Progress 07/01/03 to 06/30/06
Outputs
The major goal of this project has been focused on data collection, monitoring and wetlands performance assessment in dairy effluent treatment. The accomplishments: research results presented at three international and several local conferences; two papers accepted for an oral presentations at the 10th International Conference on Constructed Wetlands for water Pollution Control to be held in Lisbon, Portugal, September 2006; another paper selected for a publication in a book Constructed Wetlands for Agricultural Effluents Treatment, to be published by Springer Ecological Studies series in 2007. A constructed wetlands research center website has also been established (www.uvm.edu/~cwrc). Results: Operational problems, such as the deterioration of concrete splitter walls within the flume tank, the malfunctioning of the flow control equipment and continuous clogging of the aeration system, have persisted since the beginning of the systems establishment. Despite these
problems, total suspended solids (TSS) and E.coli reduction was highly efficient (average 85 to 99 %) in all four wetland cells, regardless of the presence of plants or supplemental aeration. Supplemental aeration improved removal efficiencies for organic matter (BOD5) by 24.0% in South East (SE-cell 2) and 58.60% in South West (SW-cell 4); for ammonium (NH4+- N) by 72.09% (SE-cell 2), and 43.34%; and for dissolved reactive phosphorus (DRP) by 17.4% (SE - cell 2) and 34.18% (SW-cell 4). SW-cell 4 (aerated and planted for 825 days) achieved the highest BOD5 (96.78%) and DRP (55.32%) reductions. Incorporation of an in-series design (3/30/2005) that linked NE-cell 1 and SE - cell 2, improved NE-cell 1 treatment efficiency by 12.46% (BOD5), 65.25% (NH4) and 53.50% (DRP). SE-cell 2 (aerated, planted for 228 days and connected in-series for 288 days) had the highest NH4-N reduction (52.50%). The presence of supplemental aeration in SW-cell 4 improved P removal efficiency to an average
61.04%, contributing to P reduction by nearly 30%, while the addition of the phosphorus filter technology (PFT) improved P removal efficiency by 73.7%. The NW and SW wetland cells received 104.82 kg P/ha each during this period, of which NW-cell 3 retained 34.82 kg P/ha, while SW-cell 4 retained 66.31 kg P/ha respectively. CW technology has the potential to become a recommendable practice for dairy farms nutrient management under cold climate conditions. Despite serious operational problems and higher hydraulic retention times employed, the UVM CW showed good TSS, bacteria and BOD5 treatment efficiencies in all cells, while nutrients reduction within non-aerated cells needs to be improved. Supplemental aeration had a considerable positive effect on the removal efficiencies of all investigated water quality parameters. The incorporation of the in-series design was effective at diminishing and preventing potential treatment inefficiencies caused by the deterioration of the inlet
distribution tank and the resulting uneven flow distribution, demonstrating the importance of appropriate management skills in situations where CW operational problems occur.
Impacts
This research is designed to reduce the environmental impact of dairy wastewater on water quality in a manner that will be acceptable to farmers, public and legislators. The results from our research will help fill the technology gap that currently exists in terms of nutrient removal and management in this area.
Publications
- Munoz, P., Drizo, A. and Hessoin, C. 2006. Flow Patterns of Dairy Wastewater Constructed Wetlands in a Cold Climate. Wat. Res. In Press.
- Drizo, A., Ross, D., Weber, D., Twohig, E. and Bird, S. 2006. Constructed Wetlands for Dairy Effluent Treatment in Vermont: the first two years of operation. 10th International Conference on Constructed Wetlands for Water Pollution Control, to be held in Lisbon, Portugal, 22 - 29th September 2006. Submitted 30 June 2006. Expected in Press in the Water Science and Technology, early 2007.
- Weber, D., Drizo, A., Twohig, E., Bird, S. and Ross, D. (2006). Upgrading Constructed Wetlands Phosphorus Reduction From a Dairy Effluent Using EAF Steel Slag Filters. 10th International Conference on Constructed Wetlands for Water Pollution Control, to be held in Lisbon, Portugal, 22 - 29th September 2006. Submitted 30 June 2006. Expected in Press in the Water Science and Technology, early 2007.
- Drizo, A. and Pegna, J. (2006). Environmental Impacts of Rapid Manufacturing: an overview of research to date. Journal of Rapid Prototyping 12(2):64-71.
- Giordano, R., Cunningham, M.A., Darby, B.J., Soto-Adames, F.N. and Drizo, A. 2005. Role of invertebrate communities associated with a constructed wetland. The Entomological Society of America International Meeting. Held in Ft. Lauderdale, December 2005.
