Coagulation is a chemical process used in water treatment to remove solids from water by promoting the clumping of fine floc into larger floc so that they can be more easily separated from the water). Coagulation involves adding compounds that promote the clumping of fine floc into larger floc so that they can be more easily separated from the water). Coagulation is a chemical process that involves neutralization of charge, whereas flocculation is a physical process and does not involve neutralization of charge). Coagulation can be used as a preliminary or intermediary step between other water or wastewater treatment processes like filtration and sedimentation). Iron and aluminum salts are the most widely used coagulants, but salts of other metals such as titanium and zirconium have been found to be highly effective as well). The effectiveness of the coagulation process is affected by the type of coagulant used, its dose and mass, pH and initial turbidity of the water being treated, and properties of the pollutants present). Coagulation itself results in the formation of floc, but flocculation is required to help the floc further aggregate and settle). Coagulant aids (polymers that bridge the colloids together) are also often used to increase the efficiency of the process). Coagulation is a somewhat simple chemical process that involves bringing insoluble materials together by manipulating the charges of particles, by adding iron or aluminum salts, such as aluminum sulfate or ferric sulfate, to a wastewater stream. Coagulation is a necessary step in the water treatment process, but it does not remove all of the viruses and bacteria in the water, so it cannot produce safe drinking water.