Removal of organic matter from drinking water by single and dual media filtration: a comparative pilot study

This pilot-scale research was conducted at Ahvaz water treatment plant to investigate the performance of a dual-media filter with anthracite and silica sand layers for the removal of total organic carbon (TOC) and chemical oxygen demand (COD) as the measuring indices of organic matter in water. In addition, the performance of this dual-media filter was compared with a control single-media filter with a conventional layer. The hydraulic loading rate or water flux during the filtration was in the range of 7-14m/h. All the experiments were carried out according to the standard methods, and the obtained results were analyzed using statistical tests such as paired-samples t-test. The average concentration of COD and TOC in the input water into the pilot was 7.93 and 2.73mg/L, respectively. The average efficiency for TOC removal in the single-media and dual-media pilot filters at the loading rate of 7m/h was 34.10 and 65.59%, respectively, whereas the corresponding values for COD removal in the single-media and dual-media pilot filters were 28.26 and 63.95%, respectively. Furthermore, the mean efficiency for TOC removal in the single-media and dual-media pilots at the loading rate of 14m/h was 30.25 and 64.56%, respectively. At this loading rate, the corresponding efficiencies for COD removal in the single-media and dual-media pilot filters were 25.51 and 62.23%, respectively. The results of this research showed that the use of anthracite as a layer of dual-media filter increases the efficiency of organic matter removal compared with the single-media filter.