Vízügyi Közlemények, 1997 (79. évfolyam)

4. füzet - Rövidebb tanulmányok, közlemények, beszámolók

A tudományos kutatások szerepe az ivóvízellátásban 575 Gaps of the knowledge, however, can be tolerated only as long as they do not create unacceptable risk to human healts. The science related to drinking water treatment became a "follow up" science and it is likely to stay in this state, as due to the lack of approriate research in many countries ever increasing number of unknown processes are encountered. Presently valid standards can be considered as a kind of protective umbrella, which help us to virtually solve the problems. In assessing the problems one should consider not only the contaminant uptake via drinking water but also via the food. Results of scientific research must not be neglected in solving the tasks of drinking water treatment. The study supports this statement with a number of examples: Water treatment processes of bank-filtered drinking water production are extremely complex ones. Table 1 and Figure 1. provide information on the efficiency of treatment. Coagulation and fiocculation are coupled chemical reaction and physical transport processes. These treatment means are effected by many parameters (Figure 2.) and thus the respective processes must be optimized in scientifically well supported manner. Addition of coagulants to the flushing water of rapid filters improves the initially poor treatment efficiency (Figure 3.). Application of activated carbon adsorption requires knowledge of an extremely complex system of processes and thus must be the subject of intensified research (Figure 4.). Process optimization of activated carbon treatment must be made with extreme care. Removal of micropollutatns by several oxidation processes results in a variety of oxidized products. For example some of the taste producing agents enter rapidly into reaction with ozone. Other less readily oxidizable taste-substances react with delay only, thus producing new taste-forming compounds (Figure 5). Similar is the case with the oxidation of parathion (Figure 6.) when the toxicity of paradoxon, the product of this oxidation process, is far higher than that of the parathion. The products of several oxidation processes of phenols are much more toxic ones than the phenols (Figure 7.). Thus water treatment is a typically research-demanding process. * * * Rolle der wissenschaftlichen Forschung in der Trinkwasseraufbereitung von Prof. em. Dr.-lng. Géza ÖLLŐS, DSc. und Dr.-Ing. Miklós VARGA Die Aufgaben der Trinkwasseraufbereitung können immer nur über Kompromisse bzw. geringere Vereinfachungen gelöst werden. Obzwar die Wissenschaft sich heutzutage außerordentlich rasch entwickelt, tastet man oft auch noch heutzutage im Dunklen. Der Mangel an Wissen kann jedoch nur solange gedultet werden, bis das daraus resultierende hygienische Risiko noch akzeptabel ist. Die Wissenschaft der Wasseraufbereitung wurde zu einer „nachhinkenden" Wissenschaft, und wird es wahrscheinlich noch lange bleiben, da man in zahlreichen Ländern, infolge der völlig oder teilweise mangelnden Forschungen, auf immer mehr unerschlossene Prozesse stößt. Die gegenwärtig gültigen Normen sollten in vielen Fällen nur als eine Art Schutzschirme betrachtet werden, da sie uns nur anscheinend durch die Probleme helfen. Außer den Schmutzstoff-Komponenten des Trinkwassers soll man auch diejenigen der Lebensmittel in Betracht ziehen.