三聚甲醛强降解菌的筛选鉴定及其对聚甲醛废水的生物强化

Screening and Identification of Trioxane (TOX) Degradation Bacteria and Bioaugment on Polyoxymethylene (POM) Wastewater

从某煤化工企业聚甲醛污水厂调节池底泥中分离出一株对三聚甲醛(s-Trioxane,TOX)有代谢作用的细菌,经16S rDNA基因序列分析为甲基营养型芽孢杆菌(Bacillus methylotrophicus)。该菌最适生长和降解条件为培养基起始pH为7,最佳温度为30℃,耐受NaCl和TOX质量浓度分别为3 g/L和1 200 mg/L。将该菌与麦芽糖假丝酵母(Candida maltosa)和恶臭假单胞菌(Pseudomonsa putida)等甲醛降解菌共同组成复合菌剂,对聚甲醛污水进行协同处理,最终出水的效果优劣顺序为:D组(TOX降解菌+甲醛降解菌)>C组(甲醛降解菌)> B组(TOX降解菌)>A组(对照组)。其中D组出水COD、甲醛和TOX的降解率分别为92.80%、96.52%和95.88%,均远优于其他组合。证明降解菌组合对甲醛和TOX降解的有效性,可作为聚甲醛污水处理的复合菌剂。

A strain of s-Trioxane degrading bacterium was isolated from the sediment of Polyoxymethylene wastewater treatment plant,and identified to be Bacillus methylotrophicus by 16S rDNA sequence analysis. The optimum culture conditions of the strain were at about pH 7 and 30 ℃,and the threaholds of maximal tolerable concentrations for NaCl and TOX were 3% and 1 200 mg/L,respectively. In order to detect its degradation characteristics,the strain was mixed together with formaldehyde degrading bacteria,Candida maltosa and Pseudomonas putida,to form multiple strains to treat POM wastewater at the laboratory scale. The treatment results according the order of final effluent quality were:single strain + formaldehyde degradation group > formaldehyde degradation group > single strain group > control group. In single strain + formaldehyde degradation group,the degradation rates of COD,formaldehyde and TOX were 92.80%,96.52 and 95.88%,respectively,which had much better consequences than other groups. There is a synergistic effect of the degrading bacteria combination,which could be used as multiple strains for bioaugmentation treatment of POM sewage.