1,3,5-Trimethoxybenzene (TMB) as a new quencher for preserving redox-labile disinfection byproducts and for quantifying free chlorine and free bromine

2018 ◽  
Vol 4 (7) ◽  
pp. 926-941 ◽  
Author(s):  
Stephanie S. Lau ◽  
Ryan P. Dias ◽  
Kayla R. Martin-Culet ◽  
Nicholas A. Race ◽  
Marella H. Schammel ◽  
...  

1,3,5-Trimethoxybenzene can be used to quench residual chlorine and bromine without altering disinfection byproducts that are reactive toward traditional quenchers.

2001 ◽  
Vol 1 ◽  
pp. 39-43 ◽  
Author(s):  
V. Zitko

Many countries require the presence of free chlorine at about 0.1 mg/l in their drinking water supplies. For various reasons, such as cast-iron pipes or long residence times in the distribution system, free chlorine may decrease below detection limits. In such cases it is important to know whether or not the water was chlorinated or if nonchlorinated water entered the system by accident. Changes in UV spectra of natural organic matter in lakewater were used to assess qualitatively the degree of chlorination in the treatment to produce drinking water. The changes were more obvious in the first derivative spectra. In lakewater, the derivative spectra have a maximum at about 280 nm. This maximum shifts to longer wavelengths by up to 10 nm, decreases, and eventually disappears with an increasing dose of chlorine. The water treatment system was monitored by this technique for over 1 year and changes in the UV spectra of water samples were compared with experimental samples treated with known amounts of chlorine. The changes of the UV spectra with the concentration of added chlorine are presented. On several occasions, water, which received very little or no chlorination, may have entered the drinking water system. The results show that first derivative spectra are potentially a tool to determine, in the absence of residual chlorine, whether or not surface water was chlorinated during the treatment to produce potable water.


2007 ◽  
Vol 55 (12) ◽  
pp. 213-219 ◽  
Author(s):  
Y.J. Jung ◽  
B.S. Oh ◽  
J.W. Kang ◽  
M.A. Page ◽  
M.J. Phillips ◽  
...  

The aim of this study was to investigate some aspects of the performance of electrochemical process as an alternative disinfection strategy, while minimising DBPs, for water purification. The study of electrochemical processes has shown free chlorine to be produced, but smaller amounts of stronger oxidants, such as ozone, hydrogen peroxide and OH radicals (•OH), were also generated. The formation of mixed oxidants increased with increasing electric conductivity, but was limited at conductivities greater than 0.6 mS/cm. Using several microorganisms, such as E. coli and MS2 bacteriophage, inactivation kinetic studies were performed. With the exception of free chlorine, the role of mixed oxidants, especially OH radicals, was investigated for enhancement of the inactivation rate. Additionally, the formation and reduction of DBPs was studied by monitoring the concentration of haloacetic acids (HAAs) during the process.


Processes ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 95 ◽  
Author(s):  
Lili Wang ◽  
Xiaowei Liu

Chlorine-incorporating ultraviolet (UV) provides a multiple barrier for drinking water disinfection. Meanwhile, post-UV employment can promote the degradation of micropollutants by radical production from chlorine residual photolysis. This work studied the degradation of one such chemical, tonalide (AHTN), by low-pressure UV-activated free chlorine (FC) under typical UV disinfection dosage of <200 mJ·cm−2 and water matrix of filtered tank effluent. AHTN was rapidly degraded by UV/FC in accordance with pseudo-first-order kinetics. The reaction rate constants of AHTN with reactive chlorine species and hydroxyl radical (HO•) were estimated. Mechanistic exploration evidenced that under UV/FC, AHTN degradation was attributable to direct photolysis, ClO•, and HO•. The carbonyl side chain of AHTN served as an important attack site for radicals. Water matrices, such as natural organic matter (NOM), HCO3−, Cu2+, PO43−, and Fe2+, showed noticeable influence on the UV/FC process with an order of NOM > HCO3− >Cu2+ > PO43− > Fe2+. Reaction product analysis showed ignorable formation of chlorinated intermediates and disinfection byproducts.


1992 ◽  
Vol 26 (1) ◽  
pp. 99-106 ◽  
Author(s):  
Ernest R. Blatchley ◽  
Richard W. Johnson ◽  
James E. Alleman ◽  
William F. McCoy

Author(s):  
Sumant Avasarala ◽  
John Orta ◽  
Michael Schaefer ◽  
Macon Abernathy ◽  
Samantha Ying ◽  
...  

This study investigated the reaction kinetics on the oxidative transformation of lead(ii) minerals by free chlorine (HOCl) and free bromine (HOBr) in drinking water distribution systems.


2008 ◽  
Vol 2008 (15) ◽  
pp. 1819-1831
Author(s):  
Bruce Mansell ◽  
Shiaw-Jy Huitric ◽  
Naoko Munakata ◽  
Jeff Kuo ◽  
Chi-Chung Tang ◽  
...  

2012 ◽  
Vol 4 (11) ◽  
pp. 3646 ◽  
Author(s):  
Zhimin Qiang ◽  
Yanjun Jiang ◽  
Weiwei Ben ◽  
Craig Adams ◽  
Huiyu Dong
Keyword(s):  

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