The primary purpose of a gravity thickener in wastewater treatment is to ____________

The primary purpose of a gravity thickener in wastewater treatment is to reduce the volume of sludge. Gravity thickeners operate on the principle of sedimentation, allowing solid particles, such as sludge, to settle under the influence of gravity. This process concentrates the solids by removing a portion of the liquid, effectively reducing the volume of sludge that needs to be further treated or disposed of. By decreasing the volume, it not only makes the subsequent handling and processing of the sludge more efficient but also decreases the operational costs associated with transportation and disposal.

In contrast, increasing the pH of water, removing all pathogens, or lowering the temperature of sludge are not functions of a gravity thickener. The thickening process does not directly alter the chemical properties of the water or target pathogens; it focuses solely on consolidating the sludge by decreasing its moisture content.