Applications of coagulation-flocculation and nanotechnology in water treatment

Abstract Nanotechnology holds great potential in advancing wastewater treatment to improve treatment efficiency and to supplement the water supply. Nanomaterials based on metallic, carbonaceous, polymeric, and magnetic nanoadsorbents are discussed in detail in this chapter, along with nanofiltration membranes, thin-film composite membranes, fabricated membranes, nanocomposite membranes, polymeric nanocomposite membranes, and enzyme incorporated nanotechnology-based processes. Some conventional treatment processes including coagulation-flocculation for removal of organic and inorganic pollutants along with suspended solid particles are still in use for water treatment. The recent advancements in the area of coagulation-flocculation for wastewater treatment are critically reviewed and evaluated. This chapter also emphasizes destabilization of colloids, removal of inorganic and organic matter (particulate and/or dissolved), removal of metals and anions, and removal of microorganisms using coagulation-flocculation. Various chemical or natural coagulants, flocculants and their derivatives and the use of low-cost biopolymeric materials such as algin, guar gum pectin, starch, chitin, dextran, and pullulan derivatives are also described in detail.