The Use of Zeta Potential Measurement as a Control Tool of Surface Water Coagulation

Abstract

Coagulation process implementation or optimization requires prior preliminary tests. Standard Jar-Test method is time-consuming, inaccurate and may not work well, especially for waters characterized by high variability of quality parameters. Zeta Potential Isoelectric Point (IEP) analysis may give fast and precise answers on coagulant type and dose required for efficient coagulation process maintaining. The research objects was surface waters taken directly from the Mała Panew and Odra rivers. For each sample zeta potential and set coagulant dose dependence was measured. Four aluminum-based coagulants with different characteristics were used in this research: aluminum sulfate (Alum), polyaluminum chloride (PAC), dialuminum chloride pantahydroxide (PACl), polyaluminum chloride hydroxide sulfate (PACS). Charge neutralization effectiveness, by means of Zeta Potential IEP analysis, was the basis of choice of the most effective coagulant doses. Coagulation process efficacy was based on the parameters of treated water (pH, turbidity, color, alkalinity), reduction of organic matter (Abs254, Total Organic Carbon (TOC), Dissolved Organic Carbon (DOC)) and residual aluminum contamination. Zeta Potential utility evaluation was based on DOC reduction.

Keywords

• zeta potential
• isoelectric point
• coagulation
• aluminum
• coagulants
• surface water