Flocculation-based methods of microalgae removal from the eutrophic pond enrichment culture

The method of flocculation of biomass from the water depth to the bottom can be applied in case of local algae blooms. In our research, the combined application of FeCl3 and Polyethyleneoxide-based cationic flocculant was applied for the first time for the harvesting of the enrichment culture obtained from the reservoir during eutrophication. The effects of coagulant (FeCl3 center dot 6H(2)O), various flocculants based on polyacrylamide (PAA), polyethylenoxide (PEO) and flocculated biomass as ballast agent, dosage and sedimental time on flocculation efficiency of harvesting enrichment culture obtained from Pond Chernoistochinsky during eutrophication have been studied. The results show that the flocculation efficiency achieved about 90% after 5 min of sedimentation when adding of coagulant and flocculant mixture (FeCl3 30 mg/L + PEO based Sibfloc-718 2.5 mg/L) or flocculant with ballast agent (FeCl3 30 mg/L + Sibfloc-718 2.5 mg/L + 1,7% flocculated biomass). PAA, PEO and FeCl3 center dot 6H(2)O did not demonstrate a sufficient flocculation capacity with enrichment culture containing different types of microalgae.

Automated summary

In this study, the combined application of FeCl3 and Polyethyleneoxide-based cationic flocculant was used for the first time to harvest enrichment culture from a reservoir during eutrophication, achieving a flocculation efficiency of about 90%. FeCl3, PAA, and PEO alone did not demonstrate sufficient flocculation capacity for the enrichment culture containing different types of microalgae.