Lowering BOD

Lowering BOD

What is BOD? BOD is Biochemical Oxygen Demand. It is a common yardstick used to determine the strength of wastewater.   It is a test conducted over 5 days and measures the oxygen uptake in mg/l. Your City municipal sewage treatment plant does not want high BOD wastewater as it increases the treatment time and the cost of treating.   Typical BOD from the average household is around 350 mg/l, industrial wastewater can go into the thousands of mg/l BOD.

Lowering BOD to Avoid Fees

Most municipalities will charge a fee for high BOD.   Take a look at your water and sewer bill to see if you are being charged.

Typically Used Coagulants and Flocculants Ineffective

In lowering your BOD level it is important to understand that wastewater has both soluble and insoluble COC’s (Chemicals of Concern) that contribute to the BOD. When trying to lower BOD you will want to know the soluble fraction of the BOD. This is important because the coagulants and flocculants typically used in treating industrial wastewater are usually not effective at removing the soluble fraction (dissolved fraction) of BOD.

For example, if you are a food processing plant that produces a lot of sugar in your wastewater, a DAF or gravity separator will not take out the dissolved sugar. In this case you would look at a biological treatment system. Knowing the dissolved fraction is a good way of knowing what to expect from a specific wastewater treatment system.

We Can Help

Give us a call if you want to find out how to lower the BOD of your wastewater treatment.