Experiencing High BOD and COD in Wastewater is a common issue across industrial facilities and is one of the most important indicators of wastewater quality problems. When these parameters increase beyond acceptable levels, they can disrupt treatment processes, raise operational costs, and pose significant environmental risks. Understanding the cause of high BOD and COD in wastewater is essential for implementing the right corrective actions.
What Are BOD and COD in Wastewater?
BOD (Biological Oxygen Demand) represents the amount of oxygen required by microorganisms to biologically break down organic matter in wastewater. A high BOD value indicates a large amount of easily degradable organic load, which can significantly reduce dissolved oxygen levels if the wastewater is not treated properly.
COD (Chemical Oxygen Demand) measures how much oxygen is needed to chemically oxidize organic compounds, including those that cannot be biologically degraded. COD values are typically higher because they account for a broader range of pollutant compounds.
The BOD/COD ratio is widely used to evaluate biodegradability. A high ratio means the wastewater is easy to treat biologically, while a low ratio indicates the presence of difficult-to-degrade compounds.
Read Also: How to Overcome High COD and BOD in Wastewater?
Common Causes of High BOD and COD in Wastewater
Below are the most frequent factors that contribute to High BOD and COD in Wastewater, found across various industrial sectors.
1. High Organic Content in Wastewater
A high concentration of organic material is the primary cause of elevated BOD and COD. These organic loads commonly come from raw material residues, production by-products, or spills within the process line.
Examples include:
- Food and beverage industry wastewater containing sugar, protein, and fat
- Meat processing wastewater containing blood, fat, and tissue
- Pulp and paper wastewater containing lignin and cellulose
These compounds are highly degradable, which significantly raises both BOD and COD values.
Read Also: How to Reduce Organic Content in Raw Water
2. Use of Chemicals and Synthetic Compounds
Industries that use complex chemicals often experience High BOD and COD in Wastewater because many synthetic compounds are not biodegradable. Organic solvents, dyes, surfactants, and resins drastically increase COD levels and reduce the BOD/COD ratio.
This issue is common in textile, petrochemical, cosmetic, and pharmaceutical manufacturing. In such cases, conventional biological treatment alone is insufficient to reduce COD.
3. Leakage or Spillage During Production
Leaks or spills involving raw materials or intermediate products can rapidly increase organic load in the drainage system. Even small incidents can cause short-term spikes leading to unusually high BOD and COD values.
This is often found in food processing, beverage manufacturing, and chemical production when material handling is not tightly controlled.
4. Inefficient or Suboptimal Production Process
If the production process is unstable or inefficient, excess organic compounds may unintentionally enter the wastewater system. An unbalanced chemical reaction, incomplete fermentation, or improper process control can create wastewater with high organic content.
This means upstream process stability plays a major role in controlling BOD and COD in wastewater.
5. Inadequate Pre Treatment System
Many facilities discharge wastewater into the main treatment system without proper pre treatment steps such as screening, sedimentation, or oil and grease separation. Without these processes, the organic load remains very high before entering the biological or chemical treatment stage.
This condition directly contributes to High BOD and COD in Wastewater and reduces the overall efficiency of the treatment system.
6. Mixed Wastewater Streams
Combining wastewater from multiple process lines or mixing stormwater with industrial wastewater can cause sharp variations in organic concentration. This makes it difficult for the treatment system to operate at steady conditions.
Mixed wastewater can introduce unexpected compounds, which further increases BOD, COD, and operational challenges.
Read Also: What is Wastewater Treatment? Professional Process and Solutions
Why High BOD and COD in Wastewater Must Be Addressed
Allowing High BOD and COD in Wastewater to persist can result in serious consequences for industrial operations:
- Biological processes become overloaded and microorganisms may die
- Operational costs increase due to higher oxygen demand, energy usage, and chemical consumption
- Treated wastewater may fail to meet environmental discharge standards
- Facilities face risks of sanctions or loss of environmental permits
- Odor, sludge production, and process instability worsen
Effective control is essential not only for regulatory compliance but also for maintaining efficient and sustainable operations.
Ensure Accurate Wastewater Monitoring with Lautan Air Indonesia
Managing High BOD and COD in Wastewater requires accurate monitoring, consistent evaluation, and the right technical solutions. With more than 40 years of experience, Lautan Air Indonesia provides integrated wastewater treatment services, including:
- Evaluation and testing of BOD and COD parameters
- Advanced chemical solutions for organic load reduction
- Optimization and troubleshooting of biological systems
- Pre treatment system improvements
- Complete engineering support for wastewater treatment facilities
- Performance Based Contract (PBC) for reliable operational results
Do not let high BOD and COD levels disrupt your industrial operations. Contact Lautan Air Indonesia’s team of experts today to discuss your needs and get the most effective solution for your wastewater treatment system.
