Abstract: Alkaline solutions resulting from extracting sulfide from hydrocarbon fluids can be treated in a combination of one or more electrodialysis cells and a bioreactor. The electrodialysis cell (2) includes an anode (4), a cathode (5), an electric power supply (7) and a first (12) and a second (11) compartment separated from each other by an anion exchange membrane (9). The alkaline solution is fed into the first compartment at the cathode side and the diluate (sulfide-depleted stream) leaving the first compartment has a lowered sulfide content and can be reused as the alkaline extractant solution. The concentrate (sulfide-enriched stream) leaving the second compartment is treated in the bioreactor (3) for removing sulfide and is then returned.

Abstract: The invention relates to an anaerobic purification device for purification of influent. The device has a reactor tank, an inlet for introducing influent into the tank, a water collecting device for collecting purified water, a gas collecting system for collecting gas from the fluid contained in the reactor, a gas-liquid separation device, a riser for passing liquid into the separation device by gas lifting action caused by gas collected in the gas collecting system, and a downer for returning liquid and sludge from the separation device into the lower tank section. According to the invention this device is characterized in that it is arranged to define, in the downer at the level of the liquid surface, a head pressure of, at least, approximately 1.4 m water column (approximately 0.14 bar). The invention also relates to a method for anaerobic purification device for purification of influent.

Abstract: Alkaline solutions resulting from extracting sulfide from hydrocarbon fluids can be treated in a combination of one or more electrodialysis cells and a bioreactor. The electrodialysis cell (2) includes an anode (4), a cathode (5), an electric power supply (7) and a first (12) and a second (11) compartment separated from each other by an anion exchange membrane (9). The alkaline solution is fed into the first compartment at the cathode side and the diluate (sulfide-depleted stream) leaving the first compartment has a lowered sulfide content and can be reused as the alkaline extractant solution. The concentrate (sulfide-enriched stream) leaving the second compartment is treated in the bioreactor (3) for removing sulfide and is then returned.

Abstract: The invention is directed to a process for the simultaneous removal of BOD and phosphate from a liquid containing ammonium, BOD, phosphate and magnesium, the method comprising: feeding the liquid to a reactor containing BOD-oxidising biomass; ensuring that the liquid in the reactor contains an excess to stoichiometry of ammonium and magnesium relative to phosphate, wherein the stoichiometry is related to the stoichiometry of struvite; oxidising at least part of the BOD; adjusting the pH of the liquid in the reactor at a desired value; forming solid material in the reactor, the solid material comprising struvite; separating at least part of the solid material from the reactor effluent; returning a part of the solid material to the reactor. The invention is also directed to a reactor for this process. The advantage of the process and the apparatus is that in one reactor both BOD and phosphate are removed from the liquid.

Abstract: A device for cleaning a fluid comprises at least one set of a first membrane cloth and a second membrane cloth, each being permeable to water over substantially their entire length. The membrane cloths are held taut, substantially parallel to one another in a frame delimiting between them a movement path for fluid. The cloths are displaceable with respect to one another between a first position, in which the mutually facing surfaces substantially touch one another, and a second position, in which the cloths lie at a distance from one another and the width of the movement path for the fluid is greater than in the first position. At least one of the cloths, on the side which faces towards the adjacent cloth is provided with grooves or webs for the purpose of forming channels between the cloths in the longitudinal direction of the cloths, in the first position.