生物膜贴壁培养小球藻净化猪粪沼液废水的效果

微藻处理猪粪沼液废水是一项污水资源化生物技术.本文以小球藻为研究对象,通过贴壁培养方式,对稀释不同倍数的猪粪沼液废水进行净化处理同时提取藻细胞油脂,旨在探究小球藻贴壁培养处理猪粪沼液废水的效果,分析小球藻耐受猪粪沼液废水的氨氮浓度.将猪粪沼液废水分别稀释1倍(原水)、2倍、5倍、10倍制成培养基.测定贴壁培养小球藻对各处理组猪粪沼液废水中COD、氨氮、总氮、总磷的去除效率及对重金属铜、锌、铁的富集效果,同时探究小球藻的油脂合成情况.结果表明,当猪粪沼液废水稀释5倍时,贴壁小球藻对COD、氨氮、总氮、总磷的净化效果最佳,其去除效率分别为:86.8%、94.1%、85.2%、84.3%;油脂含量高达32.7%;对重金属铜、锌、铁的去除效率分别为:72.9%、70.0%、73.0%;培养一个周期结束时生物产率达到4.21 g·(m~2·d)~(-1).该研究将微藻与难处理的猪粪沼液废水深度净化进行了有效的结合,为实现藻类生物燃料工艺生产及降低废水处理成本提供理论基础.

Purification Effect of Piggery Wastewater with Chlorella pyrenoidosa by Immobilized Biofilm-Attached Culture

Piggery wastewater treatment with microalgae is a biological recycling technology. To evaluate the purification effect, this study investigated the treatment of piggery wastewater at different dilution ratios with Chlorella pyrenoidosa by attached cultivation and lipid production of algae cells and explored the tolerance of Chlorella pyrenoidosa to the piggery wastewater, which has high ammonia nitrogen. The piggery wastewater was diluted with purified water 1-, 2-, 5-, and 10-fold in culture media. The removal efficiencies of COD, ammonia nitrogen, total nitrogen, and total phosphorus and the enrichment effect of the heavy metals copper, zinc, and iron were measured. Meanwhile, we investigated the lipid production of Chlorella pyrenoidosa in variously diluted wastewater (1-, 2-, 5-, and 10-fold). It turned out that the purification effects of COD, ammonia nitrogen, total nitrogen, and total phosphorus were best when the piggery wastewater was diluted 5-fold, and the removal efficiencies were 86.8%, 94.1%, 85.2%, and 84.3%, respectively. Correspondingly, the lipid content was as high as 32.7%, and the removal efficiencies of the heavy metals copper, zinc, and iron were 72.9%, 70.0%, and 73.0%, respectively. The biomass productivity was 4.21 g·(m²·d)^-1 at the end of the experiment. This research makes an effective connection between microalgae and piggery wastewater, which is difficult to purify deeply, and provides a theoretical basis for achieving algal biofuel production and decreasing the cost of wastewater treatment.