Abstract: In connection with processes for conditioning soft water (pH less than/equal to 6) to become drinking water, it is necessary to supply hardening agents in order to raise the carbonate-dissolving pH value into the neutral range. Subsequently the turbid materials are flocculated out and the flocculation products are filtered off. Finally, the calcite equilibrium must be set by means of a renewed addition of a hardening agent. This process is simplified by means of the invention in that the calcite equilibrium by means of the supply of highly pure lime water is only set after filtering off the flocculation products. In the flocculation stage, highly pure lime water is also preferably employed for setting the flocculation pH value.

Abstract: In UASB-type biogas reactors, the biogas is separated from the rising waste water stream by collection hoods arranged in staggered fashion, in which a zero pressure level is maintained, at which the gas transition takes place. In cross-section shapes of existing collection hoods, the zero pressure surface is sharply reduced when the water level is high, and the conversion to gas is correspondingly sharply reduced. Therefore, in accordance with the invention, a rectangular section shape is employed in which the zero pressure surface remains unchanged. The topside of the collection hoods can be formed as a smooth sliding surface in the shape of a roof for the anaerobic sludge sediment.

Abstract: In a suspension and guidance mechanism for the filter plates of a filter press, where the dollies (1) that carry filter plates (3), each dolly with two rollers (4, 5) that are staggered with respect to each other in the direction of movement and are positioned on two rails (8, 9), and that move along the rails by a transport device located between the running rollers, the derailment of the dollies is prevented in that, laterally, next to the rollers (5) that move in the direction of transport, there is a guide bar (15) or that these rollers (5) have an enlarged wheel flange (16), whereby the height of the guide bar (15) or of the wheel flange (16) is greater than the lifting movements of the roller (5) away from rail (9), caused by plate adhesion during the acceleration of the dollies.

Abstract: The waste water which is discharged from the anaerobic treatment stages of biological waste water treatment plants still contains highly volatile organic substances which, if not biodegraded, escape into the ambient air and lead to unwelcome odors. Also, the exhaust air of the anaerobic treatment stage may contain such highly volatile substances. An escape into the ambient air can be prevented if the waste water which is discharged from the anaerobic treatment stage is aerated with exhaust air sucked off from the anaerobic stage and if this exhaust air, after the aeration, is then fed to a spray washer and compost filter. The water for the spray washer is taken from the discharge of the anaerobic stage and returns there.

Abstract: When adding flocculant to a sludge suspension, which will be dewatered, within a pressure pipe between a feed pump and a dewatering equipment, the distance between the dosing point and the inlet of the dewatering equipment will be modified during operation, e.g. by displacing a lance carrying a dosing head within the sludge pipe or by selectively operating a number of dosing points being positioned at different distances to the dewatering equipment. In this way it is possible to adjust most optimally the retention time being available for the formation and consolidation of floc particles with regard to the present operation conditions and the type of added flocculant.

Abstract: A module for a UASB (upflow anaerobic sludge blanket) reactor for anaerobic waste water treatment comprises an overflow threshold for the treated waste water that determines the water level in the module. Several immersed collection domes are provided for the digester gas which are staggered over the entire module cross-section and possess a drain into a collection pipe and an upper evacuation line for the waste air collecting above the water level. All walls, covers and installation parts of the module are made of plastic, if necessary reinforced with steel profiles, and are welded to each other. Also, all drains end at a narrow side of the module where they are connected in a gas-tight manner with discharge ducts which have been installed there along several modules and which may be closed off in sections.

Abstract: The new floating sludge evacuating unit for circular tanks having a drain, and a scraper blade movable in relation thereto is characterized in that the scraper blade is lifted repeatedly in order to evacuate the tank surface by sections, advanced to a position remote from the drain where it is stopped and lowered, while the drain follows the scraper blade and pushes the floating sludge together, and that prior to the lowering motion causing the floating sludge to be evacuated a push-down unit causes the intake edge of the drain to be pre-lowered to a position which takes the level in the tank into account. Then, the lowering path for floating sludge evacuation will always be correct, and evacuation of water will be avoided. A scraper blade interacting with several stationary drains is operating according to the same principle. It is lowered behind every drain and pushes the floating sludge toward the next drain.

Abstract: A chamber filter press for dewatering waste water or product sludges, comprises a press frame with a number of filter plates movably attached at the head bracket and a crosshead that is hydraulically movable for closing the filter plate bundle. The hydraulic cylinder is supported by a replaceable receptacle device in the form of a flange pipe on the end stand of the press frame. Both flanges of the tubular receptacle device are annular flanges, with dimensions matching the flange of the hydraulic cylinder and they have identical through-bores. The flanges are permitted to pass through the hydraulic cylinder and the end stand has on the attachment side a through-hole for the hydraulic cylinder. The receptacle opening has on the opposite side an installation opening through which the back end of the hydraulic cylinder passes.

