Water Pollution: Eutrophication & Sewage

• Excessive nutrients from fertilizers wash into bodies of water through rain.
• Pollutants from fertilizers cause rapid growth of aquatic producers.
• An algal bloom on the pond's surface prevents sunlight from entering the water.
• Algae use up minerals and block sunlight, leading to their death.
• Algae are then decomposed by aerobic bacteria, which consumes most of the oxygen.
• Oxygen levels drop, causing fish and other pond organisms to die.
• Eutrophication is the process where excessive nutrients in a body of water lead to dense plant growth and the death of animal life due to lack of oxygen.
• Pesticides can contaminate water when washed into bodies of water by rain.
• Pesticides can accumulate in aquatic organisms through bioaccumulation.
• Washed-away pesticides affect entire aquatic food chains and food webs.

Sewage Wastewater

• Sewage is wastewater coming from domestic sources, industrial sources, or surface runoff.
• A significant level of water pollution is due to improper sewage disposal.
• Domestic sewage originates from residences and contains bodily wastes, food preparation wastes, laundry wastes, and household waste products.
• Industrial sewage results from industrial processes, such as the production or manufacture of goods.
• Surface runoff is precipitation that runs over the ground and reaches bodies of water.
• Surface runoff can carry gases and particulates absorbed by precipitation, dirt, solid or liquid particles washed from roads, and particles from washed-away soil.

Negative Effects of Improper Sewage Disposal

• Untreated or unprocessed sewage contains harmful materials that can damage ecosystems.
• Industrial effluents in sewage often contain harmful and toxic heavy metals like lead and mercury.
• These metals threaten the survival of fish and other aquatic organisms.
• Toxic substances from industrial sewage can bioaccumulate in food chains, posing a hazard to aquatic organisms and humans.
• Sewage can increase water turbidity, reducing light availability for plant growth and clogging fish gills.
• Sewage can increase the acidity of water due to acids in industrial sewage or acidic rainwater.
• Increased acidity can negatively affect aquatic species that cannot adapt to such pH levels.
• Sewage can alter water temperature, leading to thermal pollution.
• Thermal pollution can seriously harm ectothermic aquatic organisms with temperature changes affecting the survival of fish eggs, larvae, and aquatic insects.
• Sudden changes in water temperature from factory coolants can cause thermal shock, leading to organism death or ecosystem disappearance.
• Hot sewage from power stations decreases the oxygen content in water because hot water holds less dissolved gases than cold water.
• Increased water temperature and organic/inorganic matter in sewage can cause algal blooms and eutrophication.
• Microbial pathogens introduced by sewage can threaten public health by causing disease outbreaks in surface or groundwater.

Thermal Pollution

• Sewage can cause thermal pollution because the temperature of sewage water can be higher or lower than the water receiving the wastewater.

Female Contraceptive Hormones

• Female contraceptive pills contain synthetic hormones like estrogen and progesterone.
• The female body excretes most of these hormones in urine, which becomes part of sewage.
• Untreated wastewater containing these hormones can negatively affect aquatic animals.
• Male fish exposed to these hormones may experience decreased sperm production or change gender from male to female.
• Ingesting water containing these hormones may be linked to decreased sperm production in men.
• Other sources of synthetic and natural estrogens include products from livestock raised to increase milk production.

Explore water pollution caused by fertilizers, leading to eutrophication and its impact on aquatic life. Learn about algal blooms, oxygen depletion, and the effects of pesticides on food chains. Understand the sources and consequences of sewage wastewater.