Dechlorination of High Concentrations of Tetrachloroethylene Using a Fixed-bed Reactor

• 발행기관: 한국환경보건학회
• 저자명: Young C. Chang Chan-Koo Park Kweon Jung Shintaro Kikuchi
• 간행물 정보: 『1. 한국환경보건학회지』제36권 제4호, 323~336쪽, 전체 14쪽
• 주제분류: 공학 > 환경공학
• 파일형태: PDF
• 발행일자: 2010.08.30

영문 초록

We evaluated the properties of a fixed-bed column reactor for high-concentration tetrachloroethylene (PCE) removal. The anaerobic bacterium Clostridium bifermentans DPH-1 was able to dechlorinate PCE to cis-1,2- dichloroethylene (cDCE) via trichloroethylene (TCE) at high rates in the monoculture biofilm of an upflow fixed-bed column reactor. The first-order reaction rate of C. bifermentans DPH-1 was relatively high at 0.006 mg protein−1 · l · h−1, and comparable to rates obtained by others. When we gradually raised the influent PCE concentration from 30 μM to 905 μM, the degree of PCE dechlorination rose to over 99% during the operation period of 2,000 h. In order to maintain efficiency of transformation of PCE in this reactor system, more than 6 h hydraulic retention time (HRT) is required. The maximum volumetric dechlorination rate of PCE was determined to be 1,100 μmol · d−1l of reactor volume−1, which is relatively high compared to rates reported previously. The results of this study indicate that the PCE removal performance of this fixed-bed reactor immobilized mono-culture is comparable to that of a fixed-bed reactor mixture culture system. Furthermore, our system has the major advantage of a rapid (5 days) start-up time for the reactor. The flow characteristics of this reactor are intermediate between those of the plug-flow and complete-mix systems. Biotransformation of PCE into innocuous compounds is desirable; however, unfortunately cDCE, which is itself toxic, was the main product of PCE dechlorination in this reactor system. In order to establish a system for complete detoxification of PCE, co-immobilization of C. bifermentans DPH-1 with other bacteria that degrade cDCE aerobically or anaerobically to ethene or ethane may be effective.

키워드

Clostridium bifermentans DPH-1 dechlorination tetrachloroethylene monoculture bioreactor