Decoloration of azo dye wastewater by an anaerobic membrane bioreactor using gene engineering strain Escherichia coli JM109 (pGEX-AZR)
基因工程菌在厌氧膜生物反应器中对偶氮染料废水的脱色

Among industrial wastewaters, dye wastewater from the textile or dyestuff industries is one of the most difficult to treat. In this study an anaerobic membrane bioreactor (MBR) using gene engineering strain JM109 (pGEX-AZR) was used for the decoloration of azo dye solutions. The results from the study showed that the bioreactor with JM109 (pGEX-AZR) had a high capacity for decoloration of acid red B. The decoloration efficiency and COD degradation rate exceeded 95% and reached 68%, respectively. As in the continuous operation, the biomass increased from 0.58 g/L to 0.82 g/L, and then remained stable at 0.4g/L. Influenced by the bacteria activity, EPS changed with the biomass. The pH value fell from 6.5 to 6.2 in the beginning, and remained stable at 6.6.The membrane was washed for the first time after 27days, and the water membrane flux could recover 92%. The period of the bioreactor processing was 26days.