Apparatus and method for cleaning membrane filtration modules

A membrane module, the membrane module comprising:

• a source of a cleaning liquid, the cleaning liquid comprising a cleaning chemical;
• a source of a gas;
• a first header, the first header having one or more holes formed therein through which the gas and the liquid are introduced;
• a second header;
• a plurality of porous hollow fiber membranes, the porous hollow fiber membranes being arranged in close proximity and mounted to prevent excessive movement therebetween, the porous hollow fiber membranes being fixed at a first end in the first header and at a second end in the second header;
• and
• a junction, wherein the junction is connected to the first header, the source of the gas, and the source of the cleaning liquid.

A membrane bioreactor comprising:

• a source of a cleaning liquid comprising a cleaning chemical;
• a source of a gas;
• a membrane module, the membrane module comprising a first header, the first header having one or more holes formed therein through which the gas and the liquid are introduced;
• a second header;
• and a plurality of porous hollow fiber membranes, the porous hollow fiber membranes being arranged in close proximity and mounted to prevent excessive movement therebetween, the porous hollow fiber membranes being fixed at a first end in the first header and at a second end in the second header, the membrane module provided with means for withdrawing a filtrate from at least one end of the fiber membranes;
• a junction, wherein the junction is connected to the first header of the membrane module, the source of the gas, and the source of the cleaning liquid;
• a tank having means for introducing the cleaning liquid, wherein the membrane module is positioned within the tank so as to be immersed in an activated sludge;
• and
• means for forming the activated sludge within the tank.

A method of operating a membrane bioreactor, the method comprising the steps of:

• providing a membrane module comprising a plurality of porous hollow membrane fibers mounted at a first end to a first potting head and at a second end to a second potting head and extending longitudinally between the potting heads, the membranes having a plurality of pores, the membrane fibers being arranged in close proximity to one another and mounted to prevent excessive movement therebetween, the fibers being partitioned into one or more bundles at least at or adjacent to one of the potting heads so as to form a space therebetween, at least one of the potting heads having an array and a connection to a junction, wherein the junction is connected to a gas source and a source of a liquid comprising a cleaning chemical, the junction providing within the module, through a plurality of aeration openings formed in the array, a plurality of gas bubbles entrained within the liquid, such that, in use, the gas bubbles move past outer surfaces of the membrane fibers to dislodge fouling materials therefrom;
• providing a tank, wherein the membrane module is at least partially immersed in the tank;
• introducing a feed to the tank;
• and
• applying a vacuum to the fibers to withdraw a filtrate therefrom while periodically or continuously supplying a plurality of gas bubbles through the aeration openings to within the module such that, in use, the gas bubbles move past the outer surfaces of the membrane fibers to dislodge fouling materials therefrom.

A membrane bioreactor comprising:

• a tank having a feed inlet;
• a source of oxygen for forming an activated sludge within the tank;
• a source of a gas;
• and
• a membrane module, the membrane module comprising a first header, the first header having one or more holes formed therein through which the gas and the liquid are introduced;
• a second header;
• and a plurality of porous hollow fiber membranes, the porous hollow fiber membranes being arranged in close proximity and mounted to prevent excessive movement therebetween, the porous hollow fiber membranes being fixed at a first end in the first header and at a second end in the second header;
• a junction, wherein the junction is connected to the first header, the source of the gas, and the source of the cleaning liquid;
• the membrane module positioned within the tank so as to be immersed in the sludge, and the membrane module provided with a pump for withdrawing a filtrate from at least one end of the fiber membranes.