Interpreting main features of the differential absorbance spectra of chlorinated natural organic matter: Comparison of the experimental and theoretical spectra of model compounds

2020 ◽  
Vol 185 ◽  
pp. 116206 ◽  
Author(s):  
Bingya Chen ◽  
Chenyang Zhang ◽  
Yanmei Zhao ◽  
Dongsheng Wang ◽  
Gregory V. Korshin ◽  
...  
2018 ◽  
Vol 143 ◽  
pp. 492-502 ◽  
Author(s):  
Zheng-Qian Liu ◽  
Amisha D. Shah ◽  
Elisabeth Salhi ◽  
Jakov Bolotin ◽  
Urs von Gunten

2018 ◽  
Author(s):  
Isabela Carreira Constantino ◽  
Amanda Maria Tadini ◽  
Marcelo Freitas Lima ◽  
Lídia Maria de Almeida Plicas ◽  
Altair Benedito Moreira ◽  
...  

Abstract. Natural organic matter (NOM) is an important component for understanding the behavior of pollutants in the environment. A fraction of NOM is considered labile, fresh and less oxidized. In this work, a simple method was developed to distinguish between labile (LOM) and recalcitrant (ROM) organic matter in freshwater samples. Pyruvate, lignin and fulvic acid were chosen as model compounds of labile and recalcitrant NOM. The samples were submitted to kinetic monitoring experiments using hydrogen peroxide. Pyruvate was the best standard for the quantification of LOM (for concetrations up to 2.9 mg L−1). ROM was quantified by measuring the difference between total organic carbon (TOC) and LOM concentrations. Curves obtained with 0.5 to 5.0 mg L−1 TOC (pyruvate) in freshwater or ultrapure water samples did not indicate the existence of a matrix effect. This simple method was applied to water samples that were collected monthly for one year; the resulting LOM concentrations ranged from 0.47 to 2.1 mg L−1 and the ROM concentrations ranged from 0.08 to 3.5 mg L−1. Based on this results we concluded that hydrogen peroxide kinetics can be used as a simple method to quantify LOM and ROM concentrations in freshwater samples.


2012 ◽  
Vol 66 (9) ◽  
pp. 1941-1949 ◽  
Author(s):  
Shakiba Ayatollahi ◽  
Daina Kalnina ◽  
Weihua Song ◽  
Barbara A. Cottrell ◽  
Michael Gonsior ◽  
...  

The importance of natural organic matter (NOM) as a source of carbon in natural waters, as the source of reactive oxygen species, or for the complications its presence causes in treatment of natural waters, is undeniable. Recent studies have also pointed to the major photochemical role of triplet excited state of natural organic matter in the environmental fate of pharmaceutical and personal care products (PPCPs) in waters. However, the characterization of NOM is problematic due to its complex molecular structure. One approach to better understand NOM chemistry is the use of model compounds. As the condensation of a plant's phenolic compounds leads to humification and the formation of NOM, a structurally broad group of nine phenolic compounds were selected as model compounds for this study. With methods used in the discipline of radiation chemistry, the oxidative chemistry and transient spectra of these phenols were studied. In addition, the oxidative chemistry and transient spectra of a sample of NOM from the Black River, North Carolina, USA, was characterized. This natural water sample was used as received and represents the first studies of non-isolated NOM by pulsed radiolysis. The results of the transient spectra of the NOM revealed that the radical intermediates were very long lived. This phenomenon was not captured using the nine model compounds suggesting that more complex compounds are needed to further our understanding of the oxidation chemistry of NOM.


2008 ◽  
Vol 8 (6) ◽  
pp. 611-614 ◽  
Author(s):  
D. J. Dryer ◽  
G. V. Korshin ◽  
A. Heitz ◽  
C. Joll

This study examined the effects of changes in pH and copper concentration on the absorbance spectra of natural organic matter (NOM) from a reservoir in Western Australia. Differential absorbance spectra generated for this NOM under changing pH and copper concentration conditions revealed features that could be correlated to the activity of distinct types of chromophores. A comparison of results with those generated for experiments with standard Suwannee River fulvic acid highlighted important differences in chemistry between the two samples.


2013 ◽  
Vol 22 (9) ◽  
pp. 1153-1160 ◽  
Author(s):  
Hee-Jong Son ◽  
Jong-Moon Jung ◽  
Jin-Taek Choi ◽  
Hyung-Sik Son ◽  
Seong-Ho Jang

Sign in / Sign up

Export Citation Format

Share Document