Impacts of Typical Amino Acids on HAAs Formation

Abstract

Glycine(Gly), cysteine(Cys), aspartic acid(Asp), leucine(Leu), and lysine(Lys) were chosen as typical amino acids. Their haloacetic acids(HAAs) formation potential was tested, and their impacts on HAAs formation were investigated on a filtrated water chlorination. Results shown that HAAs could be yielded in chlorination of amino acids, leucine and aspartic acid had the HAAs formation potential as high as 0.66 molldrmol-1. The amino acids could enhance HAAs formation, and the increased levels were controlled by their characteristics and concentration. The increase in HAAs formation follow the order: Asp(840 mugldrL-1) >Leu(290 mugldrL-1)> Lys(153 mugldrL-1)>Cys(73 mugldrL-1) >Gly(61 mugldrL-1) (while: amino acids = 1.0 mgldrL-1, HAAs background = 32 mugldrL-1). The mechanisms of nitrogenous compounds enhance HAAs formation was: (a). the formation of HAAs in chlorination of nitrogenous compounds themselves; (b). the increase of chlorine demand raised HAAs formation in reaction of NOM with chlorine.