PURPOSE: To reduce the load on sludge in sewage treatment, to enhance the filterability of sludge and to realize the reduction of the adhesion of scummed oil while enabling the oil along with sludge to be incinerated by adding an oil absorbable polymer obtained by polymerizing a monomer component containing a specific monomer in a specific ratio or more.

CONSTITUTION: The additive for sewage treatment is constituted so as to contain an oil absorbable polymer obtained by polymerizing a monomer component based on a monomer with a solubility parameter (SP value) of 9 or less and containing 50wt.% or more of a monomer having one polymerizable group in its molecule. This oil absorbable polymer is granulated along with a water- insoluble powder to be formed into a granular form and used as the additive for sewage treatment. As the water-insoluble powder to be used herein, there is no limit if an insoluble or hardly soluble powder of which the water solubility at 25°C or lower is 1 pts. or less per 100 pts. of the water-insoluble powder is used, but a powder generating no harmful gas at the time of incineration and low in the content of ash is more pref.