The process that destabilizes sludge particles by decreasing repulsive forces is called __________.

The process that destabilizes sludge particles by decreasing repulsive forces is known as coagulation. In the context of wastewater treatment, coagulation involves the addition of chemicals, often called coagulants, which neutralize the charges on the suspended solids. This neutralization reduces the electrostatic repulsive forces that keep the particles apart, allowing them to come together and form larger aggregates, or flocs. These larger flocs can then be removed more easily from the water through sedimentation or filtration processes.

Coagulation is crucial in the treatment of wastewater as it enhances the efficiency of subsequent processes like flocculation and sedimentation by facilitating the aggregation of smaller particles that would otherwise remain suspended in the wastewater. This ultimately aids in producing cleaner effluent and helps in the efficient operation of treatment facilities.