Harvesting biomass of an oil-rich microalga Parachlorella kessleri TY02 by ferric chloride: Effects on harvesting efficiency, lipid production and municipal wastewater treatment

• Published in: Journal of environmental management 2020-11, Vol.273, p.111128-111128, Article 111128
• Main Authors: Lv, Junping, Liu, Guoji, Feng, Jia, Liu, Qi, Nan, Fangru, Liu, Xudong, Xie, Shulian
• Format: Article
• Language: English
• Subjects: Ferric chloride; Harvesting efficiency; Lipid production; Municipal wastewater treatment
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2020.111128

Inorganic coagulants have been widely used to harvest microalgal biomass. A great deal of attention has been mainly focused on the response of harvesting efficiency, lipid production and feasibility of the reuse of medium to inorganic coagulants. The physiological state of harvested cells and feasibility of wastewater treatment remain unclear. In this context, the effect of ferric chloride as a conventional inorganic coagulant on the harvesting efficiency, physiological state and lipid content of an oil-rich microalga Parachlorella kessleri TY02 was evaluated. Moreover, the performance of harvested cells for municipal wastewater treatment was also evaluated. When the dosage of iron ions was 0.077 mg/mg dry biomass and the sedimentation time was 5 min, the microalga had good harvesting efficiency and cell viability. As the dosage of iron ions was up to 0.15 mg/mg dry biomass, cell viability notably decreased. Cells harvested by 0.077 and 0.15 mg/mg dry biomass of iron ions showed good wastewater treatment efficiency. It was also found that long sedimentation time (40 min) not only did not promote harvesting efficiency, but also reduced cell viability. Iron ions had no notable effect on lipid content of the microalga. Through comprehensive evaluation of harvesting efficiency, lipid production, physiological state and wastewater treatment efficiency, it indicated that 0.077 mg/mg dry biomass of iron ions could be used to harvest biomass of the microalga. •Biomass of P. kessleri TY02 was efficiently harvested by ferric chloride.•The microalga harvested by ferric chloride had good wastewater treatment efficiency.•Cell viability of harvested cells was affected.•Ferric chloride had no notable effect on lipid content of the microalga.