1株白酒废水降解菌的鉴定及降解条件的优化

Identification of a liquor wastewater-degrading bacterium and its optimal conditions for degradation

采用稀释平板法从某制酒企业污水样品中分离筛选到1株好氧降解高粱白酒废水的细菌LM1,经形态观察和16S rDNA序列分析,鉴定该菌株为红球菌(Rhodococcus sp.),并研究了该菌株降解高粱白酒废水的特性。结果表明:该菌株的最佳降解条件是pH 7.0,温度30℃,接种量5%。在最适条件下,24 h内,LM1菌株对白酒废水的COD(化学需氧量)、TOC(总有机碳)、TN(总氮)去除率分别是(81.0±2.4)%、(81.2±4.1)%、(66.6±0.1)%;72 h内,对TP(总磷)的去除率可达(72.7±0.2)%。出水COD为(475.3±60.0)mg/L,接近白酒工业废水的间接排放标准(GB 27631-2011)(COD≤400 mg/L),TN为(16.6±0.1)mg/L,达到直接排放标准(TN≤25 mg/L)。经芬顿试剂进一步深度处理后,其COD为(120.0±7.0)mg/L,TOC为(36.0±3.5)mg/L,TP为0.1mg/L,TN为(13.3±0.5)mg/L,脱色率为99.8%,达到直接排放标准。

A bacterial strain LM1 which can aerobically degrade sorghum liquor wastewater was isolated from the sewage water sample of a sorghum liquor manufacturer with dilution plate method. This strain was identified as Rhodococcus sp. based on its morphological observation and 16S rDNA sequence analysis. The characteristic of its liquor wastewater degradation was studied. The optimal conditions for degrading sorghum liquor wastewater were pH 7. 0, temperature 30 ℃ with 5 % inoculation amount. Under these conditions, （81.0 ± 2.4）% reduction in chemical oxygen demand （COD）, （81.2 ± 4. 1）% reduction in total organic carbon （TOC） and （66.6±0. 1）% reduction in total nitrogen （TN）, and （72.7± 0. 2） % reduction in total phosphorus （TP） of the spent wash could be achieved within 72 h by Rhodococcus sp. LM1. The value of COD and TN in effluent was （475. 3±60. 0） mg/L and （16. 6±0. 1） mg/L,which were under the highest concentration of the second discharge standard（COD≤400 mg/L） and the first discharge standard （TN≤25 mg/L） of water pollutants for fermentation alcohol and distilled spirits industry （GB 27631--2011）, respectively. The effluent was further treated by Fenton oxidation as the advanced treatment, and the concentrations of COD, TOC, TN, TP and de-colorization ratio were （120.0±7. 0） mg/L, （36.0±3.5） mg/L,0. 1 mg/L, （13.3±0. 5） mg/L and 99.8%, respectively, fitting with the standard of discharging wastewater.