A Soydoa Vinitnantharat creator Preeda Pakpian Chairperson Ha, Sung-Ryong Examination committee Ozaki, Hiroaki Examination committee Chongrak Polprasert Examination Committee Rakshit, Sudip Kumar Examination Committee Ishibashi, Yoshinobu Examination committee Shin, Hang-Sik Examination committee Government of Japan Scholarship donor text series technical report th Bangkok Asian Institute of Technology 1999 continuing eng 200 leaves Tluee tasks were carried out to study the capability of the BAC process for the removal of phenol and 2,4-DCP as a sole carbon source. A lignite based GAC 20 x 30 mesh size was used in this study. The first task was conducted to identify the comparative roles of the major reactions to remove phenol and 2,4-DCP in the BAC system. The major reactions considered were activated carbon adsorption-desorption, biosorption and biodegradation. Freundlich isotherm analysis was used to compare the performance of each reaction. Removal of phenol by biodegradation and adsorption predominated over biosorption. Removal of 2,4-DCP by activated carbon adsorption was much higher than by biodegradation and biosorption. The adsorption capacity (Kads) of phenol and 2,4-DCP decreased from 25.04 and 43.75 mg/g in single solute to 18.95 and 22.18 mg/g in bisolute. In the presence of by-product, Kads of phenol and 2,4-DCP in single solute decreased whereas in bisolute, only Kads of phenol decreased. In the desorption experiment, a small fraction of sorbed compounds was reversible particularly, this was conspicuous in the case of 2,4-DCP. Desorption of sorbed compounds increased in the presence of by-product with which about 90 % of phenol could desorbed. As the second task, the treatability of a mixture of phenol and 2,4-DCP in the BAC SBR system was investigated and compared with the conventional SBR system. Experiments were conducted by increasing the influent concentration, varying SRTs, varying GAC dosages, and changing the operation schedule of the SBR process. The difference in effluent concentrations between BAC-SBR and SBR was high at short SRTs and enlarged by increasing influent organic strength. Among different GAC dosages, there was no obvious change in the specific removal rate but the removal efficiency increased as the GAC dosage increased. The removal of phenol and COD reached 94%, and it reached 96% for 2,4-DCP in the BAC-SBR with 0.7 g/l GAC and SRT of 3 days. Only 86% for phenol and 84% for 2,4-DCP as well as COD were removed in the SBR. The removal efficiency of phenols in the BAC-SBR and SBR systems were improved when the idle time increased. However, the effluent concentration of phenols from SBR was about two times higher than that from the BAC-SBR. As the third task, bioregeneration of GAC loaded with phenol and 2,4-DCP was investigated in a batch and the BAC-SBR system. Bioregeneration of 1 g/l of GAC showed that the sequential assimilation of desorbed compounds in the bulk solution could induce the successive desorption of sorbed compounds from GAC. From SEM observation, the microorganisms were seen to be mainly colonized on the outer surface of GAC and some of them were scattered on the inner parts of GAC. The Freundlich adsorption model was applied to predict the amount of adsorbate remaining after bioregeneration in the batch experiment and in the BAC-SBR. The Freundlich parameters obtained from the adsorption isotherm taking into account the by-product effect on the adsorption could predict the amount of phenols remaining on GAC with high consistency. In the BAC-SBR, lll bioregeneration increased as SRT increased. During the BAC-SBR operation, GAC could adsorb phenols in the fill period and bioregeneration started in the react period. Extending the idle period could enhance the bioregeneration and buffer capacity consequently to decrease the irreversible adsorption part on the GAC in the BAC-SBR. A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Technical Science, School of Environment, Resources and Development Thesis (Ph.D.) - Asian Institute of Technology, 1999 Sewage Purification Phenol removal Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B11917 http://203.159.5.9/ait-thesis/detail.php?q=B11917 091008 20260817171456.0