Comparison of commercial analytical techniques for measuring chlorine dioxide in urban desalinated drinking water

Abstract

Most drinking water industries are closely examining options to maintain a certain level of disinfectant residual through the entire distribution system. Chlorine dioxide is one of the promising disinfectants that is usually used as a secondary disinfectant, whereas the selection of the proper monitoring analytical technique to ensure disinfection and regulatory compliance has been debated within the industry. This research endeavored to objectively compare the performance of commercially available analytical techniques used for chlorine dioxide measurements (namely, chronoamperometry, DPD (N,N-diethyl-p-phenylenediamine), Lissamine Green B (LGB WET) and amperometric titration), to determine the superior technique. The commonly available commercial analytical techniques were evaluated over a wide range of chlorine dioxide concentrations. In reference to pre-defined criteria, the superior analytical technique was determined. To discern the effectiveness of such superior technique, various factors, such as sample temperature, high ionic strength, and other interferences that might influence the performance were examined. Among the four techniques, chronoamperometry technique indicates a significant level of accuracy and precision. Furthermore, the various influencing factors studied did not diminish the technique's performance where it was fairly adequate in all matrices. This study is a step towards proper disinfection monitoring and it confidently assists engineers with chlorine dioxide disinfection system planning and management.

Analytical methods for determining environmental contaminants of concern in water and wastewater

“… Class Name Drinking water EPA maximum residual disinfectant level goal (mg/L) [1] Surface water maximum recommended level (µg/L) [3] Analytical technique Ref. Disinfectants Chloramines (as Cl 2 ) 4 – 1- Amperometric titration 2- DPD ferrous titrimetric method 3- DPD colorimetric method 4- UV-Vis Spectrophotometry [90] Chlorine (as Cl 2 ) 4 – 1- Amperometric titration 2- DPD ferrous titrimetric method 3- DPD colorimetric method Syringaldazine (FACTS) method 4- Iodometric electrode technique [91 , 96] Chlorine dioxide (as ClO 2 ) 0.8 – 1- Amperometric titration 2- DPD (N,N‑diethyl-p-phenylenediamine) ferrous titrimetric method 3- The Lissamine Green B (LGB WET) colorimetric analytical technique 4- Chronoamperometry [96 , 97] THMs Bromodichloromethane 0 27 1- GC-MS 2- GC-ECD 3- GC-NiECD 4- Hach THM Plus method 5- P&T/GC-PID-ELCD [95 , 98 , 99] Bromoform 0 120 Dibromochloromethane 0.06 21 Chloroform 0.07 2000 HAAs Dichloroacetic acid 0 – 1- GC-ECD 2- Hach THM Plus method 3- IC-ESI-MS/MS 4- IC-CD [95 , 98 , 99] Trichloroacetic acid 0.02 ...…”