Water treatment apparatus, including: a ceramic filter; and a flow apparatus operable to pass water through the ceramic filter in a forward direction so as to filter the water, the flow apparatus also operable to pass water through the ceramic filter in a reverse direction so as to remove material from the ceramic filter, whereby material having been deposited by filtration of the water is removed.

A water filtration system is provided comprising first and second banks of water filter assemblies, wherein the system is arranged to provide filtered water from one bank of water filter assemblies while using some of the filtered water to reverse flush the other bank of water filtration assemblies. A method of filtering water by passing it through the system is also provided.

a filtering method, with which a fluid to be filtered is led through a filter (4), the filter (4) is back-flushed at regular time intervals and a pre-treatment agent is added to the fluid at the entry side of the filter. A process variable which describes the efficiency of the filtration is continuously computed during the filtration, and a metering quantity of the pre-treatment agent is reset on the basis of the values for the process variable or a characteristic values derived from this.

A process and system for cleaning semipermeable membranes is described that is particularly well suited for cleaning membranes contained in a water purification system, such as a reverse osmosis process. In order to clean the filter membranes, the membranes are placed in a cleaning chamber capable of allowing a reduction in pressure. In one embodiment, for instance, the membranes are contained in a filter housing and the filter housing is converted into a cleaning chamber by sealing off at least one end. The membranes are then submerged in a cleaning fluid and the pressure within the cleaning chamber is reduced causing the cleaning fluid to form bubbles. The process and system of the present disclosure is well suited to cleaning filter membranes, particularly ceramic membranes, in-line without having to remove the membranes from the water purification system.

A method of filtering a fluid with components includes providing an alternating pressure. The alternating pressure yields an oscillating transmembrane pressure through volume and pressure variations within a filtration chamber while sealing the filtration chamber. A separation surface can be housed in the filtration chamber wherein an influent is introduced. Components can be concentrated on the separation surface, effectively removing some or all of them from the fluid. To flush the filtration chamber and separation surface, a backwash fluid and components can be introduced and removed from the filtration chamber. While both the components are being concentrated and backwashed, the system can maintain the oscillating transmembrane pressure and varying volume and pressure relative to the separation surface.

A filtration system can comprise a pressure pump configured to apply a pressure on fluid flowing between a first chamber and a second chamber. The filtration system can also comprise a flow sensor configured to determine at least one parameter associated with fluid flowing across a membrane deposited between the first chamber and a second chamber. The filtration system can comprise a pressure sensor configured to determine pressure readings of the fluid flowing from the first chamber to the second chamber. The filtration system can comprise a filtration management system configured to cause the pressure pump to apply a constant pressure on fluid flowing across the membrane for a first predetermined time based on the pressure reading. The filtration management system can be configured to cause the pressure pump to reverse the fluid flow across the membrane.

A filtration system for liquid, particularly raw water, having at least one filtration module for filtering the liquid, a first inlet pipe for feeding liquid to the filtration module, a second inlet pipe for feeding liquid to the filtration module and at least one outlet pipe for discharging filtrate from the filtration module. A cleaning branch is arranged between the first inlet pipe and the second inlet pipe, and at least one dosing feeder for adding a cleaning chemical is connected to the cleaning branch. Additionally, a method for chemically rinsing such a filtration, wherein a cleaning chemical is added via a dosing feeder connected to a cleaning branch which is arranged between the first inlet pipe and the second inlet pipe.

A conventional media filter such as a gravity sand filter is converted into a membrane filter. The media is removed and replaced by immersed membrane modules. Transmembrane pressure is created by a static head pressure differential, without a suction pump, thereby creating a membrane gravity filter (MGF). Preferred operating parameters include transmembrane pressure of 5-20 kPa, 1-3 backwashes per day, and a flux of 10-20 L/m.sup.2/h. The membranes are dosed with chlorine or another oxidant, preferably at 700 minutes*mg/L as Cl.sub.2 equivalent per week or less. The small oxidant does is believed to provide a porous biofilm or fouling layer without substantially removing the layer. The media filter may be modified so that backwash wastewater is removed from near the bottom of the tank rather than through backwash troughs above the membrane modules. Membrane integrity testing may be done while the tank is emptied after a backwash.

The purpose of this invention is to provide a filtration membrane module with which is possible to improve the centrifugal separation effect of the primary-side flowpath during filtration, and the centrifugal separation effect of the area following the outer peripheral surface of the flowpath membrane element of the outer ring-shaped flowpath during backwash, and improve filtration efficiency and cleaning efficiency while curbing the accumulation of deposits on the membrane surface during filtration and during backwash. This filtration membrane module comprises: a membrane element equipped with a primary-side flowpath on the outside of a hollow cylindrical filtration surface; and a cylindrical housing positioned on the outside thereof. A flow adjuster is positioned inside the primary-side flowpath. A flow adjuster for backwash is positioned inside the secondary-side flowpath, which is an outer ring-shaped flowpath between the membrane element and the housing. The flow adjuster and the flow adjuster for backwash comprise spiral-shaped fins or the like in order to exhibit a centrifugal separation function in an area that follows the outer peripheral surface of the membrane element or the filtration surface.

A filtration system has a filter element with a filtration membrane, a feed inlet and a concentrate outlet on a first side of the membrane and a permeate outlet on a second side of the membrane. A feed line with a feed shutoff valve is in fluid communication with the feed inlet, and a concentrate return line with a concentrate shutoff valve is in fluid communication with the concentrate outlet. A feed pump is in fluid communication with the feed inlet via the feed line and the feed shutoff valve, and a backwash pump is in fluid communication with the permeate outlet. In a priming phase of a backwash operation, the feed shutoff valve and the concentrate shutoff valve are closed and the backwash supply is operable to deliver fluid to the filtration element and equalize pressure between the first side and the second side of the filtration membrane.