Effects of bromide and iodide ions on the formation of disinfection by-products during ozonation and subsequent chlorination of water containing biological source matters

Abstract

This study aims to investigate the influence of the coexistence of halogen ions (bromide/iodide) and biological source matters on the speciation and yield of trihalomethanes (THMs), haloacetic acids (HAAs), and N-nitrosodimethylamine (NDMA) during the ozonation and subsequent chlorination of water. The results show that the concentrations of brominated THMs and iodinated THMs increased with increasing bromide and iodide concentration. These results may be attributed to the higher reactivity of hypobromous acid and hypoiodous acid generated from the ozonation and subsequent chlorination in the presence of bromide or iodide ions. The presence of bromide increased the species of brominated HAAs. There was a shift from chlorinated HAAs to brominated HAAs after increasing the concentration of bromide. The effect of iodide on HAA formation was more complex than bromide. For most samples, the concentration of total HAAs (T-HAAs) increased to the maximum and then decreased with increasing iodide concentration. The components of the organic precursors also significantly influenced the formation of brominated and iodinated disinfection by-products (Br-DBPs and I-DBPs). Humic acids produced more CHBr3 (596.60 μg/L) than other organic materials. Microcystis aeruginosa cells produced the most tribromoacetic acid (TBAA, 84.16 μg/L). Furthermore, the yield of NDMA decreased with increasing bromide concentration, indicating that the formation of NDMA was inhibited by the high concentration of bromide.

Comparative removal efficiencies of natural organic matter by conventional drinking water treatment plants in Zimbabwe and South Africa

“…Band A3 (270–280 nm) is of interest to the water treatment industry, because it can be assigned to specific haloalkanes or DBPs precursors (Roccaro et al, 2015; Yang et al, 2017). The presence of DBPs was not investigated in the current study, but typical DBP precursors within this wavelength include iodated DBPs, brominated DBPs, and nitrogenous DBPs (Zha et al, 2014). Generally, the analysis of DBPs in drinking water systems, focusing on conveyance and storage systems and at the point‐of‐consumption, requires further research, especially in developing countries.…”

Identification of disinfection by-products (DBPs) halo phenols in drinking water

“…However, Liu and Zhang (2014) have reported that 2-bromo-4-chlorophenol was toxic to a heterotrophic marine polychaete (Platynereis dumerilii) and marine alga (Tetraselmis marina). The haloacetic acids and trihalomethanes have indicated that the emerging halophenolic DBPs deserve more attention (Zha et al 2014). The highest value of TDS, chloride, COD, TOC, chlorite and iodate was observed in the water samples collected from Srirangam and Tiruchirappalli which was significantly higher than that of the control water sample.…”

“…The disinfection of metropolitan drinking water is performed with chlorine in order to ensure the health of the public and to protect the people against various waterborne infirmities (Villanueva et al 2015). Chlorination is the most universally accepted method for disinfection since the early twentieth century (Paull and Barron 2004) as it prevents the contamination of potable water against pathogens like bacteria and viruses (Zha et al 2014). In (1974), Rook first discovered that hypochlorous and hypobromous acid react with naturally present organic matter to form water DBPs, few trihalomethanes (THM) substances such as chloroform (CHCl 3 ), bromo dichloromethane (CHCl 2 Br), dibromo chloromethane (CHClBr 2 ) and bromoform (CHBr 3 ).…”

Fe3+-saturated montmorillonite effectively deactivates bacteria in wastewater

“…Water disinfection practices such as chlorination, ozonation, and UV treatment are commonly used. However, chlorination and ozonation, used separately or combined, often result in disinfection by-products (Huang et al, 2005;Muller et al, 2012;Richardson and Postigo, 2011;Zha et al, 2014). Many of the disinfection by-products can pose negative impact to human health (Krasner et al, 2009).…”