Abstract: Flocculation experiments of green algaChlorellavulgarisby calcium hydroxide were carried out. Results of single-parameter experiments showed that higher recovery ofChlorellavulgariswas achieved when the flocculation time, the dosage of calcium hydroxide, and the pH of culture fluid were kept at 60-80 min, 0.6-0.8 g/L, and 8-10, respectively. Additionally, a regression model regarding toChlorellavulgarisrecovery ratio was established by the response surface analysis(RSA) and based on the results of multi-parameter experiments. The optimum conditions forChlorellavulgarisflocculation were determined correspondingly. It was demonstrated that the influence of calcium hydroxide dosage onChlorellavulgarisrecovery was the most significant and followed were the flocculation time and the pH of algae fluid. It was also known that the interaction of flocculation time with pH, and calcium hydroxide dosage with pH were relatively significant to the recovery ofChlorellavulgaris. The recovery ratio ofChlorellavulgarisreached to 93.9% when the flocculation time, the dosages of calcium hydroxide, and the pH of culture fluid were maintained at 77 min, 0.7 g/L, and 9.3, respectively.
2014, Vol. 29 
