Water Pollution: Contaminants and Testing Procedures Presented by M. Baranitharan Computer Science and Engineering Kings College of Engineering
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Water Pollution:Contaminants and Testing Procedures
Presented byM. Baranitharan
Computer Science and EngineeringKings College of Engineering
What is Water Pollution?
• Water pollution - any change in water quality that harms humans or other living organisms or makes water unsuitable for desired uses.
Application: “The Mistake by the River”
Cuyahoga River in the Fall©Tom Jones
http://csudigitalhumanities.org/exhibits/items/show/1328
A Burning River?
The Plain Dealer File
http://oceanservice.noaa.gov/education/kits/pollution/02history.html
http://www.youtube.com/watch?v=tZA9OX2joUc&feature=related
What are the sources of water pollution?
• Point Sources– Can be traced back to one
particular origin• Industrial Plants (Power,
Chemical, Waste Treatment)• Drain pipes, Sewer Lines,
Underground Mines
• Nonpoint Sources– Tend to be widespread with
many regions contributing to the water pollution.
• Agricultural Runoff• Stormwater Runoff (Roads and
Parking Lots)Fig. 11-23, p. 260
Types of Contaminants• Pathogens – Wastes from Humans and Animals• Plant Nutrients – Nitrates & Phosphates• Organics – Oil, Gasoline, Plastics, & Pesticides• Inorganics – Salt, Metal Compounds• Sediment – Total Suspended Solids• Heavy Metals• Thermal
Most Commonly Tested Parameters
• Temperature• pH• Nitrates• Phosphates• Dissolved Oxygen• Turbidity• Specific Conductivity• Total Dissolved Solids• Total Suspended Solids
Water Quality Index
Water Quality Index (WQI) is a measure of how polluted a body of water actually is.
It can take many different parameters into consideration. (6 parameters are typically used to calculate WQI)
Utilizes a weighting factor to differentiate between important parameters and less-important parameters.
Q-Values are numbers that are given in a table and correlate to the level of each parameter to characterize each on a scale of 0-100 (100 being best)
Water Quality Index
Test Result Q-Value Weight Factor Subtotal Dissolved Oxygen 103.1% Sat. 0.17
Fecal Coliform 2 / 100mL 0.16
pH 7.59 0.11
BOD (5-day) 1.75 mg/l 0.11
Temperature 1°C 0.10
Phosphates .45 mg/l 0.10
Nitrates .6 mg/l 0.10
Turbidity 50 cm 0.08
Total WQI
Water Quality Index
Test Results
Q-Value
Q-Value X
Weighting Factor
Add all Subtotals
Water Quality Index
Parameter Tested Value
Q-Value Weighting Factor
Calculation
Dissolved Oxygen
90 0.3
Nitrate 1.75 0.2
Phosphate 0.3 0.2
pH 6.70 0.3
Totals
Water Quality Index
Dissolved Oxygen: % saturation = 90
1. In the DO column find the value equal to 90.
2. Write down the Q-Value to the right of that number (Q-value = 95).
Water Quality Index
Parameter Tested Value
Q-Value Weighting Factor
Calculation
Dissolved Oxygen
90 95 0.3 95 X 0.3 = 28.5
Nitrate 1.75 0.2
Phosphate 0.3 0.2
pH 6.70 0.3
Totals
Water Quality Index
Nitrate: 1.75 mg/L
1. In the Nitrate-N Column find the values closest to 1.75. This number falls between 1.5 and 2 in this column
2. Since there is no value matching exactly to 1.75, estimate the Q-value between 92 and 90 (Q-value = 91).
Water Quality Index
Parameter Tested Value
Q-Value Weighting Factor
Calculation
Dissolved Oxygen
90 95 0.3 28.5
Nitrate 1.75 91 0.2 91 X 0.2 = 18.2
Phosphate 0.3 0.2
pH 6.70 0.3
Totals
Water Quality Index
Phosphate: 0.3 mg/L
Water Quality Index
Phosphate: 0.3 mg/L
1. In the Total Phosphate column find the value equal to 0.3 (similar to the dissolved oxygen).
2. Write down the Q-Value to the right of that number (Q-value = 90).
Water Quality Index
Parameter Tested Value
Q-Value Weighting Factor
Calculation
Dissolved Oxygen
90 95 0.3 28.5
Nitrate 1.75 91 0.2 18.2
Phosphate 0.3 90 0.2 90 X 0.2 = 18.0
pH 6.70 0.3
Totals
Water Quality Index
pH: 6.70
1. In the pH column find the values closest to 6.70. This number falls between 6 and 7.
2. Since there is no value matching exactly to 6.70, estimate the Q-value between 55 and 90 (Q-value = 81).
Water Quality Index
pH 6 7
Q-value 55 90
Water Quality Index
pH 6 6.5 7
Q-value 55 72.5 90
(55+90) / 2 = 72.5
Water Quality Index
pH 6 6.5 6.75 7
Q-value 55 72.5 81.25 90
(72.5+90) / 2 = 81.25
Water Quality Index
Parameter Tested Value
Q-Value Weighting Factor
Calculation
Dissolved Oxygen
90 95 0.3 28.5
Nitrate 1.75 91 0.2 18.2
Phosphate 0.3 90 0.2 18.0
pH 6.70 81 0.3 81 X 0.3 = 24.3
Totals
Water Quality Index
Parameter Tested Value
Q-Value Weighting Factor
Calculation
Dissolved Oxygen
90 95 0.3 28.5
Nitrate 1.75 91 0.2 18.2
Phosphate 0.3 90 0.2 18.0
pH 6.70 81 0.3 24.3
Totals 28.5 + 18.2 + 18.0 + 24.3
= 89.0
Water Quality Index
Water Quality Percentages
Excellent 90-100%
Good 70-90%
Medium 50-70%
Bad 25-50%
Very Bad 0-25%
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