EVALUATION OF THE POSSIBILITY OF REPLACING THE RAPID FILTRATION PROCESS WITH ULTRAFILTRATION IN SURFACE WATER TREATMENT SYSTEMS

The presented study aimed to compare the effectiveness of ultrafiltration and filtration through a sand bed during the water treatment process after the coagulation and sedimentation. The study was conducted in two flow-type water treatment systems: the reference and the test system. Both systems functioned continuously with a throughput of 1 m(3)/h. The research has shown that both processes ensured a very effective removal of post-coagulation suspensions, however, ultrafiltration was more effective. The filtration process allowed a slightly higher removal of organic substances as compared to ultrafiltration. The effectiveness of the removal of organic substances was determined by the biological activity of sand beds, which is not allowed in the ultrafiltration process. Besides, during the filtration process, aluminum remaining after coagulation was more effectively removed. In turn, the ultrafiltration process ensured an almost 100% effectiveness in reducing the total microorganism cell count, while the effectiveness of the filtration process was approximately half of that. In the end, the possibility of replacing the filtration process with the ultrafiltration process is determined by the costs of both processes.