Table 2 Occurrence and concentrations (µg/L) of disinfection by-products (DBPs) in tap water samples (N = 42) above the limit of quantification (LOQ).
N ≥ LOQ | % ≥ LOQ | Min | Perc25 | Perc50 | Perc75 | Max | Mean | SD | |
|---|---|---|---|---|---|---|---|---|---|
Haloacetic acids (HAAs) | |||||||||
Monochloroacetic acid (MCAA) | 0 | 0 | <2.0 | <2.0 | <2.0 | <2.0 | <2.0 | <2.0 | – |
Dichloroacetic acid (DCAA) | 17 | 41 | <0.5 | 6.4 | 9.8 | 12 | 15 | 9.2 | 3.9 |
Trichloroacetic acid (TCAA) | 20 | 48 | <0.5 | 12 | 18 | 22 | 24 | 15 | 7.9 |
Monobromoacetic acid (MBAA) | 24 | 57 | <0.5 | 0.8 | 1.0 | 1.2 | 1.7 | 1.0 | 0.3 |
Dibromoacetic acid (DBAA) | 28 | 67 | <0.5 | 3.8 | 7.4 | 8.6 | 14 | 6.3 | 3.5 |
Tribromoacetic acid (TBAA) | 18 | 43 | <0.5 | 2.0 | 2.9 | 3.9 | 6.6 | 3.0 | 1.6 |
Bromochloroacetic acid (BCAA) | 26 | 62 | <0.5 | 1.0 | 1.7 | 2.1 | 4.9 | 1.7 | 0.9 |
Dichlorobromoacetic acid (BDCAA) | 16 | 38 | <0.5 | 1.6 | 1.8 | 2.3 | 3.7 | 1.9 | 0.7 |
Dibromochloroacetic acid (DBCAA) | 17 | 41 | <0.5 | 1.0 | 1.3 | 2.0 | 3.4 | 1.6 | 0.8 |
Iodoacetic acid (IAA) | 0 | 0 | <0.5 | <0.5 | <0.5 | <0.5 | <0.5 | <0.5 | – |
Diiodoacetic acid (DIAA) | 0 | 0 | <0.5 | <0.5 | <0.5 | <0.5 | <0.5 | <0.5 | – |
Total HAAs | 41 | 98 | <LOQ | 11 | 18 | 30 | 39 | 20 | 12 |
Trihalomethanes (THMs) | |||||||||
Chloroform (TCM) | 27 | 64 | 0.3 | 1.2 | 23 | 28 | 36 | 17 | 14 |
Bromodichloromethane (BDCM) | 42 | 100 | 0.3 | 1.4 | 2.4 | 8.6 | 12 | 4.6 | 3.7 |
Dibromochloromethane (DBCM) | 42 | 100 | 1.7 | 3.3 | 8.0 | 11 | 27 | 8.5 | 5.7 |
Bromoform (TBM) | 38 | 91 | 0.2 | 12 | 25 | 29 | 58 | 23 | 15 |
Total THMs | 42 | 100 | 17 | 38 | 42 | 49 | 83 | 45 | 13 |
Haloacetonitriles (HANs) | |||||||||
Dichloroacetonitrile (DCAN) | 23 | 55 | 0.2 | 0.5 | 1.7 | 2.1 | 2.6 | 1.4 | 0.8 |
Bromochloroacetonitrile (BCAN) | 42 | 100 | 0.1 | 0.4 | 0.5 | 0.6 | 0.9 | 0.5 | 0.2 |
Dibromoacetonitrile (DBAN) | 38 | 91 | 0.1 | 0.9 | 2.7 | 3.2 | 4.3 | 2.2 | 1.4 |
Trichloroacetonitrile (TCAN) | 0 | 0 | <0.1 | <0.1 | <0.1 | <0.1 | <0.1 | <0.1 | – |
Total HANs | 42 | 100 | 1.3 | 2.6 | 3.2 | 3.9 | 5.0 | 3.3 | 0.9 |
Haloketones (HKs) | |||||||||
1,1,1-Trichloropropanone (TCP) | 15 | 36 | <0.1 | 1.1 | 1.2 | 1.3 | 2.0 | 1.2 | 0.4 |
1,1-Dichloropropanone (DCP) | 0 | 0 | <0.1 | <0.1 | <0.1 | <0.1 | <0.1 | <0.1 | – |
Other DBPs | |||||||||
Trichloronitromethane (TCNM) | 0 | 0 | <0.1 | <0.1 | <0.1 | <0.1 | <0.1 | <0.1 | – |
Chlorite | 26 | 62 | <10.0 | 16.9 | 53.9 | 113 | 149 | 61.8 | 49.8 |
Chlorate | 41 | 98 | <10.0 | 159 | 214 | 296 | 367 | 225 | 79.9 |
