Effect of Charcoal Media for the Treatment of Wastewater in a Biological Filter

Charcoal was applied as the media of biological filters to treat wastewater. The performance of two lab-scale biological filters was monitored for five months to compare the effect of charcoal with that of haydite as media. Charcoal biological filter and haydite biological filter showed excellent removals for COD under the conditions of DO 2-3 mg/L, COD loading rate 0.7~1.5 kgCOD/m³-filter-bed-d, HRT 1.6-3.2 h. In terms of removing ammonia nitrogen, the performance of the charcoal biological filter was superior to that of haydite. Under the conditions of DO 2-3 mg/L, NH₄ ⁺-N loading rate 0.08-0. lkg NH₄ ⁺-N /m³-filter-bed-d, the effluent NH₄ ⁺-N of Charcoal biological filter and haydite biological filter was in the range of 2.3-8.3 mg/L and 16.8-25.2 mg/L, respectively. This demonstrates that charcoal surface is more adaptive to growth of nitrobacteria and more nitrobacteria are concentrated on the charcoal surface. As a result, the nitrification ability of charcoal biological is enhanced.