Concurrent Purification of Organic Pollutants and Nutrients by the Slanted-Soil-Chamber Method Using a Sponge Carrier

The Slanted-Soil-Chamber-Method (SSCM) is an energy-saving aerobic purification method. We performed an experiment to elucidate this purification mechanism using a SSC reactor filled with a sponge carrier. This experiment demonstrated concurrent purification of organic pollutants, total nitrogen (T-N) and total phosphorus (T-P) for a hydraulic retention time of 20-50 min. Water and organic pollutants are separated as the gravity-fed wastewater passes through the reactor chamber. Treatment of the dissolved organic pollutants relies upon biological adsorption, which takes approximately 20-50 min. Since biological purification activity within the SSC reactor is high except the winter season, the organic matter that is trapped in the chamber is efficiently decomposed by organisms that are typically found in soil. The SSC reactor weight increased in the winter season and decreased in spring. The extent of T-N and T-P purification was dependent upon heterotrophic microbial utilization. Furthermore, T-N is purified by nitrification/denitrification, and T-P is purified by trapping the phosphorus-containing soil in the SSC reactor. The advantages of the SSC reactor are that it separates pollutants from water, degrades organic matter, reduces sludge, and simultaneously removes T-N and T-P in the same reactor chamber.