Blackwater Purification Using Sand Filter
This study aimed to determine the effect of the thickness of the sand filter and the best residence time for water purification. The type of sand used in this study was concrete sand, and the observation was focused on turbidity (NTU) parameter. Measurements of turbidity were performed before treatment, as well as at each retention time from 1 to 9 days. The method of data analysis was Linear Regression analysis on SPSS 21 program. Blackwater was collected in the morning and afternoon, and the turbidity of each sample was 1000 and 800 NTU, respectively. Wastewater turbidity was continued to decreased along with the longer retention time. The best results were obtained from the treatment 3 (sand filter 20 cm) with 9 days retention time, in which the turbidity levels decreased to 90 NTU (morning sample), and 105 NTU (afternoon sample).