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| Inamori Yuhei | |
| Head, International Water Environment Renovation Research Team | |
| Regional Environment Division | |
| National Institute for Environmental Studies | |
| Environment Agency | |
| Onogawa 16-2, Tsukuba, Ibaraki, 305-0053 Japan | |
| Tel: +81-298-50-2400 Fax: +81-298-50-2560 | |
| E-mail: inamori@nies.go.jp |
41,090,000 Yen
(FY 1999; 20,094,000 Yen)
This study of the development and evaluation of technology to control the production of CH4 and N2O from domestic wastewater treatment systems has revealed that the nitrification capacity of a biological nitrification reaction declines and its N2O production rate and conversion ratio rise as the water temperature decreases and the inflowing nitrogen load rises, and that the production of N2O by a nitrification process can be simultaneously controlled by maintaining the nitrification efficiency at a high level. The study has also shown that by incorporating an intermittent aeration process based on the entrapped immobilization carrier A. faecalis that is an effective nitrifying and denitrifying bacteria, it is possible to simultaneously improve both the nitrification efficiency and denitrification efficiency without increasing the N2O conversion ratio. It also suggests that it is possible to achieve high speed denitrification that sharply cuts the quantity of N2O produced by adding a small quantity of copper, and that a polyethylene cross-lined type porous cellulose carrier with superior copper absorption capacity can provide a new method of removing nitric acid from ground water. The pollutant load per unit activity of source of N2O in the swine wastewater treatment process is greater than it is the case of sewage treatment, presumably because NO2-N is accumulated temporarily in the wastewater treatment process. In order to control the production of N2O, it is important to prevent the accumulation of NO2-N by performing well balanced nitrification and denitrification. The quantities of CH4 and N2O from wetlands that have been polluted by artificial sources fluctuate widely between seasons. This phenomenon is assumed to be a result of fluctuation of organic matters and nitrogen metabolism caused by microorganism and vegetation in wetland ecosystems: absorption activity caused by CH4 oxidation or vegetation, denitrification reactions, or the absorption of nitrogen compounds, etc. The study has also suggested that it is possible to develop technology to reduce these gasses from wetlands polluted from artificial sources caused by the activity of wetland microorganism ecosystems. And it has shown that anaerobic filters and soil trenches provide superior organic matters, nitrogen, and phosphorus removal capacity, and that it is possible to sharply reduce the production of CH4 and N2O by performing ventilation.
Greenhouse Gas Reduction, Methane (CH4), Nitrous oxide (N2O), Bio-engineering, Eco-engineering