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: The present invention relates to a device for cleaning a fluid, wherein the device comprises a vessel, a filter bed with granular filter material, such as sand, wherein the filter bed is provided in the vessel; a transport system arranged to agitate filter material of the filter bed during operation; and a sensor system. The sensor system comprises a contact body that comes in contact with the filter material in the filter bed; and a vibration sensor connected to the contact body for sensing vibrations of said contact body. The vibration sensor is arranged for producing a signal which is dependent on the vibrations detected by the sensor. The contact body comprises the wall of the vessel and/or a rod extending into the filter bed.

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: 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: 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.

Abstract: For the biological purification of waste water, use is made of a column containing a UASB reactor (1) at the bottom and an aerobic reactor (2) at the top. The two reactors (1; 2) are separated from one another by a partition (12) in which openings are provided to allow the anaerobic effluent through into the aerobic reactor. The partition (12) is situated at some distance above the gas collection means (8) in order to form a buffer zone (13) for anaerobic sludge which has flowed through. Preferably, a floatation apparatus (3) is mounted on the aerobic reactor in order to separate biomass from the purified water.

Abstract: A process is described for the aerobic treatment of effluent in a reactor of the UASB type, into the bottom of which the effluent to be treated is fed and, at the same time, oxygen is fed in an amount such that the growth of a facultative and an aerobic biomass is promoted. An apparatus for the aerobic treatment of effluent is also described, which apparatus consists of a UASB rector, distributors for supplying liquid and aeration means being located at the bottom of the reactor and means for integrated settling of biomass and gas collection being located at the top of the reactor. The apparatus can also be an integrated anaerobic/aerobic reactor.

Abstract: A settling device (2) for a fluid containing liquid, gas and particulate material comprises liquid-discharge elements (15) fitted close to the water level of the fluid and supply elements for supplying the fluid at the bottom of the settling chamber. In the settling chamber one or more caps (12) are disposed with their longitudinal axis at an angle to the water level, such that fluid supplied at the bottom of the settling chamber flows obliquely up, forced along the bottom of the at least one cap. Whilst gas bubbles contained therein collect in the ridge (17) of the at least one cap. The gas collected in the ridge of the at least one cap is trapped by elements (18) beneath the water level of the fluid. Preferably, use is made of a row containing a multiplicity of caps (12) which are disposed in oblique, overlapping and parallel arrangement. The caps (12) can be fitted at an angle of 60.degree. relative to the water level and preferably have a mutual interval of about 6 cm.

Abstract: A process for purifying waste water containing sulphide, comprises oxidizing the sulphide to elemental sulphur in a reactor with sulphide-oxidizing bacteria in the presence of oxygen, and separating from the waste water at least a part of the sulphur formed during the oxidation, while recycling a part of the elemental sulphur separated from the reactor effluent into the reactor in such a way that a concentration of elemental sulphur of at least 1 g/l is maintained in the reactor. The sulphur, in the form of aggregates, is used as a carrier material for the sulphide-oxidizing bacteria.

Abstract: A reactor for the biological treatment of water comprises a reactor vessel (1), a fermentation chamber (3) bounded in the vessel, inlets (10) for introducing influent into the fermentation chamber, a settling chamber (4) above the top boundary (2) of the fermentation chamber (3), for separating out sludge from treated water, a downer (5) extending downwards from the settling chamber through the fermentation chamber, for returning separated-out sludge to the fermentation chamber (3), and an outlet (11) for discharging effluent from the settling chamber. In order to improve and accelerate the separation of sludge from effluent in a simple manner, at least one supply line (8a, 9a, 17) opens out tangentially into the settling chamber. A whirlpool is produced in the settling chamber by the supply line.

Abstract: The invention provides a method for removing sulphur compounds from water which contains low levels of organic matter, by anaerobic reduction of the sulphur compounds to sulphide, followed by partial oxidation of the sulphide to elementary sulphur.

Abstract: A system for purifying nitrogenous waste water by biological nitrification and denitrification, comprises at least two essentially separated reactor chambers, a liquid supply (4) and a liquid discharge (5). The first, aerated reactor chamber (1) is provided at the top with an overflow to the second, oxygen-depleted reactor chamber (2). The oxygen-depleted reactor chamber (2) is divided at the top into a degassing chamber (7) and a settling chamber (8) having an overflow (9) to the liquid discharge. The first reactor chamber is provided with an air supply (11, 18) and an air discharge (12) located above the supply. The first reactor chamber may be partly divided into a riser (14) and a downcomer (15) which allow, as a result of the air supply, mass circulation to take place in the aerated reactor chamber.

