Variables
Description
What is this formula?
This formula calculates the remaining biochemical oxygen demand (BOD) at a given time during the biodegradation process of organic matter in water.
When to use it
Use it when modeling wastewater treatment processes, river self-purification, oxygen depletion, and biological degradation of organic pollutants.
Example
Data:
L0 = 200 mg/L
k = 0.23 day⁻¹
t = 5 days
Formula:
Lt = L0 e^(-kt)
Substitution:
Lt = 200 × e^(-0.23 × 5)
Result:
Lt = 63.4 mg/L
Applications
Wastewater treatment design, activated sludge modeling, stream water quality analysis, environmental impact assessment, and biological treatment process evaluation.
Applications
Wastewater treatment design, activated sludge systems, stabilization ponds, river water quality studies, environmental monitoring, and regulatory compliance.
Note
This is an empirical first-order decay model widely used in environmental engineering. The deoxygenation constant k depends on temperature, wastewater characteristics, microbial activity, and environmental conditions. Different values of k are commonly used for municipal, industrial, and natural water systems.