Efficiency of multi-media filtration in drinking water treatment plants for the removal of natural organic matter

Abstract

The filtration is a processing unit in a Drinking Water Treatment Plant (DWTP) that is used to remove particles from the water. This study is the result of pilot-scale research on Gravity Rapid Sand Filter (GRSF). The purpose of this paper is to evaluate the performance of the Triple Media Filter (TMF) (Granular Activated Carbon (GAC) + anthracite + garnet) and Dual-Media Filter (DMF) (anthracite + sand) in the removal of Natural Organic Matter (NOM) as a precursor of trihalomethanes (THMs) and chlorination Disinfection by Products (DBPs). As well as filtration rate performed at conventional (120 m/d) and a high rate (240 m/d), and compared with full-sized Single Media Filter (SMF) with a sand media. The removal efficiency of Turbidity, Color, UV absorption at a wavelength of 254nm (UV254), and Dissolved Organic Carbon (DOC) parameters were investigated. Besides, the Specific Ultraviolet Absorbance (SUVA) was calculated from the ratio of UV254 to DOC. The results showed that the Multimedia Filter (MMF) at 120 and 240 m/d filtration rate had higher removal efficiency compared to a control SMF in removing measured parameters (p-value <0.05). Also, similar filters, have shown the same efficiency relative to each other in different loading rates and there was an insignificant difference. MMF can significantly remove organic pollutants and control the formation of DBPs during water treatment. The study suggests that SMF should be replaced with MMF to improve water quality.