02/25/2020 | Aeration Wastewater Treatment | 9 MINUTE READ
Aeration Systems for Wastewater Treatment
Wastewater aeration is a process that occurs when air is added directly to wastewater, which allows for aerobic bio-degradation of any pollutants contained within. Aeration is an essential component of treating wastewater.
The main benefit of using aeration is that it’s a natural method of getting rid of pollutants in the water. The chemicals that are used with other treatment systems can be harmful when used in high amounts. On the other hand, the aeration process uses microorganisms that already exist within wastewater to degrade the contaminants.
Aeration is important because it’s highly effective, economically viable, and great for the environment compared to other options. When the aeration process occurs, oxygen is provided to bacteria for the treatment and stabilization of wastewater. The bacteria requires oxygen in order to go through the bio-degradation process. When the bacteria is supplied with enough oxygen, it will break down all of the organic matter that’s comprised of carbon into water and carbon dioxide.
This article will go in depth about the various types of aeration systems that you can select for your wastewater treatment facility.
Types of Aeration Systems
There are three essential types of aeration systems that can be used in a wastewater treatment facility, which include a packed-tower aerator, a diffused-bubble aerator, and a spray aerator. It’s important to understand the difference between these types of aerators because each system operates differently and comes with its own benefits that you might want to be aware of before making a decision.
A packed-tower aerator is a system that consists of a tower that’s filled entirely with packing material.
These towels can be up to 10-feet tall, which means that you’ll need ample space in your facility if you want to use this aeration system. The packing material that’s contained inside of a packed tower can be anywhere from 1/2 inch to three inches in size and can consist of small pieces of plastic or ceramic. While different materials can be used with this type of aeration system, there’s no benefit towards using one material over another.
However, it’s been found that smaller pieces of material allow for better efficiency while increasing energy costs at the same time. When using this system, wastewater will fall from the upmost portion of the tower while air is blown upwards into the water. The contaminants will transfer to the air from the water before being vented outside, which makes this is a very straightforward type of aeration system.
The main benefits that come with using a packed tower system include:
- The system is relatively easy to maintain
- You can directly control the efficiency of the system by alternating between different sizes of packing materials
- These systems are known to be highly effective at getting rid of contaminants
- Can eliminate volatile contaminants from the water more effectively than other systems
A few concerns that you should keep in mind with these aeration systems include:
- Can take up a significant amount of space
- The contaminants removed from the water may need to be taken through off-gas treatment
- Better efficiency directly correlates to higher energy costs
A diffused-bubble aerator is likely the most popular type of aeration system that consists of numerous chambers as well as a diffuser that air blows through.
The diffuser will create small bubbles that flow through each chamber. The bubbles carry the chemicals and contaminants that you’re trying to get rid of. Once the contaminants flow through the entire vent system, they will be sent into the outside air. A higher number of chambers in a diffused-bubble aerator allows for a more efficient system. A small number of these aerators are outfitted with a switch that will trip an alarm in the event that the chambers are close to flooding. While there are several different types of diffused-bubble aerators, each one operates in a similar fashion.
The primary benefits that come with using a diffused-bubble aerator for wastewater treatment include:
- Can be effectively used with deep tanks
- Have a flexible design
- Offer better efficiency than other types of aeration systems
- The blower is easy to manage
- Low maintenance requirements along with a low environmental impact
- Highly durable, which offers longevity
- Consistent performance in extreme weather
The main issues with come with a diffused-bubble aerator include:
- High upfront costs
- Higher complexity than other systems
- Low efficiency in shallow tanks
- Susceptible to fouling
- Become less effective in worse environments
A spray aerator is a type of system that’s designed to get rid of low amounts of volatile contaminants.
When using this particular system, water will enter at the very top of the system before materializing from spray heads in a very fine mist. The water that has been treated by a spray aerator is collected within a vented tank that’s situated under the spray heads. The collected contaminants will then be released and vented outside.
