WATER TREATMENT METHOD COMPRISING A RAPID SETTLING STEP FOLLOWED BY A FILTRATION STEP THAT IS PERFORMED DIRECTLY ON THE MICRO- OR ULTRA-FILTRATION MEMBRANES AND CORRESPONDING DEVICE

摘要

Water treatment for removing organic pollutants and inorganic substances comprises separating a liquid-solid phase (1) followed by filtering of the phase (2) on microfiltration/ultrafiltration membranes, swabbing of the membranes, and injecting reactants of organic coagulant, mineral coagulant, organic flocculant, mineral flocculant, organic absorbent and a mineral absorbent into the water during the liquid-solid separation stage. The separation of liquid-solid phase comprises a decantation step, which is carried out at a surface speed of higher than 15 m/h. Water treatment for removing organic pollutants and inorganic substances, comprises separating liquid-solid phase (1) followed by filtering of the phase (2) on microfiltration/ultrafiltration membranes, swabbing of the membranes, and injecting reactants of organic coagulant, mineral coagulant, organic flocculant, mineral flocculant, organic absorbent and a mineral absorbent into the water during the liquid-solid separation stage. The separation of liquid-solid phase comprises a decantation step, which is carried out at a surface speed of higher than 15 m/h. The separation of liquid-solid phase is carried out by decantation with ballasted floc of fine inert granular material, which has a density higher than the water. The decantation of ballasted floc is carried out using fine sand. The separation of liquid-solid phase is carried out by recirculation of mud and by floatation. The swabbed water is recycled in an upstream of the liquid-solid separation stage. Reactive oxidant and an activated carbon powder is injected between the liquid-solid separation stage and the filtration stage. The reactive oxidant comprises ozone, chlorinated oxidants and hydrogen peroxide. An ultraviolet treatment is carried out between the separation of liquid-solid phase and the filtration membranes. A reverse osmosis treatment and nanofiltration stage is carried out in downstream of the filtration membrane. An independent claim is included for a water treatment device.