Coagulation/flocculation process of marble wastewater: A preliminary (quadratic) statistical model

Abstract

In the scope of this preliminary work, the turbidity removal of an aqueous marble waste was investigated. The effect of the Fe-coagulation and PEO-flocculation on the supernatant turbidity was statistically modelled. The obtained mathematical equation from this model adequately explained 89,86% of the variation in the response variable: turbidity. After the confirmation of the model capability, the quadratic equation was used to generate an extensive 3-D surface plot for the dependent and the independent variables. Based on this, the turbidity removal tendencies of the coagulant and the flocculant was identified. When 140-160 mg/L Fe-coagulant and 0,4-0,6 ppm PEO-flocculant was added into the suspension at pH 10-11, it was observed that the marble fines were effectively removed from the supernatant (? 0 NTU).