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On the formation of bromate and chlorate ions during electrolysis with boron doped diamond anode for seawater treatment
Author(s) -
Vacca Annalisa,
Mascia Michele,
Palmas Simonetta,
Mais Laura,
Rizzardini Simone
Publication year - 2013
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.4095
Subject(s) - bromate , chlorine , chlorate , chloride , inorganic chemistry , chemistry , electrolysis , bromide , seawater , anode , electrochemistry , electrolyte , electrode , oceanography , organic chemistry , geology
BACKGROUND The electrochemical treatment of brackish and seawaters with boron doped diamond anodes ( BDD ) can be particularly suitable for the removal of microorganisms, microalgae and pollutants: the high conductivity of these waters and the high content of chloride ions can be exploited in disinfection/oxidation processes mediated by active chlorine. A correct choice of operating conditions can limit the formation of such undesired by‐products as bromate and chlorate ions.RESULTS Galvanostatic electrolyses of synthetic waters containing chloride and/or bromide ions using BDD anode were carried out both in batch and continuous mode in an undivided cell. Bromide ions were oxidized to form bromate ions with high conversion rate, while chlorate ions were found as by‐products of the oxidation of chloride ions together with active chlorine. When solutions containing Br − and Cl − were treated, the increase in the concentration of chloride up to that of seawater (20 g dm −3 ), hinders the formation of BrO 3 − and ClO 3 − .CONCLUSIONS The electrochemical process with BDD anode could be applicable to the disinfection of high salinity waters: in synthetic solution simulating the composition of seawaters, high amounts of active chlorine are formed and the occurrence of bromates and chlorates is highly limited. © 2013 Society of Chemical Industry