Formation of regulated and unregulated disinfection byproducts during chlorination of algal organic matter extracted from freshwater and marine algae

WATER RESEARCH

卷:142

Article

Liu, Chao¹  Ersan, Mahmut S.¹  Plewa, Michael J.^2,3  Amy, Gary¹  Karanfil, Tanju¹ 

[1] Clemson Univ, Dept Environm Engn & Earth Sci, Anderson, SC 29625 USA

[2] Univ Illinois, Dept Crop Sci, Urbana, IL 61801 USA

[3] Univ Illinois, Safe Global Water Inst, Urbana, IL 61801 USA

关键词: Disinfection byproducts;    Algal organic matter;    Bromide;    Iodide;    Total organic halogen;    Bromine substitution;   

DOI  :  10.1016/j.watres.2018.05.051

来源: Elsevier

【 摘 要 】

Seasonal algal blooms in freshwater and marine water can increase the input of algal organic matter (AOM) to the pool of dissolved organic matter. The impact of bromide (Br-) and iodide (I-) on the formation of regulated and unregulated disinfection byproducts (DBPs) was studied from chlorination of AOM solutions extracted from three species of cultured isolates of freshwater and marine algae (Microcystis aeruginosa (MA), Synechococcus (SYN), and Alexandrium tamarense (AT)). Comparable concentrations of DBPs were formed from three types of AOM. In the absence of Br-, trihalomethanes (THMs), haloacetic acids (HAAs), and haloacetaldehydes (HALs) were the main groups of DBP formed, and haloacetonitriles (HANs) were formed at lower concentrations. In contrast, the formation of iodinated THMs was <8 nM (1.7 mu g/L) since most of initial I- was oxidized to iodate. Increasing initial Br- concentrations increased the formation of THMs and HANs, while concentrations of total organic halogen and HAA remained stable. On the contrary, total HAL concentrations decreased due to the instability of bromated HALs. Decreasing the specific UV absorbance (SUVA) value of AOM favours bromine substitution since bromine more preferentially reacts with low reactivity organic matter than chlorine. Increasing the pH enhanced the formation of THMs but decreased the formation of HANs. Concentrations of HANs and HALs decreased at high pH (e.g., 9.0), high initial chlorine concentration and long reaction time due to the decomposition. Based on the cytotoxicity calculations, unregulated HANs and HALs were the main contributors for the total toxicity of DBPs measured, even though based on the weight regulated THMs and HAAs predominated. (C) 2018 Elsevier Ltd. All rights reserved.

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