城市生活废水用于产油微藻培养

Cultivating an oleaginous microalgae with municipal wastewater

摘要:

将废水与产油微藻培养结合起来，可以实现废水的无害化处理，还可为微藻的培养提供营养组分和大量水源。利用高产油栅藻，以城市生活废水为水源，在气泡柱式光反应器中，考察了添加不同营养组分对栅藻细胞的生长、生物质产量、总脂含量以及氮磷去除情况的影响。结果表明：生活废水非常适合于产油微藻的培养。利用生活废水进行微藻培养中，仅需补充添加无机氮、无机磷、柠檬酸铁铵以及微量元素。但这些营养组分的加入量对藻细胞的生长、生物量和油脂积累有重要影响。在优化的废水培养基中微藻细胞浓度可达8.0 g/L左右，远高于标准BG11培养基5.0 g/L的水平。微藻细胞对于无机氮与磷有着高的吸收能力，在废水中加入185.25 mg/L以下无机氮，16.1 mg/L以下无机磷的条件下培养3~4 d后，培养液水体中未检测到有氮磷残留。由此表明利用城市生活废水培养含油微藻可以在获得微藻油脂产品的同时实现水体的氮磷无害化处理。

Abstract:

Municipal wastewater is usually problematic for the environment. The process of oleaginous microalgal culture requires large amounts of nutrients and water. Therefore, we studied the feasibility of oleaginous microalgal culture of Scenedesmus dimorphus in bubbled column photobioreactor with municipal wastewater added with different nutrients. S. dimorphus could adapt municipal nutrient-rich wastewater by adding some nutrients as nitrogen, phosphorus, ferric ammonium citrate and trace elements, and the amounts of such nutrients have significant effects on cell growth, biomass yield and lipid accumulation. At optimum compositions of wastewater medium, the algal cell concentration could reach 8.0 g/L, higher than that of 5.0 g/L in standard BG11. Furthermore, S. dimorphus had strong capacity to absorb inorganic nitrogen and phosphorus from its culture water. There was almost no total nitrogen and phosphorus residues in culture medium after three or four days culturing when the adding mounts of nitrate and phosphate in wastewater medium were no more than 185.2 mg/L and 16.1 mg/L respectively under the experimental conditions. As a conclusion, it was feasible to cultivate oleaginous microalgae with municipal nutrient-rich wastewater, not only producing feedstock for algal biodiesel, but also removing inorganic nitrogen and phosphorus from wastewater.