Settling is one of the widely used low cost operations. The solid contained in slurry mixture was separated by settling process. The process was performed in 500 ml capacity graduated measuring cylinder. Treated water sample was stirred slowly by glass rod and 250 ml measuring cylinder was taken for settling study. Fig. 6 shows the time-course of the settling of sludge in terms of dimensionless height of the solid–liquid interface (H/Hi) as a function of settling time at different initial system pHi. At the beginning, a steady state decrease in the height of the solid/liquid interface (zone settling) was noted. Thereafter, the transition settling zone occurs. Finally, a steady state compression settling takes place. The settling rate was observed in order pH 8 > pH 10 > pH 2 > pH 4 > pH 6. At pH 8 solid interphase of 0.2 obtained in one hour. The data shows to good settling at basic and acidic pH as compared to neutral pH. Settling rate depends on viscosity of liquid, concentration of solids and nature of flocks. In sedimentation studies, batch sedimentation data is enormous importance. Using the data of batch sedimentation, a continuous thickener may be designed