スポンジキューブを結合固定化担体とした硝化液循環プロセスに関する研究

反応槽の攪拌が処理効率に及ぼす影響

抄録

A sequencing batch reactor operating by nitrified liquor recycling process has been added 10% of poly-urethane form sponge cubes (size 12×12×15mm) as a biomass support medium to the reactor. The laboratory experiments using artificial sewage have been carried out to collect the data of effects on biomass support to the sponge cubes vs. mixing intensity magnitude in the reactor. And, the nitrification and denitrification coefficients have been measured comparing to a suspended growth reactor as controlled.
The mixing intensity magnitude of biomass attached sponge cubes in suspension was almost same as the magnitude of 3g per litre of mixed liquor suspended solids in suspension in the controlled reactor. The dry weight of attached biomass in the cubes was fluctuated depending on the magnitude of mixing intensity. Approx. 22g of biomass in a litre of cubes was yielded from 112 sec^-1 of the G-value, while approx. 10g in a litre was from 560sec^-1 in the reactor. It was found that the magnitude of mixing intensity had influence upon the biomass attached depth in the cube. A space of extremely little biomass attached in the cube was yield near core when 560sec^-1 was given as the G-value, while abundant biomass was found not only in subsurface layer but also at core when 112sec^-1 was given in the reactor. At the range of 14 to 26°C of water temperature, the denitrification and nitrification coefficients were 0.9 to 3.6 mgN·g^-1VSS·h^-1 and 1.2 to 3.4 mgN·g^-1VSS·h^-1 respectively at the reactor and they were exceeded 64% and 52% respectively than those of controlled reactor.