Optimasi Kecepatan dan Waktu Pengadukan pada Proses Koagulasi dalam Menurunkan Kekeruhan Menggunakan Biji Ketapang

Abstract

The need for clean water in Jember City is supplied by two water treatment plant the Tegal Gede and Tegal Besar IPAs, which get their supply from the Bedadung River. The turbidity level in the Bedadung River has exceeded the maximum water quality requirements, so immediate reduction is needed. One method to reduce turbidity in water is coagulation-flocculation. In the coagulation-flocculation process, it is necessary to add a substance that helps the particle deposition process, called a coagulant. The coagulant used in this research is a biocoagulant derived from ketapang seeds. This research aims to determine the effective stirring speed and stirring time and to analyze the effect of variations in stirring speed and stirring time in optimizing turbidity removal efficiency using Ketapang seeds with variation stirring speed 100, 120, 150 and 200 rpm and variation stirring time is 15, 30, 60, 120 and 300 second . The method used in this research is quantitative in the form of experiments. The results of this research show that the effective stirring speed and stirring time in the coagulation process using Ketapang seed biocoagulant is 200 rpm in 60 seconds, and 30 rpm in 20 minutes in the flocculation process, with a removal efficiency value of 76%. It can be concluded that the stirring speed significantly impacts to the turbidity efficiency with Pr<0.05.