Effect of the Packed Media on the Fixation of Bdelloid Rotifer, Philodina erythrophthalma and Water Purification in the Wastewater Treatment Process.

Philodina erythrophthalma is one of the species of bdelloid rotifer belonging to micrometazoa. It is known that these species play an important role in contribution toward getting transparency from wastewater treatment system. The fixation of these species in bioreactor is effective for enhancement of floculation and solid-liquid separation. The purpose of this study is to make clear the fixation ability of P. erythrophthalma to the attached media by changing the pore sizes of the media. The following results were obtained. It was made clear that the sticking ability of the rotifer to the attached media depends on its pore size of the media. In the case of the pore size of the media is larger than about 300μm, which is the average length of rotifer, the rotifer sticks to the media quickly after inoculation to the reactor, and is easy to get into the media. The shape and the pore size of the media were the most important factors of the fixing efficiency to the packed media.