Surfactant-aided dispersed air flotation was investigated as a low cost microalgae harvesting technique for biodiesel, using the microalgae Chlorella saccharophila and the surfactant CTAB (cetyl trimethylammonium bromide). Response Surface Methodology (Box-Behnken design) was used for optimization of both recovery and concentration factor. The effects of CTAB concentration, column height, pH and air flow rate were investigated. The measured responses were initially analyzed separately to obtain models for each response variable. It was determined that only CTAB concentration and flow rate were significant for the recovery, while all tested variables were significant for the concentration factor. Next, optimization was performed to maximize both responses (recovery and concentration factor) simultaneously. The overall optimum processing parameters determined were CTAB concentration of 100 mg L⁻¹, a column height of 795 mm, pH of 10 and flow rate of 57.9 mL min⁻¹. The expected values for recovery and concentration factor were 91.1% ± 1.62% and 17.9 ± 6.19, respectively. Experimental testing resulted in a recovery of 94.5 ± 2.7% and a concentration factor of 13.23 ± 0.98, which indicates that the experimental values agree with the predicted by 96% and 74% for recovery and concentration factor, respectively. This study demonstrates that surfactant-aided dispersed air flotation is a promising harvesting technique for microalgae biodiesel production processes as its energy requirement is low, can achieve high recoveries and substantially decreases the working volume of microalgae culture. However, a secondary dewatering step is recommended for further concentration prior to product conversion.

使用微藻小球藻小球藻，研究了表面活性剂辅助分散气浮法作为一种低成本的生物柴油微藻收获技术。和表面活性剂CTAB（十六烷基三甲基溴化铵）。响应面方法（Box-Behnken设计）用于优化回收率和浓缩因子。研究了CTAB浓度，柱高，pH和空气流速的影响。最初分别对测得的响应进行分析，以获得每个响应变量的模型。已确定，只有CTAB浓度和流速对回收率很重要，而所有测试变量对浓度因子都很重要。接下来，执行优化以同时最大化两个响应（回收率和浓度因子）。确定的总体最佳工艺参数为CTAB浓度为100 mg L ^-1，柱高为795 mm，pH为10和流速为57.9 mL / min^-1。回收率和浓缩系数的预期值分别为91.1％±1.62％和17.9±6.19。实验测试的回收率为94.5±2.7％，浓缩系数为13.23±0.98，这表明实验值分别与回收率和浓缩系数的预测值相符，分别为96％和74％。这项研究表明，表面活性剂辅助分散气浮法是微藻生物柴油生产过程中一种很有前途的收获技术，因为它的能源需求低，可以实现高回收率并大大减少了微藻培养的工作量。但是，建议在产品转化之前进行二次脱水步骤以进一步浓缩。