Chemical Oxygen Demand Calculator
Calculate Chemical Oxygen Demand (COD) for water analysis using dichromate method and organic matter oxidation calculations.
Enter COD Data
mL
mL
mL
N
mL
mL
M
mL
Results
Enter COD data to calculate oxygen demand
Chemical Oxygen Demand
Dichromate Method
COD = (Blank - Sample) × N × 8000 / V
- • Blank = Blank titration volume
- • Sample = Sample titration volume
- • N = Normality of FAS
- • V = Sample volume
Applications
- • Wastewater treatment
- • Water quality assessment
- • Environmental monitoring
- • Process control
Typical COD Ranges
Clean Water
- • Surface water: 5-20 mg/L
- • Groundwater: 2-10 mg/L
- • Drinking water: <5 mg/L
- • Distilled water: <1 mg/L
Wastewater
- • Domestic sewage: 200-600 mg/L
- • Industrial: 500-5000 mg/L
- • Food processing: 1000-10000 mg/L
- • Textile: 2000-20000 mg/L
Treatment Levels
- • Primary effluent: 100-300 mg/L
- • Secondary effluent: 20-100 mg/L
- • Tertiary effluent: 5-20 mg/L
- • Advanced treatment: <5 mg/L
COD vs BOD
Chemical Oxygen Demand (COD)
- • Measures total oxidizable matter
- • Uses chemical oxidant (K₂Cr₂O₇)
- • Fast analysis (2-3 hours)
- • Includes biodegradable and non-biodegradable
Biochemical Oxygen Demand (BOD)
- • Measures biodegradable matter
- • Uses biological oxidation
- • Slow analysis (5 days)
- • Only biodegradable organics