L5 And 6 Flashcards
What are the three main parameters used to assess water quality?
Physical, Chemical, and Biological parameters
List some physical parameters of water.
- Temperature
- Colour
- Odour
- Total suspended solids (TSS)
- Total dissolved solids (TDS)
- Taste
- Turbidity
- pH range
What does TSS stand for in water quality assessment?
Total Suspended Solids
What does TDS stand for in water quality assessment?
Total Dissolved Solids
Give examples of chemical parameters in water quality.
- Dissolved Oxygen (DO)
- BOD (Biochemical Oxygen Demand)
- COD (Chemical Oxygen Demand)
- Chloride (as Cl)
- Alkalinity (as CaCO3)
- Nitrate (as NO3)
- Nitrite (as NO2)
- Fluoride (as F)
- Total phosphates (as PO4)
- Total Hardness (as CaCO3)
- Total iron (as Fe)
- Sulphate (as SO4)
- Metals
- Pesticides
- Surfactants
What are some biological parameters used in water quality assessment?
- Escherichia coli (E. coli)
- Total Coliform bacteria
- Fecal Coliform bacteria
What can cause reddish color in water?
Iron-oxides
What is the Sri Lankan Standard (SLS) for Iron (Fe) in water?
0.3 mg/L
What is turbidity?
A measure of water clarity
What are the effects of turbidity on water?
- Diffuses sunlight
- Absorbs heat
- Clogs fish gills
- Reduces light for photosynthesis
- Increases water treatment costs
What device is used to measure turbidity?
Turbidimeter
What is the WHO standard for turbidity in water?
5 NTU
What is the pH scale range?
0 to 14
What is considered neutral pH?
pH 7
What happens if pH < 5.5 in water?
The water may be too acidic for aquatic organisms to survive
How is pH measured?
Using a pH-meter or pH paper
What is the normal pH range for surface water systems?
6.5 to 8.5
What is conductivity in water?
The measure of water’s ability to conduct an electric current
How is conductivity measured?
Using a Conductivity meter in microsiemens per centimeter (μS/cm)
What is total hardness in water?
The sum of Calcium hardness and Magnesium hardness
What are the two types of water hardness?
- Carbonate hardness (Temporary Hardness)
- Non-carbonate hardness (Permanent Hardness)
What is the Sri Lankan Standard (SLS) for total hardness in water?
250 mg/L as CaCO3
What are nontoxic metals commonly found in water?
- Sodium
- Iron
- Calcium
- Manganese
- Aluminum
- Copper
- Zinc
What are some toxic metals that may be found in water?
- Arsenic
- Barium
- Cadmium
- Chromium
- Lead
- Mercury
- Silver
What is bioaccumulation?
The increase in concentration of pollutants in an organism over time
What is biomagnification?
The increase in concentration of a substance in a food chain
What disease was caused by mercury poisoning in Japan?
Minamata disease
What is the Sri Lankan Standard (SLS) for fluoride in drinking water?
< 1.0 mg/L
What health issues can excessive fluoride intake cause?
Dental fluorosis and bone fluorosis
