Evaluation of Preozonation As a Pretreatment of Biological Activated Carbon Process

Kim, Woo-Hang; Okada, Mitsumasa

Environmental Engineering Research 1998;3(4): 229-235.

¹Faculty of Ocean & Naval Architecture Engineering, Mokpo Natural Maritime University, 571 Chukkyo-dong, Mokpo, Chonnam 530-729, Korea
²Faculty of Engineering, Hiroshima University, Higashi-Hiroshima, Japan

Corresponding Author: Woo-Hang Kim ,

Received: August 6, 1998; Accepted: December 8, 1998.

ABSTRACT

The objective of this study is to evaluate the removal efficiency of biodegradable DOC in a biological activated carbon (BAC) process compared with granular activated carbon (GAC) process, and to clarify the effects of preozonation in an BAC process. Bench scale experiment was carried out dosing 1.5 mg/mg DOC of ozone with an ozone contact time of 15 minutes and empty bed contact time (EBCT) of biological activated carbon reactor of 30 minutes. Influent DOC concentration was 10 mg/1 with fulvic acid. Effluent DOC in the BAC process was almost the same as that in the GAC process in the beginning of operation. DOC removal efficiency after breakthrough, however, was 15 % higher in the BAC process than in the GAC process. A&BDOC which has both adsorbability and biodegradability was removed mainly there biodegradation on activated carbon in the BAC process before the adsorption capacity of the activated carbon was exhausted. Activated carbon service life in the BAC process was extended by as much as 35 % than that in the GAC process. This was due to the increase in biodegradable DOC by ozonation followed by biodegradation on activated carbon in BAC process. Ozone dosage of 1.5 mg/mg DOC in continuous operation was within the range for the optimum production of biodegradable DOC. EBCT of 30 minutes was enough for the complete biodegradable DOC in the continuous operation of the BAC process.

Keywords: Ozonation | Dissolved Organic Carbon (DOC) | Adsorbable and non Biodegradable DOC (ADOC) | Biodegradable and non Adsorbable DOC (BDOC) | Adsorbable and Biodegradable DOC (A&BDOC)