Difference Between Aerobic and Anaerobic Wastewater Treatment

Key Difference – Aerobic vs Anaerobic Wastewater Treatment
 

Proper wastewater treatment is an important requirement to prevent waterborne diseases and maintain a healthy environment for organisms. A treatment process which involves microbes or living organisms is named as biological wastewater treatment. There are two types of biological waste water treatments namely aerobic wastewater treatment and anaerobic waste water treatment. Aerobic wastewater treatment is carried out by aerobic microorganisms. Aerobic microorganisms require oxygen; hence, oxygen is supplied for aerobic wastewater treatment tanks. Anaerobic wastewater treatment is carried out by anaerobic microorganisms. Thus, anaerobic wastewater treatment process occurs without an oxygen supply. The key difference between aerobic and anaerobic wastewater treatment is that in aerobic wastewater treatment, treatment tanks are constantly supplied with oxygen while, in anaerobic wastewater treatment, gaseous oxygen is prevented from entering into the system.

CONTENTS

1. Overview and Key Difference
2. How is Wastewater Treatment Carried Out
3. What is Aerobic Wastewater Treatment
4. What is Anaerobic Wastewater Treatment
5. Similarities Between Aerobic and Anaerobic Wastewater Treatment
6. Side by Side Comparison – Aerobic vs Anaerobic Wastewater Treatment in Tabular Form
7. Summary

How is Wastewater Treatment Carried Out?

Wastewater treatment process occurs via several major steps such as preliminary treatment, primary treatment, secondary or biological treatment, tertiary treatment and anaerobic digestion. Biological wastewater treatment is the key step in the wastewater treatment process, and it is carried out by organisms such as microorganisms, nematodes, small organisms, etc. The organic matter present in the wastewater is broken down by these organisms. Biological treatment comes after the primary treatment for further removal of organic matter in the wastewater. As mentioned above, there are two types of biological treatments named aerobic wastewater treatment and anaerobic waste water treatment.

What is Aerobic Wastewater Treatment?

Aerobic wastewater treatment process is governed by aerobic organisms which need oxygen for the breaking process. Aerobic wastewater treatment tanks are constantly supplied with oxygen. It is been done by circulating air through the tanks. For effective functioning of aerobic organisms, sufficient amounts of oxygen should be present in the aerobic tanks at all times. Therefore, aeration is properly maintained throughout aerobic treatment.

There are two main types of aerobic wastewater treatments: attached culture systems or fixed film reactors and suspended culture systems.

Attached Culture System

In attached culture system, biomass is grown on solid surfaces or media and wastewater is passed over the microbial surfaces. Trickling filter and rotating biological contactor are two attached culture systems.

Suspended Culture System

In suspended culture systems, biomass is mixed with wastewater. Activated sludge system and oxidation ditch are two popular suspended culture systems.

What is Anaerobic Wastewater Treatment?

Anaerobic wastewater treatment is a biological treatment process where organisms, especially bacteria, break down organic material in the wastewater in an oxygen absent environment. Anaerobic digestion is a well-known anaerobic wastewater treatment process. The degradation of organic material is done anaerobically. For the effective anaerobic digestion of organic materials, the entry of air into anaerobic tanks is prevented. During anaerobic digestion, methane and carbon dioxide are produced. Methane is a biogas. Hence, anaerobic digestion process can be used to produce biogas which can be utilized as electricity.

Anaerobic wastewater treatment process occurs via four major steps named hydrolysis, acidogenesis, acetogenesis, and methanogenesis. All these steps are governed by anaerobic microorganisms, especially bacteria and archaea.

What are the Similarities Between Aerobic and Anaerobic Wastewater Treatment?

• Aerobic and anaerobic wastewater treatment processes are biological wastewater treatment processes which involve living organisms.
• Complex organic materials are broken down during both processes.
• Both processes mainly govern by bacteria.

What is the Difference Between Aerobic and Anaerobic Wastewater Treatment?

Summary – Aerobic vs Anaerobic Wastewater Treatment

Wastewater treatment is an essential process which should be properly maintained to safe guard human health. Waste water treatment has four major steps, and biological wastewater treatment process plays a key role in the overall process. Biological treatment has two ways named aerobic wastewater treatment and anaerobic wastewater treatment. Aerobic wastewater treatment process needs oxygen while anaerobic treatment process does not need oxygen. Aerobic wastewater treatment process is carried out by aerobic organisms while anaerobic wastewater treatment is carried out by the anaerobic organisms. This is the difference between aerobic and anaerobic waste water treatment.

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References:

1.”Biological Wastewater & Waste Treatment.” RWL Water. N.p., n.d. Web. Available here. 08 Aug. 2017.
2.”Anaerobic Digestion | Anaerobic Wastewater Treatment Systems.” RWL Water. N.p., n.d. Web. Available here. 08 Aug. 2017.
3.”Energie- en milieu-informatiesysteem voor het Vlaamse Gewest.” Anaerobic Biological Wastewater Treatment | EMIS. N.p., n.d. Web. Available here. 08 Aug. 2017.

Image Courtesy:

1. “Activated Sludge 1” By derivative work: LennyCZ (talk)Activated Sludge 1.png: Original uploader was Mbeychok at en.wikipedia – Activated Sludge 1.png (Public Domain) via Commons Wikimedia
2. “Anaerobic digesters overhead view” –  The original uploader was Vortexrealm at English Wikipedia – Transferred  Commons by Teratornis (CC BY-SA 2.5) via Commons Wikimedia