This article investigates the coagulation-flocculation of surface water from the Djiri River using aluminum sulfate via jar tests, considering pH and coagulant dosage as the primary operating variables. The study reports improved TOC removal rates of 67% and 92%, respectively, at a moderately acid pH (5.5 to 6.5) and with increasing coagulant dosages (1 to 4 mL), for initial TOC concentrations in the 6 to 21 mg/L range. The manuscript also interprets the removal mechanisms using correlation analysis and a Freundlich adsorption-type approach. Analysis of the Freundlich isotherm reveals very good R2 correlation coefficients, ranging from 0.88 to 0.99, for various TOC concentrations and varying coagulant dosages. The experimental TOC removal process could be the result of a phenomenon favoring adsorption onto aluminum hydroxide flocs.
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