Performance of Powdered Activated Carbon Adsorption/Membrane Filtration System for Treating the River Water with a High Particulates and Natural Organic Matters

The surface water (river and lake waters) being used as drinking water source has been polluted by micro-particulates such as colloid and microplastics (MPs) and natural organic matters (NOMs) such as total organic carbon and taste and odor (T&O) matters. Adsorption and filtration processes have been expanded as an alternative to conventional clarification and filtration processes to meet increasingly stringent regulations related to the treated water quality and in particular to MPs and T&O matters. The membrane filtration (MF) as a filtration process must be combined with other conventional technologies such as activated carbon adsorption to effectively remove these micropollutants. This study evaluated the water purification efficiency and membrane fouling behaviors of powdered activated carbon (PAC), flat-sheet membrane and their hybrid process in treating natural polluted water. This study explores the impact of filtration characteristics in a PAC/MF system on water treatment using a polluted river water: TOC 16.8±1.5㎎/ℓ, 2-methylisoborneol (2-MIB) 36.8 ± 4.6 ng/L, MPs including 20-50 ㎛(3.25×102), 50-100 ㎛ (1.17×102), and 100-500 ㎛ (0.18×102). Results showed that the PAC-membrane hybrid process could alleviate the membrane fouling caused by micro-particulates and NOMs. Addition of PAC notably improved the removal performance of the MF for organic matters in natural water, and effectively controlled membrane fouling. As the PAC dosage increased, the normalized permeate flux (J/Jo) improved due to flocs formation. This suggests that the PAC dosage is crucial in determining the effectiveness of MF, The J/Jo in the membrane process declined with increasing driving pressure and decreasing stirring strength.