抄録
In order to eliminate nitrogen from wastewater, simple and stable method was developed using methanol permeable polymer bag containing methanol inside. Polyethylene membrane was suited as the methanol permeable polymer in comparison with polyvinylchloride in a point of endurance. Permeation rate of methanol through polyethylene membrane 0.1mm thickness, was 2.1g-McOH/m2/day at 20°C. The permeation rate increased in proportion to temperature and decreased in proportion to thickness of the membrane. Effect of temperature, hydraulic retention time and nitrate concentration on the denitrification of this process using polyethylene membrane was examined. The results showed that the denitrification proceeded on the surface of the membrane including biofilm, and the rate depended on the methanol permeation rate which was affected with temperature. And also, denitrification rate was affected in proportion to nitrate concentration below 15mg-N/l, but the rate was held approximately 1g-N/m2/day of maximum revel above 20mg-N/l of nitrate concentration, using 0.1mm polyethylene membrane at 20°C. We actually applied this process as a denitrifying reactor to small-scale on site wastewater treatment plant for human waste. We got similar results of denitrifying ability, 1.25g-N/m2/day and 80% nitrogen removal at 20-25°C, under actual condition.
