| This study was carried out to evaluate the treatment characteristics of raw water using biofiltration process. Biodegradable characteristics of phenol and affect of chlorine on attached microbes in the biofilm are studied. The empty bed contact time(EBCT) of biofiltration process was controlled at 42min for all tests. In the biofiltration process, the KMnO₄ consumption, NH₄^+-N, turbidity, color, and UV_(254) removal averaged 83%, 91%, 95%, 94%, and 91% respectively. This result indicates that, using only biofiltration process could improve treatment efficiency. When phenol was injected in the biofilter low concentration(as 0.25㎎/L), the concentration of phenol in the effluent was 0.035㎎/L with its removal rate about 70% in 1 hr. the removal rate of phenol was 95% after 4 hr. In the case of high concentration of phenol(as 2.5㎎/L), effluent concentration of phenol and removal efficiency after 1hr was 0.743㎎/L, 70%, respectively. The removal of phenol was increased gradually. After 72hr, the concentration of phenol in the effluent was 0.163㎎/L and removal efficiency was 94%. The removal of KMnO₄ consumption and NH₄^+-N with feeding phenol(0.25㎎/L) was 84%, 92% respectively. Therefore, it was found that phenol feeding didn`t affect on treatment of the KMnO₄ consumption and NH₄^+-N. When the chlorine concentration of 0.28㎎/L∼0.40㎎/L was injected to the biofilter, the treatment efficiency of KMnO₄, consumption and UV_(254) absorbance were decreased by 15% in the early period. However, the values had recovered gradually within 10∼15 days. Also, in the evaluation of attached microbial activity, protein contents decreased within 15days. Afterward, a dramatic change was not observed. Consequently, toxic effect of chlorine on attached microbes in biofilm was not significant for 10∼15days. Movever, the any affection was not recognized after acclimation period. |
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