耐冷细菌的筛选及对畜禽废水处理研究

Screening of Psychrotrophic Bacteria and Their Application to Treatment of Livestock Wastewater

摘要:

从若尔盖高原湿地采集沼泽土, 驯化后分离获得了14株对畜禽废水具有降解能力的耐冷细菌, 对供试菌株6°C的生长代时、对畜禽废水CODcr去除能力进行了测定。结果表明, 供试菌株的代时介于4.9 h~11.6 h之间, 据此选取了生长代时在4.9 h~6.5 h的9株耐冷细菌(NLJ1、NLJ6、NLJ7、NLJ9、NLJ10、NLJ11、NLJ12、NLJ13和 NLJ14)用于畜禽废水处理。在6°C~9°C条件下, 单个菌株对畜禽废水CODcr去除率存在差异, 其中, 6株耐冷细菌NLJ6、NLJ7、NLJ9、NLJ10、NLJ11和NLJ13的 CODcr去除率约为60%~70%, 其余菌株的 CODcr去除率小于50%。因此, 用这6个菌株混合接种处理灭菌畜禽废水6 h, 其CODcr去除率达85.42%。进而, 将采自雅安、都江堰和成都等地污水处理厂的活性污泥混合接种上述6株耐冷细菌后处理畜禽废水6 h, 其CODcr平均去除率分别为81.67%、76.32%和70.56%; 方差分析表明, 不同处理间CODcr去除率无显著差异, 说明这6株耐冷细菌对活性污泥的适应性较好。

Abstract:

Fourteen psychrotrophic bacteria were isolated from swamp soil collected in Ruoergai plateau wetland, and their generation time and degrading ability of livestock wastewater CODcr was determined. The results showed that the generation time was within 4.9 h to 11.6 h. Based on the generation time, 9 psychrotrophic strains (NLJ1, NLJ6, NLJ7, NLJ9, NLJ10, NLJ11, NLJ12, NLJ13 and NLJ14), whose generation time was within 4.9 h to 5.6 h, were chosen to treat livestock wastewater. The results suggested that these 9 strains had different CODcr disposal ability when treating livestock wastewater singly at 6°C for 6 h, and strains NLJ6, NLJ7, NLJ9, NLJ10, NLJ11 and NLJ13 had good ability to degrade livestock wastewater, the CODcr degrading rate was about 60%~70%, hence, they were used as high efficient strains; However, the CODcr degrading rate of the other strains was less than 50%. After inoculating mixture culture of these six strains into the distilled livestock wastewater, after 6 h’s treating, the CODcr degrading rate reached to 85.42%. Furthermore, activated sludge collected from Yaan, Dujiangyan and Chengdu were inoculated by the mixture culture of those six strains, and used to treat livestock wastewater for 6 h. The results showed that the average CODcr degrading rate was 81.67%, 76.32% and 70.56%, respectively; Variance analysis showed that there was no significant differentiation between each treatment, which revealed that those six psychrotrophic strains had good adaptability to different source of activated sludge.