Aerated Grit Chamber Processes
An aerated grit removal system removes particles by forcing water that has passed through bar screens into a grit chamber, which has air pumped into it. The air causes a spiral of water to flow through the tank and heavier particles are thrown out of the water's streamline. Eventually, after hitting the wall, the heavier particles settle to the bottom of the tank, while the lighter organic particles are suspended and eventually passed through the tank.
Having the right amount of air is important because excessive quantities of air can cause the roll velocity to be too high, which results in poor grit removal. Insufficient quantities of air result in low roll velocities, and excessive organic matter will settle with the grit.
The grit chamber and microorganism processes are often combined in one process. When this happens, the grit basin is dedicated to removing solids, and activated sludge is added to a separate aeration operation.
