On Site Experiments The Slanted Soil Treatment Systems For Domestic Gray Water

In order to make a breakthrough for the acute problem of water shortage in the 14 world, the key words "decentralization and reuse" are very important for new sustainable sanitation systems that will be developed. Therefore we focused on a new treatments system IF called "a slanted soil treatment system" which combines a biotoilet system with a domestic gray water treatment system. Because this system is a low cost and compact system, the system can be easily introduced to homes in urban areas or in the suburbs of cities in many developing countries. In this study, we performed on site experiments done on Shikoku Island of Japan for several years. We obtained following results. The slanted soil treatment system could remove organic pollutants and total nitrogen and total phosphorus in gray water effectively. Furthermore, The system performance became high in case of the high concentration of the influent water. The nitrification reaction and denitrification reaction were speculated to exist due to aerobic zones and anaerobic zones present in the slanted soil treatment system. The slanted soil treatment system could perform for about 3 years with zero maintenance. The plug flow model of 1st order reaction kinetics could describe the reaction in the slanted soil treatment system. However it is necessary to improve the system to maintain the performance at all seasons.