Wastewater treatment is essential for maintaining proper balance throughout the world’s ecosystems. Wastewater contains toxic substances that harm wildlife and humans, including (and especially) aquatic life. This toxic water comes from a variety of sources, including sewage systems.
When organic matter enters a water source, like a river, aquatic lifeforms consume it as food. As the organic pollutants break down, the animals require more oxygen for the process. This leaves less oxygen in the water overall. When oxygen levels become dangerously low, animals in the water suffocate and die.
Wastewater is toxic
Although some fish and other animals can break down toxins, toxic water is a serious risk to human health and is responsible for millions of deaths each year, mostly in developing nations.
Unclean water also causes diseases like cholera and schistosomiasis. Although these diseases generally occur in developing countries that don’t treat their wastewater, they can occur anywhere.
What is wastewater treatment? How does it work?
Wastewater treatment is the process of filtering contaminants out of water that has been previously used for another purpose. This process can occur both naturally and through manmade efforts.
Our ecosystem has a natural water treatment system that involves microorganisms that eat waste material, along with different layers of substrate and soil that filter the water as it absorbs into the earth. However, this process is too slow to efficiently filter the enormous amount of wastewater produced by humans. That’s where water treatment facilities come into play.
Water treatment plants are complex systems
What exactly happens at a wastewater treatment plant? While there are different methods, some of the systems use similar components. For example, the Four Rivers Sanitation Authority in Illinois treats wastewater by first pumping it to a higher elevation for gravity to pull the water through the first part of the treatment and filtering process.
The treatment process begins by filtering out the largest debris like plastic to prevent the pumps from becoming damaged. Debris that gets filtered out is then sent to a landfill.
Next, abrasive materials like sand and coffee grounds are filtered out of the wastewater. This grit is separated and sent to a landfill.
Settling tanks are then used to filter out fats, oils, and greases. These tanks also separate solids, most of which are sent to a separate processing facility. A small amount of solids are sent to the aeration tanks to maintain the proper environment required for microorganisms to devour the solids.
The water is then processed through a second set of settling tanks and is then disinfected with high-powered bleach. Sodium bisulfite is used to reduce the amount of chlorine in the water to make it less harmful to plant life when it’s discharged into the river.
What is in wastewater, exactly?
Since wastewater comes from human use, thousands of contaminants are present, although not all are present in every batch of water. In general, there are both inorganic and organic compounds found in wastewater.
Organic matter found in wastewater includes:
- Synthetic compounds from detergents
Inorganic matter found in wastewater includes:
Most of these contaminants come from industrial wastewater and aren’t easily broken down. When these inorganic compounds collect in water sources, they build up over time, making the water increasingly toxic to animals and humans.
Other matter found in wastewater includes:
- Nutrients: High levels of nitrogen and phosphorous create “dead zones” by feeding large algae blooms. These blooms block sunlight, causing plants to die. Bacteria then proliferate by feeding on the dead plant matter.
- Microorganisms: Harmful microorganisms include E. coli, parasites, and bacteria.
- Pharmaceuticals: Pharmaceuticals enter wastewater through human waste and people flushing drugs down the toilet.
Wastewater treatment can help with water scarcity
There are many places across the world that experience droughts and water shortages on a regular basis. Without treating wastewater, drinking water sources become (and remain) contaminated. This includes rivers, lakes, and streams.
Treating wastewater in these areas would provide residents with a clean source of water to use for drinking, washing clothes, and bathing. After continually treating the wastewater, it would eventually bring the rivers, lakes, and streams back to a less-polluted state over a long period of time.
However, getting a treatment system set up takes money, time, and resources. The nations that need it the most can afford it the least. However, there are people and organizations working on solutions to this problem.
It’s not an overnight fix, but hopefully, one of those organizations will soon create a successful model that works for developing nations.