Experimental application of the ICW concept for examining various - PowerPoint PPT Presentation

Experimental application of the ICW concept for examining various wastewater treatment. Dr. Caolan Harrington

Meso-scale ICW  Experimental platform to test treatment efficacies for water-vectored constituents  Complimentary to full-scale ICW systems  Experimental investigation of ‘conventionally difficult’ wastewater treatment  Practical test bed for preliminary experimental treatment

Meso-scale ICW  Versatile ◦ Inherent concepts/design allow for the examination of a wide range of wastewaters  Affordable ◦ Using easily sourced materials and equipment keeps construction and maintenance costs to a minimum  Replicable ◦ Affordability allows for high-replication of parameters and treatment methods  Adjustable ◦ Use of simple mechanics allows for the systems to be high adjustable upon initial setup  Accurate ◦ High replicate count rules out erroneous results and errors that can occur: delivering high confidence values

Swine wastewater treatment in Ireland Primary method: Land spreading Other methods: Anaerobic digestion, Composting

Initial development of Meso-scale ICW  Creation and operation of a low-cost, linearly scaled ICW system dealing with anaerobically digested (AD) piggery liquid  Examination of the treatment of AD liquid using an Integrated Constructed Wetland approach  Examine the reliability of such an approach and potential future use of the meso-scale as a test-bed system for experimental examination of various wastewaters

Drivers  Water Framework Directive ◦ Directive 2000/60/EC ◦ S.I. 327 of 2012  Nitrates Directive ◦ Directive 91/676/EEC ◦ S.I. 610 of 2010  Septic Tank Infrastructure ◦ EU decision and penalties (2012)  Convention on Biodiversity ◦ RAMSAR

Constructed wetlands and Wastewater treatment • World-wide application • Environmentally beneficial vs. • Cost effective • Amenities

Design

Design High replication M ultiple inflows Easily controlled

Design

Design

Operations Hydraulic Effluent Operation Ammonia-N loading recycling Normal 100 mg NH 4 /l 37 m 3 /ha/d no Recycling 100 mg NH 4 /l 37 m 3 /ha/d Yes (100%) High nutrient 200 mg NH 4 /l 37 m 3 /ha/d no loading High flow rate 100 mg NH 4 /l 74 m 3 /ha/d no

Operational timeframe  Construction ◦ June 2008 to September 2008  Operation ◦ November 2008 to June 2010 ◦ 18 months fully operational

Operational difficulties  Siphon effects  Overloading  Extreme weather

Ammonia-Nitrogen NH 3  Ammonia NH 3 ◦ Primary basis for dilution of influent 1000.00 Tank 1 Tank 2 Normal High flow Low flow Recycling HNL HFR 100.00 Ammonia-nitrogen (mg/l) 10.00 1.00 Threshold: 0.5 mg/l 0.10 0.01 10/12/2008 10/01/2009 10/02/2009 10/03/2009 10/04/2009 10/05/2009 10/06/2009 10/07/2009 10/08/2009 10/09/2009 10/10/2009 10/11/2009 10/12/2009 10/01/2010 10/02/2010 10/03/2010 10/04/2010 10/05/2010 Date

Hydraulic loading  Initial loading @ 100 m 3 /ha/d  After 15 weeks reduced to 68 m 3 /ha/d  After 17 weeks, reduced to 37 m 3 /ha/d Ammonia (NH 4 ) 1000 120 100 100 80 Cell 1 10 NH 4 (mg/l) 60 Cell 4 1 Storage 40 tank Influent loading 0.1 20 0.01 0 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 Sampling week

Molybdate reactive Phosphorus (MRP)  MRP Effluent levels ◦ Phosphorus is a key parameter in eutrophication High flow Low flow 10 Molybdate reactive phosphorus (mg/l) Threshold: 1 mg/l 1 Tank 1 0.1 Tank 2 Date Normal Recycling 0.01 HNL HFR 0.001 10/12/2008 10/01/2009 10/02/2009 10/03/2009 10/04/2009 10/05/2009 10/06/2009 10/07/2009 10/08/2009 10/09/2009 10/10/2009 10/11/2009 10/12/2009 10/01/2010 10/02/2010 10/03/2010 10/04/2010 10/05/2010

 Exceptional removal with reduced loading rates Normal Recycling HNL HFR Ammonia 99.7% 99.9% 99.8% 99.1% MRP 97.7% 96.0% 94.6% 89.1% Nitrite 95.2% 96.2% 98.4% 83.8% Nitrate 93.0% 92.2% 81.7% 75.7% TON 93.4% 93.1% 92.9% 77.4%

Variability in the systems 1000.000 100.000 Ammonia-N mg/l 10.000 Replicate 1 Replicate 4 Replicate 3 1.000 Replicate 2 0.100 0.010 1 6 11 16 21 26 31 36 41 46 51 56 61 66 Sample Week

Variability in the systems 1000 100 10 Ammonia-N mg/l Series4 1 Series3 Series2 Series1 0.1 0.01 0.001 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 Sample Week

Variability in the systems 1000.000 100.000 Ammonia-N mg/l 10.000 Replicate 4 Replicate 3 Replicate 2 1.000 Replicate 1 0.100 0.010 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 Sample Week

Variability in the systems 1000.000 100.000 Ammonia-N mg/l 10.000 Replicate 4 Replicate 3 Replicate 2 1.000 Replicate 1 0.100 0.010 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 Sample Week

Discussion  Linearly-scaled meso-scale systems functioned similarly to other full-scale ICW systems  Exceptional nutrient removal rates  High replicate count shows reliability in recorded results.

Potential applications  Ongoing discussion for development of sludge treatment from municipal WTP  Mine wastewater treatment (heavy metal content)  Landfill leachate investigation  High ammonia content wastewaters

Conclusion Meso-scale approach  ◦ Reliable test-bed ◦ Flexible interim experimental scale ◦ Easily maintained ◦ Low cost  Land and equipment ◦ Feasible to have high replicate count ◦ Analysis of data ◦ Result comparison Loading rates  ◦ Capable of dealing with higher nutrient loadings (>200 mg/l) ◦ High flow showed substantial mass removal, but effluent nutrient levels higher Recycling  ◦ Effluent recycling yielded consistently low effluent nutrient levels (ammonia-N) ◦ Year-round performance increase ◦ 4-fold effect; longer retention time, further dilution, extended treatment time, reduced effluent volume