[Experiment of biodegradation of chlorobenzenes]

Four strains of microorganisms which were able to grow at the presence of 1,4-dichlorobenzene 1,2,4-trichlorobenzene and hexachlorobenzene were isolated from the sludge collected from two different sites after incubating about 2 months. During the growth of the mixed microorganisims on chlorobenzenes, the accumulating consumption of oxygen, the microbial population curve and the concentration of released Cl- were investigated. The result showed that the mixed microorganisms were able to utilize 1,4-dichlorobenzen and 1,2,4-trichlorobenzene as sole carbon source and energy source. The concentration of released Cl- may depend strongly on the activity of the living cells. The order in which the chlorobenzenes were readily degraded was 1,4-dichlorobenzenez[356.7 micrograms/(L.d)] > 1,2,4-trichlorobenzene[110.4 micrograms/(L.d)] > hexachlorobenzene[approximately 6 micrograms/(L.d)]. The number of the substituted chlorine on the chlorobenzenes directly resulted in the resistance to biodegradation.