Natural polymer based smart hydrogels have wide field of applications. They follow a green approach right from the synthesis methods to their applications. They are currently the hot topic for researchers and are widely used as they are highly biodegradable, bio-compatible and bio-erodible in nature. Their applications in addition to industrial scale toxic dye and heavy metal ion removal for waste water management include wound dressing formation, drug delivery, tissue engineering, biosensors and even in agricultural area. The book covers all the areas of applications to somewhat and sequentially explains the dye removal process by hydrogels and its further studies. Thus, researchers can have one-way idea about the currently demanding and vaste field of smart hydrogels and its applications using this book.