Chlorophyll-<i>a</i> concentrations (micrograms per liter) in the top 5 mL of 50 mL cyanobacteria suspensions incubated for one hour with different concentrations of the local red soil (LRS), bauxite (BAU), gravel (GRA), aluminum modified zeolite (AMZ), lanthanum modified bentonite (LMB) solely (A) or with combination the flocculants PAC (poly-aluminium chloride, 2 mg Al L^-1; B) or chitosan (2 mg L^-1; C).

<p>Statistically significantly exponential decay curves were fit to chl-<i>a</i> data over different ballast concentrations. Error bars indicate one standard deviation (<i>n</i> = 3).