不同碳源培养胶球藻C-169净化糖蜜酵母废水

Cultivation of Coccomyxa subellipsoidea C-169 using Different Carbon Sources to Purify Molasses Yeast Wastewater

本项目系统研究了三种碳源(CO_2、醋酸和甘油)添加到预处理后的糖蜜酵母废水,在藻菌共生条件下培养胶球藻C-169的生长情况及强化废水净化效果。结果表明,与通入空气相比,补充2%CO_2,能显著提高细胞的平均比生长速率、生物质产率,分别是通入空气的6.49、10.4倍,显著提高了对脱色废水的总氮、总磷和氨氮去除率(p<0.05),但降低了废水COD(化学需氧量)去除率。研究发现胶球藻C-169能够利用甘油作为其生长的碳源,在0～20 g/L甘油浓度时,随着甘油浓度的提高,细胞生长速率增大,总氮、总磷去除率提高,并在20g/L时获得最高生物量干重达到8.80g/L,平均比生长速率是不添加甘油的2.07倍,生物量产率达0.70 g/(L·d)。甘油浓度在15 g/L以上时,总氮、总磷去除率分别高达85%、95%以上,极显著地提高了废水COD(p<0.01)。添加1～4g/L醋酸,均会抑制胶球藻C-169的生长,降低废水净化效果。因此在使用C-169净化COD较高的废水时,可添加甘油作为其生长的碳源。

In this study,three carbon sources(CO2,acetic acid and glycerol)were added to the pretreated molasses wastewater,and then the growth of Coccomyxa subellipsoidea C-169 in a symbiotic algal-bacterial system cultured in such enhanced wastewater and the outcome of such an enhancement were examined.Compared with the results related to aeration with air,supplementation with 2%CO2 could significantly increase the average cell growth rate and biomass yield by 6.49 and 10.4 times,respectively,and remarkably increased the total nitrogen,total phosphorus and ammonia nitrogen(p<0.05)but reduced the removal rate of COD(chemical oxygen demand)of wastewater.It was found that Coccomyxa subellipsoidea C-169 could use glycerol as its carbon source.At a glycerol concentration within 0~20 g/L,an increase of glycerol concentration led to an increased cell growth rate,and total nitrogen and total phosphorus removal rates.At 20 g/L,the highest dry weight of biomass reached 8.80 g/L,the average specific growth rate was 2.07 times as high as that without glycerol(the biomass yield,0.70 g/(L·d).When the glycerol concentration was above 15 g/L,the removal rates of total nitrogen and total phosphorus were over 85%and 95%,respectively,which significantly increased the wastewater COD(p<0.01).Addition of 1~4 g/L acetic acid would inhibit the growth of Coccomyxa subellipsoidea C-169 and reduce wastewater purification efficiency.Therefore,when C-169 is used to purify wastewater with a high COD,glycerin can be added as a carbon source for its growth.