Abstract: A wastewater treatment system using aerobic granules has a large number of sequencing batch reactor tanks with high volumetric exchange rate, a variable cycle length and constant batch volume. The batch reactors are operated for C, N removal and P is removed chemically, optionally under BioP enhanced conditions. SS are removed in a downstream separation step.

Abstract: A static screen used upstream of a membrane assembly within a water treatment system has a screening surface with a number of openings distributed over its area. Liquid flows through the screening surface to reach the membrane assembly. Various shapes of screening surfaces are described including undulating panels and geometric shapes. Methods for cleaning the screen are described including aeration and backwashing. Various treatment systems or process designs incorporating the screen are described.

Abstract: A continuous flow reactor or method promotes aerobic granule formation. The reactor may comprise three or four zones that may comprise one or more of an aerobic zone, an alternately aerobic and anoxic zone or discrete aerobic and anoxic zones, and a settling zone. The reactor may have a single sludge removal flow. An anaerobic zone may be located at the bottom of a mass of settled granules. Feed may be introduced through the settled granules generally in a plug flow. An aerobic/anoxic zone may be structured or operated partially like a continuously stirred tank reactor (CSTR) but with aeration varying in space or time. Sludge granules may move intermittently from an aerobic zone to an aerobic/anoxic zone, for example by an air lift pump. A settling zone may have an upflow of >4 m/hr or >5 m/hr and wash off flocculated biomass.

Abstract: A process has steps of one or more of aerobic treatment to remove COD and nitrify a waste stream, anoxic treatment to denitrify a waste stream, anoxic treatment to remove selenium and anaerobic treatment to remove heavy metals and sulphur. The process may be used to treat, for example, FGD blow down water. The process may further include one or more of (a) membrane separation of the waste stream upstream of the anoxic digestion to remove selenium, (b) dilution upstream of the biological treatment step, (c) physical/chemical pretreatment upstream of the biological processes or dilution step to remove TSS and soften the waste stream, or (d) ammonia stripping upstream of the biological treatment steps or dilutions step. These processes may be provided in a variety of suspended growth or fixed film reactors, for example a membrane bioreactor or a fixed film reactor having a GAC bed.

Abstract: A filtration apparatus has a horizontally oriented permeate conduit supported on the floor of a tank. A module of filtering membranes may be placed on or over the permeate conduit and communicate with the permeate conduit. The module may be of a variety of configurations including one with vertically oriented hollow fibers. A permeate collector may be connected to the permeate conduit by a second permeate conduit. The connection may be made near the top of the module and may be through an isolation valve. The apparatus is suitable, among other things, for installation in a sand filter tank. Permeation may be by gravity flow. This abstract is not to be used to construe the claims.

Abstract: A process and apparatus is described for filtering water with immersed membranes. In a batch process, permeate is withdrawn while the flow of feed is reduced or stopped at the end of a permeation cycle. The water level is reduced to a level where a portion of the membranes are exposed to air before draining the tank. In this or another process, the level of liquid is reduced to correspond with an area of the membrane fibers having an accumulation of solids. Aeration is provided for a period of time with the liquid at this level to dislodge at least a portion of the solids from the membranes. In these or other processes, the tank is partially drained between cycles to deconcentrate the tank, aeration is provided during backwashing and intermittently while permeating, and/or retentate is withdrawn from the tank during a portion of a permeation step.

Abstract: An immersed membrane system or process may use measured or calculated process information to optimize one or more process operating parameters to improve performance or reduce operating costs. An on-line process control system or method may use the resistance in series method in operating an immersed membrane water treatment system. A process control system or process may consider resistance values and adjust operational parameters such as membrane aeration frequency factor, membrane aeration flow, permeate flux, permeation duration, backwash flow and duration, relaxation duration or maintenance or recovery chemical cleaning frequencies in order to reduce the operational costs related to membrane fouling removal.

Abstract: A system for extracting a liquid by pressing a humid mass, the system including at least one extraction channel, while extraction channel being provided with at least one inlet allowing to feed the extraction channel with the humid mass to be treated; with walls provided with holes allowing the flow of the liquid contained in the humid mass being pressed, and with at least one outlet allowing the discharge of the dehydrated mass obtained by pressing in the extracting channel, wherein the outlet of the channel, positioned between the walls provided with holes and the exterior, is free of contraints or only includes weak constraints whose level is controlled as a function of physical parameters. This systems is suitable for the efficient continuous dewatering treatment of a feeding source with a composition, consistency and nature of the solid particles present in the feeding source susceptible to vary during the processing.

Abstract: An aeration system for a submerged membrane module has a set of aerators connected to an air blower, valves and a controller adapted to alternately provide a higher rate or air flow and a lower rate of air flow in repeated cycles. In an embodiment, the air blower, valves and controller, simultaneously provide the alternating air flow to two or more sets of aerators such that the total air flow is constant, allowing the blower to be operated at a constant speed. In another embodiment, the repeated cycles are of short duration. Transient flow conditions result in the tank water which helps avoid dead spaces and assists in agitating the membranes.

Abstract: The invention relates to a method and an apparatus for encoding images, more particularly to an encoding unit in conjunction with a library of pictorial entities and image qualifiers. The method and apparatus provide encoding an image by using a code factor table in conjunction with a set of element codes. The resulting image code allows the set pictorial elements of an image and their associated image qualifiers to be represented by a compact code uniquely representing a given configuration of pictorial elements. The use of the resulting image code facilitates the transmission and storage of images requiring only the code to be sent or stored. The invention further provides a computer readable medium comprising a program element that direct a computer to implement the encoding process.

