Water QualityChapter 6 Water Sources

Water QualityChapter 6 Water Sources

WQT 121

Lecture 1

WQT 121

Lecture 1

How was the reading assignment?

How was the reading assignment?

Awes

ome

(5 s

ta...

Good

(4 s

tar)

Ok

(3 s

tar)

Bad

(2 s

tar)

A w

aste

of m

y ...

58%

29%

4%4%4%

1. Awesome (5 star)

2. Good (4 star)

3. Ok (3 star)

4. Bad (2 star)

5. A waste of my time (1 star)

1. Awesome (5 star)

2. Good (4 star)

3. Ok (3 star)

4. Bad (2 star)

5. A waste of my time (1 star)

Objectives Objectives

1. Review Principle Water Quality Characteristics

2. Understand common secondary MCLS.

3. Effect of pH, Taste, Odor, Corrosion on water quality

3. Review of MCLS & key contaminants in water

4. Hard verse soft water

1. Review Principle Water Quality Characteristics

2. Understand common secondary MCLS.

3. Effect of pH, Taste, Odor, Corrosion on water quality

3. Review of MCLS & key contaminants in water

4. Hard verse soft water

Reading assignment: Handout: Chapter 6 Water Quality

Reading assignment: Handout: Chapter 6 Water Quality

Mineralogical Analysis of WaterMineralogical Analysis of Water

• Concentration (Mg/L) Quantity of a constituent in a standard volume (1 liter) is measured by its weight (in milligrams). 1 ppm (old school) = 1mg/L (correct)

• General Mineral Content Ca, Na, Mg, Fe, Mn, HCO3, CO3, SO4 and Cl2.

– Rivers < 500 mg/L to 2,000 mg/L– Groundwater 100-10,000 mg/L

• Concentration (Mg/L) Quantity of a constituent in a standard volume (1 liter) is measured by its weight (in milligrams). 1 ppm (old school) = 1mg/L (correct)

• General Mineral Content Ca, Na, Mg, Fe, Mn, HCO3, CO3, SO4 and Cl2.

– Rivers < 500 mg/L to 2,000 mg/L– Groundwater 100-10,000 mg/L

In the water treatment field, mg/L and ppm are considered to be

equivalent units.

In the water treatment field, mg/L and ppm are considered to be

equivalent units.

Tru

e

Fal

se

0%

100%1. True

2. False

1. True

2. False

3.5% salinity or 35,000 TDS (mg/L), 10,5000 mg/L Na, 19,700 mg/L Cl2, 2,650 mg/L SO4, 1,310 mg/L Mg, Ca 410 mg/L,

Br 65 mg/L, Bicarbonate 152 mg/L, pH 8.1

3.5% salinity or 35,000 TDS (mg/L), 10,5000 mg/L Na, 19,700 mg/L Cl2, 2,650 mg/L SO4, 1,310 mg/L Mg, Ca 410 mg/L,

Br 65 mg/L, Bicarbonate 152 mg/L, pH 8.1

Rai

nwat

er

Sea

water

Lak

e W

ater

Gro

undw

ater

5% 5%5%

85%

1. Rainwater

2. Seawater

3. Lake Water

4. Groundwater

1. Rainwater

2. Seawater

3. Lake Water

4. Groundwater

Groundwater in comparison to surface water is generally:

Groundwater in comparison to surface water is generally:

Lower

in tu

rbi..

.

Hig

her in

turb

...

More

susc

eptib

...

More

susc

eptib

...

War

mer

and is

...

95%

0%5%

0%0%

1. Lower in turbidity and higher in mineral content

2. Higher in turbidity and lower in mineral content

3. More susceptible to seasonal changes

4. More susceptible to algal blooms

5. Warmer and is quite soft

1. Lower in turbidity and higher in mineral content

2. Higher in turbidity and lower in mineral content

3. More susceptible to seasonal changes

4. More susceptible to algal blooms

5. Warmer and is quite soft

7.1 TDS mg/l, 7 mg/L Na, 1 mg/L Cl2, 2 mg/L SO4, 0.74 mg/L Mg, Ca 5.5 mg/L, pH

6.9

7.1 TDS mg/l, 7 mg/L Na, 1 mg/L Cl2, 2 mg/L SO4, 0.74 mg/L Mg, Ca 5.5 mg/L, pH

6.9

Rai

nwat

er

Sea

water

Lak

e W

ater

Gro

undw

ater

53%

35%

12%

0%

1. Rainwater

2. Seawater

3. Lake Water

4. Groundwater

1. Rainwater

2. Seawater

3. Lake Water

4. Groundwater

180 TDS mg/l, 7 mg/L Na, 23 mg/L Cl2, 40 mg/L SO4, 8.6 mg/L Mg, Ca 53 mg/L, pH

6.0-8.5

180 TDS mg/l, 7 mg/L Na, 23 mg/L Cl2, 40 mg/L SO4, 8.6 mg/L Mg, Ca 53 mg/L, pH

6.0-8.5

Rai

nwat

er

Sea

water

Lak

e W

ater

Gro

undw

ater

0%

48%52%

0%

1. Rainwater

2. Seawater

3. Lake Water

4. Groundwater

1. Rainwater

2. Seawater

3. Lake Water

4. Groundwater

Key WordsKey Words

• Dissolved Solids very stable inorganic or organic substances that remain in suspension.

