Characteristics of biomass in biological activated carbon (BAC) filters and its contribution to DOC removal
活性炭滤池中微生物特征及其对溶解性有机碳的去除作用

Heterotrophic plate count (HPC) determination is applied to measure the biomass on the carbon used in the biological activated carbon (BAC) filter in a water treatment plant in Beijing.The effect of the DOC component in the filtered water, the adsorption of active carbon, the biological activity, and their contribution to DOC removal is analyzed.The results indicate that the biomass fluctuates greatly with the service time of the carbon filter and the operation stage.The micro-biological degradation in BAC filters contributes little to the total DOC removal because of the low ratio of BDOC to DOC in the filtered water.The micro-biologically degraded DOC in the 1.5a-carbon filter comprises only 18.8% of total DOC removed, and 26.4% in the 5a-carbon filter.Furthermore, the micro-biological degradation process is not significant for odorous material removal and contributes 32% and 29% to the total removal of 2-MIB and geosmin, respectively, even in the 5a carbon filter.Therefore, the contribution of micro-biological degradation in DOC removal is less than the adsorption of the carbon in this water plant.