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Progress 10/01/04 to 09/30/05
Outputs
This project examines the use of constructed wetlands (CW) technology to treat barn yard runoff and milk house wash water at the UVM dairy farm. The results from the first two years of operation show very high efficiency in organic matter removal (90% in aerated and 60% in non aerated cells, with an average of 75% for all four cells) and total suspended solids removal (average 90-95%). Although ammonium (N) and soluble phosphorus (SP) reductions in the two aerated cells were relatively high (66 and 60%, respectively), the overall nutrient reduction by all four wetlands was low (42 and 31% for N and SP) and needs to be improved. Tracer studies carried out during cold winter months (December 2004 to March 2005) revealed preferential flows in all four wetlands. However, the extent and occurrence of the preferential flows was smaller in the two aerated wetland cells, suggesting that supplemental aeration has a positive effect on the systems hydraulic efficiency by
promoting the breakdown of organic matter and by diminishing ice build-up. In addition, the compost layer of the four different wetland cell surfaces has been characterized by examining the genetic diversity of denitrifying bacteria as well as the abundance and variation of nematodes and microarthropods (mites and Collembola). Wetland repairs of the inlet and outlet structures were carried out throughout the month of September 05, in order to further improve and optimize the CW treatment efficiency.
Impacts
This research is designed to reduce the environmental impact of dairy wastewater on water quality in a manner that will be acceptable to farmers, public and legislators. The results from our research will help fill the technology gap that currently exists in terms of nutrient removal and management in this area.
Publications
- Drizo, A., Ross, D., Lewis, T., Bird, S. and Munoz, P. (2004). Constructed wetlands for Agricultural Effluent Treatment at the University of Vermont: first six months of operation. Conference Proceedings of the 9th IWA Conference on Wetland Systems in Water Pollution Control, held in Avignon, France, October 2004 .
- Drizo, A. (2005). Summary Report on the Research Carried out at Massey University, Palmerston North, New Zealand, November 16th 2004-February 4th 2005. Organization for Economic Co-operation and Development (OECD) Fellowship Program 2004: Biological Resource Management for Sustainable Agricultural Systems. Paris, OECD.
- Weber, D. and Drizo, A. (2005). Alternative Technology for Phosphorus Removal from Agricultural Effluents. ASA-CSSA-SSSA International Annual Meeting, Salt Lake City, UT November 6 - 10, 2005 Conference Proceedings.
- Cunningham, M.A., Giordano, R., Murray, R.E., Ross, D.S. and Drizo, A. (2005). Assessment of diversity of denitrifying bacteria in the surface compost of a constructed wetland using nitrite reductase genes. EPSoR Symposium Conference Proceedings 2005, Burlington, Vermont.
- Shilton,A., Pratt, S., Drizo, A., Mahmood, B., Banker, S., Billings, L., Glenny, S. and Luo, D. (2005). Active filters for upgrading phosphorus removal from pond systems. Water Science and Technology 51 (12): 111-116.
- Amy, G., Chen, Hsiao-Wen, Drizo, A., Von Gunten, Urs, Brandhuber, P., Hund, R., Chowhury, Z., Kommeni, S., Sinha, S., Jekel, M and Banerjee, K. (2005). Adsorbent treatment Technologies for Arsenic removal. American Water Works Association, September 2005.
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Progress 07/01/03 to 06/30/05
Outputs
Data collection occurred for 18 months of the constructed wetlands (CW) operation. Total suspended solids and E.coli dairy effluent reduction was highly efficient in all four wetland cells, regardless of the presence of plants or supplemental aeration. Aeration had a significant effect on both organic matter and nutrient removal. Biochemical oxygen demand (BOD5) reduction was highly efficient in aerated wetland cells 2 and 4 (90.6 % in unplanted (UP) and 91.4% in planted cells (PL), respectively). The reduction in non-aerated cells (1 and 3) was lower (56.4 and 64.2 %, respectively), resulting in an average of 75.6% for the whole wetland system. Expressed in tons/ha/year, wetlands retained 93 t BOD5/ha/year of the total 126.7 t /ha/year that entered to the system. Except for the unplanted (UP) aerated cell (2), ammonium (NH4-N) reduction was erratic and needs to be improved with further research. Aerated cells had higher efficiency in NH4-N reduction than non-aerated
cells (71 and 55.8% in UP and PL cells, respectively). In non-aerated cells (1 and 3) average treatment efficiency was lower (29.29 and 14.6 % in UP and PL cells, respectively). A total of 9.1 t NH4-N entered the system, of which 3.8t/ha/y was retained by the wetlands, resulting in an average of 42% removal efficiency. Dissolved phosphorus (P) reduction was very low in non-aerated cells 1 and 3 (3.0 in UP and 15.7% in PL cells respectively). Aerated cells achieved 17 and 3.8 fold higher efficiency than non-aerated cells (51.2 and 59.2% in UP and PL cells, respectively). The establishment of electric furnace slag (EAF) based P filters yielded very encouraging results: the four filters (1-4) fed by the cell 3 wetland effluent reduced P load by an average of 84% over the operating period of 255 days, therefore improving overall CW P removal by 69.5% (5 fold). The two filters (5-6) fed directly with the barnyard runoff and milk parlor effluent (tested for their efficiency as stand alone
units), achieved an average of 71.3% P reduction over a period of 186 days. The research on hydraulic performance of the wetlands included four bromide tracer studies that were carried out throughout the winter of 2004-2005. The results showed evidence of preferential flows during winter season. Supplemental aeration contributes to an increase in temperature and dispersion, therefore decreasing the occurrence of preferential flow patterns. Bacterial community succession was also assessed. Data has not shown striking trends in the number of terminal restriction fragment profiles (T-RFs)detected, but rather indicated a rather erratic pattern varying within a 2-fold range of detected richness. Preliminary investigations were conducted to investigate the diversity of denitrifying bacteria in the surface compost of constructed wetlands,utilizing PCR and subsequent DNA sequencing of the nitrite reductase genes nirK and nirS. The nirK and nirS gene sequences retrieved from Genbank that were
similar to those found in the compost layer of the constructed wetland, originated from a variety of habitats.
