SBIR-STTR Award

Rural Wastewater Treatment Lagoon Enhancement with Dome Shaped Submerged Bio-Film Devices
Award last edited on: 1/6/2011

Sponsored Program
SBIR
Awarding Agency
USDA
Total Award Amount
$90,000
Award Phase
1
Solicitation Topic Code
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Principal Investigator
Kraig J Johnson

Company Information

Wastewater Compliance Systems Inc

PO Box 58065
Salt Lake City, UT 84103
   (801) 999-8271
   fred@wcs-utah.com
   www.wastewater-compliance-systems.com
Location: Single
Congr. District: 02
County: Salt Lake

Phase I

Contract Number: ----------
Start Date: ----    Completed: ----
Phase I year
2010
Phase I Amount
$90,000
Shallow lagoon systems are the most common form of engineered domestic wastewater treatment in the United States and the world. Municipalities, particularly smaller rural communities, use this low cost treatment method. These lagoon systems are generally effective at reducing biochemical oxygen demand (BOD) to acceptable levels prior to discharge. They are generally ineffective at nutrient removal, specifically nitrogen and phosphorous compounds dissolved in the discharge water. The biological removal of nitrogen compounds takes place in two stages when naturally occurring nitrifying, then denitrifying bacteria consume them. Biological removal of dissolved phosphorous compounds occurs through uptake by a class of bacteria known as polyphosphate accumulating organisms (PAOs). In open lagoon systems, these nutrient consuming bacteria are generally out-competed by the more robust bacteria that consume the carbonaceous BOD, and do not proliferate. Because of this, municipalities using lagoon systems often have difficulties meeting nutrient discharge requirements. To promote the proliferation of nitrifying and denitrifying bacteria and PAOs in shallow lagoon systems, specially designed aerated dome structures (Poo-Gloos) have been developed. These dome structures are nested hemispheres made out of ABS black plastic. Fine-bubble diffuser hose is attached in the gap between the inner and outer annulus around the bottom of each dome. Nested dome structures are mounted on a sturdy base and rest on the bottom of a lagoon so they are fully submerged. The space between the dome shells is filled with a high surface area to volume packing material made out of polypropylene plastic. Low-pressure air is supplied to the diffusers and the released bubbles travel up the inside of each dome. The dome structures retard the upward movement of the aeration bubbles, forcing the bubbles against naturally occurring bio-film colonizing the surfaces, promoting oxygen transfer. The rising air bubbles also drag the wastewater up from near the bottom of the lagoon, along through the insides of the dome structures, and out the top. This promotes micro-mixing of nutrients into the bio-film. By providing surface area, oxygen, mixing, and blocking of sunlight, these dome structures greatly enhance the growth and metabolism of nitrifying bacteria. In addition, denitrifying bacteria proliferate in the deeper portions of the inside bio-film surfaces as well as the non-aerated backside surfaces of the domes and during times the aeration bubbles are cycled off. The performance of PAOs is also enhanced by aeration cycling. This cycling should provide the necessary aerobic/anoxic/ anerobic phases for these bacteria. The benefit to rural communities will be a low-cost technology that can be manufactured in rural areas, and can be easily added to existing lagoon systems. The installed dome structures will increase lagoon performance, allowing the communities to meet increasingly stringent nutrient level discharge requirements while retaining existing lagoon systems. OBJECTIVES: Technical Objectives Funds are sought for the period 1 May, 2010 to 31 December, 2010 to accomplish the following goals: 1. Upgrade pilot plant with 6 new scale Poo-Gloos (outer domes 1.6' radius) and parallel paths for simultaneous control runs. 2. Verify previous work for CBOD and NH4+ removal rates while establishing biofilm on new Poo-Gloos. 3. Begin a series of controlled runs that vary air cycling times, organic and hydraulic loading rates, and temperature. 4. Analyze results and modify factors to optimize N removal through nitrification and de-nitrification. 5. Analyze results and modify factors to optimize P uptake and release. 6. Perform statistical analysis on all results to show significant results. 7. Write report, and develop preliminary Operations Manual for full-scale applications. 8. Begin preliminary monitoring of full scale application (35 Poo-Gloos, each 6' diameter at base and 4' high dome) in Wellsville, Utah. Expected Outputs Lab analysis of each experimental run will produce the following factors: Temp, HRT, organic loading, COD/CBOD5, NH4+, NO3-/NO2-, TN, PO43-, TP, ORP, DO, Air Flow Rate, Air Flow On/Off Cycling. In addition, pH, TDS and ALK will be monitored to ensure that conditions are favorable for biological growth. Adjustments to the controllable factors (HRT, Air Flow Rate and Air Flow On/Off Cycling) will be made based on results as the experimental runs progress. All factors will be input into the software program STAT-EASE DX7.1 for statistical analysis. The product of this will be a data set, along with figures that will show the effect of air cycling on effluent NO3-/NO2-, as well as PO43- uptake and release at different loading rates. Based on HRT, loading rates for CBOD, N and P compounds will be analyzed. Mass balances will be calculated for N and P compounds. Finally, the cost/benefit ratios for the BOD removal rate (g BOD/m2/d), nitrogen compound (g N/m2/d), and phosphorus removal rate (g P/m2/d) will be calculated and compared to the typical values in the industry. The system costs (capital and O&M) will be estimated and defined in terms of $/lb BOD, $/lb N, and $/lb P removed

Phase II

Contract Number: ----------
Start Date: ----    Completed: ----
Phase II year
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Phase II Amount
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