Dewatering agent and method for manufacturing dewatering agent, method for dewatering sludge to provide a dewatering agent with excellent performance for reducing the water content of sludge

The present invention provides a dewatering agent with excellent performance for reducing the water content of sludge, a manufacturing method thereof, and a method for dewatering sludge. The invention relates to a dewatering agent, a manufacturing method of dewatering agent, and a method for dewatering sludge. The dewatering agent contains polysaccharide and urea. The manufacturing method of the dewatering agent includes the following steps: a compounding step in which polysaccharide, urea, polymer compound and water are compounded to obtain a mixed product; a granulation step in which the above mixed product is granulated by extrusion granulation or stirring granulation to obtain granules; a drying step in which the above granules are dried to obtain a dried product; a crushing step in which the above dried product is crushed to obtain a crushed product; and a grading step for grading the above crushed product. Furthermore, the manufacturing method of the dewatering agent may also include the following steps