• Colloidal Solids Tiny clay and organic materials that float in water and repel each other.

• Suspended Solids Large particles of silt and sand that settle out in a sedimentation basin or clarifier.

• National Secondary Drinking Water Regulations (NSDWRs): are non‑enforceable guidelines regulating contaminants that may cause cosmetic effects (such as skin or tooth discoloration) or aesthetic effects (such as taste, odor, or color) in drinking water

• Dissolved Solids very stable inorganic or organic substances that remain in suspension.

• Colloidal Solids Tiny clay and organic materials that float in water and repel each other.

• Suspended Solids Large particles of silt and sand that settle out in a sedimentation basin or clarifier.

• National Secondary Drinking Water Regulations (NSDWRs): are non‑enforceable guidelines regulating contaminants that may cause cosmetic effects (such as skin or tooth discoloration) or aesthetic effects (such as taste, odor, or color) in drinking water

Turbidity and CorrosionTurbidity and Corrosion

• Turbidity: A measure of the light scattering property of water

• The unit of measure is the NEPHELOMETRIC TURBIDITY UNIT, or NTU.

• Corrosion: The destruction of metal by electro-chemical processes.

• Corrosion is simply natures way to return metals back to their natural state: OXIDES

• Turbidity: A measure of the light scattering property of water

• The unit of measure is the NEPHELOMETRIC TURBIDITY UNIT, or NTU.

• Corrosion: The destruction of metal by electro-chemical processes.

• Corrosion is simply natures way to return metals back to their natural state: OXIDES

Corrosion FactorsCorrosion Factors

1.Low pH, which is often associated with EXCESS CARBON DIOXIDE in water

2.High oxygen

3.High total dissolved solids (salts) in the form of chlorides or sulfates

4.Soft water, or low hardness water

5.High temperature often exaggerates corrosion problems

6. Low alkalinity

1.Low pH, which is often associated with EXCESS CARBON DIOXIDE in water

2.High oxygen

3.High total dissolved solids (salts) in the form of chlorides or sulfates

4.Soft water, or low hardness water

5.High temperature often exaggerates corrosion problems

6. Low alkalinity

Corrosion ControlsCorrosion ControlsAggressive soil and water

1.Protective coatings inside and outside of pipe (cement lining is very effective for ductile iron pipe plastic wrap can effectively protect ductile iron pipe from soil corrosion)

2.Cathodic protection, using zinc or magnesium sacrificial anodes to coat

3.Adjust water chemistry by increasing the pH, adding alkalinity, or adding hardness ions

4. Galvanic corrosionElectro-chemical process similar to a battery

that occurs when dissimilar metals are joined.

Aggressive soil and water1.Protective coatings inside and outside of pipe

(cement lining is very effective for ductile iron pipe plastic wrap can effectively protect ductile iron pipe from soil corrosion)

2.Cathodic protection, using zinc or magnesium sacrificial anodes to coat

3.Adjust water chemistry by increasing the pH, adding alkalinity, or adding hardness ions

4. Galvanic corrosionElectro-chemical process similar to a battery

that occurs when dissimilar metals are joined.

What does TDS stand for?What does TDS stand for?

Tota

l dis

solv

e...

Tem

poraril

y di..

.

Tota

l dis

aggr

e...

Tota

l dis

solv

e...

96%

0%0%4%

1. Total dissolved solids

2. Temporarily dissolved solids

3. Total disaggregated solids

4. Total dissolved salts

1. Total dissolved solids

2. Temporarily dissolved solids

3. Total disaggregated solids

4. Total dissolved salts

The total solids in water would be a combination of:

The total solids in water would be a combination of:

Fix

ed s

olids

a...

Dis

solv

ed s

oli...

Dis

solv

ed s

oli...

Susp

ended

soli.

..

Fix

ed s

olids

a...

8%4%

0%0%

88%1. Fixed solids and

settleable solids

2. Dissolved solids and volatile solids

3. Dissolved solids and suspended solids

4. Suspended solids and fixed solids

5. Fixed solids and dissolved solids

1. Fixed solids and settleable solids

2. Dissolved solids and volatile solids

3. Dissolved solids and suspended solids

4. Suspended solids and fixed solids

5. Fixed solids and dissolved solids

Total Dissolved Solids are dried at this temperature Total Dissolved Solids are dried at this temperature

103

oC

105

oC

180

oC

550

oC

27%23%

38%

12%

1. 103oC

2. 105oC

3. 180oC

4. 550oC

1. 103oC

2. 105oC

3. 180oC

4. 550oC

The secondary MCL for TDS in drinking water is?

