08/31/09 British Patent No. 22952, Filed 11 October 1913 Subject: Wastewater aeration based on a porous diffuser. 1916 - San Marcos, Texas - l20,000 gpd (approx.) at continuous-flow operation - diffused aeration
08/31/09 PROCESSES: BNR SBR MBR UASB CONVENTIONAL EXTENDED AERATION FIXED FILM DESIGN TOOLS: PROCESS SIMULATION (i.e. Biowin) 3d MODELING MANUFACTURER WEB SITES
PROCESS SIMULATION 08/31/09 Model your plant to determine how changes in SRT and Anoxic/aerobic volumes affect your effluent before you make those changes.
08/31/09 BLOWER TYPES: MULTISTAGE CENTRIF. SINGLE STAGE CENTR. ROOTS TYPE BLOWERS CONTROL SYSTEMS: MANUAL D.O. CONTROL FEED FORWARD
08/31/09 BLOWER CONTROL SYSTEMS Conventional D.O. control Feed Forward Off-Gas control
08/31/09 INPUT DATA Aeration system design requires consideration of many factors. BOD, COD, NH3-N, Process Type, Wastewater temperature, Air temperature from blowers and distance from blower room, Altitude at site, Treatment goals, Average to Peak ratios, Industrial influent, target MLSS, Chlorides in the wastewater, Scaling potential of wastewater, Future growth plans for plant and/or growing community, Previous experience with diffusers, elastomers and metals at the plant, Priority for capital cost of energy efficiency (cost of power$$) To do a proper job of aeration system design, your supplier will need a lot of information from you!
08/31/09 TUBE DIFFUSERS <ul><li>Consider quantity and location of orifice and seal </li></ul><ul><li>Consider method of rubber molding and materials of construction </li></ul>
08/31/09 FINE BUBBLE DISC DIFFUSERS – CONNECT TO PIPE WITH SADDLES, GROMMETS OR GLUE-ON BASES
COARSE BUBBLE DIFFUSERS <ul><li>These are often used in digesters, sludge holding tanks, and equalization basins. </li></ul>08/31/09
JET AERATORS <ul><li>Used only in the smallest SBR’s, due to their high energy consumption. Jets require a pump + a blower, whereas diffusers need only a blower. Useful in Digesters with highly thickened solids. </li></ul>08/31/09
SURFACE AERATORS <ul><li>Pictured are low and high speed surface aerators </li></ul><ul><li>Maintenance and freezing are concerns </li></ul><ul><li>“ dead zones” may appear at corners </li></ul><ul><li>Useful in Anoxic/Anaerobic zones </li></ul>08/31/09
STATIC AERATORS <ul><li>Used only in lagoons. Efficiency is similar to coarse bubble diffusers . </li></ul>08/31/09
FLOATING LATERAL SYSTEMS 08/31/09 Used in earthen lagoons with membrane liners where decanting is not possible, and floor prohibits installation of a fixed grid.
DID YOU KNOW….? 08/31/09 90% of failures of a membrane diffused aeration system are caused by failed membranes ?
08/31/09 DID YOU KNOW….? In most cases, the cost of replacing membranes in a tank is higher than the cost of those membranes , when you consider hidden costs? LABOR & CLEANING OUT OF SERVICE = NO INCOME!! STEADILY DECLINING PERFORMANCE = ENERGY $$
08/31/09 DID YOU KNOW….? EPDM is a very durable material, but it is susceptible to fouling, which may include permanent swelling, shrinking, or crust? Calcium Carbonate (lime) Calcium Sulfate (gypsum) Petroleum Dairy Products Animal Fat Vegetable Oils Alcohol
08/31/09 DID YOU KNOW….? Plastic gas cans are made of polyethylene, which is not recommended for gasoline or diesel service. Lab bottles that store aggressive solvents are also made of polyethylene, which is not recommended for those solvents.
08/31/09 DID YOU KNOW….? The first PTFE coated frying pan was developed in France by TEFAL in 1954?
08/31/09 DID YOU KNOW….? Re: PTFE coated EPDM membranes Those diffusers have a track record in service since late 2004, and have outlasted plain EPDM membranes in aggressive applications by a 10:1 margin.
08/31/09 PTFE MEMBRANES – Failure Mode? Not Yet We observe that a biofilm layer does form on PTFE Membranes, though it takes a long time to form, and when it Does, even in aggressive environments, it can be removed With a fingertip. The scale does not affect performance and Does not enter the slits. See below…
08/31/09 Why PTFE??? – Don’t let this happen to you!
08/31/09 DID YOU KNOW….? Test report #84395 dated April 30, 2009 proves that SSI’s patent-pending surface fluorination reduces plasticizer loss in an aggressive hot acetone solution compared to standard EPDM membranes by 25%. Phoenix 91 st Ave is retrofitting 2 basins in 2009 with fEPDM from SSI. Not with fEPDM!!! New Old Older Fossil
08/31/09 DID YOU KNOW….? Not all EPDM is created equal. One manufacturer uses Compression Molding and 700% elongation material. Most others are using injection molding and 500% elongation material, to save cost.
08/31/09 THE DEVIL IS IN THE DETAILS <ul><li>EPDM compounds are specially formulated for wastewater </li></ul><ul><li>applications providing: </li></ul><ul><li>Even specific gravity, thickness, and tear resistance </li></ul><ul><li>Greater resistance to elongation and tearing </li></ul><ul><li>(multidirectional tear resistance) </li></ul><ul><li>Resistant to material property changes. </li></ul><ul><li>High modulus for elasticity. </li></ul><ul><li>Proper taper to reduce unit stress. </li></ul><ul><li>High oxygen transfer efficiency. </li></ul><ul><li>Extended service life </li></ul>
08/31/09 The following graph depicts the performance of two tanks in Denmark. Tank 1 has Nopon TM 300 size diffusers. In Tank 2, SSI replaced the Nopon TM membranes with SSI 12” retrofit membranes. The two tanks ran side by side. Notice how the valve to the air supply in the SSI tank is mostly closed, and the valve to the air supply in the Nopon TM tank is mostly open, yet the DO is higher in the SSI tank, in spite of receiving much less air.
08/31/09 Hi Tom. Here the first result of changing from Nopon TM 215 to AFD 350/PTFE. Saving ca 16%. But we have to adjust the plant concerning the pressure, so I ’ ll be back. I would like to end about 25%. Med venlig hilsen/With best regards Pumpteknik ApS/SSI North Europe Dan Christensen www.pumpteknik.dk Tlf.: ++45 49161676, Fax.: ++45 49161696 Mobil: ++45 31655158 - e-mail mobil: [email_address] Skype member: Pumpteknik Ad1) Totalt elforbrug Elforbrug til beluftning Procent beluft ud af total Indløbsflow Elforbrug total pr. m3 vand Elforbrug beluftning pr. m3 vand kwh kWh % m3 kWh(total)/m3 kWh(beluftning)/m3 maj-07 49958,00 12238,00 24% 201744,00 0,25 0,060661036 jan-08 66713,00 12719,00 19% 232016,00 0,29 0,054819495 feb-08 58877,00 11429,00 19% 224598,00 0,26 0,050886473 Besparelse 16%
08/31/09 XII. OPERATION, MAINTENANCE, AND TROUBLESHOOTING MANUALS