What is Degassing? Degassing is removing dissolved gases from liquids. Applications includes: Removing biogenic hydrogen sulfide from groundwater, used for drinking water Removing carbon dioxide from water used for regenerating ion exchange resins Removal of dissolved oxygen from boiler feed water Removing ammonia from wastewater

Traditional Degassing Methods Traditional methods of degassing have involved heating, turbulence, spraying under reduced pressure, or stripping with other gases. Problems includes: Requires number of pieces of equipment; Degassing efficiency is usually low, without considerable energy consumption; Usually creates additional stream, which has substantial flow, and needs further treatment

Traditional Degassing Methods continued Traditional Stripping Towers with Packing Media Disadvantages Large footprint and significant energy consumption in gas blower and recycle pump for liquid; Clogging of packing media due to precipitation of salts, Biological growth, requiring chemical cleaning; Post treatment of exhaust gas containing the contaminant- Hydrogen sulfide/ammonia/volatile compounds; Large gas flow that requires further treatment; and Significant investment and operating costs

What is Membrane Degassing? VACUUM SIDE WATER SIDE WITH DISSOLVED HYDROGEN SULFIDE/ AMMONIA GAS DISSOLVED HYDROGEN SULFIDE/ AMMONIA GAS PHASE HYDROGEN SULFIDE/ AMMONIA DENSE MEMBRANE POROUS MEMBRANE

Advantages of Membrane Degassing Compact system capable of treating large flows Very Efficient – Efficiency is high due to large surface areas Low Energy Consumption Creates small flows of contaminant (dissolved) gas, which can be easily handled Investment and operating costs significantly lower than the traditional stripping tower and post treatment systems

MEMBRANE DEGASSING SYSTEM Uses spiral wound, pleated-membrane cartridges, that can be easily changed in the field Depending on the application, these membrane cartridges can last 3-7 years, with minimal maintenance Compact footprint compared to stripping towers Reliable operation with no operator intervention Very cost-effective compared to other degassing methods

Removing Biogenic Hydrogen Sulfide from Well Water Biogenic hydrogen sulfide is formed by natural soil bacteria converting dissolved sulfate to sulfide SO CH 2 O  HS - + 2HCO H + Sulfate Sulfide Organic Carbon This sulfide dissolves in the water, making the well water smell of “rotten eggs” and taste bad

Traditional Aeration Methods

Tray Aerators Create H 2 S Ground Water Collection Pan Treated Water Ambient Air Draft Biofilm Growth on Pollution organics in Ambient air Biofilms grow on the surface of the tray, converting sulfate to sulfide, so the dissolved sulfide in the treated water is higher than in the feed

Membrane Degassing System System degassifies 300 gpm of drinking water to remove dissolved Hydrogen sulfide; Footprint is 52 in x 26 in x 26 in (ht)

Performance Data Havana Test Results for Membrane Degassifier Supplier: PRD Tech, Inc. MeasurementTest 1Test 2Test 3 Inlet water sulfide (ppm) Sulfide Conc. after Membrane Degassifier pH of water Water Temperature (deg C)25.4 Sulfide after Tray Aerator (ppm)2.4 % Removal Efficiency for Degassifier83%85% % Removal Efficiency for Tray Aerator-4%

Performance of Membrane Degassifier

Fort Drum Membrane Degassifier

Applications of Membrane Degassification Makes traditional Packed Gas Absorption and Gas Stripping towers obsolete; Gas Absorption is the opposite of Degassification; Degassification system has significant lower investment and operating costs than traditional stripping towers and tray aerators; Membrane Degassification has a significantly higher efficiency than a traditional packed tower, because the membrane contact area is significantly larger than any known packing material; Membrane Degassifiers have a very compact footprint and post treatment of a concentrated contaminant is much simpler than treating large volumes of air with low contaminant concentration

Conclusions Degassification of liquids is required in many applications Traditional methods of liquid degassification have involved stripping towers, steam injection, vacuum stripping, etc.  Energy intensive and high investment cost Membrane Degassification offers a simple, compact, reliable process that makes traditional stripping towers obsolete.