丰满爆乳一区二区三区,精品少妇人妻AV免费久久久,热RE99久久精品国产99热,亚洲AV成人中文无码专区,成人熟女视频一区二区三区,国产又色又爽又黄的网站在线,欧美裸体XXXX,无码人妻AV一区二区三区蜜臀

Combining denitrification with deep bed filtration, denitrifying deep bed  filter is a  treatment unit integrating biological  nitrogen removal and filtration. After the secondary sedimentation tank discharges the effluent, the model can be integrated with other treatment units perfectly, with the functions of nitrogen removal, phosphorus removal, and removal of suspended solids, etc.

Denitrification deep bed filter is especially suitable for the upgrading and reconstruction of municipal wastewater treatment plant, such as upgrading from the Grade B of Level I to Grade A of Level I, or from Grade A of Level I to IV Category of surface water.