Zenon Environmental Inc.

Bl Technologies, Inc.

General Electric Company

Jason Cadera

Pierre Lucien Cote

Steven Kristian Pedersen

Arnold Frederic Janson

Nicholas Adams

Nicholas William H Adams

Nicholas William Harcsar Adams

Hua Wang

Zamir Alam

Jose Luis Plasencia Cabanillas

Daniella B Mosqueda-Jimenez

Nicholas William Adams

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/h. The membranes are dosed with chlorine or another oxidant, preferably at 700 minutes*mg/L as Clequivalent 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.

Conversion of media filter into membrane gravity filter

A method of producing purified water in a subsurface environment is provided in which ambient subsurface source water is introduced into and through one or more ultrafiltration membrane units of a subsurface water treatment system and producing thereby an ultrafiltrate substantially free of solid particulates having a largest dimension greater than 0.1 microns. An electrochemical unit in fluid communication with at least one ultrafiltration membrane unit provides an antifoulant solution. An ultrafiltrate-rich backwash fluid and at least a portion of the antifoulant solution are delivered to at least one non-producing ultrafiltration membrane unit during a backwash cycle. A flux of source fluid through each of the ultrafiltration membrane units of less than thirty gallons per square foot per day limits the need for backwash cycles. A reduction in the number of backwash cycles enhances system autonomy and useful life, and limits the need for intervention for maintenance and component replacement.

Subsurface water purification method

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.

Immersed membrane filtration system and overflow process

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.

In an apparatus for providing a continuous integrity test for suction driven filtering membrane assemblies a monitoring line diverts a portion of permeate to a monitoring device (e.g. a turbidimeter). Both ends of the monitoring line are connected to the permeate pipe upstream from the permeate pump and at points of relatively higher and lower pressures respectively, to cause fluid to flow through the monitoring line. The relatively higher and lower pressures may be caused by a source of head loss (e.g. a valve) in the permeate line. The source of head loss may be adjusted to provide a required flow through the monitoring device by a control communicating with a flow meter in the monitoring line. Membrane assemblies may be individually monitored although many of them may be connected to a common permeate pump (FIG. 2).

Growing community of inventors

Guelph, Canada

Jason Cadera