Brominated river water

Another approach consists of an in-situ acetylation and extraction of NPEOs and further analysis of the acetyl derivatives. The method has been applied to analyse effluent water and sewage sludges [102,103], sediments [104] and river waters [105]. Silylated derivatives [106] using BSA or BSTFA have also been used to determine NPEO (n < 6) in seawater [107] and wastewater [107,108], sediments [109] and sludges from wool scour effluents [110]. Halogenated derivatives of alkylphenols (AP) can also be formed as a result of chlorination practices in water treatment or wastewater if bromide is present. Brominated OPs and NPs (BrAPEOs) have been identified by GC-MS in sewage [111] and tap water [89], respectively. 

Shimoishi and Toei [766] have described a gas chromatographic determination of selenium in non saline waters based on l,2-diamino-3,5-dibromobenzene with an extraction procedure that is specific for selenium (IV). Total selenium is determined by treatment of non saline water with titanium trichloride and with a bromine-bromide redox buffer to convert selenide, elemental selenium and selenate to selenious acid. After reaction, the 4,6-dibromopiazselenol formed from as little as lng of selenium can be extracted quantitatively into 1 ml of toluene from 500ml of natural water up to 2ng L 1 of selenium(IV) and total selenium can be determined. The percentage of selenium(IV) in the total selenium in river water varies from 35 to 70%. 

Uchida et al. [793] determined various selenium species in river water and sea water by electron capture detection gas chromatography after reaction with l,2-diamino-3,5-dibromobenzene. This reagent reacts with seleniumflV) to form 4,6-dibromopiazselenol which is extracted into toluene. After Se(-ll) and Se(0) has been reduced by a bromine-... 

Regarding ozonation processes, the treatment with ozone leads to halogen-free oxygenated compounds (except when bromide is present), mostly aldehydes, carboxylic acids, ketoacids, ketones, etc. [189]. The evolution of analytical techniques and their combined use have allowed some researchers to identify new ozone by-products. This is the case of the work of Richardson et al. [189,190] who combined mass spectrometry and infrared spectroscopy together with derivatization methods. These authors found numerous aldehydes, ketones, dicarbonyl compounds, carboxylic acids, aldo and keto acids, and nitriles from the ozonation of Mississippi River water with 2.7-3 mg L 1 of TOC and pH about 7.5. They also identified by-products from ozonated-chlorinated (with chlorine and chloramine) water. In these cases, they found haloalkanes, haloalkenes, halo aldehydes, haloketones, haloacids, brominated compounds due to the presence of bromide ion, etc. They observed a lower formation of halocompounds formed after ozone-chlorine or chloramine oxidations than after single chlorination or chlorami-nation, showing the beneficial effect of preozonation. 

ICP-MS and ion chromatographic method with suppressed conductivity detection were used to measure bromine species in water samples. ICP measures the total bromine concentration while the IC detects the bromide ions. In river water samples [70] no significant differences were obtained between concentration values determined by the two different methods. This shows that the bromine exists mostly as bromide ion. 

Emerging Contaminants in the Water-sediment System Case Studies of Pharmaceuticals and Brominated Flame Retardants in the Ebro River Basin... 

About 97% of Earth s water is in the oceans. This saline water contains vast amounts of dissolved minerals. More than 70 elements have been detected in the mineral content of seawater. Only four of these—chlorine, sodium, magnesium, and bromine—are now commercially obtained from the sea. The world s fresh water comprises the other 3%, of which about two-thirds is locked up in polar ice caps and glaciers. The remaining fresh water is found in groundwater, lakes, rivers, and the atmosphere. 

Another kind of plastic additive, brominated flame retardants (i.e. PBDEs), was detected in high concentrations of up to 133 pg/L in the landfill leachate from tropical Asian countries (Kwan et al. n.d., forthcoming). Again, this is evidence that high concentrations of PBDEs are foimd in the more industrialized and populated tropical Asian countries like Thailand, the Philippines and Malaysia. These concentrations were higher than those normally observed in water and sediments from rivers, canals and sewage, indicating... 

Underground waters in general have much lower concentrations than rivers and lakes but here again, there are high local concentrations [21], and they often contain a much higher proportion of brominated derivatives than surface waters. 

Uchida et al. [793] have described a method for determination of selenium in river and sea water by gas chromatography with electron-capture detection. The specific reaction of l,2-diamino-3,5-dibromo-benzene with selenium(IV) is used, the product (4,6-dibromopiazselenol) being extracted into toluene and determined from its peak height in the gas chromatogram. Selenium (-II, 0) is oxidised to selenium(IV) by bromine solution and selenium(VI) is reduced to the same state by bromine/ bromide redox buffer solution and determined as the piazselenol as above. 

---