INNOVATIVE TECHNOLOGY OF LANDFILL STABILIZATION COMBINING LEACHATE RECIRCULATION WITH SHORTCUT BIOLOGICAL NITROGEN REMOVAL TECHNOLOGY = INNOVATIVE TECHNOLOGY OF LANDFILL STABILIZATION COMBINING LEACHATE RECIRCULATION WITH SHORTCUT BIOLOGICAL NITROGEN REMOVAL TECHNOLOGY

다국어 초록 (Multilingual Abstract)

Leachates from aged landfills are often rich in ammonium nitrogen although the concentration of organic matter is relatively low. This study was performed to evaluate the possibility of applying leachate recirculation to enhance landfill stabilization. The concept of this technology is that ammonium in the leachate is nitrified to nitrite in an above-ground reactor and then the leachate containing nitrite is recirculated to the landfill, in which nitrite is reduced to nitrogen gas. Column experiments were conducted to demonstrate the feasibility of denitrification in a landfill. Shortcut biological nitrogen removal (SBNR) process was tested to see how ammonium in the leachate converted to nitrite under certain operating conditions, using a pilot- scale reactor. The results were: 1) Nitrite was denitrified in a landfill material, apparently consuming less COD than in nitrate denitrification; 2) Ammonium in the leachate converted to nitrite under an alkaline pH around 8. A logical combining of the two results leaded to an expectation that a leachate of high ammonium could be treated in-situ by leachate recirculation and SBNR technology. An experiment that combines the SBNR technology and the in-situ nitrite denitrification is undergoing, using six sets of lab-scale reactors and a pilot-scale plant.