Aerobic Vs Anaerobic Wastewater Treatment

To protect human health, wastewater treatment is a crucial process that needs to be properly maintained. The process of biological wastewater treatment is one of the four main processes in the treatment of wastewater. 

In biological wastewater treatment, there are two methods named aerobic wastewater treatment and anaerobic wastewater treatment. While anaerobic wastewater treatment does not require oxygen, aerobic wastewater treatment does.

Anaerobic organisms treat wastewater anaerobically, while aerobic organisms handle the process of treating wastewater aerobically. This is how aerobic and anaerobic wastewater treatment differ.

In this post, we’ve discussed various ways to distinguish between and describe the differences between these two wastewater treatment methods and we have covered the following topics:

1. Process of Wastewater Treatment
2. Aerobic Wastewater Treatment
3. Different Types of Aerobic Treatments
4. Anaerobic Wastewater Treatment
5. Different Types of Anaerobic Treatment
6. Major Differences between Aerobic and Anaerobic Wastewater Treatments

1. Primary treatment, 
2. Secondary or biological treatment, 
3. Tertiary treatment, and 
4. Anaerobic digestion.

The most important step in the wastewater treatment process is biological wastewater treatment, which is carried out by creatures like microbes, nematodes, tiny organisms, etc. 

These microbes decompose the organic material in the wastewater. After initial treatment, biological treatment is used to further remove organic debris from wastewater. 

The terms aerobic wastewater treatment and anaerobic wastewater treatment refer to two different biological treatment methods. Let us understand both these treatments separately.

Aerobic organisms, which require oxygen for the breaking process, control the aerobic wastewater treatment process. Tanks used for aerobic wastewater treatment are continuously oxygenated. By moving air through the tanks, it has been accomplished.

A sufficient amount of oxygen should be present in the aerobic tanks at all times for aerobic organisms to function properly. As a result, optimum aeration is kept throughout aerobic therapy. Attached culture systems, also known as fixed-film reactors, and suspended culture systems, are the two basic categories of aerobic wastewater treatment.

In an attached culture system, wastewater is routed over the microbial surfaces while biomass is grown on solid surfaces or mediums. Two associated culture systems are a revolving biological contactor and a trickling filter. 

Biomass and wastewater are combined in suspended culture systems. Popular suspended culture systems include the oxidation ditch and the activated sludge systems.

Equipment like surface aerators or diffusers is frequently used in aerobic wastewater treatment to mix air into the water column. When using surface aerators, the mechanical churning on the wastewater’s surface mixes in oxygen. 

The air bubbles that rise from the tank’s bottom with diffusers aid in the transport of oxygen. Beneficial oxygen-feeding bacteria, protozoa, and other waterborne microbes are stimulated by the oxygen present to aid in the treatment of waste by decomposing organic materials.

Here are a few various aerobic wastewater treatment methods and how they operate:

1. Activated sludge: 

An aeration tank with aerators or diffusers is used in the activated sludge process. Large bacteria-filled pieces called flocs are created as the organic content in the trash decomposes. The flocs then sink to the tank’s bottom, where it is simple to remove them. 

The resultant activated sludge may then be reintroduced into earlier stages of treatment by wastewater treatment facilities so the bacteria can help with waste breakdown.

2. Fixed-bed bioreactors: 

Fixed-bed bioreactors (FBBRs) squeeze tens of thousands of microscopic media components into small spaces. The media elements don’t move, and the large amount of surface area they have draws bacteria, which stick to the surfaces and create a biofilm. 

The bacteria then aid in the degradation of garbage. Anoxic denitrification zones are permitted in several of these chambers as well.

3. Moving-bed bioreactors: 

In a sizable tank of effluent, hundreds of microscopic media carriers are suspended in the water. The suspended media carriers are free to float and offer microorganisms a favorable habitat for growth. 

The media carriers aid in the digestion of organic waste material because they offer a large surface area for helpful microorganisms to flourish on.

4. Membrane bioreactors: 

Using cutting-edge technology, membrane bioreactors (MBRs) can handle wastewater with extremely high suspended solids contents. 

MBRs function by fusing membrane filtration with activated sludge processes. They successfully separate and recycle the suspended solids to treat the trash.

In the biological process of anaerobic wastewater treatment, bacteria, in particular, break down organic material in the wastewater in the absence of oxygen. One common method for treating anaerobic wastewater is anaerobic digestion.

Anaerobic bacteria break down organic substances. The entry of air into anaerobic tanks must be stopped for optimal anaerobic digestion of organic materials. Carbon dioxide and methane (methane is biogas) are created during anaerobic digestion.

Consequently, biogas can be generated through the anaerobic digestion process and also can be used as electricity. The four main processes of the anaerobic wastewater treatment process are hydrolysis, acidogenesis, acetogenesis, and methanogenesis. Anaerobic microorganisms, particularly bacteria and archaea, control all of these processes.

The following are some examples of various anaerobic wastewater treatment devices and how they operate: 

1. Lagoons: 

Large ponds are anaerobic lagoons. They are frequently employed by plants in the initial stages of the industrial, agricultural, and municipal wastewater treatment processes. 

Water settles into distinct strata in the lagoons, with liquid placed over sludge to prevent oxygen from reaching it during microbial digestion.

2. Sludge blanket reactors: 

Anaerobic sludge blanket reactors pass wastewater over a sludge layer that floats like a blanket. 

Anaerobic bacteria break down the organic material as the wastewater travels through the sludge, and the facility can recycle the pieces that collect at the bottom of the tank for use in other procedures.

3. Anaerobic filter reactors: 

It uses a tank with a filter medium connected. A biofilm is created when microorganisms adhere to the filter medium. 

The biofilm and associated bacteria are efficient in reducing organic materials in wastewater after they have formed.

For the following reasons, the anaerobic wastewater treatment method is often more cost-effective:

• It is possible to enhance soil using the sludge left behind after anaerobic wastewater treatment.
• As a sustainable energy source that successfully displaces fossil fuels, biogas can be used to generate power and heat.

The anaerobic wastewater treatment procedure ensures that the methane-rich biogases are effectively released. To reduce its negative effects on the environment, methane should be flared.

Make Aquamech your trusted source for all types of wastewater treatment:

Contact Aquamech to receive high-quality solutions and guidance on the best wastewater treatment for your business. 

We provide several customized solutions for wastewater treatment and our technical teams have the knowledge and the problem-solving skills to design complete systems.

To discuss a design, or installation, or to learn more about what Aquamech can provide, get in touch with our design head, Navdeep Singh Sethi.