**Calculating BOD, COD, or SS loading on an aeration process **

When calculating COD, BOD, or SS loading on an aeration process (or any other treatment process),loading on the process is usually calculated as lb/day. The following equation is used: **BOD, COD, or SS loading (lb/day) = mg/L x MGD x 8.34 lb/gal**

Example:-

The BOD concentration of the wastewater entering an aerator is 210 mg/L. If the flow to the aerator is 1,550,000 gpd, what is the BOD loading in lb/day?

BOD (lb/day) = BOD (mg/L)x flow (MGD) x 8.34 lb/gal

= 210 mg/L x 1.55 MGD x 8.34 lb/gal

= 2715 lb/day

Very Useful for beginners