Aerobic Water Treatment

The two main ways to treat wastewater in the United States are through public sewage treatment plants and septic tanks. Both use a multi-step process to turn the water you flush down the toilet into water you can drink. Microorganisms play a huge part in this process. Systems that use microorganisms to treat wastewater fall into two classes: aerobic and anaerobic. Aerobic systems supply oxygen to the system and anaerobic systems are closed systems that do not. Aerobic systems are ideal for areas that do not have access to public treatment facilities, but cannot support a septic system.

Function

• Standard residential waste materials consist of proteins, fats, carbohydrates, detergents, soaps and urea. These products are made up of oxygen, carbon and hydrogen. Microorganisms treat water by breaking down waste, converting it into carbon dioxide and water. These microorganisms use oxygen as fuel to complete this process. Aerobic systems keep a constant supply of oxygen available to the microorganisms so they have a constant supply of fuel to do their job. They do not have to use the oxygen in the waste to complete the breakdown, so more oxygen is retained in the water, which is better for the environment.

Aerobic Microorganisms

• There is a wide range of aerobic bacteria at work in this process. Fungi, bacteria, rotifers, protozoa, along with other microbes, are naturally found in waste products. Harmful pathogens are only a tiny part of the array of bacteria in waste. These bacteria thrive on the compounds found in wastewater. By giving them a constant supply of waste and oxygen, aerobic treatment systems provide the ideal conditions for the bacteria to do their job and to multiply, which only make the process more efficient.

Impact

• Aerobic water treatment is eco-friendly, because the microorganisms invived are the ultimate recyclers. They take compounds we can't use, break them down into their simplest elements and release them back into the environment. These very same microorganisms exist in surface water, so any that make it out in the reclaimed water are not invading the water or causing a negative impact.

Large Systems

• Public waste treatment systems use both aerobic and anaerobic treatment processes in treating wastewater, but it is only one step of many. They also filter the water several times to remove solids, as well as disinfect and mineralize the water. Nature uses wetlands, which are full of aerobic microorganisms as part of their complex ecology, as a form of aerobic water treatment system.

Home Systems

• One of the better-known aerobic wastewater treatment systems for homes is the composting toilet. Waste enters a drum, where it is collected and stored. The drum is airtight so that smell won't leak out, except for a air tube with a chimney that allows for an outlet for smell and a constant supply of oxygen to the microorganisms in the drum. The system also contains a heater to keep the contents of the drum at the optimum temperature. The user turns the mixture periodically to keep an even mixture of liquid and solid in the drum and to regulate the internal temperature of the drum contents. Clean water drains out, and after a few months, the clean, dry solid residue is removed. Many use it as a fertilizer for plants and trees.