| 摘要: |
| 研究了氢氧化钠对不同生长时期小球藻液的絮凝效果, 比较了絮凝沉降法和溶气气浮法的采收效果, 并初步优化了气浮操作参数。结果表明, 在小球藻液中添加氢氧化钠能够取得很好的絮凝效果,添加700 mg/L 氢氧化钠, 沉降30 min 即能达到90%的沉降采收率; 同等氢氧化钠添加量下, 溶气气浮法的采收效果要优于絮凝沉降法; 确定的气浮采收最佳操作参数: 指数生长期和稳定期藻液的最佳氢氧化钠添加量分别为350 mg/L 和600 mg/L, 溶气水进水流速为60 L/h, 溶气水/藻液体积比为25%。絮凝沉降法中指数生长期和稳定期的小球藻液采收效果相差不大, 而溶气气浮法中同等采收条件下指数生长期的采收率高于稳定期, 其采收浓缩倍数也略高于稳定期。 |
| 关键词: 小球藻 氢氧化钠 絮凝沉降 溶气气浮 生长时期 |
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| 基金项目:国家支撑计划项目(2006BAD09A12); 中国科学院创新工程重要方向性项目(KGCX2-YW-374-4) |
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| Recovery of Chlorella cells by sedimentation and dissolved air flotation |
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| Abstract: |
| Harvest of cell biomass is one of the key segments in large-scale microalgae culture. The type and dosage of coagulant, as well as the operating conditions, are key parameters for this operation. We compared sedimentation and dissolved air flotation (DAF) methods for harvesting Chlorella cells by using sodium hydroxide as coagulant. We found that the recovery of Chlorella cells by DAF was better than that of sedimentation with the same dosage of sodium hydroxide. The operation factors such as coagulant dosage, flow rate (V) of air dissolved water, and water-feed volume ratio (α) were also investigated. The optimal conditions were determined as exponential phase 350mg/L, stable phase 600mg/L,V 60L/h, andα25%. For either growth period, the recovery efficiency was not significantly different by sedimentation under the same conditions; however, for the DAF method, the recovery rate at the exponential phase was higher than that of stable phase. |
| Key words: Chlorella sodium hydroxide sedimentation dissolved air flotation growth period |
