Biodegradability of Danube bank filtrate and its enhancement by ozonation

The reduction of organic content through transformation processes in the Danube aquifer along a studied area, biodegradability of Danube bank filtrate and its enhancement by ozonation have all been examined in a study carried out in order to assess amenability of Danube bank filtrate for bio-filtration. As determined during the study period Dissolved Organic Carbon (DOC) varied from 4.6–6.5 mgC/L and from 2.8–3.7 mgC/L in Danube River and Danube bank filtrate respectively. As determined 11.2% of Danube bank filtrate DOC was bio-degradable. A substantial enhancement of biodegradability has been observed after the application of Ozone dosages ranging from 0.45 to 0.9 mgO₃/ mgC. It was concluded that Danube bank filtrate itself is not amenable for bio-filtration but an enhancement of its bio-degradability by ozonation could make bio-filtration a reasonable and economical option for reducing of DOC content to the levels that provide low risk of excessive disinfection by-products formation and prevent bacterial re-growth in distribution networks of cities using Danube bank filtrate as the source water.