Coagulant plus ballast technique provides a rapid mitigation of cyanobacterial nuisance

Natalia P. Noyma (Corresponding author), Leonardo de Magalhães, Marcela Miranda, Maíra Mucci, Frank van Oosterhout, Vera L. M. Huszar, Marcelo M. Marinho, Eduardo R. A. Lima, Miquel Lürling

Research output: Contribution to journal/periodicalArticleScientificpeer-review

120 Downloads (Pure)


Cyanobacteria blooms are a risk to environmental health and public safety due to the potent toxins certain cyanobacteria can produce. These nuisance organisms can be removed from water bodies by biomass flocculation and sedimentation. Here, we studied the efficacy of combinations of a low dose coagulant (poly-aluminium chloride—PAC—or chitosan) with different ballast compounds (red soil, bauxite, gravel, aluminium modified zeolite and lanthanum modified bentonite) to remove cyanobacterial biomass from water collected in Funil Reservoir (Brazil). We tested the effect of different cyanobacterial biomass concentrations on removal efficiency. We also examined if zeta potential was altered by treatments. Addition of low doses of PAC and chitosan (1–8 mg Al L-1) to the cyanobacterial suspensions caused flock formation, but did not settle the cyanobacteria. When those low dose coagulants were combined with ballast, effective settling in a dose-dependent way up to 99.7% removal of the flocks could be achieved without any effect on the zeta potential and thus without potential membrane damage. Removal efficacy was influenced by the cyanobacterial biomass and at higher biomass more ballast was needed to achieve good removal. The combined coagulant-ballast technique provides a promising alternative to algaecides in lakes, ponds and reservoirs.
Original languageEnglish
Article numbere0178976
JournalPLoS One
Issue number6
Publication statusPublished - 09 Jun 2017


  • international


Dive into the research topics of 'Coagulant plus ballast technique provides a rapid mitigation of cyanobacterial nuisance'. Together they form a unique fingerprint.

Cite this