The secondary MCL for TDS in drinking water is?

10

mg/L

500

mg/L

1,0

00 m

g/L

1 m

g/L

47%

11%

26%

16%

1. 10 mg/L

2. 500 mg/L

3. 1,000 mg/L

4. 1 mg/L

1. 10 mg/L

2. 500 mg/L

3. 1,000 mg/L

4. 1 mg/L

Key WordsKey Words

• Turbidity A measure of the light scattering property of water (cloudiness)

• The unit of measure is the NEPHELOMETRIC TURBIDITY UNIT, or NTU.

• Corrosion The destruction of metal by electro-chemical processes.

• Corrosion is simply natures way to return metals back to their natural state: OXIDES

• Turbidity A measure of the light scattering property of water (cloudiness)

• The unit of measure is the NEPHELOMETRIC TURBIDITY UNIT, or NTU.

• Corrosion The destruction of metal by electro-chemical processes.

• Corrosion is simply natures way to return metals back to their natural state: OXIDES

NTU stands for?NTU stands for?

Nep

helo

met

ric tu

rbid

i..

Nep

helo

met

ric to

tal s

...

Nep

elom

etric

turb

idity

...

Nom

inal

Tur

bidity

Unit

Nom

inal

Tub

idity

Util

i...

0% 0% 0%0%0%

1. Nephelometric turbidity unit

2. Nephelometric total solids utilization

3. Nepelometric turbidity utilization

4. Nominal Turbidity Unit

5. Nominal Tubidity Utilization

1. Nephelometric turbidity unit

2. Nephelometric total solids utilization

3. Nepelometric turbidity utilization

4. Nominal Turbidity Unit

5. Nominal Tubidity Utilization

Turbidity is caused by?Turbidity is caused by?

Dis

solv

ed s

oli...

Susp

ended

par

t...

Dis

solv

ed g

ase.

..

Dis

solv

ed c

olo...

0% 0%0%0%

1. Dissolved solids

2. Suspended particles

3. Dissolved gases

4. Dissolved colored solids

1. Dissolved solids

2. Suspended particles

3. Dissolved gases

4. Dissolved colored solids

Which of the following is a major part of a turbidimeter?

Which of the following is a major part of a turbidimeter?

light

asp

irato

r

Ref

eren

ce e

lec.

..

Obje

ctiv

e nos

e...

0% 0%0%0%

1. light

2. aspirator

3. Reference electrode

4. Objective nosepiece

1. light

2. aspirator

3. Reference electrode

4. Objective nosepiece

Turbidimeters must be calibrated:

Turbidimeters must be calibrated:

Mont

hly

Quar

terly

If fa

ctory

cal

...

Dai

ly

Wee

kly

0% 0% 0%0%0%

1. Monthly

2. Quarterly

3. If factory calibrated, never

4. Daily

5. Weekly

1. Monthly

2. Quarterly

3. If factory calibrated, never

4. Daily

5. Weekly

Which of the following parameters is used to indicate

the clarity of water?

Which of the following parameters is used to indicate

the clarity of water?

pH

Chlo

rine

resi

d...

Turb

idity

Bac

terio

logi

ca...

0% 0%0%0%

1. pH

2. Chlorine residual

3. Turbidity

4. Bacteriological

1. pH

2. Chlorine residual

3. Turbidity

4. Bacteriological

Which of the following substances will reduce the effectiveness of chlorine

disinfection?

Which of the following substances will reduce the effectiveness of chlorine

disinfection?

colo

r

rado

n

Turb

idity

Car

bon dio

xide

0% 0%0%0%

1. color

2. radon

3. Turbidity

4. Carbon dioxide

1. color

2. radon

3. Turbidity

4. Carbon dioxide

According to the Interim Enhanced Surface Water Treatment Rule, a public water system serving a population of 10,000 or more must maintain the combined effluent turbidity of direct or conventional

filtration 95% of all measurements taken each month at :

According to the Interim Enhanced Surface Water Treatment Rule, a public water system serving a population of 10,000 or more must maintain the combined effluent turbidity of direct or conventional

filtration 95% of all measurements taken each month at :

0% 0%0%0%

1. ≤0.3 ntu

2. ≤0.5 ntu

3. ≤1.0 ntu

4. ≤5.0 ntu

1. ≤0.3 ntu

2. ≤0.5 ntu

3. ≤1.0 ntu

4. ≤5.0 ntu

The conductivity of the source water indicates the quantity of

dissolved material present

The conductivity of the source water indicates the quantity of

dissolved material present

Tru

e

Fal

se

0%0%

1. True

2. False

1. True

2. False

In general for every 10 units of Electrical Conductance reported represents 6 to 7 mg/L increases

of dissolved solids

In general for every 10 units of Electrical Conductance reported represents 6 to 7 mg/L increases

of dissolved solids

Tru

e

Fal

se

0%0%

1. True

2. False

1. True

2. False

Electrical Conductance is reported in mhos/cm at 25oC.

