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The continuous photoreduction of methyl viologen by 5,5″‐bis(aminomethyl)‐2,2′:5′,2″‐terthiophene (AT) and 2,2′:5′,2″‐terthiophene‐5,5″‐dicarboxylic acid (CT), using EDTA as a sacrificial electron donor, has been investigated in aqueous solution at various pH. Apparent rates and efficiencies of production of the methyl viologen radical cation (MV+) were found to be dependent on the pH, the concentrations of all three components and the intensity of the incident light. The highest conversion efficiency (77%) was shown by the bis(aminoniethyI (‐substituted terthiophene AT at pH 7.7. The quantum yield for the formation of MV+ under these conditions was 0.24, which is comparable with other common systems

To collect fundamental data for the improvement of drinking water quality, focusing on the removal of 2-MIB, Geosmin, IPMP, IBMP and TCA, a total of 20m3/d pilot plant was operated with process schemes of GAC with post-O3(PP-I), and without ozonation(PP-II). Five taste and odor causing substances could be removed to non-detectable concentration with PP-I, but GAC alone was not so effective as PP-I. The larger the EBCT and Iodine Number of GAC column employed, the higher the removal efficiencies expected. The minimum EBCT and Iodine Number were respectively 15 min and 1,000 mg/g of GAC column. Geosmin removal efficiencies ranged 30 to 40% at 15.6 ng/l during conventional process scheme, but 70 to 80% removal was achieved by the PP-I and 60 to 70% by PP-II was achieved. IPMP removal efficiencies were 60 to 80% with GAC only. IBMP and TCA were seldom detected in raw water samples, but TCA was the most difficult to remove of five taste and odor causing substances.

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