Recent Applications of Coagulation, Flocculation and Ballast Flocculation in Treatment of Wastewater—a Review

A chemical water treatment technique basically used beforetosedimentationandfiltrationthis enhancesthe ability of a treatment process to remove particles. Coagulation and flocculation provide the water treatment process by virtue of which finely divided,suspended and colloidal matter in the water is made to agglomerate and form flocs. This enables their removal by sedimentation, dissolved air flotation or filtration.Ballasted flocculation is a high-rate, physical-chemical clarification process, using rapid mixing flocculation and sedimentation for enhanced reduction of suspended solids and biochemical oxygen demand (BOD). The aim of this work was to review studies, on the wide and versatile range of feasible applications employed in the purification of different types of wastewater. The coagulation-flocculationapplications discussed here were for differentcategories: leachate, textile wastewater; pulp and paper industry wastewater; food industry wastewater; other types of industrial wastewater.In addition, this paper presents an overview of the optimum processconditionsand removal efficiencies (mostly high) achieved for the technology applicationsdiscussed