Water Chemistry

temperature

temperature

measure of the average kinetic energy of water molecules

Physical Properties

temperature, color, taste, odor, urbidity

Temperature

measure of the average kinetic energy of water molecules

Mean Annual Temperature

10 to 21 degrees Celsius

Color

indicates presence of organic substances and potentially toxic organic materials

colored water

unfit to drink

Taste

simple compounds - sour and salty; complex organic compounds - sweet and bitter

Odor

produced due to decomposition of organic matter; measured through H2S meter

Turbidity

light-transmitting properties of water and is composed of suspended and colloidal material

Total Suspended Solids (TSS)

small amounts of organic matter and inorganic salts in water

Solids

settleable (gravity) and suspended (colloid)

Chemical Characteristics

pH, salinity, alkalinity, hardness, major ions, heavy metals, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD)

pH Level

indicates acidity (0) to basicity (14) of water

Salinity

increases due to dissolved sodium, chloride, carbonate and sulfate

Alkalinity

measures the capacity of water to neutralize acids and protect aquatic life against rapid pH changes

Hardness

natural characteristic that enhances potability and is caused by presence of calcium and magnesium minerals

Major Ions

can influence chemical nature of natural water mineral content, and it occurs due to dissolved inorganic chemicals

Heavy Metals

metallic chemical elements that are toxic at low concentration and have a high density

Examples of Heavy Metals

mercury, arsenic, nickel, chromium, cadmium, lead, copper, cobalt

Dissolved Oxygen (DO)

needed by aquatic organisms to grow and survive

require high DO

trout and stoneflies

can survive with low DO

catfish, worms, dragonflies

Biochemical Oxygen Demand (BOD)

the amount of dissolved oxygen required by aerobic biological organisms to degrade the organic material present in a water body at a certain temperature over a specific time

used as indication of organic quality of water

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Chemical Oxygen Demand (COD)

the amount of oxygen needed to oxidize the organic matter in a water body considering specific conditions like temperature, time, and oxidizing agent

indicates the amount of organic materials that can be degraded by microorganisms

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calcium

healthy growth and bone development

magnesium

immune system, blood cell turnover and muscle movement

sodium

balancing electrolyte and water in body

fluoride

to reduce levels of tooth decay

Water Quality Indicators

DO, temperature, pH level, E.coli, specific conductance, nitrates, transparency

Escherichia Coli

fecal coliform bacteria from human and animal waste and can increase during flooding

Specific Conductance

electrical conductivity affected by inorganic dissolved solids

Nitrates

an organic compound that occurs under a variety of conditions and can increase algae growth

Transparency

how far light can penetrate water and is measured with Secchi disk

Types of Impurities

Physical, Chemical and Biological

Physical Impurities

turbidity, color, taste, odor, temperature, radioactivity

Chemical Impurities

organic compounds, pH level

Biological Impurities

caused by presence of living microorganisms

Types of Wastewater Collection Systems

Sanitary, Storm, Combined Sewer

Sanitary Sewer

collects commercial and household wastes

Storm Sewer

collects runoffs from streets, lands and roofs

Combined Sewer

collects sanitary and storm water