Estimation of the settling time of wastewater using the Buoyancy Weighing Bar Method

The Buoyancy Weighing Bar Method (BWM) is a new method for estimating wastewater’s settling time, which is useful in wastewater treatment. This study aims to apply BWM to calculate the optimal settling time of industrial wastewater consisting of two liquid samples, namely the industrial company ABC Ltd wastewater and XYZ landfill wastewater, which differ in viscosity. In this BWM, the change in the bar’s mass suspended from the liquid suspension of wastewater will be measured over time. The variations carried out were the diameters of the bars of 5 mm, 10 mm, and 15 mm, with variations in the shape of the bars consisting of cylinders, rectangular, hexagon, and sheets. The comparison parameter for this research is the measurement of the purity of Total Suspended Solid (TSS). Based on the results obtained, the BWM can be used to estimate the optimal settling time in ABC Ltd wastewater and XYZ landfill wastewater, and the diameter of the bar with the latest constant of bar mass is 5 mm and a length of 210 mm. Using a bar diameter of 5 mm, the optimal time for ABC Ltd wastewater and XYZ landfill wastewater is 50 minutes and 310 minutes, respectively. The TSS content in wastewater is 168 mg/L and 205 mg/L, respectively. In the variation of the shape of the bar, the settling time is close for each condition. The results obtained indicate that BWM can estimate the optimal settling time for wastewater.