氯苯类化合物的生物降解

经过2个月的驯化,从某染料厂和某毛纺厂活性污泥中分离出能够生长于1,4-二氯苯、1,2,4-三氯苯和六氯苯的4种微生物.通过测定该混合菌降解氯苯类化合物过程中的累积好氧量、微生物生长曲线及降解产物Cl^-的释放,证明在好氧条件下该混合菌能够以1,4二氯苯和1,2,4-三氯苯为唯一碳源和能源,降解产物Cl^-浓度的变化与微生物生长周期有关.通过好氧振荡瓶培养法测得3种氯苯的生物降解顺序为:1,4-二氯苯356.7μg/(L·d)]>1,2,4-三氯苯110.4μg/(L·d)]>六氯苯～6μg/(L·d)],说明氯取代数越多,氯苯类化合物越难被好氧降解.

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-dichlorobenzenez356.7 micrograms/(L.d)] > 1,2,4-trichlorobenzene110.4 micrograms/(L.d)] > hexachlorobenzeneapproximately 6 micrograms/(L.d)]. The number of the substituted chlorine on the chlorobenzenes directly resulted in the resistance to biodegradation.