The purpose of this study was the evaluation of chitosan flocculation ability to recover microalgal-bacterial
biomass from an open pond treating fish processing wastewater. A second order factorial design followed
by response surface methodology was applied to estimate the effect of chitosan concentration
and agitation speed on flocculation activity. Second-order polynomial model fitted quite well with the
experimental results. Chitosan concentration exhibited a higher effect on the flocculation process than
agitation speed. The highest flocculation efficiency (92%) was obtained at a concentration of 214 mg L−1
and an agitation speed of 131 rpm.