一株石化废水中脱氮产微生物絮凝剂菌株的鉴定与性能

筛选出了一株适用于石化污水处理的异养硝化-好氧反硝化产微生物絮凝剂菌株HAD-2,鉴定其为门多萨假单胞菌(Pseudomonas mendocina),考察了其最佳硝化条件、反硝化性能及在模拟污水中的脱氮能力。菌株为耐热菌,偏碱性(pH=8.5)和高碳氮比(25∶1)时硝化性能最佳。在异养硝化体系中,12 h时菌株对氨氮的去除率达到92.29%,硝酸盐和亚硝酸盐积累少;在反硝化体系中,12 h时菌株对亚硝酸盐和硝酸盐的去除率分别达到86.40%和84.92%;在模拟废水中,48 h时菌株对氨氮、硝态氮和亚硝态氮的降解率分别达到95.25%、65.47%和72.40%。菌株在多种培养基中可产微生物絮凝剂,在葡萄糖培养基中絮凝能力最佳,絮凝率为94%。

Identification and characterization of a nitrogen removal bacterial strain with the flocculate capability in the oil-refinery sewage

The given paper is concerned with the identification and characterization of a nitrogen removal bacterial strain with the flocculate capability in the oil-refinery sewage treatment.For the said purpose,we have managed to isolate a heterotrophic nitrification and aerobic denitrification bacteria strain HAD-2 with the flocculating capability from the active sludge of a petrochemical sewage treatment plant.What is more,we have also managed to amplify and sequence the 16S rRNA gene and housekeeping gene rpoB.Strain HAD-2 is identified as Pseudomonas mendocina by the phylogenetic tree and physiochemical analysis.We have also done such processing treatments of the napA gene,which is the function gene of the aerobic denitrification.The results of our study have confirmed the taxonomic status and aerobic denitrification ability of the strain HAD-2,with the best nitrification conditions,the denitrification capability and the nitrogen removal rate in the simulated sewage being carefully analyzed.The strain HAD -2 is by nature a kind of thermoduric bacteria which grow under the temperature of 45 ℃.Its ammonium removal rate can be promoted to the highest extent under alkaline (at the pH value of 8.5) and high C/N ratio(25:1) conditions.In the heterotrophic system,the ammonia nitrogen removal rate of strain HAD-2 can be raised up to 92.29％ in a period of 12 h with little nitrite and nitrate accumulation.On the other hand,in the aerobic denitrification system,the nitrite and nitrate nitrogen removal rate can be upgraded to 86.40％ and 84.92％ as against their original.Furthermore,in the stimulated sewage system,the strain can also increase its removing rates to 95.25％ of ammonium,65.47％ of nitrate and 72.40％ of nitrite nitrogen in a period of 48 h.Furthermore,strain HAD-2 can be made to produce the flocculation in various media,with the flocculate rate being up to 92％ in LB media and 88％ in the stimulated sewage,while the highest flocculate rate can be upgraded to 94％ in the glucose media.Strain HAD-2 can also be isolated from the petrochemical sewage and adapted to the purification from the petroleum contaminants.It can also be made to deposit the organic matters which are difficult to be obtained for biotransformation in the nitrogen removing process.