Abstract: The present invention provides a floated biological treatment apparatus and a process for purifying refractory wastewater or raw water for drinking water. The treatment apparatus of the present invention includes a supporting plate for dividing the treatment apparatus into upper and lower portions. The upper portion is formed into a reactor, and porous compressible carriers are filled with the reactor in an amount of 80 vol % to 100 vol % of the reactor volume. The lower portion is provided with a liquid inlet for introducing the refractory wastewater or raw water and a gas inlet. The reactor is provided with at least one top carrier blocking plate at the top, such that the carriers can be limited by the top carrier blocking plate to be retained in the reactor, and the carriers can become a floating state.

Abstract: A submerged membrane bioreactor includes a tank containing a mixed liquor having microorganism; and a filtration module immersed in the mixed liquor and having a permeate side in fluid communication with the mixed liquor only through the filtration module. The filtration module includes a porous support having a first surface forming the permeate side and a second surface opposing to the first surface; and a non-woven fabric membrane covering the second surface and having a thickness of 0.1-2 mm and a pore size of 0.2-100 &mgr;m.

Abstract: The present invention provides a floated biological treatment apparatus and a process for purifying refractory wastewater or raw water for drinking water. The treatment apparatus of the present invention includes a supporting plate for dividing the treatment apparatus into upper and lower portions. The upper portion is formed into a reactor, and porous compressible carriers are filled with the reactor in an amount of 80 vol % to 100 vol % of the reactor volume. The lower portion is provided with a liquid inlet for introducing the refractory wastewater or raw water and a gas inlet. The reactor is provided with at least one top carrier blocking plate at the top, such that the carriers can be limited by the top carrier blocking plate to be retained in the reactor, and the carriers can become a floating state.

Abstract: A process for removing fluoride from wastewater is presented. Calcium (or magnesium), sodium and aluminum reagents are added into a fluidized bed crystallizer to remove most of the fluoride in wastewater. The remaining fluoride is removed by aluminum hydroxide. Alternatively, two fluidized bed crystallizers are used in series to treat the fluoride-containing wastewater: in the first fluidized bed crystallizer, calcium (or magnesium), sodium and aluminum reagents are used to treat the wastewater which contains high concentrations of fluoride, so that the fluoride concentrations thereof are largely reduced. Then, in the second fluidized bed crystallizer, a calcium reagent is added to further remove fluoride therein.