight
,N - ANSWER normal
N2O - ANSWER nitrous oxide
Na2CO3 - ANSWER sodium carbonate
Na2HPO4 - ANSWER disodium hydrogen phosphate
Na2S2O3 - ANSWER sodium thiosulfate
mS/m - ANSWER millisiemens per meter
a unit of electrical conductance, equal to one-thousandth of a siemens (S), the SI unit for
conductance, which measures how easily a material carries electric current (the reciprocal of
resistance)
Na2SO3 - ANSWER sodium sulfite
Na2SO4 - ANSWER sodium sulfate
NaCl - ANSWER sodium chloride
NaHCO3 - ANSWER sodium bicarbonate
NaOH - ANSWER sodium hydroxide
,NFPA - ANSWER National Fire Protection Association
NH3 - ANSWER Ammonia
NH4Cl - ANSWER ammonium chloride
NH4OH - ANSWER ammonium hydroxide
(NH4)2SO4 - ANSWER ammonium sulfate
NIST - ANSWER National Institute of Standards and Technology
NOEC - ANSWER No Observed Effect Concentration
NPDES - ANSWER National Pollutant Discharge Elimination System
NTU - ANSWER Nephelometric Turbidity Unit
PCB - ANSWER polychlorinated biphenyls
Pi (π) - ANSWER 3.14159
PID - ANSWER Photoionization detector
SiO2 - ANSWER silicon dioxide
, SO2 - ANSWER sulfur dioxide
sq ft - ANSWER square foot
SS - ANSWER suspended solids
S.U. - ANSWER Standard Unit
SVI - ANSWER sludge volume index: is an indication of the density the settled sludge attains
in a 30 minute settling test
1. Sample: Take mixed liquor from the aeration tank.
2. Settle: Let it settle for 30 minutes in a graduated cylinder.
3. Measure: Record the settled sludge volume (mL) and Mixed Liquor Suspended Solids (MLSS)
concentration (mg/L).
4. Calculate: SVI = (Settled Sludge Volume (mL/L) / MLSS (mg/L)) * 1000.
5. Monitor: Operators adjust aeration, sludge wasting, or chemical dosing based on SVI to
maintain good settling and meet discharge limits for Total Suspended Solids (TSS).
TC - ANSWER to contain
TD - ANSWER to deliver
TKN - ANSWER Total Kjeldahl Nitrogen: used for the quantitative determination of organic
nitrogen plus ammonia (NH3), and ammonium (NH4+) in the chemical analysis of a compound.
Certification Exam – EXAM STUDY
GUIDE 2026/2027 COMPLETE
QUESTIONS WITH VERIFIED CORRECT
ANSWERS || 100% GUARANTEED PASS
MLVSS - ANSWER Mixed Liquor Volatile Suspended Solids
Only organic portion of sludge
MnO4 - ANSWER permanganate
MnSO4 - ANSWER manganous sulfate
mol - ANSWER mole
(6.022 x 10²³ elementary entities (atoms, molecules, etc.), a number known as Avogadro's
number)
MPN - ANSWER most probable number
MW - ANSWER molecular weight
,N - ANSWER normal
N2O - ANSWER nitrous oxide
Na2CO3 - ANSWER sodium carbonate
Na2HPO4 - ANSWER disodium hydrogen phosphate
Na2S2O3 - ANSWER sodium thiosulfate
mS/m - ANSWER millisiemens per meter
a unit of electrical conductance, equal to one-thousandth of a siemens (S), the SI unit for
conductance, which measures how easily a material carries electric current (the reciprocal of
resistance)
Na2SO3 - ANSWER sodium sulfite
Na2SO4 - ANSWER sodium sulfate
NaCl - ANSWER sodium chloride
NaHCO3 - ANSWER sodium bicarbonate
NaOH - ANSWER sodium hydroxide
,NFPA - ANSWER National Fire Protection Association
NH3 - ANSWER Ammonia
NH4Cl - ANSWER ammonium chloride
NH4OH - ANSWER ammonium hydroxide
(NH4)2SO4 - ANSWER ammonium sulfate
NIST - ANSWER National Institute of Standards and Technology
NOEC - ANSWER No Observed Effect Concentration
NPDES - ANSWER National Pollutant Discharge Elimination System
NTU - ANSWER Nephelometric Turbidity Unit
PCB - ANSWER polychlorinated biphenyls
Pi (π) - ANSWER 3.14159
PID - ANSWER Photoionization detector
SiO2 - ANSWER silicon dioxide
, SO2 - ANSWER sulfur dioxide
sq ft - ANSWER square foot
SS - ANSWER suspended solids
S.U. - ANSWER Standard Unit
SVI - ANSWER sludge volume index: is an indication of the density the settled sludge attains
in a 30 minute settling test
1. Sample: Take mixed liquor from the aeration tank.
2. Settle: Let it settle for 30 minutes in a graduated cylinder.
3. Measure: Record the settled sludge volume (mL) and Mixed Liquor Suspended Solids (MLSS)
concentration (mg/L).
4. Calculate: SVI = (Settled Sludge Volume (mL/L) / MLSS (mg/L)) * 1000.
5. Monitor: Operators adjust aeration, sludge wasting, or chemical dosing based on SVI to
maintain good settling and meet discharge limits for Total Suspended Solids (TSS).
TC - ANSWER to contain
TD - ANSWER to deliver
TKN - ANSWER Total Kjeldahl Nitrogen: used for the quantitative determination of organic
nitrogen plus ammonia (NH3), and ammonium (NH4+) in the chemical analysis of a compound.
