Chapter 22

Water Pollution and Treatment

Biochemical Oxygen Demand• The amount of oxygen required for

biochemical decomposition process

• 3 zonesA pollution zone

An active decomposition zone

A recovery zone

Draw 2 graphs:

Temp vs. O2

Pressure vs. O2

Waterborne Disease• Outbreaks of waterborne diseases

– Milwaukee, WI– Haiti Cholera Outbreak– Waterborne Disease is World’s Leading Killer

Nutrients

• Eutrophication– The process by which a body of water develops

a high concentration of nutrients

• Cultural Eutrophication– When eutrophication is accelerated by human

processes that add nutrients to a body of water

Acid Mine Drainage• Water with a high concentration of sulfuric

acid that drains from mines

• Serious water pollution problem

• Damages aquatic ecosystems, pollutes bodies of water and degrades water quality

Surface Water Pollution

• Water Pollutants are emitted from– Point Sources

• Distinct and confined sources such as pipes from industrial or sites

– Nonpoint Sources• Diffused and intermittent

• Ex) runoffs from streets

Groundwater Pollution• Bioremediation:

– a method of treating

groundwater pollution

problems that utilizes

microorganisms in the

ground to consume or

break down pollutants

Wastewater Treatment

• Septic Tank Disposal Systems

• Waste Treatment Plants– Primary Treatment– Secondary Treatment– Advanced Treatment– Chlorine Treatment

Wastewater Renovation and Conservation Cycle

• Steps:– 1. Return of treated wastewater to crops– 2. Renovation or natural purification by slow

percolation of the wastewater into soil to eventually recharge the groundwater resource with clean water

– 3. Reuse of the treated water

Water ReuseInadvertent: – water is withdrawn, treated and returned to the

environment

Indirect:– Ex) the wastewater renovation and conservation cycle

Direct:– The use of treated wastewater that is piped directly

from a treatment plant to the next user

Water Pollution and Environmental Law

• Environmental Law– The branch of law dealing with conservation

and use of natural resources and control of pollution

– Click here for an overview of the laws we have to protect our water and resources!