Hidrológiai Közlöny 2006 (86. évfolyam)

3. szám - Kaposvári Kázmér: Effect of the intervening ozonizing and Biologie Activated Carbon treatmant to drinking water produced by water supply intake at the River Tisza Szolnok

26 HIDROLÓGIAI KÖZLÖNY 2006. 86. ÉVF. 3. SZ. MECHANICAL CLEANING, PRE-TREATMENT STANDBY WATER RESERVE WELL OZONE MIXING AND ABSORPTION BASINS Fig 1: The operational scheme of the Szolnok Surface Water Plant This paper does riot present and discuss the operative process control and quality measurement systems which are inseparable parts of the optimization of the purification plant. The adaptation of the new stages in to the process scheme was different from the standard arrangements in case of the ozonizer only. The semiplant experiments drew the attention to the fact that the pre-ozone formed high residual organic matter, while the post-ozone - located right upstream of the activated carbon filter - regularly created secondary dispersed phase. These observations require the reconsideration of the use of these methods. The interfacial ozonization applied after the flocculation was promising in the achievement of the defined water quality targets. (Palicska J., 1989, Chedal J., 1982, Chedal J., 1985, Glaze W. H., 1990, DugnetJ. P., 1985) 4. The quality of the potable water after the commissioning of the enhanced process The values and limits in the MSZ 450-1/1989 Hungarian standard for the evaluation of the potable water parameters and the 21/2002. KöViM ministerial decree (effective from 1

s

t April, 2003) are in compliance with the potable water requirements of the WHO and the EU. According to the results of the auditory tests carried out by the concerned authorities, as well as the quality certifications provided by the operators; the treated, discharged water satisfies the requirements even in respect of the earlier complained components and parameters (

Magyar P-né. - Palicska J. - Süveges GY. Kaposvári K., 2003). The consumers' complaints have also disappeared. The consumers recognized the "improvement" of the potable water. Besides the major consumers, who are in the knowledge of the quality parameters, a number of average consumers have also indicated their favorable observations. The sensible water quality improvement is steady, whereas the taste and odor effects in the raw and in the flocculated Tisza water are still detectable. The ozonization and the activated carbon adsorption together ensure that the materials responsible for the taste and odor observations remain below the detection limits in the supplied water. After the ozonization, the iron and the manganese components are presented in an oxidized, precipitated form irrespectively from their original composition. Their concentration falls below the detection limit after the sand filtering. The break-through of the manganese in the purification system which was typical during the total freezing periods of the Tisza river - has totally disappeared. The reduction of the algae was spectacular. While the typical number of algae was between 10

4—

10

5 in the treated water before, presently we can steadily achieve 1 10

2—

5 10

2 e/L values (irrespective of the incoming number of algae) with the enhanced process. The frequency of occurrences between 1 10-1 10

4e/L is less than 2 %. The previous process was ineffective especially against the micro algae, which problem has been satisfactorily solved by the enhanced process. We can reduce the adverse consequences of the destruction of the alga cells - like the geosmin and the 2-MIB increase - with the intermittent injection of pre-chlorine and with using smaller than 0,5 g/m

3 dosage. The Daphnia tests show significant reduction of the xenobiotic materials. The frequency of the previously complained test results is zero. It must also be mentioned that the typical 35 % insufficiency cases for the raw