Abstract: The invention provides a method for removing sulphur compounds from water by anaerobic reduction of the sulphur compounds to sulphide, followed by a partial oxidation of the sulphide to elementary sulphur. The anaerobic reduction is carried out at elevated temperature, either continuously at a temperature of 45.degree.-70.degree. C., or periodically at a temperature of 55.degree.-100.degree. C. If the reduction is carried out periodically, a single rise in temperature for a few hours to several days over a period of 3-6 months can suffice. The method is particularly applicable to the removal of sulphate, sulphite and thiosulphate.

Abstract: A process is provided for the treatment of water containing sulphide wherein the sulphide is oxidized in an aerobic reactor having a minimum sulphide sludge load. The minimum sulphide load is at least 10 mg of sulphide per mg of the nitrogen present in the sludge per hour, the sludge load being calculated on the basis of the sulphide oxidizing part of the biomass. The minimum sulphide load may also be defined as 25 mg of sulphide per liter of reactor material per hour. The sulphide can be largely oxidized to elemental sulphur which is then separated and reused. Waste water also containing organic matter in addition to varying levels of sulphide is purified without interference of filamentous bacteria using a two-step aerobic process. The process for sulphide removal can be used for the treatment of waste water having high levels of sulphur compounds such as sulphate, sulphite and thiosulphate by first reducing these sulphur compounds in an aerobic step.

Abstract: The invention relates to a process for the biological treatment of essentially solid organic material, such as fruit, vegetable and garden waste, wherein the material is successively treated in a hydrolysis tank and in an anaerobic methane reactor, and at least a part of the solids issuing from the hydrolysis tank is treated in a second anaerobic reactor with at least one a microorganism of the rumen flora of ruminants; the liquid soluble material produced in the second reactor is further treated in the methane reactor. The material is preferably pretreated mechanically in a destructor. The invention furthermore provides an apparatus for carrying out this process.

Abstract: A process is provided for the treatment of water containing sulphide wherein the sulphide is oxidized in an aerobic reactor having a minimum sulphide sludge load. The minimum sulphide load is at least 10 mg of sulphide per mg of the nitrogen present in the sludge per hour, the sludge load being calculated on the basis of the sulphide oxidizing part of the biomass. The minimum sulphide load may also be defined as 25 mg of sulphide per liter of reactor material per hour. The sulphide can be largely oxidized to elemental sulphur which is then separated and reused. Waste water also containing organic matter in addition to varying levels of sulphide is purified without interference of filamentous bacteria using a two step aerobic process. The process for sulphide removal can be used for the treatment of waste water having high levels of sulphur compounds such as sulphate, sulphite and thiosulphate by first reducing these sulphur compounds in an aerobic step.

Abstract: A process for the removal of sulphur compounds from a gaseous effluent, comprising the steps of: a) contacting the gaseous effluent with an aqueous solution wherein sulphur compounds are dissolved; b) adjusting the concentration of buffering compounds such as carbonate and/or bicarbonate and/or phosphate in the aqueous solution to a value between 20 and 2000 meq/l; c) subjecting the aqueous solution containing sulphide to sulphide-oxidizing bacteria in the presence of oxygen in a reactor wherein sulphide is oxidized to elemental sulphur; d) separating elemental sulphur from the aqueous solution; and e) recycling the aqueous solution to step a). This process is suitable for removing H.sub.2 S from biogas, ventilation air etc. It can be used for removing SO.sub.2 from combustion gases by introducing the additional step, after step a) and before step c), of subjecting the aqueous solution containing the sulphur compounds to a reduction of the sulphur compounds to sulphide. H.sub.2 S and SO.sub.

Abstract: A bioreactor comprising a reactive vessel having an inlet system for material and a reaction chamber located above the inlet system. The inlet system has outflow openings that are at least partially tangentially oriented. A partition separates the reaction chamber from a chamber in which the inlet system is disposed, and the partition has at least one radial slit formed by two radial edge strips overlapping one another and vertically spaced apart. This slit interconnects the chamber in which the inlet system is disposed and the reaction chamber. The partition consists of at least two segments partially overlapping one another. The partition is substantially conical.