Electrical Conductance is reported in mhos/cm at 25oC.

Tru

e

Fal

se

0%0%

1. True

2. False

1. True

2. False

ColorColor

• Apparent color: from light that is reflecting off the particles (giving it a yellow or straw color)

• True color: tea color that remains after filtering (organic acids from vegetation)

• Units are CU or color units

• Apparent color: from light that is reflecting off the particles (giving it a yellow or straw color)

• True color: tea color that remains after filtering (organic acids from vegetation)

• Units are CU or color units

What is apparent color?What is apparent color?

Colo

r in a

sam

...

Colo

r in a

sam

...

Colo

r in a

sam

...

Colo

r in a

sam

...

0% 0%0%0%

1. Color in a sample after it is filtered

2. Color in a sample before it is filtered

3. Color in a sample after it is disinfected

4. Color in a sample before it is disinfected

1. Color in a sample after it is filtered

2. Color in a sample before it is filtered

3. Color in a sample after it is disinfected

4. Color in a sample before it is disinfected

__________ can interfere with a turbidity meter measurement.

__________ can interfere with a turbidity meter measurement.

SS c

oncentra

ti...

pH

Colo

r

Tem

perat

ure

0% 0%0%0%

1. SS concentration

2. pH

3. Color

4. Temperature

1. SS concentration

2. pH

3. Color

4. Temperature

Sludge accumulations in settling basins over a period of time

usually:

Sludge accumulations in settling basins over a period of time

usually:

Add h

ardne

ss t.

..

Incr

ease

the

a...

Res

ult in

tast

...

Res

ult in

the

...

0% 0%0%0%

1. Add hardness to the water

2. Increase the algae growth

3. Result in taste and odor problems

4. Result in the growth of pathogenic organisms

1. Add hardness to the water

2. Increase the algae growth

3. Result in taste and odor problems

4. Result in the growth of pathogenic organisms

As water temperatures decrease, the disinfecting action of

chlorine:

As water temperatures decrease, the disinfecting action of

chlorine:

0% 0%0%0%

1. Decreases

2. Increases

3. Remains the same

4. Depends on the altitude

1. Decreases

2. Increases

3. Remains the same

4. Depends on the altitude

As temperatures increase chemical reactions speed up

Arrhenius equation: reaction rate doubles every 10 degree celsius

As temperatures increase chemical reactions speed up

Arrhenius equation: reaction rate doubles every 10 degree celsius

Lake StratificationLake Stratification• Epilimnion- top of the lake• Thermocline- middle layer that may change depth

throughout the day• Hypolimnion- bottom layer

• Temperature change- from season create a cyclic pattern that is repeated from year to year.

• Epilimnion- top of the lake• Thermocline- middle layer that may change depth

throughout the day• Hypolimnion- bottom layer

• Temperature change- from season create a cyclic pattern that is repeated from year to year.

The formation of layers of different temperature in a body

of water is called what?

The formation of layers of different temperature in a body

of water is called what?

0% 0%0%0%

1. Thermal stratification

2. Thermal justification

3. Limnoptic layering

4. Limnoptic stratification

1. Thermal stratification

2. Thermal justification

3. Limnoptic layering

4. Limnoptic stratification

Reservoir turnover is? Reservoir turnover is?

0%

13%

0%

87%1. Related to the pH of

water

2. Caused by denser water at the surface sinking toward the bottom

3. Caused by wind cracking ice on the surface

4. Needed to control algae growth

1. Related to the pH of water

2. Caused by denser water at the surface sinking toward the bottom

3. Caused by wind cracking ice on the surface

4. Needed to control algae growth

Hard vs Soft WaterHard vs Soft WaterHardness:Ca+2 & Mg+2

250 mg/L *poor suds / soap ring*mineral buildup (scale)*fixture staining (white chalky)

*Ion exchange softening*Lime - soda softening*sequestering agents

1. Hard WaterHard water is any water containing an appreciable

quantity of dissolved minerals. > 250 mg/L (mostly Ca+2 and Mg+2).

Precipitates on pipes, Soap hard to lather because it reacts with Ca and Mg salts in hard water. Need to use ion exchange or treat with lime

1. Hard WaterHard water is any water containing an appreciable

quantity of dissolved minerals. > 250 mg/L (mostly Ca+2 and Mg+2).

Precipitates on pipes, Soap hard to lather because it reacts with Ca and Mg salts in hard water. Need to use ion exchange or treat with lime

2. Soft WaterSoft water is treated water in which the only cation

(positively charged ion) is sodium.

2. Soft WaterSoft water is treated water in which the only cation

(positively charged ion) is sodium.

Hardness #2340Hardness #2340

What are typical values in nature?

