2,4-二氯酚降解细菌菌株对含2,4-二氯酚废水的好氧处理

Application of 2 , 4-dichlorophenol degrading bacteria strains to treat imitating waste water

从土壤中分离到两株能以2,4-二氯酚为唯一碳源和能源生长的、具有降解2,4-二氯酚能力的细菌GT241—1和GT141—2,鉴定后确定它们是假单胞菌属(Pseudomonas sp.).菌株GT241—1和菌株GT141—2在最适温度25～30℃下,能将60～100 mg/L的2,4-二氯酚分别降解到8～12 mg/L和25～30 mg/L.经驯化的活性污泥在投加污泥总量0.59％和1.18％(以干重计)的假单胞菌GT241—1菌体后,对含2,4-二氯酚60 mg/L和COD 1500 mg/L的模拟废水分批处理20 h左右后可使2,4-二氯酚含量降到最低值9 mg/L,与未投加GT241—1菌体的对照相比它们对2,4-二氯酚降解速度较快.用活性污泥法对含2,4-二氯酚废水进行连续处理时,投加GT241—1菌体可加快反应器的起动;反应器以2,4-二氯酚浓度60 mg/L、HRT 20 h通入模拟废水运行时,投加GT241—1菌体者与未投加菌体的对照的出水中2,4-二氯酚含量分别为11.2 mg/L和16.7 mg/L,前者对2,4-二氯酚的处理效果较好.

Two 2,4-dichlorophenol degrading bacteria strains, designed as GT241-1 and GT141-2 respectively, were isolated from soil. They were identified as Pseudomonas sp. At optimal temperature of 25-30 ℃ , both of them were able to decompose 2,4-dichlorophenol from level of 60-100 mg/L down to 8-12 mg/L and 25-30 mg/L, respectively. In batch treatment., an acclimated sludge was applied to treat the imitating waste water containing 60 mg/L 2,4-dichlorophenol and 1500 mg/L COD after addition of 0. 58% or 1. 18% (dry weight basis) of strain GT241-1. The result showed that 2,4-dichlorophenol was decomposed to the lowest level of 9 mg/L within 20 hours with a significantly high rate of decomposition as compared with the treatment without addition of strain GT241-1. In treatment whose strain was continually applied, the start of the active sludge bioreactor was advanced. When loaded imitating waste water containing 60 mg/L 2,4-dichlorophenol and 1500 mg/L COD with 20 hours hydraulic retaining time (HRT), the 2,4-dichlorophenol concentrations in the effluent water of the bioreactor with and without strain GT241-1 were 11. 2 mg/L and 16. 7 mg/L, respectively, indicating that operation of bioreactor benefited from addition of strain GT241-1.