Chemical characterization and relative toxicity assessment of disinfection byproduct mixtures in a large drinking water supply network

Abstract

In order to reduce the formation of disinfection by-products (DBPs) during potabilization of water it is necessary to explore the potential of the source water and the applied treatment to generate these chemicals. This is actually more challenging in large drinking water networks that use different source waters to satisfy drinking water demand. In this regard, this work investigated the formation of DBPs in water matrices that are commonly supplied to the city of Barcelona and its metropolitan area. The regulated trihalomethanes and haloacetic acids were the most abundant DBP classes in these waters, followed by haloacetamides and haloacetonitriles or trihalogenated acetaldehydes (THALs). On the contrary, the formation potential of iodo-DBPs was minor. Mixing of drinking water treatment plant finished waters with desalinated water decreased the overall DBP formation potential of the water but resulted in the increased formation of brominated DBPs after long chlorine contact time. The formation of most DBPs was enhanced at high water temperatures (except for Br-THALs) and increasing residence times. Potential cytotoxicity and genotoxicity of the DBP mixtures were mainly attributed to the presence of nitrogen-containing DBPs and HAAs.

Waterworks-specific composition of drinking water disinfection by-products

“…4,5 Other than disinfectant type, formation of DBPs depends on the concentration and characteristics of NOM, water temperature, pH, disinfectant dosage, and contact time. 6,7 For example, speciation of free chlorine in water is highly dependent on pH and reactive species can shift from HOCl at lower pH (e.g. pH 5) to OCl − at pH 7.5 and higher.…”

Analysis of Haloacetic Acids (HAA5) in Waters of Public Schools and Residencies in Maringá-Brazil

“…In the process of purifying water intended for human consumption, Water Treatment Plant (WTP) analyzes the parameters of raw water such as turbidity and organic matter to regulate the concentration of chemicals to be added (for example, chlorine concentration). Thus, water with higher concentrations of organic matter will require higher dosages of chlorine or other chlorine-based disinfectant, increasing the production of disinfection byproducts, DBPs [1] [2] [3].…”

“…According to [1] studies indicate that trihalomethanes, haloacetic acids and other halogen compounds have high potential for toxicity and carcinogenicity.…”

“…and F). Possibly due to the variable cleaning period of the reservoir, the concentration of HAAc increased from the consumption register to the reservoir at three points (A, D and E) and decreased by three points (B, C and F).At the points where HAAc values greater than 0.080 mg/L were found, it is important to highlight the concern about the health of the people who use this water because studies relate the incidence of cancer and the ingestion of disinfection byproducts such as THMs and HAACs[1] [12].…”

Study on the Inactivation of Pseudomonas sp and the Degradation of Trichloroethylene by Fenton-Like Reaction

“…It is also harmful to the human body [2]. Disinfection is an essential step to protect people from waterborne diseases [3]. At present, the addition of chlorine-containing disinfectant and maintaining a certain amount of chlorine residual is the most common method for controlling the regrowth of bacteria in WDN [4].…”