Submerged membrane unit with single drop aeration

A water treatment system, comprising:

• a clarifier stage;
• a submerged membrane unit disposed within the clarifier stage, the submerged membrane unit comprising:
• a housing having a top side, a bottom side opposed to the top side, and at least one wall disposed between the top side and the bottom side, wherein the wall forms at least a partially enclosed space inside the housing;
• a membrane mounted to the wall inside the housing, the membrane comprising a set of capillaries having one or more pores that are configured to filter out particulates of pre-determined size from a permeate that passes into the capillaries when the membrane is submerged underwater;
• a plurality of connecting lines connecting set of capillaries to a permeate manifold disposed at least partially around the wall along the top side of the housing, wherein the permeate flows through the set of capillaries in a direction from the bottom side to the top side and is removed from the membrane at the top side of the housing via the permeate manifold;
• a drop pipe disposed inside the housing and through the membrane, the drop pipe having a proximal end and a distal end, the distal end being closer to the bottom side than the proximal end;
• and
• a diffuser connected to the distal end of the drop pipe;
• and
• a gas pump connected to the drop pipe and configured to pump gas through the drop pipe.

A method of treating water using a submerged membrane unit, comprising:

• submerging the submerged membrane unit in wastewater, wherein the submerged membrane unit comprises:
• a housing having a top side, a bottom side opposed to the top side, and at least one wall disposed between the top side and the bottom side, wherein the wall forms at least a partially enclosed space inside the housing,
• a membrane array mounted to the wall inside the housing, the membrane comprising a set of capillaries having one or more pores that are configured to filter out particulates of pre-determined size from a permeate that passes into the capillaries when the membrane is submerged underwater,
• a plurality of connecting lines connecting set of capillaries to a permeate manifold disposed at least partially around the wall along the top side of the housing, wherein the permeate flows through the set of capillaries in a direction from the bottom side to the top side and is removed from the membrane at the top side of the housing via the permeate manifold,
• a drop pipe disposed inside the housing and through the membrane array, the drop pipe having a proximal end and a distal end, the distal end being closer to the bottom side than the proximal end, and
• a diffuser connected to the distal end of the drop pipe, wherein the drop pipe and the diffuser extend into the water;
• and
• pumping a gas through the drop pipe and through the diffuser into the water such that bubbles emerging from the diffuser rise through the membrane array before reaching a surface of the water.