Impacts
The USDA CSREES funded Constructed Wetland Project for research, education and outreach at the UVM Paul Miller dairy farm represents the first project of its kind and the first application of the constructed wetlands (CW) technology to treat dairy effluent in Vermont. The results from this research show a potential to transfer existing constructed wetlands and phosphorus filter technology (CWAF) to the agricultural sector and, in so doing, provide a solution which could be implemented in agricultural policy practices at a local, regional and national scales. The P filters technology is at the vanguard of P removal technologies from the scientific point of view, both in terms of its specific focus on P removal from dairy wastewater and, in particular, because of its focus on the mechanisms of media regeneration. The P removal efficiency that was achieved both by combined CWAF and PF treatments is one of the highest reported in the international literature to date. The
practical application of our results on other farms in the Lake Champlain region could result in a significant reduction of nutrients from dairy effluents. In addition, they would advance the use of CW and filter systems by improving both their design and cost-effectiveness, and also by extending system longevity. The results from this research could help fill the technology gap that currently exists in terms of nutrient removal for this agricultural pollution source.
Publications
- Drizo, A., Forget, C. , Chapuis, R.P. and Comeau, Y. (2005). Phosphorus removal by electric arc furnace (EAF) steel slag and serpentinite. Water Research. In press.
- Cunningham, M.A., Giordano, R., Murray, R.E., Ross, D.S. and Drizo, A. (2005). Assessment of diversity of denitrifying bacteria in the surface compost of a constructed wetland using nitrite reductase genes.EPSoR Symposium Conference Proceedings, Burlington,Vermont.
- Shilton, A., Pratt, S., Drizo, A., Mahmood, B., Banker, S., Billings, L., Glenny, S. and , D.Luo (2005).Active filters for upgrading phosphorus removal from pond systems. Wat.Sci.Tech. 51(12):111-116.
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Progress 10/01/03 to 09/30/04
Outputs
Accomplishments: We have now collected data on the first 9 months of the wetlands performance in treating barn yard runoff and milk house wash water (Drizo et al, 2004). This enabled us to test the effect of two parameters (contribution of plants and aeration) on the wetlands treatment performance. The effect of aeration was first tested on the two northern Cells (1 and 3) for 4 months (January- April). In May 04, the mode of aeration was changed to two southern Cells (2 and 4). The results from the first nine months of operation showed that biochemical oxygen demand (BOD5), total suspended solids (TSS) and E.coli reduction was highly efficient (close to 100 %, 85-95 % and 85-99%) in planted Cells (3 and 4). NH4+- N removal was generally poor, except in Cell 3 (northern planted cell) which achieved 72 % removal. Planted Cell 4 (southern) showed the poorest performance (- 5.6 %), followed by Cells 1 and 2 (6.2 and 7.2 % respectively). However, the performance of Cell 4
was significantly improved by aeration, reaching an average of 90.6 % after 3 weeks. Dissolved phosphorus (P) removal performance was better than that of ammonium. Cells 2 and 4 had average removal efficiency of 50.8 and 54.6 %. The efficiency of Cells 1 and 3 was lower (28.1 and 15.4 %), respectively. In August 04, plant samples were taken from the wetlands inlets and outlets in order to determine the amount of nutrients taken by the plant biomass. The results revealed that planted Cells 3 and 4 achieved 241.2 and 462.4 kg N ha-1 y-1 and 59.2 and 86.2 kg P ha-1 y-1 uptake respectively. This is in accordance with the data reported in a literature. The research is currently underway to improve nutrients removal performance. Four slag based P filters, and four shale based filters with subsurface horizontal (SSF) and vertical downward (VDF) and vertical upward (VUF) flow, connected in series are currently under construction. Three filters will be fed by the effluent coming from the
planted unaerated cell (3) to assess the capacity of filters to upgrade wetlands P removal performance. One filter will be fed directly from the flume, in order to test the capacity of filters to remove P without a wetland pre-treatment. Monitoring of the filters performance will commence by the end of October. In addition, we plan to conduct a study on nitrifying and denitrifying bacteria in order to improve wetland N treatment performance. Of other parameters, temperature distribution is monitored through 76 thermocouples that have been installed this spring.
