The effect of selected organics on breakpoint chlorination

Abstract

A synthetic secondary effluent, comprised of an animal feed and distilled water, was chlorinated under the influence of three selected organics: dextrose, phenol, and phenylalanine. The initial ammonia nitrogen and organic compound concentrations were varied. The breakpoint curves and total Kjeldahl nitrogen removal efficiencies were determined, and it was demonstrated that each organic has a specific effect on the nature of the breakpoint curve and the nitrogen removal efficiency. It was found that both effects are highly dependent upon the organic compound to ammonia nitrogen weight ratio.

Nitrogen in the form of total Kjeldahl nitrogen was generally removed as well with organics present as without organics, as long as the breakpoint was reached. An exception was noted with a phenol to ammonia nitrogen weight ratio greater than one to one. At this point nitrogen removal was· substantially hindered. Increased initial ammonia nitrogen concentrations increased the nitrogen removal efficiency regardless of the presence of organics.