Haag, F; Reinhard, M; Mccarty, PL
The degradation of aromatic hydrocarbons (benzene, toluene, ethylbenzene, p-xylene, o-xylene, 1,3,5-trimethylbenzene, and naphthalene) under anaerobic conditions was studied in column microcosms developed with aquifer material from the vicinity of a gasoline spill at Seal Beach, California. In one column, which did not receive any electron acceptors other than those naturally present (sulfate and carbon dioxide), more than 60% of the toluene was oxidized to CO2. The other six added substrates were not degraded when the toluene supply was constant. In another column, the addition of toluene was discontinued after 126 d, which coincided with the onset of p-xylene degradation. Addition of sulfate, the only electron acceptor that was detected, stimulated the transformation of toluene in batch experiments.