Impacts
Ultimately the results of this research are designed to reduce the environmental impact of dairy wastewater on water quality in a manner that will be acceptable to both the farmer and the public. Other positive impacts are that this research has the potential not only to develop but also to transfer this new phosphorus removal technology to the agricultural sector and, in so doing, provide a solution which could be implemented in agricultural policy practices at local, regional and global scale. The practical application of these results on other farms could significantly improve P removal performance over existing practices. In addition, they would advance the use of constructed wetlands and filter systems by improving their design, improving their cost-effectiveness, and extending system longevity. By adapting this technology to dairy wastewater treatment, our work is helping in filling the technology gap that currently exists in terms of nutrient removal in this
area and to address the significant environmental and economic risk that U.S. agriculture faces in this respect.
Publications
- Drizo A.,Ross, D., Lewis, T., Munoz. P., Weber, D. and Bird, B. (2004). Constructed wetalnds for aggricultural effluent treatment at the University of Vermont: first eight months of operation. Poster presentation. CD Rom. Proceedings of the 9th International Conference on Wetland Systems, 26 September - 1st October, Avignon, France.
- Shilton, A., Pratt, S., Drizo, A., Mahmood, B., Banker, S., Billings, L. Glenny, S. and Luo, D. (2004). "Active" filters for upgrading phorsphorus removal from pond systems. Proccedings of the 6th Internationsl Conference on Waste Stabilization Ponds, 28th September - 1st October, Avignon, France.
- Drizo, A. and Pegna, J. (2004). Environmental Impacts of Rapid Manufacturing: an overview of research to date. Journal of Rapid Prototyping. In press.
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Progress 01/01/03 to 12/31/03
Outputs
The overall goal of this research project is to design, build and operate a sub-surface flow constructed wetland at the university dairy farm to study the treatment of cow yard runoff and milk house wash water. The constructed wetland provides an environmentally sound approach to reduce pollutants in farm wastewater. This state-of-the-art wetland facility is designed to enable research on the feasibility and cost-effectiveness of using a sub-surface flow wetland in harsh northern climates to purify farmstead wastewater. Innovative technologies at the site include the design of the wetland itself, modern instrumentation including sensors and flow rate equipment, sampling ports, as well as large and small wetland cells to enable multiple studies to occur simultaneously. Accomplishments: a)Wetland construction was completed and operation began on October 8, 2003 when both barnyard runoff and milk house waste were diverted into the wetland. Use of the wetland as a
research and education resource began immediately. Two student groups from an environmental science course conducted semester long studies to sample and analyze water as it flowed through the wetland. A graduate student studied initial water flow patterns. Results were presented at seminars and in written reports. b)Sampling and analysis of influent and effluent began in October, 2003 and continues on a bi-weekly basis. The four large wetland cells each have a different combination of plants and aeration treatments. Because there is no significant root growth in the planted cells, the results are averaged with the no-plant cells. Early results show improved water quality in all wetlands, particularly with aeration. Initial performance measurements October to December:E.Coli (cfu) influent 1,400,000;effluent-aerated 20,000;effluent non-aerated 160,000: BOD(mg/l)influent 1640;effluent aerated 30;effluent non-aerated 830: Total suspended solids(mg/l)influent 602;effluent-aerated 53;
effluent non-aerated 132. c)For the microbial studies, we have taken monthly samples of water and gravel from each of the 4 treatment wetlands. These samples include time points before planting, and before the establishment of flow from the cattle yard or milk house. Preliminary studies with readily available soils and peat from ongoing studies, have produced material of sufficient purity for cDNA synthesis. The samples obtained from the treatment wetland have unique characteristics, having biomass in both suspended and attached forms. Our first extractions of nucleic acids from wetland water and gravel enabled cDNA synthesis, however the yield of RNA was lower than desired for optimum taxonomic representation. We continue to try alternative RNA preparation methods with this first sample. We also continue to collect samples.
Impacts
Ultimately the results of this research are designed to reduce the environmental impact of dairy wastewater on water quality in a manner that will be acceptable to both the farmer and the public.
Publications
- No publications reported this period
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