Water pollution is generally defined as the contamination of streams, rivers, lakes, oceans, or groundwater with substances produced through human activities and that negatively affect organisms. Its important to learn about water pollution because as a result of the pollution it has potential impact to both aquatic and terrestrial organisms.
Point sources are distinct locations such as particular factory that pumps its waste into a nearby stream or a sewage treatment plant that discharges its wastewater from a pipe into the ocean. Nonpoint sources are more diffuse areas such as an entire farming regio, a suburban community with many lawns and septic systems, or storm runoff from parking lots. The differ because in point sources we are able to distinguish exactly where the pollution is coming from while nonpoint we aren't.
The most common types of pollutants include human and anima waste, inorganic substances, organic compounds, synthetic organic compounds, and nonchemical pollutants. page 385
When BOD is higher values indicate that a water body is more polluted by waste water. Therefore high BOD influences bad water quality.
A dead zone is when there is so little oxygen, and therefore so little life. Nitrogen and phosphorous are generally the two most important elements for limiting the abundance of producers in aquatic ecosystems. The decomposition of wastewater-because it adds these elements- can provide an abundance of fertility to a water body, a phenomenon known as eutrophication. When a body of water experiences an increase in fertility due to anthropogenic inputs of nutrients this is called cultural eutrophication.
These pathogen cause cholera, hepatitis, typhoid fever, various types of stomach flu, and diarrhea. All of these are a threat because they can cause death.
The inorganic nutrients can still have undesirable effects on the waterways into which they are released. Although nitrogen and phosphorus are important nutrients for increasing primary productivity, when high concentrations of these nutrients are released into bodies of water from sewage treatment plants they fertilize the water, which can lead to large increases in the abundance of algae and aquatic plants.
One way is a septic system in which wastewater form a house is held in a large spetic tank where solids settle to the bottom and bacteria breaks down the sewage. The liquid moves through a pipe at the top of the tank and passes through perforated pipes that distribute the water through a leach field. Another one is a sewage treatment plant which in large municipalities, great volumes of wastewater are handled by separating the sludge from the ater and then using bacteria to break down both components.
Septic systems rely on gravity and no electricity is needed to run it. However a disadvantage is that sludge formt he septic tank must be pumped out periodically and taken to a sewage treatment plant. Dewage treatment plants are very effective at breaking down the organic matter into carbon dioxide and inorganic nutrients. However these inorganic nutrients can still have undesirable effects on the waterways into which they are released.
The bacteria in the treatment of human and animal waste simply breaks down the matter. This can be done in a manure lagoon. page 394
Lead poses serious health threat, especially in infants the lead and exposure can damage the brain, nervous system and kidneys. Arsenic is drinking water is associated with cancers of the skin, lungs, kidneys, and bladder. Inoragnic mercury is not particulary harmful, but its release into the enviroment can be hazardous because of a chemcial transformation it undergoes.
Wet-acid deposition occurs in the form of rain and snow, whereas dry-acid deposition occurs as gases and particles that attach to the surfaces of plants, soil, and water.
Some examples are pesticides, pharmaceuticals, and industrial cleaners. Synthetic