Abstract: The invention relates to a method and an apparatus for encoding images, more particularly to an encoding unit in conjunction with a library of pictorial entities and image qualifiers. The method and apparatus provide encoding an image by using a code factor table in conjunction with a set of element codes. The resulting image code allows the set pictorial elements of an image and their associated image qualifiers to be represented by a compact code uniquely representing a given configuration of pictorial elements. The use of the resulting image code facilitates the transmission and storage of images requiring only the code to be sent or stored. The invention further provides a computer readable medium comprising a program element that direct a computer to implement the encoding process.

Abstract: Modules of ultrafiltration or microfiltration membranes are arranged in a tank open to the atmosphere to substantially cover the cross sectional area of the tank. A filtration cycle has permeation steps and deconcentration steps. During permeation, supply of feed substantially equals feed removed and little if any aeration is used. During deconcentration, aeration with scouring bubbles is provided with one or both of backwashing and feed flushing. In feed flushing, feed water is supplied to the tank from below the modules. Excess tank water created during deconcentration flows generally upwards through the modules and out through a retentate outlet or overflow at the top of the tank.

Abstract: A membrane supported biofilm reactor uses modules having fine, hollow fibres, for example, made from melt spun thermoplastic polymers treated after spinning to increase their permeability to oxygen, used, for example, in tows or formed into a fabric. In one module, one or more sheets of the fabric are potted into a module to enable oxygen containing gas to be supplied to the lumens of the hollow fibres. Various reactors and processes, for example to treat wastewater, using such modules are described. In one process, oxygen travels through fibers, optionally through an attached biofilm, to oxygenate surrounding water. Mechanical, chemical and biological methods, for example endogenous respiration, are used to control the thickness of the biofilm.

Abstract: Various filtration processes using low amounts of aeration are disclosed. One process comprises a cycle of permeating and then backwashing, aerating, partially draining the tank and refilling the tank. Another process comprises steps of (a) permeating and withdrawing retentate; (b) after (a), backwashing; and (c) during (a), providing gentle aeration.

Abstract: This document describes a kit to integrate an immersed membrane into existing sand filters while minimizing changes to the existing plant. The kit is installed in-situ, optionally from all-plastic components that can be transported by a man, without the use of machinery. Permeate and air headers are built in-situ at the bottom of the sand filter tank. Modules are installed and removed from the top without having to disassemble any piping. Air (from degassing or after a membrane integrity test) is removed via the bottom through a fine tube inserted into the header. Modules can be installed without removing existing backwash channels. The retrofitted plant can be used with the existing feed inlet and filtrate outlets. The membrane modules produce a similar filtration rate to the existing sand filter to reduce the extent of any changes required to the remainder of the plant.

Abstract: An element for use in ultrafiltration or microfiltration of potable water has a large number of small diameter hollow fibre membranes attached between two headers. Side plates attached to the sides of the headers define vertical flow channels containing the membranes. The elements may be placed side by side and stacked on top of each other to form cassettes having continuous vertical flow channels through the entire cassette. The membrane modules or cassettes may be arranged to cover a substantial part of the cross sectional area of an open tank. Tank water may flow upwards or downwards through the flow channels. A tank may be deconcentrated by at least partially emptying and refilling the tank with fresh water while permeation continues. Excess tank water created during deconcentration may flow generally upwards through the modules and out through a retentate outlet or overflow at the top of the tank.

Abstract: A process for operating filtering membranes submerged in a tank involves, in one aspect, periodically deconcentrating the tank by partially emptying and refilling the tank with fresh water. The emptying and refilling may be performed generally simultaneously or sequentially. In another embodiment, the membrane modules are arranged in a series of filtration zones between a feed water inlet and a retentate outlet of a tank and the zone adjacent the outlet is emptied and refilled.

Abstract: A process for operating filtering membranes submerged in a tank involves, in one aspect, periodically deconcentrating the tank by partially emptying and refilling the tank with fresh water. The emptying and refilling may be performed generally simultaneously or sequentially. In another embodiment, the membrane modules are arranged in a series of filtration zones between a feed water inlet and a retentate outlet of a tank and the zone adjacent the outlet is emptied and refilled.

Abstract: A reactor has an aerobic tank, an anoxic tank and a sealed membrane tank with conduits for circulating mixed liquor between them. Permeation starts when the mixed liquor reaches a high level and stops when the mixed liquor reaches a low level. A sensor, for detecting the mixed liquor level, may stop and start permeation. Pressure builds in the membrane tank when membrane air is on. Transmembrane pressure is also provided by gravity flow or siphon. Membrane air generates an air lift which drives the mixed liquor circulation. The total amount of air provided by an air source is divided and varied in time between the membrane aerator and the process aerator. The process aerator acts as a screening inlet to the conduit to the membrane tank. Chemical maintenance cleaning is provided by gravity flow.

Abstract: A method of chemically cleaning normally immersed suction driven filtering membranes involves backwashing a chemical cleaner through the membranes while the tank is empty in repeated pulses in which the chemical cleaner is pumped to the membranes separated by waiting periods in which chemical cleaner is not pumped to the membranes. The duration and frequency of the pulses is preferably chosen to provide an appropriate contact time of the chemical, preferably without allowing the membranes to dry between pulses and without using excessive amounts of chemical. In other aspects, such membranes preferably used for filtering water to produce potable water in a batch process are backwashed with a chemical cleaner substantially at the same time as the tank is being drained. The chemical cleaner is optionally supplied in pulses.