Chlorination Byproducts in Drinking Water Produced from Thermal Desalination in United Arab Emirates

Abstract

Oil activities in the Arabian Gulf can potentially affect the quality of the intake water available for coastal desalination plants. This paper addresses such situation by investigating the quality of intake water and desalinated water produced by a desalination plant located near a coastal industrial complex in United Arab Emirates (UAE). Analyses of the organic compounds on the intake seawater reported non-detected levels in most samples for the three tested organic groups; namely Polyaromatic Hydrocarbons (PAHs), Phenols, and Polychlorinated Biphenyls (PCBs). Trihalomethanes (THMs) and Haloacetic Acids (HAAs) were also tracked in the intake sea water, throughout the desalination processes, and in the final produced drinking water, to evaluate the undertaken pre- and post chlorination practices. The levels of considered Chlorination Byproducts (CBPs) were mostly found below the permissible international limits with few exceptions showing tangible levels of bromoform in the intake seawater and in the final produced drinking water as well. Lab-controlled experiments on the final produced distillate showed little contribution of its blending with small percentage of seawater upon the formation of trihalomethane and in particular, bromoform. Such results indicate that the organic precursors originated in the seawater are responsible for bromoform formation in the final distillate.

Survey of Haloacetic Acids in Household Drinking Water Produced from Thermal Desalination in Kuwait

“…These findings are different from those previously reported by studies on the desalinated water produced in SA [21] and UAE [22]. The inside and downstream samples of the desalination plant in UAE [22] showed nominal levels of HAA5 components, except for the DBAA component that was found in the range of 0.52 -13.4 g/L. In contrast, DBAA exhibited the second lowest level in this study.…”

“…In addition, the percent dominance of the nine HAA components were TCAA (34%) > MCAA (18%) > MBAA (17%) > CDBAA (9%) > DBAA (7%) > BDCAA (6%) > TBAA (4%) > DCAA (3%) > BCAA (2%). These findings are different from those previously reported by studies on the desalinated water produced in SA [21] and UAE [22]. The inside and downstream samples of the desalination plant in UAE [22] showed nominal levels of HAA5 components, except for the DBAA component that was found in the range of 0.52 -13.4 g/L.…”

“…Furthermore, other studies of drinking water obtained from surface water sources reported that the highest levels among HAA components were of TCAA and DCAA [27][28][29], and the brominated ones were the lowest. In this study, the higher levels and detection frequency of MBAA relative to those found in all previous studies [21,22,[27][28][29] may be attributed to the prevalence of bromide in the source seawater. Brominated acetic acids are formed during the disinfection of water that contains bromide ions and organic matter [30,31].…”

“…However, a literature survey indicated that only two studies have addressed the topic when the source of drinking water is seawater and the treatment process is thermal desalination [21,22]. These studies have been conducted in two Arabian Gulf countries (Saudi Arabia (SA) and United Arab Emirates (UAE)), but none in Kuwait, even though all Gulf countries rely heavily on the desalination of seawater as their primary source of drinking water.…”

“…They found that the mean values of THAAs in seawater, product water and blended water were 7.0, 1.56 and 2.4 g/L, respectively. In the second study, El-Shorbagy and Abdulkarim [22] analyzed CDBPs in drinking water produced from desalination in UAE. They reported that desalination plant intake water samples showed lower levels of HAA5 than the equipment quantification limit of 1.0 g/L.…”