摘要:
A process for the treatment of water using a granular bed (3) of granular support materials of a volumic mass less than that of the water to be treated. According to this process, each washing cycle comprises interrupting the withdrawal of treated water and stopping the feed of water to be treated in such a manner that the granular bed (3) floats in a given volume VL of water, admitting cleansing air into the reactor for assuring agitation of the floating bed, interrupting the admission of air in order to permit a separation of the granular materials and sediment by their difference in volumic mass, with decantation of said sediment and flotation of said materials, and evacuating the sediments at the base of the reactor as well as the water contained therein for evacuating the granular bed (3).
摘要:
The invention concerns a process for increasing the purification yield in the activation tank of a station for the purification of waste waters employing the so-called "activated sludge" process. According to the invention, talc, pyrophyllite, kaolin or mica, possibly cationized, are added to the biomass, these having a particle size less than 100 .mu.m in quantities of up to 2.0 g per liter of waste waters. A great improvement in solid/liquid separation is observed at the outlet from the activation tank as well as an increase in the purification yield for carbonaceous pollution, nitrogenous pollution and phosphate-containing pollution even when the station operates at medium or high load.
摘要:
A granular water treatment material and a process for the production thereof, the material being in the form of spherical granules, each having a thermoplastic polymeric matrix (1) and a more dense adjuvant in the form of micro-grains (3) dispersed in the matrix; each granule has on the surface a porosity in the form of micro-cavities (4) and cationic hydrophilic sites distributed on the surface; the process includes providing a mixture of an oxidizable thermoplastic resin and an adjuvant in powdered form, heating the mixture to make it plastic, extruding the plastic material to a diameter corresponding to the size of the granules to be obtained and cutting the extrusions to a length equal to this diameter, achieving a beading of the extruded pieces, oxidizing the surface of the spherical granules thus obtained, then ionically grafting a cationic polyelectrolyte to the surface of said granules.