Air Quality

Air quality calculators and formulas for pollutant dispersion and mass balance. Includes emission rate, concentration gradient, and Gaussian plume dispersion calculations.

13Formulas

All levels Difficulty

Updated Oct 2026

← All Environmental Engineering (29) Air Quality (13)

Fundamental

Simplified Ecological Footprint

Footprint (gha) = Consumption / Yield Factor

Fundamental

Carbon Sequestration by Trees (Simplified)

CO2 Sequestered = Tree Biomass Growth * Carbon Fraction * 3.67

Fundamental

Landfill Gas Generation Estimate (Simplified)

LFG Rate ≈ L0 * k * W * e^(-k*t)

Fundamental

Carbon Footprint from Fuel Combustion

CO2 Emissions = Fuel Used (L or kg) * Emission Factor

Fundamental

Carbon Footprint from Electricity Use

CO2 Emissions = Electricity Used (kWh) * Emission Factor

Fundamental

Particulate Matter Mass Concentration

C = m / V

Fundamental

Combined Sound Level from Multiple Sources

L_total = 10*log10(Σ 10^(Li/10))

Fundamental

Noise Level Attenuation with Distance

L2 = L1 - 20*log10(d2/d1)

Fundamental

Air Changes per Hour (Ventilation Rate)

ACH = (Airflow Rate (m3/hr)) / Room Volume (m3)

Fundamental

Stack Emission Rate

E = C * Q

Fundamental

Air Quality Index (AQI) Linear Interpolation

AQI = ((AQI_hi - AQI_lo)/(C_hi - C_lo)) * (C - C_lo) + AQI_lo

Fundamental

Gaussian Plume Concentration

C(x,y,0) = Q/(πuσ_yσ_z) · exp(−y²/2σ_y²)

Fundamental

Mass Balance (General)

Accumulation = In − Out + Generation − Consumption