Classification mg/L

Soft 0 - 17.10 Slightly hard 17.1 - 60Moderately hard 60 - 120Hard 120 – 180Very Hard 180 & over

What are typical values in nature?

Classification mg/L

Soft 0 - 17.10 Slightly hard 17.1 - 60Moderately hard 60 - 120Hard 120 – 180Very Hard 180 & over

Drinking water average is about 250 mg/L as calcium carbonate hardness

Drinking water average is about 250 mg/L as calcium carbonate hardness

Hardness #2340Hardness #2340How is it done?How is it done?

Before w/ indicator Before w/ indicator

After EDTA titrationTo endpoint

After EDTA titrationTo endpoint

Hardness #2340Hardness #2340What are the units and conversions?

•hardness in mg/l as CaCO3

What are the units and conversions?

•hardness in mg/l as CaCO3

Calculations and Formulas?

Hardness as CaCO3 mg/L=

(ml of EDTA (sample) – ml of EDTA (blank))(0.01 M EDTA)(100 mg=CaCO3 milliMole)(1000 ml/L) ml of sample volume titrated

Calculations and Formulas?

Hardness as CaCO3 mg/L=

(ml of EDTA (sample) – ml of EDTA (blank))(0.01 M EDTA)(100 mg=CaCO3 milliMole)(1000 ml/L) ml of sample volume titrated

Hard Waters in the USAHard Waters in the USA

Alkalinity and hardness are both analyzed by adding a known reagent to the sample. This

process results in a ______ change.

Alkalinity and hardness are both analyzed by adding a known reagent to the sample. This

process results in a ______ change.

93%

7%0%0%

1. Color

2. Temperature

3. Time

4. Ionic strength

1. Color

2. Temperature

3. Time

4. Ionic strength

This is the titrant used for the Hardness analysis.

This is the titrant used for the Hardness analysis.

100%

0%0%0%

1. EDTA - A Chelating Agent

2. 0.03 N Sulfuric acid

3. 0.125 N Hydrochloric acid

4. Sodium hydroxide

1. EDTA - A Chelating Agent

2. 0.03 N Sulfuric acid

3. 0.125 N Hydrochloric acid

4. Sodium hydroxide

Hardness is defined as the sum of the _____ and ____ ions, although any divalent metal ion can contribute to

hardness.

Hardness is defined as the sum of the _____ and ____ ions, although any divalent metal ion can contribute to

hardness. 100%

0%0%0%

1. Calcium and Magnesium

2. Magnesium and Sodium

3. Calcium and Sulfate

4. Struvite

1. Calcium and Magnesium

2. Magnesium and Sodium

3. Calcium and Sulfate

4. Struvite

pHpH• Definition: The potential of hydrogen. Negative log of the

hydrogen ion activity/concentration.

• Formula pH= -log10(αH+)

• The pH scale:• -?.................................. 7 ....................................14• Acid Neutral Basic

• The pH range for drinking water is 6.5 to 8.5

• Definition: The potential of hydrogen. Negative log of the hydrogen ion activity/concentration.

• Formula pH= -log10(αH+)

• The pH scale:• -?.................................. 7 ....................................14• Acid Neutral Basic

• The pH range for drinking water is 6.5 to 8.5

Some characteristics of water, such as pH and dissolved oxygen, change so

quickly that they need to be measured immediately.

Some characteristics of water, such as pH and dissolved oxygen, change so

quickly that they need to be measured immediately.

Tru

e

Fal

se

27%

73%1. True

2. False

1. True

2. False

Acid-Base pH BalanceAcid-Base pH Balance

Figure 2.7Figure 2.7

Which of the following pH readings indicates an acidic

source water?

Which of the following pH readings indicates an acidic

source water?

94%

6%0%0%

1. 3

2. 7

3. 9

4. 12

1. 3

2. 7

3. 9

4. 12

A water with a pH value of 7.00 is considered to be:

A water with a pH value of 7.00 is considered to be:

8%0% 0%

92%

0%

1. Basic

2. Acidic

3. Hot

4. Neutral

5. Cold

1. Basic

2. Acidic

3. Hot

4. Neutral

5. Cold

When operating a surface water treatment plant, which of the following laboratory tests is of most significance for establishing chemical

dosages for coagulating water?:

When operating a surface water treatment plant, which of the following laboratory tests is of most significance for establishing chemical

dosages for coagulating water?:

33%

7%

47%

13%

0%

1. pH and alkalinity

2. Sulfates

3. Chlorides

4. Calcium and magnesium

5. Total hardness

1. pH and alkalinity

2. Sulfates

3. Chlorides

4. Calcium and magnesium

5. Total hardness

The pH is a measure of the concentration of _____ ____ in a

solution

The pH is a measure of the concentration of _____ ____ in a

solution

100%

0%0%0%

1. Hydrogen ions

2. Hydrozide ions

3. Acid equivalents

4. Base equivalents

1. Hydrogen ions

2. Hydrozide ions

3. Acid equivalents

4. Base equivalents

Which one of the following statements is true in regard to

the concept of pH?

