抄録
In order to solve the eutrophication problem in closed water area, it is well-known fact that to reduce the nitrogen and phosphorus is one of the important ways. However, such nutrients in present sewege systems are not sufficiently removed. The objective of this study is to propose a treatment system for secondary effluent by using reed bed treatment system with different packed media. The effect of por osity of packed media on nitrogen and phosphorus removal was discussed.
The results indicated that the removal rate of nitrogen in reed bed treatment system packed with gravel was higher (1.54 gN·m-2·d-2) than those packed with sand and net material. According to numeral analysis 50 percent of nitrogen in the sand system was removed due to adsorption on sand, whereas in the gravel and net material systems 60 percent of it was removed by biological denitrification at the root zoon of reed. It was found that nitrification- denitrification at the root zoos of reed was important way for nitrogen removal, and the nitrogen removal at the root zoon was effectively carried out as the porosity of packed media increased. On the other hands 80 percent of phosphorus in the sand and gravel systems was adsorbed on packed media.