Abstract: A device for extending the operable range of a hydraulic cylinder in a filter press is disclosed herein. The filter press includes an overhead beam, first and second end stands connected to respective ends of said beam, a plurality of filter plates movably suspended from said overhead beam between the end stands, and a follower movably mounted and suspended from said overhead beam. The second end stand includes a guide bush and a flange for removably attaching a hydraulic cylinder therein. The device for extending the range of the hydraulic cylinder includes a tube dimensioned to receive the hydraulic cylinder therein, the tube including a shaft at one end thereof receivable in the guide bush, the shaft including a flange extending thereabout to bear against the flange of the guide bush, and a flange extending about the other end of the tube to bear against the flange of the hydraulic cylinder.

Abstract: A method of thermal disposal of sewage sludge. The sludge is dried and incinerated. The flue gases from the incineration are washed. The flue gas dust resulting from the incineration and the sludge resulting from washing of the flue gases are treated together with high temperature combustion which includes melting of solids.

Abstract: A new apparatus for extracting water from product or sewage sludge on the spot is provided. It is characterized by a frame matched to the dimensions of a low loader and having lifting supports which can be pivoted in and out and which have multi-step vertical adjustability. Filter presses of substantially higher capacity than those on known apparatuses employing a semitrailer can be used.

Abstract: Phosphates which are dissolved or contained in suspension are substantially completely removed from a low-solids waste water which has been clarified. Precipitating and flocculating agents for transforming the dissolved phosphated to an undissolved form are added to the low-solids wate water and precipitation products and suspended matter are removed by microsieving through mesh openings in the range of about 10 to 150 .mu.m. Microsieving is preferably effected in two stages including a preliminary sieving through mesh openings from 60 to 150 .mu.m and a fine sieving through mesh openings from 10 to 80 .mu.m.

Abstract: To improve the dewaterability of sludge, which is dewatered in a dewatering device, in particular a plate filter press, a polymeric filter aid is added to the sludge. Since the flocs require a certain ripening time to form, a part stream of the unfiltered sludge is to be taken off according to the invention at the point opposite the feed and recycled into the main stream. The recycled flocs serve as flocculation nuclei. A further advantage of the sludge recycle is that the floc structure and/or size can then be scanned in the recycled part stream. The representative measured results are utilized for changing parameters which determine the dewaterability.

Abstract: The plate filter press is designed for removing water from product and sewage sludges and includes several filter plates displacably suspended on horizontal carriers. Each of the filter plates includes grooves formed thereon leading to outlet openings located in corners of the plates. The grooves are covered by a filter cloth stiffened by a supporting fabric. Each of the corners further includes a stopper inserted into the outlet opening of the corner with each of stopper provided with a plate-like cover member and a through opening to allow filtrate to pass under the cover member and through the outlet opening. The filter cloth and the supporting fabric are secured in relation to the cover member of the stopper such that, in use, the outlet opening of the plate will remain unclogged.

Abstract: During conditioning of a suspension to be dewatered through incorporation of flocculant, the optimum dewaterability depends on the amount of added flocculant and on the mixing energy expended. According to the invention, the sludge flocs present or formed in the suspension after incorporation of the flocculant are determined metrologically, and the amount of flocculant and/or the mixing energy expended and/or the location of flocculant addition is controlled as a function of the floc number, size and/or structure.

Abstract: The invention relates to filter plates of plate filter presses, particularly for freeing sewage sludge from water.The problem of premature failure of the filter cloth is overcome in that the filter cloth is fastened only at some of the support bosses surrounding the central inlet opening and is laid loose over the other bosses. Excessive bulging of the filter cloth when the cake is thrown off is thereby avoided. The filter cloth may be held by a subsequently fastened boss or by a cap engaging over the boss.

Abstract: Water, especially waste water, from which organic compounds such as, in particular, halogenated hydrocarbons are to be separated by extraction using a lipophilic extraction agent is passed through an open-cell carrier of large internal contact surface area in which the extraction agent is deposited on the contact surface and/or floods the carrier over at least part of its height to form a continuous liquid layer.

Abstract: In order to enlarge the size of the filter plates of a plate filter press without prejudicing the handling of the filter plates, an additional filter plate is arranged beneath each filter plate and is connected to this uppermost filter plate by members, such as by articulated connecting elements. Suspension and guide means are provided only for the uppermost filter plates.

Abstract: Filter apparatus embodying a filter bed back-washing unit comprising a raisable and lowerable suction bell, the side walls of which define division walls to compart the respective partial volume of the filter bed to be cleaned. The side walls of the suction bell are of a height at least equal to the height of the filter bed, and the suction bell is raisable and lowerable by a stroke length which corresponds at least approximately to this height.

Abstract: A filter press with filter plates slidable individually by a transport element has on each filter plate a locking hook which cooperates for locking with a locking bolt of the adjacent filter plate. A pivotable blocking element, which in the blocked position, positively blocks the locking hook locking this filter plate against unlocking and is connected to an actuating member which projects into the path of the transport element so that immediately before the latter takes along the relevant filter plate it engages the actuating member and thus pivots the blocking element into a release position so that the filter plate is separable after release of the locking hook. Each respective filter plate to be slid thus remains positively locked to the as yet unopened plate stack until immediately before it is taken along by the transport element and cannot become separated from the stack accidentally.