Drinking water: the problem of chlorinous odours

Abstract

Chlorinous off-flavours in drinking water are a leading cause of complaints to Australian water utilities and other utilities worldwide. The occurrence and causes of chlorinous odours in drinking water were investigated with the use of an odour panel, trained using a modified flavour profile analysis technique. A new system for classifying water types according to the causes of chlorinous odours was developed in order to enable improved management strategies for the reduction of these off-flavours.Waters of 'Type 1' exhibit a chlorinous odour only when the free chlorine equivalent concentration is equal to or above the odour threshold concentration (OTC) for free chlorine. Waters exhibiting a chlorinous odour both above and below the OTC of free chlorine are designated 'Type 2'. 'Type 3' waters are those in which the possible presence of a chlorinous odour is masked by another odour.Although causative compounds of the chlorinous off-flavours were not determined, bromine was proposed to play an important role in distribution systems where source waters have high concentrations of bromide that may not be removed by the available treatment processes.Management strategies for improvements in aesthetic water quality for each water type are proposed.

Identification and characterization of phenylacetonitrile as a nitrogenous disinfection byproduct derived from chlorination of phenylalanine in drinking water

“…The odors of 2-chlorobenzyl cyanide and 2,6-diphenylpyridine are not available in the literature (Table 2). Phenylacetonitrile is perceived as having a chlorinous odor by some subjects (Table 2) and therefore may be responsible for some non-free chlorine caused chlorinous odors that are acknowledged to occur in drinking water (McDonald et al, 2013). Phenylacetonitrile's diverse descriptors among subjects (Table 2) is consistent with previous studies of odor descriptors by trained and untrained subjects (Dietrich et al, 2014).…”

“…Some DBPs possess unpleasant odors and can be a major source of off-flavour complaints from consumers. For decades, consumers have complained of chlorinous odors in their tap water that could not be attributed to inorganic chlorine although the exact cause could not be identified (Bruchet, 1999;McDonald et al, 2013). Aldehydes, produced by chlorination of amino acids, were identified to be odorous byproducts in drinking water (Hrudey et al, 1988).…”

Occurrence and formation of disinfection by-products in the swimming pool environment: A critical review

“…<33 mg/L, than that detected in drinking waters (e.g. 1.8 to 3.6 mg/L, McDonald et al, 2013), DBP formation is a magnified issue in swimming pool waters compared to drinking waters. Swimming pools have a wide variety of uses and therefore the swimming pool water matrix is quite unique.…”