The aim of this research was to find how the biological activated carbon (BAC) filters operate in conditions of raised salinity and rapid changes in organic pollutants concentration. The experiments were realized in bench scale and were continued for 18 months. The efficiency of BAC was determined as organics removal by measuring the absorbance in UV, COD and TOC. The result of the research proved that salinity up to 1000 mgCl./L has not disturbed the microorganisms growth. There was no influence of salinity on. COD and TOC removal. The absorbance measured by UV in higher salinity showed about 10% lower effect of BAC. To gain the high effect of SAS and phenol removal on BAC in water of high salinity the increased contact time was necessary. The very stable effect of biodegradation on BAC was observed in conditions of rapid increase of micropollutants concentration, regardless of water salinity.
