Data on the relationship between bromide content and the formation potential of THMs, HAAs, and HANs upon chlorination and monochloramination of Karoon River water, Iran

This data article reports the relationship between of the bromide ion concentration and the formation potential of disinfectant byproducts (DBPs) including, trihalomethanes (THMs), haloacetic acids (HAAs), and haloacetonitriles (HANs) upon chlorination and monochloramination of the raw water of Karoon River water in Iran. Water samples were collected at an intake of a drinking water treatment plant during July 2014. All tests were performed in triplicate (n=3) and the mean of three measurements reported herein. The data of the formation potential of DBPs was determined under different bromide ions content. The data show the relationship between bromide concentration and DBPs formation that will be useful in the future management, operation and design of water treatment plants.


a b s t r a c t
This data article reports the relationship between of the bromide ion concentration and the formation potential of disinfectant byproducts (DBPs) including, trihalomethanes (THMs), haloacetic acids (HAAs), and haloacetonitriles (HANs) upon chlorination and monochloramination of the raw water of Karoon River water in Iran. Water samples were collected at an intake of a drinking water treatment plant during July 2014. All tests were performed in triplicate (n ¼ 3) and the mean of three measurements reported herein. The data of the formation potential of DBPs was determined under different bromide ions content. The data show the relationship between bromide concentration and DBPs formation that will be useful in the future management, operation and design of water treatment plants. &

Value of the data
The data provides details on which strategy (chlorination and monochloramination) will be effective on the lowering of brominated-DBPs as most dangerous DBPs.
The data will be beneficial for minimizing the DBPs formation and for an optimal designating of the disinfection plant in water treatment plants.
This data article directly assesses what impact the switch from chlorine to monochloramine would have on the concentrations of the DBPs found; thus it will be useful in the future management and operation of water treatment plants. Table 1 is presented the chlorine and monochloramine residue as function of the disinfectant types (i.e., chlorination and monochloramination). The data regarding to the relation of bromide ion content and THMs, HAAs, and HANs species upon chlorination and monochloramination of Karoon River water were depicted in Tables 2-4, respectively.

Water sampling
Water sampling was done in July 2014 at a water intake in Karoon River where the water is pumped to the Mahshahr water treatment plant. About ten liters of water were collected at the water intake from a depth of approximately 50 cm below the water surface with a hand-held open-mouth bottle. The samples were placed in a cooler on ice, shipped to a laboratory within the same day, and stored at 4°C before further test. Two liter of water was passed through a glass fiber filter (0.42 μm) to analysis the initial content of bromide ion of water samples.

Experimental procedure of chlorination/chloramination test
A stock of free chlorine (HOCl) solution was prepared by 5% sodium hypochlorite (NaOCl) (Sigma-Aldrich) and dilution to 1000 mg/L as Cl 2 . The prepared solution was stored in an aluminum foilcovered glass stoppered flask for further tests. The stock 5% NaOCl was purchased from Sigma-Aldrich. The monochloramine was obtained daily by mixing a given volume of NH 4 Cl and NaOCl solutions (Cl 2 /N ratio was 4/1 w/w) and the mixture was then incubated for 0.5 h in the dark. The monochloramine and chlorine were weekly standardized by the N,N diethyl-p-phenylenediamine (DPD) titrimetric method before disinfection test, and then, the known dosage of disinfectant solution was added to the bottles. The batch experimental runs were conducted in 100-mL amber bottles with PTFE-lined screw cap. After regulation the bromide ion content of the samples, a specified chlorine  dose was poured to the water samples and then well-mixed at 120 rpm using a shaker incubator (Parsazma, Iran) under anaerobic conditions. Upon expire the reaction time, the residue of Cl 2 and NH 2 Cl and disinfection by products (THMs, HAAs, and HANs) were determined under various Br À concentrations (10, 100, 200, and 400 mg/L). All samples were done in triplicate (n ¼ 3) to minimize the error from the experimental procedure.

Measurements
The residual concentrations of monochloramine and chlorine were determined by using a Hanna photometer HI-93711,based on DPD/FAS titration according to method presented in standard Methods for the Examination of Water and Wastewater (method number: 4500-Cl-G) [1]. THMs analyses were performed using a gas chromatography (GC) with an electron capture detector (ECD; series 6890 Agilent with DB 624 column, J&W Science), based on EPA method 551.1. The concentration of nine HAAs species including, CAA, BAA, DCAA, TCAA, BCAA, DBAA, BDCAA, DBCAA, and TBAA was measured by liquid-liquid extraction with methyl-tertiary-butyl-ether (MTBE) followed by derivatization with acidic methanol and by GC-ECD according to a modified version of EPA method 552.2 [1]. HANs including, DCAN, TCAN, BCAN, and DBAN analyses were carried out using a GC (Finnigan TRACE GC) with an electron capture detector [2]. Further details of THMs, HAAs, and HANs   measurements including, continuing calibration check, detection limits, quality assurance-quality control, and recovery percentage are available elsewhere [3][4][5].