Introduction
When it comes to wastewater treatment methods, processes like filtration, aeration, and MBBR might be the first to come to mind. However, bacteria also play a role in this process. These tiny organisms can decompose pollutants, remove harmful nutrients, and naturally improve water quality. As a water treatment solution provider, AquaSust will explore how bacteria help manage wastewater in this blog.
Types of Beneficial Bacteria in Wastewater
Different microbes in wastewater treatment specialize in breaking down various pollutants. Below are the most common types:
|
Bacteria Type |
Role in Wastewater Treatment |
|
Aerobic Bacteria |
Require oxygen to decompose organic matter (e.g., Bacillus, Pseudomonas). |
|
Anaerobic Bacteria |
Function without oxygen, breaking down sludge and producing methane (e.g., Methanogens). |
|
Facultative Bacteria |
Adapt to both oxygen-rich and oxygen-poor conditions (e.g., Escherichia coli). |
|
Nitrifying Bacteria |
Convert ammonia into nitrates (Nitrosomonas, Nitrobacter). |
|
Denitrifying Bacteria |
Reduce nitrates into nitrogen gas (Pseudomonas denitrificans). |
How Bacteria Assist in Wastewater Treatment
1. Organic Matter Decomposition
When wastewater enters a treatment plant, aerobic bacteria metabolize organic compounds such as fats and proteins, converting them into carbon dioxide, water, and microbial biomass. This ultimately reduces the Biochemical Oxygen Demand (BOD) in water, which is an indicator of water pollution. Its high values signify severe organic contamination.
2. Nutrient Removal (Nitrogen and Phosphorus)
Excessive ammonia and phosphates in wastewater can cause algal blooms, oxygen-depleted "dead zones," and unpleasant odors in water bodies. Microbes in sewage remove these nutrients through the following processes:
Nitrification: Nitrosomonas oxidizes ammonia to nitrites, which are then converted to nitrates by Nitrobacter.
Denitrification: Pseudomonas denitrificans reduces nitrates to harmless nitrogen gas, which is released into the atmosphere.
Phosphorus Removal: Acinetobacter absorbs phosphates and stores them within its cells, which are later removed with the sludge.
3. Sludge Reduction
In anaerobic digesters, hydrolytic bacteria break down complex sludge into simpler compounds. Methanogens then convert these compounds into methane and carbon dioxide. As these gases escape, the total volume of sludge decreases. The generated biogas (methane) can be reused as a renewable energy source.
4. Floc Formation (Improving Sedimentation)
Certain bacteria in wastewater (primarily Zoogloea) produce Extracellular Polymeric Substances (EPS), which help form flocs-aggregates of microbes and organic matter. These flocs are more easily removed through sedimentation and filtration, clarifying the water.
5. Bioaugmentation
When natural bacterial populations are insufficient, we often introduce specialized strains into the sewage to:
Accelerate organic matter decomposition in high-load systems.
Restore balance in overloaded treatment plants.
Reduce odors by targeting sulfur-reducing bacteria.
Common examples include Bacillus, Pseudomonas, and Rhodococcus.
Conclusion
Bacteria can improve our wastewater management by decomposing organic matter, removing nutrients, reducing sludge, and improving water quality. At AquaSust, we provide sustainable wastewater solutions. If you're interested, feel free to contact us to discuss your ideas with our expert team!