Tertiary treatment of domestic wastewater using zeolite ceramics and aquatic plants

In this study, we examined tertiary treatment of domestic wastewater using zeolite ceramics and aquatic plants, especially reeds, Phragmites australis. The experiment was made at real domestic wastewater treatment facilities, and comparison of treatment performance was made between the method with zeolite ceramics and that with pebble stones as conventional way. SEM observation of the ceramics' surface was also made to examine its possibility as the habitat of bacteria. The results obtained are as follows. Through the tertiary treatment experiment, it was suggested that the water purification system with zeolite ceramics and reeds could keep higher nitrogen removal efficiency for a long time. Zeolite ceramics would be useful when nitrogen compound, NH₄-N in particular, in the influent was higher. under SEM observation, bacteria-like objects were observed on the ceramics' surface. Appropriate operation and maintenance would be needed to keep long-term performance of both the NH ⁺₄ absorption and nitrogen removal with use of zeolite ceramics.