Review of Recent Patents on Coagulation / Flocculation (C/F) Process: Methods and Applications with Emphasis on Phosphates Removal

The present review describes the most recent patents and outlines the progress made over the last decade in the field of wastewater treatment focusing on the application of Coagulation/Flocculation (C/F) process, which is mainly used as primary treatment for the effective removal of colloidal particles and organic matter. Various materials/chemical reagents have been developed in recent years as coagulation/flocculation agents. Among them are inorganic-based coagulants, organic-based flocculants, as well as hybrid materials, or tannin-based polymeric coagulants. Furthermore, a recent patent application for treating wastewater is using nanoparticles of clay as anionic coagulant agent. In many sensitive catchment areas, the effective removal of phosphorus is also required. Several alternative processes, methods and treatment systems have been provided in recent patents for lowering the concentration of phosphorus in wastewaters, noting that the conventional use of alum or ferric chloride for phosphorous removal is rather problematic due to acidity of coagulants, being added to the wastewater. A coagulation-sedimentation apparatus is specifically designed to treat water at higher rates and a more recent patent discloses a system for continuous optimization of the relevant wastewater treatment.