In industrial wastewater management, COD (Chemical Oxygen Demand) and BOD (Biochemical Oxygen Demand) are the most critical parameters regulated by law. Utilizing high-precision measurement technology is key to mitigating legal risks and enhancing environmental efficiency.
COD vs. BOD: Engineering Perspectives
- BOD: Oxygen demand for microbial decomposition (5-day analysis).
- COD: Oxygen demand for chemical oxidation (2-3 hour analysis), ideal for real-time Process Control.
Legal Effluent Standards (Thailand)
According to the Ministry of Industry (2017) regulations:
- Standard COD: Max 120 mg/L
- Standard BOD: Max 20 mg/L
Measurement Technology & Automation
Modern plants utilize Online COD Analyzers for continuous monitoring:
- UV-Vis Spectroscopy: Reagent-free, fast measurement via light absorption.
- Dichromate Method: Highest accuracy, compliant with Standard Methods.
- SCADA Integration: Connectivity via Modbus TCP/IP for real-time alarming and closed-loop control.
BOD/COD Ratio Analysis
- Ratio > 0.5: Biodegradable; suitable for Biological Treatment.
- Ratio < 0.3: Non-biodegradable; requires Physico-chemical processes.
