Polymer aggregator and method for removing matter suspended in water using said aggregator

Provided are a polymer aggregator by which coarse and fine suspended solids can be quickly and easily removed, using the same process, from wastewater in which both types of suspended solids are present, said solids being removed without the use of an inorganic aggregator, and irrespective of any increase in the amount used. The processed water is clear, with no cloudiness, and precipitates that have aggregated and settled can be processed with ease. A polymer aggregator principally containing a cationic or amphoteric copolymer, in which the value obtained by multiplying the weight-average molecular weight (Mw) of the copolymer by the square of the cation colloid equivalent (CE) at a pH of 7 is divided by 1,000,000 to yield an N value of 5-60; and a method by which this aggregator is used to remove coarse and fine suspended solids in the same process from wastewater in which both types of suspended solids are present.