The kinetics of the degradation of chloroform and benzene in anaerobic sediment from the River Rhine |
| |
Authors: | P Van Beelen F Van Keulen |
| |
Institution: | (1) National Institute of Public Health and Environmental Protection, P.O. Box 1, 3720 BA Bilthoven, The Netherlands |
| |
Abstract: | In anaerobic methanogenic sediment microcosms14C labelled chloroform was degraded mainly to carbon dioxide. At a concentration of 4 g.l–1 the mineralization followed first order kinetics with a half life of 12 days at 10°C and 2.6 days at 20°C. At a concentration of 400 g.l–1 the mineralization rate increased with time and followed logarithmic kinetics with a max of 0.02.d–1 at 10°C. The logarithmic kinetics can be explained by growth of the bacteria on the higher concentration of chloroform with a generation time of 35 days. Shaking and oxygenation did not inhibit the mineralization of chloroform, probably because of bacterial consumption of the dissolved oxygen.
14C labelled benzene was mineralized only for a small percentage to14C labelled carbon dioxide while other, not acid extractable, degradation products were formed. Under anaerobic conditions after one day when 5% of the benzene was degraded to carbon dioxide, the mineralization ceased, while the disappearance of benzene proceeded. With air in the headspace of the incubation bottles 25% of the benzene was mineralized to carbon dioxide. The anaerobic degradation of benzene at a concentration of 100 .l–1 showed similar kinetics as the degradation at 1 g.l–1. Hence no adaptation of the microflora in the sediment occurred during the 63 days of the experiment at 100 g.l–1. |
| |
Keywords: | Biodegradation chloroform benzene sediment kinetics |
本文献已被 SpringerLink 等数据库收录! |