The Relationship Between Aluminium Sulfate and Poly Aluminium Chloride On pH and Total Dissolved Solid ( Study Case : Water Treatment Plant In Terbanggi Besar - Pematang Panggang - Kayuagung Tollroad)

This research will discuss the relationship between coagulant aluminium sulfate and poly aluminium chloride (PAC) on pH and total dissolved solid parameter : study case of water treatment plant in terbanggi besar – pematang panggang – kayuagung tollroad. The study will describe the impact on water treatment especially on coagulation process with coagulant aluminium sulfate and poly aluminium chloride will affect pH and total dissolved solid in the final product. It was found that the use of aluminium sulfate coagulant resulted in average deviation of 9.8 % in total dissolved solid and 14.6% in pH compared to poly aluminium chloride coagulant. It happens due the characteristic of aluminium sulfate, which has density of 2.672 g/cm3 and pH range of 4.5 – 6.5. The dosage of aluminium sulfate required is higher than poly aluminium chloride to achieve the same result for adequate Indonesia regulation, increasing operational cost, particulary for aluminium sulfate coagulant needs. Therefore, poly aluminium chloride is the appropriate coagulant and can meet the quality standards according to Minister of Health Regulation Number 2 of 2023 by considering pH and total dissolved solid parameters in the water treatment plant at rest area 306 B on the terbanggi besar – pematang panggang – kayuagung tollroad. Monitoring these two parameter will affect other parameter, particularly iron (Fe) and manganese (Mn). This study will help operator at rest area 306 B to achieve the best dosage with jar test method for poly aluminium chloride coagulant and reduce operational and maintenance cost form previously using aluminium sulfate as coagulant.