Vacuum air lift systems including a fluidic oscillator

A vacuum airlift system for treating an aqueous effluent comprising:

• a. an upflow liquid column, the upflow liquid column having a top and a bottom, a vertical orientation, a diameter and a height, wherein the upflow liquid column is configured to retain a fluid;
• b. a fluid inlet, the fluid inlet being fluidly coupled with the upflow liquid column, wherein the fluid inlet is positioned at about the bottom of the upflow liquid column;
• c. a first aerator, the first aerator being fluidly coupled with the upflow liquid column, wherein the first aerator is operably configured to deliver a gas phase to the upflow liquid column such that a plurality of bubbles are formed within the upflow liquid column, wherein the first aerator is fed by a fluidic oscillator;
• d. a downflow liquid column, the downflow liquid column having a top and a bottom, a vertical orientation, a diameter, and a height;
• e. a fluid outlet, the fluid outlet being fluidly coupled with the downflow liquid column, wherein the fluid outlet is positioned at about the bottom of the downflow liquid column;
• f. a gas headspace above the top of the upflow liquid column;
• g. an offgas stream fluidly coupled with the gas headspace;
• and
• h. a vacuum pump, wherein the vacuum pump is operably configured to create a vacuum in the gas headspace.

A vacuum airlift system for treating an aqueous effluent comprising:

• a. an upflow liquid column, the upflow liquid column having a top and a bottom, a vertical orientation, a diameter and a height, wherein the upflow liquid column is configured to retain a fluid;
• b. a fluid inlet, the fluid inlet being fluidly coupled with the upflow liquid column, wherein the fluid inlet is positioned at about the bottom of the upflow liquid column;
• c. a first aerator, wherein the first aerator is operably configured to deliver micro-bubbles to the fluid;
• d. a second aerator, wherein the second aerator is operably configured to deliver macro-bubbles to the fluid;
• e. a fluidic oscillator feeding the first aerator or the second aerator;
• f. a downflow liquid column, the downflow liquid column having a top and a bottom, a vertical orientation, a diameter, and a height, wherein the diameter of the downflow liquid column is greater than the diameter of the upflow liquid column, and wherein the height of the upflow liquid column is greater than the height of the downflow liquid column;
• g. a fluid outlet, the fluid outlet being fluidly coupled with the downflow liquid column, wherein the fluid outlet is positioned at about the bottom of the downflow liquid column;
• h. a gas headspace above the top of the upflow liquid column, wherein the gas headspace is defined at least partially by a cap;
• i. an offgas stream fluidly coupled with the gas headspace;
• j. a vacuum pump, wherein the vacuum pump is operably configured to create a vacuum in the gas headspace;
• and
• k. an evacuation tank associated with the offgas stream.