Chloramines V: Products and Implications of the Chlorination of Lysine in Municipal Wastewaters

The chlorination reactions of lysine (Lys) in water and wastewater were studied. 5-Chloraminopentanal ( VIII ) and 5-dichloraminopentanal ( IX ) are the main products at Cl 2 /Lys molar ratios of 1 and 2 after 30-min contact time. Formation of N, N‘ -dichlorolysine ( V ) was suggested but not confirmed. 5-Dichloramino- N -chloropentanimine ( XII ) and 5-dichloraminopentanenitrile ( XV ) are the main producs at Cl 2 /Lys molar ratios of 4 and 5. At a Cl 2 /Lys molar ratio of 3, a compound believed to be 5-chloramino- N -chloropentanimine ( XI ) was observed, but its yield was small. Half-lives of lysine chlorination products in model solutions were found to be as follows: 0.8 ( V ), 1.5 ( XI ), 23 ( XII ), >45 ( VIII and IX ), and 210 h ( XV ). The concentrations of lysine and its chlorination products after 30-min contact time were determined in a primary municipal wastewater. All have the potential to interfere with the proper measure ment of disinfection levels in chlorinated wastewaters.