Technical Note: Reactivity of C1 and C2 organohalogens formation – from plant litter to bacteria

Wang, Junjian; Ng, Tsz Wai; Zhang, Q.; Yang, Xiaoqing; Dahlgren, Randy A.; Chow, Alex T.; Wong, Po Keung

doi:10.5194/bg-9-3721-2012

Cited by 22 publications

(18 citation statements)

References 46 publications

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“…It suggests that there may be a potential concern for nitrogenous DBPs in managing drinking water supply following wildfires, especially during the first leaching events. In this study, the TS extracts did not show as high SHAN-FP as later extracts of SLS, suggesting that the reactive fire-produced HAN precursors in the AS were possibly photo-/bio-degraded/transformed, or rapidly diluted with less reactive precursors such as the recovered plant/ soil-derived carbon-rich DOM (Wang et al, 2012) under field conditions. Thus, although HANs are an important concern as they are more potent carcinogens than common carbonaceous DBPs such as THMs or HAAs (Richardson et al, 2007) and high SHAN-FP has been found in lab-burned ashes (>10 mg-HAN/mg-DOC; Majidzadeh et al, 2015;Wang et al, 2015b), the extremely high reactivity of DOM to form HANs observed for the sequential AS extracts may not persist in field AS samples (<5 mg-HAN/mg-DOC in Wang et al, 2015a) or source waters ( 2.7 mg-HAN/mg-DOC in Writer et al (2014)).…”

Section: Dbp Precursors In Water Extracts From Ash/soilmentioning

confidence: 56%

“…The highly toxic nitrogenous DBPs such as haloacetonitriles (HANs) and N-nitrosodimethylamine (NDMA) (Plewa and Wagner, 2009), although unregulated, are often detected in chlorinated and chloraminated drinking waters, respectively (Lee et al, 2007;Shah and Mitch, 2012). Previous studies have clearly shown that different DOM chemical compositions have a wide range of reactivity with oxidants to form DBPs (Dotson et al, 2009;Lee and Hur, 2014;Wang et al, 2012Wang et al, , 2014. Wildfires cause major transformations in DOM quantity and chemical composition depending on fire temperature and oxygen availability (Bladon et al, 2014;Santin et al, 2015;Wang et al, 2015a,b).…”

Section: Introductionmentioning

confidence: 99%

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Temporal variations of disinfection byproduct precursors in wildfire detritus

et al. 2016

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a b s t r a c tThe Rim Fire ignited on August 17, 2013 and became the third largest wildfire in California history. The fire consumed 104,131 ha of forested watersheds that were the drinking water source for 2.6 million residents in the San Francisco Bay area. To understand temporal variations in dissolved organic matter (DOM) after the wildfire and its potential impacts on disinfection byproduct (DBP) formation in source water supply, we collected the 0e5 cm ash/soil layer with surface deposits of white ash (high burn severity) and black ash (moderate burn severity) within the Rim Fire perimeter in Oct 2013 (pre-rainfall) for five sequential extractions, and in Dec 2013 (~87 mm cumulative precipitation) and Aug 2014 (~617 mm cumulative precipitation) for a single water extraction. Water-extractable DOM was characterized by absorption and fluorescence spectroscopy and DBP formation tests. Both increasing cumulative precipitation in the field or number of extractions in the lab resulted in a significant decrease in specific conductivity, dissolved organic carbon, and DBP formation potential, but an increase in DOM aromaticity (reflected by specific UV absorbance). However, the lab sequential leaching failed to capture the increase of the NO x À -N/NH 4 þ -N ratio and the decrease in pH and dissolved organic carbon/nitrogen ratio of ash/soil extracts from Oct 2013 to Aug 2014. Increasing cumulative precipitation, inferring an increase in leaching after fire, led to an increase in DOM reactivity to form trihalomethanes, haloacetic acids, and chloral hydrate, but not for haloketones, haloacetonitrile, or N-nitrosodimethylamine, which were more related to the original burn severity. This study highlights that fire-affected DBP precursors for different DBP species have distinct temporal variation possibly due to their various sensitivity to biogeochemical alterations.

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Section: Dbp Precursors In Water Extracts From Ash/soilmentioning

confidence: 56%

Section: Introductionmentioning

confidence: 99%

Temporal variations of disinfection byproduct precursors in wildfire detritus

et al. 2016

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“…Despite findings that specific HAN FP increases with a decreasing C/N ratio of the original organic matter during the humification process, 45 the enhanced specific HAN and NDMA FP with increasing burn severity cannot be simply explained by DON, TDN, DOC/TDN, or DOC/DON patterns (P > 0.05; Table 1). The change of organic nitrogen structure with increasing burn severity is probably the major factor because specific HAN FP linearly increased with P II,n (r 2 = 0.52, P < 0.001; Figure 3D) and decreased with P I,n (protein-like compound; r 2 = 0.59, P < 0.001; Figure S4, Supporting Information).…”

