Chlorinated aromatic compounds which are used a lot in many fields are persistent when released into the environment, and even toxic to biological treatment processes. In this respect, it was studied to treat steadily the refractory wastewater with chlorophenols using biological activated carbon(BAC) process. For doing this, activated sludges which could degrade these compounds were investigated. And then, according to the result of batch test, continuous experiments and engineering analysis of the process were carried out.
2,4-DCP as a biorefractory wastewater compound was decomposed by both municipal wastewater activated sludge and papermill sludge. And in low concentration, lag time was disappeared by acclimation period, but in high concentration, it was not. For the investigation of primary substrate effect, yeast extract was added to the 2,4-DCP. In that case, 2,4-DCP without yeast extract was degraded much faster.
Through the continuous operation of three columns; adsorption with only activated carbon, BAC with activated carbon covered with microorganisms, and biofilm column with glass bead, the degradation rates of 2,4-DCP were compared. In adsorption column with influent concentration, 100ppm, breakthrough curve was appeared as operating time goes on. The influent 2,4-DCP was completely degraded in BAC column, but not in biofilm column. Effluent pH was dropped from 7.5 to 6. It was believed that biological oxidation of chloro-organic chemicals resulted in stoichiometric release of chloride ions and hydrogene ions that consumed the buffer capacity. From the breakthrough curve analysis, retardation factor, R(C) and apparant dispersion coefficient, $D_{app}$ could be analyzed.
