CWEA LABORATORY ANALYST
EXAM
What does turbidity measure - ANSWERS-The amount of light
scattering material found in water
Turbidity measurement is used to - ANSWERS-Measure the
operational effectiveness of filtration in potable and reclaimed water
treatement
Turbidity if measured with - ANSWERS-Nephelometer
Nephelometers consist of - ANSWERS-Light source, sample cell,
detector, and readout device
How do nephelometers work - ANSWERS-Measures the intensity of
light deflected ninety degrees
Units of turbidity - ANSWERS-Nephelometric Turbidity Units (NTU)
Primary use of chlorine - ANSWERS-Disinfection, odor control,
oxidation of iron and manganese, destruction of ammonia, and control
of filamentous bacteria in activated sludge
,Chemicals that remove chloride interference in COD test -
ANSWERS-Mercuric Sulfate
Holding time for acidity - ANSWERS-14 days
Holding time for alkalinity - ANSWERS-14 days
Holding time for BOD - ANSWERS-48 hours
Holding time for COD - ANSWERS-28 days
Holding time for chloride - ANSWERS-28 days
Holding time for chlorine, total, residual - ANSWERS-0.25 hours
Holding time for color - ANSWERS-48 hours
Holding time for odor - ANSWERS-24 hours
Holding time for pH - ANSWERS-0.25 hours
Holding time for solids - ANSWERS-7 days
Holding time for temperature - ANSWERS-0.25 hours
, Holding time for turbidity - ANSWERS-48 hours
Interference of turbidity analysis - ANSWERS-Dirty bottles
pH meter ranges - ANSWERS-Should be reproducible to 0.1 pH unit
and range of 0-14
Short term storage of pH electrodes - ANSWERS-pH 4 buffer
pH meter calibration - ANSWERS-1. Place in initial buffer solution
and set isopotential point
2. Select second buffer within 2 pH units
Chloride - ANSWERS-- Major anion found in many natural waters
- Can impart salty taste in H2O
What increases concentration of chloride in wastewater - ANSWERS-
Chloride in human diet and softeners flushed into sanitary sewer
system
2 most prevalent methods of measuring chloride - ANSWERS-
argentometric and mercuric nitrate
EXAM
What does turbidity measure - ANSWERS-The amount of light
scattering material found in water
Turbidity measurement is used to - ANSWERS-Measure the
operational effectiveness of filtration in potable and reclaimed water
treatement
Turbidity if measured with - ANSWERS-Nephelometer
Nephelometers consist of - ANSWERS-Light source, sample cell,
detector, and readout device
How do nephelometers work - ANSWERS-Measures the intensity of
light deflected ninety degrees
Units of turbidity - ANSWERS-Nephelometric Turbidity Units (NTU)
Primary use of chlorine - ANSWERS-Disinfection, odor control,
oxidation of iron and manganese, destruction of ammonia, and control
of filamentous bacteria in activated sludge
,Chemicals that remove chloride interference in COD test -
ANSWERS-Mercuric Sulfate
Holding time for acidity - ANSWERS-14 days
Holding time for alkalinity - ANSWERS-14 days
Holding time for BOD - ANSWERS-48 hours
Holding time for COD - ANSWERS-28 days
Holding time for chloride - ANSWERS-28 days
Holding time for chlorine, total, residual - ANSWERS-0.25 hours
Holding time for color - ANSWERS-48 hours
Holding time for odor - ANSWERS-24 hours
Holding time for pH - ANSWERS-0.25 hours
Holding time for solids - ANSWERS-7 days
Holding time for temperature - ANSWERS-0.25 hours
, Holding time for turbidity - ANSWERS-48 hours
Interference of turbidity analysis - ANSWERS-Dirty bottles
pH meter ranges - ANSWERS-Should be reproducible to 0.1 pH unit
and range of 0-14
Short term storage of pH electrodes - ANSWERS-pH 4 buffer
pH meter calibration - ANSWERS-1. Place in initial buffer solution
and set isopotential point
2. Select second buffer within 2 pH units
Chloride - ANSWERS-- Major anion found in many natural waters
- Can impart salty taste in H2O
What increases concentration of chloride in wastewater - ANSWERS-
Chloride in human diet and softeners flushed into sanitary sewer
system
2 most prevalent methods of measuring chloride - ANSWERS-
argentometric and mercuric nitrate