Section: ■ Results and Discussionmentioning

confidence: 92%

“…45 Before burning, the detritus contained a substantial amount of biopolymers, such as lignin and protein. The lignin phenols and aromatic moieties of proteins are both known to be highly reactive THM and HAA precursors, 45,46 e.g., up to 328 μg-THM/mg-C for acetosyringone and 138 μg-THM/mg-C for tyrosine. The fire consumes many of these precursors and transforms them to condensed aromatics (such as PAHs).…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Wildfire Altering Terrestrial Precursors of Disinfection Byproducts in Forest Detritus

Wang

Dahlgren

Erşan

et al. 2015

Environ. Sci. Technol.

105

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Wildfire occurrence and intensity are increasing worldwide causing severe disturbances to forest watersheds used for potable water supply. The effects of wildfire on drinking water quality are not well understood, especially in terms of terrestrial dissolved organic matter (DOM) and DOM-associated formation of disinfection byproducts (DBP). As the forest floor layer is a major source of terrestrial DOM, we investigated characteristics and DBP formation of water extractable organic matter (WEOM) from the 0−5 cm depth of nonburned detritus (control) and burned detritus with black ash (moderate severity) and white ash (high severity) associated with the 2013 Rim Fire in California. Spectroscopic results suggested that the aromaticity of WEOM followed white ash > control > black ash and fluorescence region II (excitation 220−250 nm; emission 330−380 nm) of the emission-excitation-matrix was identified as a potential burn severity indicator. Compared to the control, WEOM from white and black ashes had lower reactivity in forming trihalomethanes (55%-of-control) and haloacetic acids (67%-of-control), but higher reactivity in forming the more carcinogenic haloacetonitrile after chlorination (244%-of-control) and N-nitrosodimethylamine after chloramination (229%-of-control). There was no change in reactivity for chloral hydrate formation, while WEOM from black ash showed a higher reactivity for haloketone formation (150%-of-control). Because wildfire consumed a large portion of organic matter from the detritus layer, there was lower water extractable organic carbon (27%-of-control) and organic nitrogen (19%-of-control) yields in ashes. Consequently, the wildfire caused an overall reduction in water extractable terrestrial DBP precursor yield from detritus materials.

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“…Generally specific THM formation of these biomolecules usually low than 10 μg-THM/mg-C except few exceptions such as tryptophan and tyrosine which can be over 100 μg-THM/mg-C (34,35). Differences from other previous studies, we examined DBP formation directly disinfecting bacterial cells.…”

Section: Microbial Cells and Cellular Components As Dbps Precursormentioning

confidence: 96%

Formation of Disinfection By-Products from Bacterial Disinfection

Chow

et al. 2015

ACS Symposium Series

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hk. Tel.: +852 3943 6383. Fax: +852 2603 5767.Controlling the disinfection by-product (DBP) formation, while balancing the risk of bacterial contamination in finished water, requires an in depth understanding in both the chemistry of DBPs and the kinetic and mechanism of bacterial disinfection. Although numerous studies have examined different strategies on the reduction of DBP formation in finished waters, their main focuses are on natural organic matter (NOM) in source waters. Few studies evaluated the contributions of bacterial organic matter (BOM) on DBP formation. Breaking down of bacterial cells, releasing BOM into water, is an essential process in water disinfection. Prevalence of bacterial contamination in source waters and occurrences of biofilms in water treatment units and distribution systems are frequently reported. The contributions of organic matter from bacterial and microbial sources in drinking water treatment cannot be ignored. In this study, we compared the contributions of bacterial cells and humic acid (HA), under controlled laboratory environments, on the DBP formation from chlorination. We also evaluated the effects of HA, pH, and chlorine dosage on both disinfection efficiency and DBP formation. The results showed that bacterial cells are also potential DBP precursor. Presence of HA not only increased the DBP formation, but also decreased the disinfection efficiency of chlorination. pH and chlorine dosage also affect the disinfection efficiency and DBP formation of chlorination. High dosage of chlorine would increase both the disinfection efficient and DBP formation, while low pH increase the disinfection efficient with a lower DBP formation. The results suggest that high disinfection efficiency with low DBP formation of chlorination can be achieved by optimization of operation conditions. Based on our knowledge, this pioneering work is the first study to investigate the relationship between bacteria and DBP contaminations in water treatment processes at the same time.

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Technical Note: Reactivity of C1 and C2 organohalogens formation – from plant litter to bacteria

Cited by 22 publications

References 46 publications

Temporal variations of disinfection byproduct precursors in wildfire detritus

Temporal variations of disinfection byproduct precursors in wildfire detritus

Wildfire Altering Terrestrial Precursors of Disinfection Byproducts in Forest Detritus

Formation of Disinfection By-Products from Bacterial Disinfection

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