Microbial degradation of oil contaminated biosludge in a full scale compost reactor

摘要

A continuous composting process has been run in a 23m~3 horizontal cylinder reactor connected to a biofilter. The material used in the process was oil-contaminated biosludge from a wastewater treatment plant of an oil refinery. The sludge was mixed with pine bark in a ratio of 1:1 and added fertilizer before composting. The high content of available carbon in the biosludge resulted in high temperatures and high O_2 consumption and CO_2 production rates which indicated high microbial activity in the reactor process. Chemical analysis (GC/MS) of the compost showed that the high microbial activity was accompanied by a high reduction of PAH (polyaromatic hydrocarbons). Even heavy degradable hydrocarbons as phytane and hopanes and PAH compounds like pyrene and benzo(a,e)pyrene showed reduction during the process. The concentrations were further reduced during storage after the reactor process. The reduction of oil compounds was accompanied by a reduction in measured toxicity and a reduction of the strong and unpleasant odor of the biosludge.