Biological and Agricultural Engineering Department, Texas A&M University, 2117 TAMU, College Station, TX 77843, USA.
Bioresour Technol. 2012 Aug;118:418-24. doi: 10.1016/j.biortech.2012.04.057. Epub 2012 Apr 25.
Process variables affecting harvesting efficiency of Nannochloris oculata by AlCl(3) flocculation such as, cell density, ionic strength, coagulant dosage, media pH, and cell surface charge were investigated. Initial cell density and coagulant dosage had a significant effect on the removal efficiency; however, levels of ionic strength tested were not significant. Best flocculation conditions of investigated variables were: 0.0016 ng of AlCl(3)/cell, 3.0×10(7) cell/mL, and pH 5.3. Removal efficiency at optimum conditions and salt concentrations of: 0, 15, and 30 g/L NaCl was 96, 98, and 97 %, respectively. Low cell density cultures ∼10(6) cell/mL, required five times greater AlCl(3) dosage to achieve the same removal efficiency. Destabilization of algal cultures using 0.0032 ng of AlCl(3)/cell was observed by reducing the zeta potential to -22 mV. Acidification with HCl for conducting flocculation at pH 5.3 could be a significant cost burden unless is mitigated by selecting a low-buffering-capacity media.
研究了影响 AlCl(3)絮凝法收获 Nannochloris oculata 的过程变量，如细胞密度、离子强度、混凝剂用量、介质 pH 值和细胞表面电荷。初始细胞密度和混凝剂用量对去除效率有显著影响；然而，测试的离子强度水平并不显著。研究变量的最佳絮凝条件为：0.0016 ng 的 AlCl(3)/细胞、3.0×10(7)细胞/mL 和 pH 5.3。在最佳条件和盐浓度为 0、15 和 30 g/L NaCl 下的去除效率分别为 96%、98%和 97%。需要五倍于最佳条件的 AlCl(3)用量才能达到相同的去除效率。使用 0.0032 ng 的 AlCl(3)/细胞使藻细胞失稳，将 ζ 电位降低至-22 mV。在 pH 5.3 下进行絮凝时酸化用 HCl 可能会带来巨大的成本负担，除非通过选择低缓冲容量的介质来减轻这种负担。
