Identification, Occurrence, and Cytotoxicity of Haloanilines: A New Class of Aromatic Nitrogenous Disinfection Byproducts in Chloraminated and Chlorinated Drinking Water

Abstract

Identifying disinfection byproducts (DBPs) with high health risk is an unresolved challenge. In this study, six members of a new class of aromatic nitrogenous DBPs2-chloroaniline, 2-bromoaniline, 2,4-dichloroaniline, 2-chloro-4-bromoaniline, 4-chloro-3-nitroaniline, and 2-chloro-4-nitroanilineare reported as DBPs in drinking water for the first time. Haloanilines completely degraded within 1 h in the presence of chlorine (1 mg/L), while about 20% remained in the presence of chloramine (1 mg/L) after 120 h. Haloanilines showed high stability in the absence of disinfectants, with <30% degradation at pH 5–9 over 120 h. Eight haloanilines were determined in chloraminated finished water and tap water at total concentrations of up to 443 ng/L. The most abundant was 2-bromoaniline, with a median concentration of 104 ng/L. The cytotoxicity of eight haloanilines and regulated trichloromethane and dichloroacetic acid (DCAA) was evaluated using Hep G2 cell assay. The EC50 values of eight haloanilines were 1–2 orders of magnitude lower than those of the regulated DBPs. The lowest toxic concentration of 2-chloro-4-nitroaniline was 1 μM, 500 times lower than that of DCAA. The formation and control of haloanilines in drinking water warrant further investigation.

Simple and Sensitive Method for Synchronous Quantification of Regulated and Unregulated Priority Disinfection Byproducts in Drinking Water

“…Relative standard deviations of all DBPs in parallel samples were <30%. Method detection limits (MDLs) were calculated by multiplying the appropriate one-sided 99% t-statistic by the standard deviation, as shown in Text S4. , LOQs were determined using each calibration curve: an obvious peak (peak area >100 and signal-to-noise ratio >3), and ranging from 0.01 to 0.5 μg/L (Table ). Nine calibration curve points (0.01, 0.05, 0.1, 0.5, 1, 2, 5, 10, and 20 μg/L) were made using Milli-Q water with 1,2-DBP as internal standard to quantify the individual DBPs with an r 2 > 0.99 except for four HAMs.…”

Predicting THM Formation and Revealing Its Contributors in Drinking Water Treatment Using Machine Learning

“…The wide diversity and large quantity of DBPs that can be formed in drinking water present a daunting obstacle for an explicit understanding of their analysis, occurrence, toxicity, formation, and mitigation. Moreover, with the majority of newer DBPs being present at low levels (ng/L to subμg/L), their detection becomes tedious and requires advanced instrumentation and sophisticated analytical skills. , Additionally, optimum conditions for reducing the formation of DBPs in drinking water treatment vary greatly among different DWTPs. The complexity of DBP precursors in water can result in DBPs with varying concentrations and characteristics, which are difficult to identify and quantify within a limited time and with limited skilled labors.…”

The degradation of ciprofloxacin in the UV/NH2Cl process: kinetics, mechanism, pathways and DBP formation

“…), or human emissions of pollutants reaction will generate disinfection byproducts (DBPs). 17,20,21 Most DBPs are carcinogenic and genotoxic. 22 Some chlorinated DBPs may increase the risk of bladder cancer and colon cancer and have adverse effects on reproduction and development.…”