Microalgae harvesting is a major hurdle for the production of high-value microalgal bioproducts on a large scale. Among harvesting techniques, pH-induced sedimentation stands out as an inexpensive and technically viable method. Nevertheless, there is little information available on the application of this method for microalgae cultivated in wastewater. In this context, the present study investigated the optimization of sedimentation parameters for Chlorella sorokiniana harvesting from wastewater. Parameter optimization was statistically determined by the Response Surface Methodology. The optimal values included a velocity gradient of 250 s⁻¹, mixing time of 10 s, and pH of 12 which reached efficiencies higher than 97.8%. These optimal parameters also showed resilience through the physico-chemical variation of the photobioreactor effluent. Furthermore, wastewater quality improved significantly after microalgae harvesting. High removal was found for turbidity (97.9–98.3%), apparent color (92.2–97.2%), TKN (91.0–94.4%), and total phosphorus (92.8–98.6%). Centrifugation as the dewatering method and its operational parameters were also evaluated. Sedimentation followed by centrifugation increased the initial microalgae concentration around 123 times. This study showed the importance of operational optimization and the results can be used as practical guidelines for microalgae harvesting on a large scale.