Fig. 2From: Pre-concentration of microalga Euglena gracilis by alkalescent pH treatment and flocculation mechanism of Ca3(PO4)2, Mg3(PO4)2, and derivativesFlocculation efficiency of E. gracilis under varying pH treatments. a The FE was determined over a range of pHs. b The FE was used to determine the critical point of pH value. FE flocculation efficiency; * represents p < 0.05. The values represent mean ± S.D. n = 3Back to article page