Characteristic of Dissolved Organic Matter Removal in Overflow Wastewater by Coagulation Flocculation Process

Abstract:

The fractions variation and the removal efficiency of dissolved organic matter (DOM) by polyaluminum ferric chloride sulfate (PAFCS) in coagulation flocculation process were investigated by taking a storm sewer system in Shanghai for example. The results show that in overflow wastewater, hydrophobic matter (HoM) and hydrophilic matter (HiM) account for 68% and 32% respectively; and molecular weight (MW) more than 300 kDa and 10～50 kDa fractions account for 29.76% and 37.87% respectively. PAFCS is effective on DOM removal and total organic carbon (TOC) removal efficiency is 17% approximately, and the removal efficiency of HoM fraction is higher than HiM fraction. The removal efficiency of MW more than 300 kDa and 100～300 kDa is between 20% and 25% approximately, but the MW less than 10 kDa and 50～100 kDa fractions are rarely removed in coagulation flocculation process.

Key words:overflow wastewater; dissolved organic matter; fractions; coagulation flocculation process