Bromate analysis in groundwater and wastewater samples

Abstract

Bromate (BrO(3)(-)) is a disinfection by-product formed during ozonation of potable water supplies containing bromide (Br(-)). Bromate has been classed by the World Health Organisation as a 'possible human carcinogen', leading to implementation of 10-25 microg L(-1)(as BrO(3)(-)) drinking water limits in legislative areas including the United States and European Union. Techniques have been developed for bromate analysis at and below regulatory limits, with Ion Chromatography (IC) coupled with conductivity detection (IC-CD), post-column reaction and ultra-violet (UV) detection (IC-PCR), or inductively coupled plasma-mass spectrometry detection (IC-ICPMS) in widespread use. The recent discovery of bromate groundwater contamination in a UK aquifer has led to a requirement for analysis of bromate in a groundwater matrix, for environmental monitoring and development of remediation strategies. The possibility of bromate-contaminated water discharge into sewage treatment processes, whether accidental or as a pump-and-treat strategy, also required bromate analysis of wastewater sources. This paper summarises techniques currently available for trace bromate analysis in potable water systems and details studies to identify a methodology for routine analysis of groundwater and wastewater samples. Strategies compared were high performance liquid chromatography (HPLC) with direct UV or PCR/UV detection, IC-CD, IC-PCR, and a simple spectrophotometric technique. IC-CD was the most cost-effective solution for simultaneous analysis of bromate and bromide within groundwater samples, having a 5 microg L(-1) detection limit of both anions with limited interference from closely-eluting species. Wastewater samples were successfully analysed for bromate only using HPLC with PCR/UV detection, with detection limits below 20 microg L(-1)(as BrO(3)(-)) and low interference. HPLC with direct UV detection was unsuitable for bromate analysis within the concentration range 50-5000 microg L(-1) which was required for this project, but column choice was shown to be a major factor in determining limits of detection. Spectrophotometry could not reproducibly determine bromate concentration, although the technique showed promise as a quick field method for high-level groundwater bromate analysis.

Bromate removal by electrochemical reduction at boron-doped diamond electrode

“…Although evidence of carcinogenicity in humans is inadequate, the International Agency for Research on Cancer has classified it as a Group 2B substance. The world Health Organization recommends a provisional guideline value of 0.01 mg/L for drinking water [2].…”

Photometric redox determination of chlorine and bromine oxoanions in the hypochlorite disinfectants solutions

“…Альтернативой методу ИХ может являться спектро-фотометрия с применением избирательных и вы-сокочувствительных реагентов. Однако каждая из известных фотометрических методик предназна-чена для определения лишь одного-двух оксоани-онов, находящихся в смеси: гипохлорита или перх-лората с тионином [9,10], хлорита и (или) хлората с индигокармином [11,12], хлорита с бензидином [13], перхлората или бромата с фенотиазиновыми красителями [14,15]. Ранее [16] нами представлено теоретическое обоснование и исследована избирательность фо-тометрического определения оксоанионов хлора с применением редокс-индикаторов различных клас-сов, включая метиленовый голубой.…”

On identifiability for chemical systems from measurable variables

“…Then, the system is perturbed in a way that the concentrations of the chemical species change and the relaxation to the precedent equilibrium point is followed to derive the kinetic information of the system. The chemical species like Br − or HOBr cannot be followed easily in real time, but others like O 3 , Br 2 or Br − 3 can be followed with an spectrophometer [1,5]. Consequently, in an hypothetical experiment design only the state variables x 1 , x 6 or x 7 or combinations of two of these state variables are accessible and the structural identifiability analysis is restricted to this knowledge.…”