Which one of the following statements is true in regard to

the concept of pH?

0% 0% 0%8%

92%1. pH indicates the amount of total alkalinity available.

2. A raw water sample with a pH of 6.5 is slightly basic.

3. The range of pH is between 0 and 14

4. A pH meter gives the percent hydrogen ion concentration as its direct readout value.

5. Accurate pH measurements on raw water require that a 24-hour flow-proporational sample be collected.

1. pH indicates the amount of total alkalinity available.

2. A raw water sample with a pH of 6.5 is slightly basic.

3. The range of pH is between 0 and 14

4. A pH meter gives the percent hydrogen ion concentration as its direct readout value.

5. Accurate pH measurements on raw water require that a 24-hour flow-proporational sample be collected.

pH sensors consist ofpH sensors consist of

31%

8%

62%1. A glass electrode and reference electrode

2. A pH electrode and temperature electrode

3. A junction electrode and null electrode

1. A glass electrode and reference electrode

2. A pH electrode and temperature electrode

3. A junction electrode and null electrode

The range of a pH analyzer isThe range of a pH analyzer is

0% 0%

100%

0%

1. 2 to 14 pH units

2. 4 to 14 pH units

3. 0 to 14 pH units

4. 1 to 14 pH units

1. 2 to 14 pH units

2. 4 to 14 pH units

3. 0 to 14 pH units

4. 1 to 14 pH units

pH sensors measure the activity of which ion?

pH sensors measure the activity of which ion?

0% 0%0%

100%1. Sodium

2. Hydrogen

3. Chlorine

4. Caustic

1. Sodium

2. Hydrogen

3. Chlorine

4. Caustic

What is the maximum recommended holding time for a sample that is to

be analyzed for pH?

What is the maximum recommended holding time for a sample that is to

be analyzed for pH?

93%

0%0%7%

1. None; it must be analyzed immediately

2. 48 hours

3. 7 days

4. 14 days

1. None; it must be analyzed immediately

2. 48 hours

3. 7 days

4. 14 days

What is the minimum number of pH standards needed for

calibration of a pH meter?

What is the minimum number of pH standards needed for

calibration of a pH meter?

44%

6%

25%25%

1. 1

2. 2

3. 3

4. 4

1. 1

2. 2

3. 3

4. 4

Temperature does not affect pH measurement.

Temperature does not affect pH measurement.

Tru

e

Fal

se

100%

0%

1. True

2. False

1. True

2. False

Water PropertiesWater Properties• Dipolar Molecule• High surface tension= hydrogen bonding• Expands upon freezing (10%)-more dense as liquid

– Freezing point 0oC boiling point 100oC. • Most abundant liquid on surface of earth• Exist in 3 phases on earth (Triple point)• Universal solvent• High heat capacity• High heat of fusion• High heat of evaporation• High heat of vaporization

• Dipolar Molecule• High surface tension= hydrogen bonding• Expands upon freezing (10%)-more dense as liquid

– Freezing point 0oC boiling point 100oC. • Most abundant liquid on surface of earth• Exist in 3 phases on earth (Triple point)• Universal solvent• High heat capacity• High heat of fusion• High heat of evaporation• High heat of vaporization

+

+

-

104.5°

Water ImpuritiesWater Impurities• Dissolved, Colloidal, and Suspended solids- (acid, base,

sand, clay, organics)• Inorganic acids: sulfuric, nitric, hydrochloric, carbonic• Bases: caustic soda, soda ash, hydrated lime• Salts: ferric chloride, aluminum sulfate, sodium chloride• Organics: volatile organic compounds (VOCs), synthetic

organic compound

• Dissolved, Colloidal, and Suspended solids- (acid, base, sand, clay, organics)

• Inorganic acids: sulfuric, nitric, hydrochloric, carbonic• Bases: caustic soda, soda ash, hydrated lime• Salts: ferric chloride, aluminum sulfate, sodium chloride• Organics: volatile organic compounds (VOCs), synthetic

organic compound

SMCL Water Quality Problem Treatment Methods

Iron 0.3 mg/L *red water complaints*taste and odor*staining of clothing and fixtures (red -brown)

*chlorine + filtration*aeration + filtration*manganese green sand + permanganate*sequestering agents

Manganese 0.05 mg/L *staining of clothing and fixtures (black or dark purple)

*chlorine + filtration*aeration + filtration*manganese green sand + permanganate*sequestering agents

Hardness:Ca+2 & Mg+2

250 mg/L *poor suds / soap ring*mineral buildup (scale)*fixture staining (white chalky)

*Ion exchange softening*Lime - soda softening*sequestering agents

Sulfate 250 mg/L *salty off taste*temporary diarrhea

*reverse osmosis / ion exchange

TDS 500 mg/L *high mineral content (salts) does not quench thirst, leaves mineral deposit

*reverse osmosis / ion exchange

Chloride 250 mg/L *salty taste*contributes to corrosion

*reverse osmosis / ion exchange

HydrogenSulfide

0.1 mg/L *rotten egg odor *oxidize with chlorine, chlorine dioxide or permanganate

Odor 3 T.O.N. *makes water un-palatable *permanganate*activated carbon (PAC, GAC)*flushing programs

Color 15 colorunits *makes water un-palatable *effective coagulation

pH Effect Water QualitypH Effect Water Quality• Disinfection with Chlorine:

– Water pH has a big impact on chlorine effectiveness. Chlorines effectiveness is reduced at pH values above pH 7.

