栅藻贴壁培养处理沼液效果的研究

The treatment of piggery biogas slurry with Scenedesmus sp. by attached culture

以栅藻(Scendesmus dimorphus)为研究对象,将微藻培养和养猪沼液废水处理相结合,通过贴壁培养在处理沼液废水的同时耦合藻类油脂生产,并比较了栅藻贴壁培养与悬浮培养藻细胞生长情况及对N的利用效率,为藻类生物燃料生产及降低沼液废水处理成本提供理论依据。结果表明:贴壁培养下藻细胞生物产率为6.15 g·m-2·d-1,高于栅藻悬浮培养的生物产率5.48 g·m^(-2)·d^(-1);贴壁培养下藻细胞对N的吸收率为85.23%,高于悬浮培养N的利用率77.84%。在初始NH_3-N、TP及COD浓度分别为281.2、29.1、551 mg·L^(-1)的沼液废水中贴壁培养栅藻,藻类生长状况与正常BG11培养相近,生物产率分别为6.26 g·m^(-2)·d^(-1)与6.23 g·m^(-2)·d^(-1);油脂含量相差不大,分别占细胞干重的34.6%、35.2%;沼液废水中NH_3-N、TP及COD去除效率分别为99.04%、73.06%和72.32%。

The current study investigated the treatment of swine（piggery）wastewater with Scenedesmus sp. by using attached cultivation technique, coupled with lipid production. Firstly, we compared the attached culture of Scenedesmus sp. with aqueous-suspension cultivation in BG11 medium, and studied the growth of algae and nitrogen removal efficiency. Results showed that the biomass productivity of Scenedesmus sp. with attached culture was 6.15 g·m-2·d-1, as compared with the 5.48 g·m-2·d-1 of the aqueous-suspension cultivation. The nitrogen removal efficiency of the attached culture was also significantly higher than that of the aqueous-suspension cultivation, which were 85.23%and 77.84%, respectively. In addition, results showed that Scenedesmus sp. could grow well in swine wastewater at light intensity of 100μmol·m-2·s-1 and temperature of（25±1）℃. Compared with algae cultured in BG11 medium, the biomass productivity and lipid con-tent were 6.26 g·m-2·d-1 vs 6.23 g·m-2·d-1 and 34.6%vs 35.2%, respectively. Notably, Scenedesmus sp. with attached culture could treat swine wastewater efficiently, with ammonia nitrogen, total phosphorus（TP）and COD removal efficiency of 99.04%, 73.06%and 72.32%. Based on the results, a process combining algae-based wastewater treatment with attached cultivation and biodiesel production can be pro-posed as an effective way to treat raw swine wastewater as well as produce profitable byproducts.