Extraction and ozonation of organic pollutants in drinking waters

The continuous liquid-liquid. CLLE. and solid-phase. SPE. extraction techniques were used to study a problem of international relevance. The work was incident on the evaluation of the efficiency and optimization of extracting techniques, CLLE. SPE and CLLE+SPE, towards chlorinated pesticides and phenolic compounds from the Giza treatment plant station [Egypt], where the degree of pollution of such substances in drinking waters must be reduced. The total recoveries, using SPE ranged between 0.74 - 0.87, whereas, the values were much less using the other two methods [0.158 - 0.196]; indicating the preferrability of the SPE technique. Analytical results were obtained through the various chromatographic techniques, liquid or gas, with adequately chosen detectors. A simple mathematical algorithm has been empirically developed allowing the assessment and comparison of the efficiencies of the three extracting procedures. Futher treatment with ozone resulted in the oxidation and elimination of organic pollutants, with consequent improvement of water quality [total pesticide content 0.332-0.19 micro gL[-1]]. A useful ozone treatment unit, capable of dealing with the ozonation of contaminants in tap water, was built

Electronic spectra and electron-donating properties of Bipyridyls

A quantitative analysis of the electronic absorption spectra of 2, 2 and 4, 4-bibpyridyls was carried out. The solvent effect, on these spectra, was studied giving particular attention to the type and extent of interaction between the two pyridyl moieties. A study of the intermolecular charge-transfer complexes of the two bipyridyls with the representative acceptors was carried out and their electron- donating properties were compared to that of pyridine