RO浓水-废水联合培养小球藻的实验研究

Study on cultivating Chlorella in RO brine and wastewaters

为了实现微藻培养基的低成本化和废水资源化利用多重目的的耦合,对反渗透浓缩液(RO浓水)作为培养基培养小球藻(Chlorella sp.)的可行性及其影响因素进行了探讨。实验取一级、二级处理出水和消化反应上清液及3种废水与RO浓水混合液制成6种培养基培养小球藻,探究最佳培养基;在此基础上探究浓度与温度对小球藻生长的影响。结果表明,培养15 d后,3种添加了RO浓水的培养基比3种纯废水培养基更有利于小球藻的生长,其中消化反应上清液-RO浓水混合液是最佳培养基;浓水浓度0%~90%的该混合液中小球藻生物量增加315%~780%,且小球藻的生物量表现为随RO浓水浓度的增大先增加后减小的变化趋势,30%是小球藻最佳培养浓度;在10、20和30℃下,浓度0%~90%的培养基中小球藻生物量增加了140%~570%,各浓度中的小球藻均在20℃下生长最好。

In order to reduce the cost of cultivating microalgae and reclaiming of wastewaters,wastewaters from different locations within a wastewater treatment plant were selected and blended with reverse osmosis(RO)concentrate and used as a culture media.In this study,Chlorella sp.was grown to evaluate 6 different waters as culture media;primary effluent,secondary effluent,digester supernatant and then each of these blended with a RO discharge concentrate.These tests were used to determine which culture medium blend could provide the best growing conditions.Growing occurring at different temperatures was also investigated.Results showed that the chlorella biomass growth was stimulated and increased when blending the RO concentrate and its minerals with the wastewaters.The digester supernatant-RO concentrate blend was found to be the best of the different media combinations evaluated.After 15 days of incubation,the chlorella biomass growth in the 0% ~ 90%(by volume) RO concentrate blends increased from 315% to 780% above the initial biomass levels.The 30% RO concentrate blend was found to be the most favorable.Overall,growth of the 0% ~ 90% RO concentrate blends evaluated at 10℃,20℃ and 30℃ demonstrated biomass increases from 140% to 570%.The temperature where better growth of Chlorella in the 0% ~ 90% RO concentrate blends occurred was 20℃.