Improvement of Flocculation Efficiency of Water Treatment by using Polymer Flocculants

Abstract

As water treatment plants have to supply water with satisfactory quality, timely responses to fluctuations in raw water quality are of importance. In most cases, metal salts type inorganic flocculants have been sufficient to maintain the water quality. However, due to various reasons there are situations where metal salts cannot solve the problem caused by the poor quality of inflow water. In this study, organic polymers such as polyamine and poly(diallyldimethylammonium chloride(DADM)) were synthesized and were applied to Nak-dong river raw water in Korea to check their efficiency in reducing turbidity and total organic carbon (TOC). Synthesized polyamine and poly(DADM) flocculants were effective as flocculants for water treatment and the addition of 1 mg l⁻¹ of organic polymer caused a reduction of 50 % of the consumption of polyaluminium chloride (PAC). The effects of polymer, polymer amount, initial turbidity, and pH on the removal of turbidity and TOC were investigated. The adsorption and separation mechanisms for the removal of turbidity and TOC by using the polymer flocculants were also observed.

Keywords:

• Flocculation
• polymer flocculant
• turbidity
• TOC