• Corrosion: Lead and Copper. – Low pH tends to make water more corrosive. A basic

treatment technique to control lead and copper corrosion is to increase the pH.

• Coagulation of Turbidity– Alum, the most popular coagulant if very sensitive to

pH. Alum works best at a pH range of 6.5 - 7.5.

• Disinfection with Chlorine: – Water pH has a big impact on chlorine effectiveness.

Chlorines effectiveness is reduced at pH values above pH 7.

• Corrosion: Lead and Copper. – Low pH tends to make water more corrosive. A basic

treatment technique to control lead and copper corrosion is to increase the pH.

• Coagulation of Turbidity– Alum, the most popular coagulant if very sensitive to

pH. Alum works best at a pH range of 6.5 - 7.5.

pH AdjusterspH Adjusters

Raise pH Lower pH

Raise pH Lower pH

Soda ash X

Caustic soda X

Lime X

Sodium bicarbonate

X

Carbon dioxide X

Sulfuric acid X

TasteTaste

4 tastesSweetSaltyBitterSour

4 tastesSweetSaltyBitterSour

4 taste sensationshotcoolastringentacrid

4 taste sensationshotcoolastringentacrid

ODORODOR

• Treated or finished water is diluted with odor free water until there is no perceptible odor. The dilution factor needed to achieve no odor is the ODOR THRESHOLD NUMBER. Odor free water is produced by treating tap water with activated carbon.

• Treated or finished water is diluted with odor free water until there is no perceptible odor. The dilution factor needed to achieve no odor is the ODOR THRESHOLD NUMBER. Odor free water is produced by treating tap water with activated carbon.

Causes of Bad Taste and OdorCauses of Bad Taste and Odor

•Plankton: various species of algae, especially blue green algae

•Decayed vegetation-Decaying leaves are especially important in the late summer, early fall.

•Dissolved minerals/gasses: sulfates, chlorides, iron, etc.

•Industrial chemicals: phenolic compounds are especially a problem in very small concentrations, VOC, SOC,

•Plankton: various species of algae, especially blue green algae

•Decayed vegetation-Decaying leaves are especially important in the late summer, early fall.

•Dissolved minerals/gasses: sulfates, chlorides, iron, etc.

•Industrial chemicals: phenolic compounds are especially a problem in very small concentrations, VOC, SOC,

MCL Inorganics ReviewMCL Inorganics ReviewNitrate and NitriteMCL are: nitrate = 10 mg/L, nitrite = 1 mg/L, nitrate + nitrate = 10 mg/LBlue baby syndrome or methemeglobinemia, results in loss of oxygen to the brain, with possible brain damage. Infants 0 - 6 months most at risk.Sources include fertilizer, animal manure, and septic tank leachate

Lead and CopperAction Levels for lead and copper (When the Action Levels are exceeded, corrosion control is required), lead = 0.015 mg/L, copper = 1.3 mg/LThe health effect of lead is damage to the nervous system and lowered intellectual development, especially in developing children.The health effect of copper is minor, but can cause severe reaction in some individuals who are allergic to copper.Lead and copper are regulated in a Treatment Technique which requires systems to take tap water samples at sites with lead pipes or copper pipes that have lead solder and/or are served by lead service lines. The action level, which triggers water systems into taking treatment steps if exceeded in more than 10% of tap water samples, for copper is 1.3 mg/L, and for lead is 0.015mg/L.

FluorideFluoride MCL = 4 mg/LCauses mottling of teeth and may cause bone deformation or fluorosisFluoride is a naturally occurring mineral that is normally present in groundwater.

MCL IOC and SOCMCL IOC and SOCIOCsCertain inorganic chemicals can be toxic when found in drinking water. Health effects include nervous system damage and cancer. Some of the regulated IOCs:arsenic, antimony, asbestos, barium, beryllium, cadmium, chromium, copper, cyanide,

fluoride 4 mg/L, lead regulated by action levels as part of the lead/copper rulemercurynitrate, nitrite 10, 1 mg/L (nitrate + nitrite must not exceed 10)seleniumThallium

SOCsMCL, Health Effects, Sources, SamplingSynthetic Organic Chemicals make up most of the regulated contaminants in drinking water!