The benefits of using a spray aerator for your wastewater treatment needs include:
- This type of system is particularly effective at getting rid of such volatile contaminants as radon
- It’s a very simplistic system that’s easy to maintain
- Helps to oxidize manganese and iron
- Effectively increases the amount of dissolved oxygen within the water
- Is relatively affordable compared to other aeration systems
- Typically doesn’t take up too much space
On the other hand, there are some downsides to using a spray aerator, the primary of which include:
- These systems are less efficient when you’re attempting to treat high amounts of wastewater
- They are more limited in scope when compared to the other systems in this article
- The spray heads may need to be cleaned regularly if the water consists of high amounts of iron and manganese
Maintenance of Aeration Systems
Once you’ve selected an aeration system that meets your needs, you’ll likely want to perform regular maintenance on your system of choice. Maintaining an aeration system is important because a lack of maintenance will cause the system to become much less effective and efficient, which will increase your costs of operation. If you select a diffused-bubble aerator or packed-tower aerator, the blower will need to be maintained consistently by switching the old air filters with new ones and by lubricating the motor. It’s highly recommended that you keep some kind of log book of all of the maintenance that you perform over the years. This log book should also include records of your water test results, which will allow you to keep track of the efficacy of the aeration system.
When you’re using one of the three types of aeration systems available to you, it’s also important that the area is properly ventilated. The trays and tanks within the aeration system should be cleaned occasionally as well, which is necessary if you want to get rid of the buildup of rust, algae, and sulfur. All of these substances can make your system less efficient.
If you follow these maintenance guidelines, you should be able to keep your aeration system in great shape, which will increase the lifespan of the system while also allowing you to save money on repairs.
Why Aeration Wastewater Treatment?
Using an aeration system for wastewater treatment is highly important if you want to keep costs down and make sure that your business is as Eco-friendly as possible. By using the activated-sludge method of wastewater treatment, it’s possible to get rid of the contaminants in the wastewater without having to use any kind of chemicals, which is better for the environment. The activated-sludge process is also highly efficient and can save you a significant amount of time and money when it comes to treating wastewater.
If the oxygen supply with your aeration system of choice is distributed evenly and at the right amounts, the organic matter in the wastewater will be broken down into harmless substances. Other treatment methods for wastewater are less effective and are typically more harmful to the environment. It’s essential that you effectively treat wastewater because it gives you the ability to eliminate as many suspended solids from the water as possible before the water is sent back into the environment. When solid materials are left in the water, they will eventually begin to decay, which is a process that uses up nearby oxygen.
This oxygen is necessary for animals and plants that live in the water, which is why contaminated water is very bad for the environment. If you want to make sure that your method of wastewater treatment is effective, it’s highly recommended that you use an aeration system. If you don’t properly treat the water, solid materials won’t be eliminated before the water is sent into the environment, which can do significant harm to the environment.
How to Pick the Right Aeration System for Your Wastewater Treatment
When you’re trying to choose the right aeration system for your wastewater treatment needs, some of the factors that will determine which option is the best one include:
- Your maintenance cost, energy cost, and capital cost goals
- Total wastewater volume
- Oxygen requirements for the wastewater
- Plant climate and location
- Efficiency requirements
- Tank size
- Your maintenance reduction goals
When you’re looking at all of your options, make sure that you determine how effective the system will be with different tank sizes. For instance, diffused-bubble aerators are less effective when used with small tanks. It’s also important that you determine how much wastewater you need to treat at a given time. Spray aerator are typically unable to treat as much wastewater as diffused-bubble and packed-tower aerators.
Because of how important it is that you properly treat wastewater before it’s sent into the environment, you might want to think about measuring the water after it’s been treated, which can be performed by using any number of the water treatment sensors that we provide here at Sensorex. There are also many different types of sensors that can be used to ascertain the quality of water, the primary of which include pH sensors and conductivity sensors. You could also use a dissolved oxygen sensor since aeration directly increases the amount of dissolved oxygen that enters the water.
For your wastewater treatment needs, it’s recommended that you consider selecting a long-lasting sensor that will hold up to rigorous use. On that front, you could select the SD7500CD sensor for pH, the SensoPRO monitoring system for conductivity, or the Lumin-S optical sensor for dissolved oxygen.
Posted by Sensorex on February 25, 2020
Sensorex is a global leader in the design and manufacture of quality sensors for water quality and process applications. The company offers more than 2000 sensor packages for pH, ORP, conductivity, dissolved oxygen, free chlorine, chlorine dioxide, UV transmittance and other specialty measurements, as well as a full line of sensor accessories and transmitters. Its expert technical support engineers solve analytical sensor challenges with custom designs and off the shelf products.