ABSTRACT
The methods for the determination of organics discussed in this chapter include the biochemical oxygen demand (BOD) method, the chemical oxygen demand (COD) manual method: dichromate reflux, chemical oxygen demand (COD) ampule method, and oil and grease partition-gravimetric method, among others. The BOD test determines the relative oxygen necessary for biological oxidation of wastewaters, effluents, and polluted waters. It is the only test available to determine the amount of oxygen required by bacteria while stabilizing decomposable organic matter. Complete stabilization requires too long an incubation period for practical purposes; therefore, the 5-day period has been accepted as a standard. The COD determination provides a measure of the oxygen equivalent of that portion of the organic matter in a sample that is susceptible to oxidation by a strong chemical oxidant. Most types of organic matter are destroyed by boiling a mixture of chromic and sulfuric acids.
