[Redox zones and its functional bacteria in a contaminated landfill site].

A column filled with sandy soil was constructed to investigate biogeochemical process of leachate polluted zones. Experimental results demonstrated that four sequent redox zones appeared in pollution plume. The zones can be named sulfate reduction zone, iron reduction zone, nitrate reduction zone and oxygen reduction zone, ranges of them were 0-27 cm, 27-62 cm, 47-74 cm, 74-91 cm. In the redox zones bacterial community structure changed, and the preponderant bacteria were sulfate reduction bacteria (SRB), iron reduction bacteria (IRB), nitrate reduction bacteria (NRB) correspondingly, however there were other bacteria in the redox zones. Distribution of redox zones and functional bacteria means that there is not a significant boundary between redox zones, moreover one redox zone overlaps others. Evolvement of functional bacterial community brings the redox zones substitute.