Development of a Measuring Method for the Determination of Bisulfite and Sulfite in Seawater

Abstract

In conventional reverse osmosis processes for seawater desalination, a disinfection of the process stream with chlorine compounds is carried out for antifouling. After disinfection the reduction agent Na2S2O5 is used for the removal of residual chlorine in a strongly overstoichiometric way in order to protect the membranes from oxidational damages. To save chemicals a controlled dosing of Na2S2O5 based on a reliable concentration measurement is desirable. Therefore, a measuring method for the determination of the sulfur(IV) components bisulfite and sulfite in seawater is developed based on the combination of UV spectroscopy and a PLS regression method. Experimental results as well as the development of the regression model for sulfur species in ultrapure and seawater is described.

Ionophore-modified polyaniline-based optode for the determination of hydrogen sulfite levels in beverages, wastewater, and soil

“…The strong evidence of the hydrogen sulte interaction with the PANI polymer is the disappearance of the -OH band at 3562.19 cm −1 in hydrogen sulte, where at pH = 5.6, the sulte ion exists as HSO 3 − by about 95%; upon interaction with PANI, protonation of the polymer takes place and the hydroxyl band disappears. 42 This conrms that the interaction depends on hydrogen bonding and protonation-based redox reactions. Also, this mechanism is conrmed by the existence of the band at 1159 cm −1 due to PANI protonation; also, the existence of the band at ∼3700 cm −1 , which is attributed to the existence of -NH 2 conrms the protonation of the polymer.…”