Ultrasound, a new separation technique to harvest microalgae
Ultrasound, a new separation technique to harvest microalgae
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DOI：
10.1023/a:1023807011027
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发表时间：
2003-03-01
影响因子：
3.3
通讯作者：
Wijffels, RH
中科院分区：
文献类型：
--
作者：
Bosma, R;van Spronsen, WA;Wijffels, RH
在这篇文章中，它被证明可以使用超声波收获微藻。分离过程是基于温和的声学诱导的聚集，然后是增强的沉降。在本文中，收获的效率和进入的生物质浓度的浓度因子进行了优化，并确定了该过程与其他收获过程相比的相关性。对于优化，五个参数同时使用的实验设计建模。由于不同参数之间可能存在相互作用，因此选择了实验设计。该过程的效率以0.88的R平方建模。进水流量和生物质浓度对工艺的效率有很大的影响。在高生物质浓度和4-6 L/天的流速下，达到高于90%的效率。最多可收获92%的微生物，在这些设置下可实现11的浓缩因子。由于其小尺寸和与水的小密度差，不可能以更高的效率收获这种微生物。该过程的浓缩因子以0.75的R平方建模。进水流量、生物量浓度和收获流量与进水流量之比对浓缩系数有显著影响。在生物量浓度低和收获流量低的情况下，浓缩系数最高可达20。在工业规模上，离心机可以更好地用于收获微藻，因为其功耗更低，效率更高，浓缩系数更高。在实验室或中试规模上，超声波收获过程具有可以连续操作、不引起剪切应力和占用空间非常小的优点。此外，当藻类分泌可溶性高价值产物时，该系统可用作生物过滤器。
In this article it is proven that ultrasound can be used to harvest microalgae. The separation process is based on gentle acoustically induced aggregation followed by enhanced sedimentation. In this paper, the efficiency of harvesting and the concentration factor of the ingoing biomass concentration are optimized and the relevance of this process compared to other harvesting processes is determined. For the optimisation, five parameters were modeled simultaneously by the use of an experimental design. An experimental design was chosen, because of possible interaction effects between the different parameters. The efficiency of the process was modeled with a R-squared of 0.88. The ingoing flow rate and the biomass concentration had a lot of influence on the efficiency of the process. Efficiencies higher than 90% were reached at high biomass concentrations and flow rates of 4-6 L day(-1). At most, 92% of the organisms could be harvested and a concentration factor of 11 could be achieved at these settings. It was not possible to harvest this microalga with higher efficiencies due to its small size and its small density difference with water. The concentration factor of the process was modeled with a R-squared of 0.75. The ingoing flow rate, biomass concentration and ratio between harvest flow and ingoing flow rate had a significant effect on the concentration factor. Highest concentration factors, up to 20, could be reached at low biomass concentrations and low harvest flows. On industrial scale, centrifuges can better be used to harvest microalgae, because of lower power consumption, better efficiencies and higher concentration factors. On lab- or pilot-plant scale, an ultrasonic harvesting process has the advantages that it can be operated continuously, it evokes no shear stress and the occupation space is very small. Also, when the algae excrete a soluble high valued product this system can be used as a biofilter.