Abstract
Abstract
This article summarizes a preliminary investigation of the treatment of humic acid (HA) in drinking water by a novel combination of potassium manganate, ferrous sulfate, and magnetic ion exchange (MIEX) resin. Manganate (MnO42−) is a stronger oxidant than permanganate, which has received little attention to date as a water treatment chemical, but in combination with ferrous sulfate (FeMnO) can offer a potentially advantageous and more economical means of achieving preoxidation objectives and in-situ coagulation by Fe(III) species. To enhance removal of organic substances, particularly low-molecular-weight and more hydrophilic compounds, subsequent treatment by MIEX was included as part of the overall process. Using model HA solutions of 5 mg/L dissolved organic carbon (DOC), a solution pH of 6.5, and a constant Fe:Mn molar ratio (2:1), the optimal FeMnO dose for organics (DOC) removal was 0.06 mM (as K2MnO4). At this optimal dose, and with 10 mL/L of MIEX, the DOC remaining after treatment was only 0.4 mg/L, representing an overall organics removal of 92%. Synchronous fluorescence spectra of solutions during the treatment stages showed a corresponding major reduction in fluorophore peaks with a near complete removal of fluorophore compounds in the ranges, 360 nm<λex<420 nm and λex>420 nm.
Get full access to this article
View all access options for this article.