Abstract: The novel high-molecular-weight biocide was immobilized into a polymeric matrix consisting of poly vinyl alcohol (PVA) hydrogel to form small PVA balls with biocidal capabilities. Their biocidal activities were evaluated. Experiments show that when the PVA balls dosage is 10 mg/mL, the bactericidal ratereaches (92±2)%. The scanning electron microscope (SEM) results of the PVA balls reveal that they are some porous sphericity solid which has close-grained structureand is filled well. To apply to circulating cooling water treatment more effectively, a column apparatus was devised by biocidal PVA balls, and some parametersof the column apparatus were researched such as length of filled column, treating time of water and outflux, etc. As far as the 　30　mm×300 mm column apparatus is concerned, the better applying is that filling length exceeds 20 cm; contacting time is beyond 0.5 h and outflux is 2.7 mL/s. As for the 　50 mm×500 mm column apparatus, the bactericidal rate reaches (93±1)% when filling length is 10　cm; contacting time is 0.5 h, and outflux is 2.7 mL/s. The study indicates that a column apparatus made by the PVA balls with biocidal activities is a very feasible and effective measure in circulating cooling water treatment.