Microbial degradation of typical amino acids and its impact on the formation of trihalomethanes, haloacetonitriles and haloacetamides during chlor(am)ination

Ruihua Zhang; Feifei Wang; Wenhai Chu; Chao Fang; Hong Wang; Mengtian Hou; Rong Xiao; Guixia Ji

doi:10.1016/j.watres.2019.04.032

Microbial degradation of typical amino acids and its impact on the formation of trihalomethanes, haloacetonitriles and haloacetamides during chlor(am)ination

Water Res. 2019 Aug 1:159:55-64. doi: 10.1016/j.watres.2019.04.032. Epub 2019 Apr 29.

Authors

Ruihua Zhang¹, Feifei Wang², Wenhai Chu³, Chao Fang⁴, Hong Wang⁵, Mengtian Hou⁴, Rong Xiao⁴, Guixia Ji⁶

Affiliations

¹ State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Key Laboratory of Yangtze River Water Environment, Ministry of Education, Shanghai, 200092, China; School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, China.
² School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China.
³ State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Key Laboratory of Yangtze River Water Environment, Ministry of Education, Shanghai, 200092, China. Electronic address: feedwater@126.com.
⁴ State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Key Laboratory of Yangtze River Water Environment, Ministry of Education, Shanghai, 200092, China.
⁵ State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
⁶ School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, China.

PMID: 31078752
DOI: 10.1016/j.watres.2019.04.032

Abstract

Nitrogenous disinfection by-products (N-DBPs) in chlorinated drinking water are receiving increasing attention due to their elevated toxicities. An effective strategy to control the formation of N-DBPs is to reduce their nitrogenous precursors (e.g., amino acids [AAs], believed to be the important N-DBP precursors) before disinfection. So far, little information is available about the effectiveness of conventional microbial degradation at controlling the formation of N-DBPs. In this study, the biodegradability of 20 AAs was investigated, and the impacts of microbial degradation for the selected 6 typical AAs on the formation of N-DBPs (haloacetonitriles and haloacetamides) and traditional carbonaceous DBP (chloroform) were investigated. The results indicated that glycine, arginine, aspartic acid, asparagine, alanine and serine were susceptible to biodegradation, and the formation potentials (FPs) of DBPs were remarkably reduced after biodegradation. The highest chloroform FP reduction rates from tryptophan and tyrosine were 85.4% and 56.2%, respectively. The FPs of dichloroacetonitrile and trichloroacetamide were also reduced after biodegradation of the all selected AA samples during chlor(am)ination. Dichloroacetamide FPs decreased continuously with incubation time during chlorination for phenylalanine, asparagine, aspartic acid, and the mixed AAs, and the highest reduction rates were 78.7%, 74.6%, 46.7% and 35.3% respectively. The results of integrated toxicity analysis indicated that the pre-treatment of microbial degradation significantly decreased the integrated toxicity of DBPs formed from AAs. Moreover, the microbial community analysis revealed that Proteobacteria was predominant at phylum level in the mixed AA sample, and the dominant genera were Acinetobacter and Pseudomonas. Proteobacteria may play an important role in controlling DBP precursor.

Keywords: Amino acids; Chloroform; Disinfection by-products; Haloacetamides; Haloacetonitriles; Microbial degradation.

MeSH terms

Amino Acids
Chloramines
Disinfectants*
Disinfection
Halogenation
Trihalomethanes
Water Pollutants, Chemical*
Water Purification*

Substances

Amino Acids
Chloramines
Disinfectants
Trihalomethanes
Water Pollutants, Chemical