An Investigation on the Turbidity Removal from Natural Stone Processing Plant Wastewater by Flocculation

This study aimed to determine the effects of three different high molecular weight (HMW) flocculants (anionic, cationic and non-ionic flocculants) on the fine particles removal from natural stone (foid-bearing rock) processing plant wastewater at alkaline pH conditions. The test results were investigated in terms of turbidity values depending on pH of the medium, flocculant concentration and time (0–60 min). According to the results obtained, the turbidity values of the wastewater in the absence of the flocculants were pH dependent and decreased as the pH increased, resulted in the minimum turbidity values at pH 12. In the presence of the flocculants, the pH depended turbidity removal efficiencies varied with flocculant type, flocculant concentration and time. The best results were obtained at highly alkaline pH values (pH 12) with the turbidity removal efficiency of ≤99% in the presence of non-ionic flocculant. In the case of anionic and cationic flocculants, the minimum turbidity values were also obtained at pH 12 with turbidity removal efficiencies over 90%.