PENGARUH KOAGULAN TERHADAP PERUBAHAN KARAKTERISTIK AIR PAYAU DENGAN PROSES FILTRASI DUAL FILTER MEDIA DAN MEMBRAN REVERSE OSMOSIS

Research about raw water treatment units using coagulation-aeration, dual media filtration, microfiltration, reverse osmosis, aluminum sulfate (alum) coagulants and poly aluminum chloride (PAC) is designed to treat brackish water into fresh water for drinking. This research aims to compare the right type of coagulant in the processing of raw water into fresh water for drinking. The type of coagulant used affects the physical properties and chemical properties of the raw water. The parameters observed in this research were pH, turbidity, salinity, dissolved solids (TDS), iron (Fe) and manganese (Mn) contained in the raw water. This research was done by using a jar test for determining the optimum dose and for treatment of raw water into drinking water using a reverse osmosis membrane. The results showed that the water treatment by using the coagulant poly aluminum chloride (PAC) was the most effective with %rejection manganese (Mn) amounted to 93.33% and% rejection of iron (Fe) amounted to 72.73%. While the water treatment by using the aluminum sulfate (alum) coagulant % rejection manganese (Mn) amounted to 66.67% and% rejection of iron (Fe) amounted to 59.09%. At overall, brackish water treatment unit from this design results has produced potable water to the specific characteristics of pH, turbidity, TDS (Total Dissolved Solid), salinity (salt content), levels of iron (Fe) and manganese content (Mn) which suitable with the standards PERMENKES No. 492 / Menkes / Per / IV / 2010