Chlorination of soil-derived dissolved organic matter: Long term nitrogen deposition does not increase terrestrial precursors of toxic disinfection byproducts
Persistent URL
Author(s)
Li, Li-Ping
Huang, Wan-Ling
Yang, Meng-Ting
Liu, Yan
Bowden, Richard D. (Rich)
Simpson, Myrna J.
Lajtha, Kate
Tian, Li-Qiao
Wang, Jun-Jian
Date Issued
October 15, 2020
Abstract
Terrestrial dissolved organic matter (DOM) in forested watersheds is a known precursor of disinfection byproducts (DBPs) in drinking water. Although the characteristics of terrestrial DOM may change with increasing nitrogen (N) deposition in forests, how these changes alter formation potential and toxicity of DBPs remains unexplored. We analyzed the speciation and toxicity of DBPs from chlorination of DOM derived from soils (O, A, and B horizons) in an experimental temperate forest with 22 years of N addition. With long-term N addition, the DOM reactivity toward the formation of trihalomethanes (from 27.751.8 to 22.8-31.1 mu g/mg-dissolved organic carbon (DOC)) and chloral hydrate (from 1.25-1.63 to 1.141.36 mu g/mg-DOC) decreased, but that toward the formation of haloketones increased (from 0.23-0.26 to 0.26-0.33 mu g/mg-DOC). The DOM reactivity toward the formation of haloacetonitriles was increased in the deeper soil but reduced in the surface soil. The DBP formation potential of DOM draining from a certain area of forest soils (in mu g-DBP/m(2)-soil) was estimated to be reduced by 20.3% for trihalomethanes and increased by 37.5% for haloketones and have minor changes for haloacetonitriles and chloral hydrate (both <7%). Furthermore, the DBPs from chlorination of the soil-derived DOM showed lowered microtoxicity with N addition possibly due to reduced brominated DBP formation. Overall, this study highlights that N deposition may not increase drinking water toxicity through altering terrestrial DOM characteristics.
Journal
Water Research
Department
Environmental Science / Studies
Citation
Li, Li-Ping, Wan-Ling Huang, Meng-Ting Yang, Yan Liu, Richard D. Bowden, Myrna J. Simpson, Kate Lajtha, Li-Qiao Tian, and Jun-Jian Wang. "Chlorination of Soil-Derived Dissolved Organic Matter: Long Term Nitrogen Deposition does Not Increase Terrestrial Precursors of Toxic Disinfection Byproducts." Water Research 185, (2020): 116271. doi:10.1016/j.watres.2020.116271. http://dx.doi.org/10.1016/j.watres.2020.116271.
Publisher
Pergamon-Elsevier Science LTD
DOI
10.1016/j.watres.2020.116271
ISSN
0043-1354