The key is to very clearly determine the best technology for the given situation. Definitions Flocculant Long chained polymers of tremendous molecular weight are gently mixed to increase contact through collisions. The result is a faster settling action within a design specific vessel. Typically adequate mixing and settling periods must be provided in order for the coagulation, flocculation, and sedimentation to take place. When the coagulant is introduced, the zeta potential in the water is altered thus allowing the individual contaminant particle to agglomerate.
Coagulants can be a liquid or a solid and can be added in batch or continuous type reactors.
Encapsulants Sometimes the material that is flocced out of water contains contaminants that are toxic. In that situation an additional material may be added to the process, called an encapsulant. The purpose of the encapsulant is to bind and surround the toxic substances in the flocced material in a matrix. In addition, the encapsulants add the necessary mass to the coagulated particles enabling them to settle quicker. RGF's EC-2000 and QF series flocs incorporate these encapsulants allowing the settled sludge cakes to pass rigorous leachability tests.