Abstract
Hydroxypropylcellulose (HPC) powder was selected as polymer gel material, and the HPC hydrogel was prepared applying the radiation crosslinking technique. The hydrogel was packed into a carbon felt hollow cylinder (carrier), and then the carrier was submerged in the reactor. After a 2-week bacterial acclimatization period, the continuous denitrification experiments were carried out over three months. In the experiment using the carrier without the hydrogel, total nitrogen (TN) concentration in the reactor was not decreased. On the other hand, a significant difference between influent and effluent TN concentrations was recognized in the experiment using the carrier with the hydrogel. The use of the hydrogel stimulated the denitrification in the reactor. These results showed that the hydrogel could be used as an electron donor and/or carbon source in the denitrification.