These chemicals are typically carcinogens. Examples of SOCs includePesticides like 2-4,D, methoxychlor, chlordane, di-methly bromide, dioxinSolvents like TCE, carbon tetrachloride, benzeneIndustrial chemicals like styrene, PCBs

IOCsCertain inorganic chemicals can be toxic when found in drinking water. Health effects include nervous system damage and cancer. Some of the regulated IOCs:arsenic, antimony, asbestos, barium, beryllium, cadmium, chromium, copper, cyanide,

fluoride 4 mg/L, lead regulated by action levels as part of the lead/copper rulemercurynitrate, nitrite 10, 1 mg/L (nitrate + nitrite must not exceed 10)seleniumThallium

SOCsMCL, Health Effects, Sources, SamplingSynthetic Organic Chemicals make up most of the regulated contaminants in drinking water!

These chemicals are typically carcinogens. Examples of SOCs includePesticides like 2-4,D, methoxychlor, chlordane, di-methly bromide, dioxinSolvents like TCE, carbon tetrachloride, benzeneIndustrial chemicals like styrene, PCBs

MCLs DPB, Radionuclides, VOCMCLs DPB, Radionuclides, VOCTHMs and other Disinfection By-Products (DBPs)Tri Halo Methane, or THM is the original regulated disinfection by-product. Most familiar is chloroform. THM MCL = 0.1 mg/L Considered a carcinogenTHMs form as the result of chlorine reacting with organic material in water, especially humus-like substances.Sampling required for chlorinated systems greater than 10,000 pop., once each quarter. A running average is calculated.Halogenated Acetic Acid, or HAA6 is an important new disinfection by-product

MCLs for disinfectants:*free chlorine

4 mg/L*chloramine

4 mg/L*chlorine dioxide

4 mg/L*ozone

0

RadionuclidesRadionuclides emit alpha, beta and gamma radiation that can result in an increased risk of cancer from exposure. Contamination of water is the result of natural radioactive minerals in geologic strata.

VOCsVolative Organic Compounds that are readily lost from water if it is exposed to air. They are a problem in groundwater not surface water. VOCs are chemicals used as solvents, cleaning agents, and gasoline additives VOCs are suspected carcinogens; examples are the gasoline additives called BTEX*benzene*toluene*ethylbenzene*xylene*MTBE is a new concern in drinking water!

MCL Microbiological & TurbidityMCL Microbiological & Turbidity

Coliform Bacteria and TurbidityColiform bacteria are generally harmless indicator bacteria. They indicate possible fecal contamination and the potential for waterborne pathogens to be present.No more than 5.0% samples total coliform‑positive in a month. (For water systems that collect fewer than 40 routine samples per month, no more than one sample can be total coliform‑positive). Every sample that has total coliforms must be analyzed for fecal coliforms. There cannot be any fecal coliforms. Fecal coliform and E. coli are bacteria whose presence indicates that the water may be contaminated with human animal wastes. Microbes in these wastes can cause diarrhea, cramps, nausea, headaches, or other symptoms.

Turbidity does not have a health effect. Turbidity is regulated for the following reasons:*it may interfere with the disinfection process*it may hide or protect microorganisms from the action of disinfectants

At no time can turbidity (cloudiness of water) go above 5 nephelolometric turbidity units (NTU); systems that filter must ensure that the turbidity go no higher than 1 NTU (0.5 NTU for conventional or direct filtration) in at least 95% of the daily samples in any month.

Breakpoint ChlorinationBreakpoint ChlorinationZone I: Chlorine is destroyed by reducing agents such as iron,

manganese, clay and silt. Chlorine reduced to chloride

Zone II: Chlorine comes into contact with organics and ammonia. Chloroorganics and chloramines are formed.

Zone III: Chloroorganics and chloramines are partially destroyed. Chloramines are broken down and converted to nitrogen gas which leaves the system

Zone IV: Breakpoint. Beyond this point, free available residual is formed. Some chloroorganics still remain as combined residual.

Chlorine demand is difference between applied chlorine and the free chlorine residual at any two points on the breakpoint curve.

Zone I: Chlorine is destroyed by reducing agents such as iron, manganese, clay and silt. Chlorine reduced to chloride

Zone II: Chlorine comes into contact with organics and ammonia. Chloroorganics and chloramines are formed.

Zone III: Chloroorganics and chloramines are partially destroyed. Chloramines are broken down and converted to nitrogen gas which leaves the system

Zone IV: Breakpoint. Beyond this point, free available residual is formed. Some chloroorganics still remain as combined residual.

Chlorine demand is difference between applied chlorine and the free chlorine residual at any two points on the breakpoint curve.

The objectives for this week to become familiar with basic characteristics of drinking water quality has been met

The objectives for this week to become familiar with basic characteristics of drinking water quality has been met

Stro

ngly A

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Agre

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63%

0%0%

38%

1. Strongly Agree

2. Agree

3. Disagree

4. Strongly Disagree

1. Strongly Agree

2. Agree

3. Disagree

4. Strongly Disagree