Biological processes for recreational water quality improvement€¦ · Biological processes for...
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Biological processes for recreational water quality improvement Emma Boyson Mentored by Bruce McMillin Today, most swimming pools require intense chemical treatment in order to prevent the spread of disease and eliminate any contaminants as well as maintain clinical standards. Typical chemical pool additives such as chlorine (Cl) and bromine (Br) can cause lifelong respiratory ailments including asthma and irritation of the mucous lining in the nose and throat. In order to combat these effects, scientists have worked to create a new definition of “pool”, thus the natural swimming pool was born. The basic principle of a “swimming pond” is to use the natural purifying properties of plants and micro-organisms to sustain clean, clear and healthy water. Natural swimming ponds consist of a “regeneration zone” separate of the “swimming zone.” The regeneration zone serves as a large biological filtration system that utilizes the metabolic processes of aquatic substrates and plants in order to create properly filtered effluent. A biological filter consists of a non-corrosive material such as ceramic, rock, fiberglass, or plastic with a significant amount of surface area for the bacteria to colonize. This bacterium then consumes potentially harmful debris creating clear water suitable for swimming. Despite the accessibility and inventiveness of this technology it has yet to be implemented in the United States. The purpose of this study was to construct and evaluate three treatment systems that could possibly be utilized in oncoming years. Materials and Methods Three treatment systems were created; a suspended-growth filter, a gravitational feed filter, and an upflow filter. Data for each system was collected as the influent was filtered at three rates of 5 gal/hr, 10 gal/hr, and 15 gal/hr respectively; for week long periods. The filtration media was chosen based on available microbial action. The suspended growth system (Figure 1) consisted of a layer of volcanic rock, river gravel, and pea pebbles, as well as floating Lemnaceae (duckweed) and Eichhornia (water hyacinth). Biologically aerated filtration processes (BAF) are what encompasses the gravitational feed technique (Figure 2); the filter was comprised of three layers of filtration media each 8 cm in depth; volcanic rock, river gravel, and pea pebbles all separated by uniformly needle- punched coir fiber 0.5 in (12.5 mm) thick. The upflow filter (Figure 3) consisted of the same separate layers of filtration media but the influent was forced upwards rather than falling downward through the treatment system. Overall filtration performance was determined based on the treatment rate in comparison to the nutrient removal levels of total suspended solids (TSS), ammonia, nitrate, nitrite, and turbidity in the source water (Beagle & Justin, 1993). With the lab setups shown, measurements were taken on these various aspects of water pollution. Results Graph 1. Change in purity of water in mg/L in the Suspended Growth Filtration System for TSS, turbidity, nitrite, nitrate, and ammonia. Graph 2. Change in purity of water in mg/L in the Gravitational Feed Filtration System for TSS, turbidity, nitrite, nitrate, and ammonia. Introduction Results (cont’d) Graph 3. Change in purity of water in mg/L in the Upflow Treatment System for TSS, turbidity, nitrite, nitrate, and ammonia. Acknowledgements I would like to thank my advisor Mrs. McDonough, my mentor, Mr. Bruce McMillin, as well as Donna Geiger for her help throughout. References Beagle, G., & Justin, J. (1993). Using a constructed wetland to treat waste water and propagate wetland species. Tree Planters' Notes, 44(3), 93-97. Retrieved from http://www.rngr.net/publications/tpn/44 3/44_3_93_97.pdf/at_download/file Brix, H. (1994). Functions of macrophytes in constructed wetlands. Wat. Sci. Tech., 29(4), 71-78. Retrieved from http://mit.biology.au.dk/ ~biohbn/cv/pdf_files/Wat_Sci_Tech_29 (1994) 71-78.pdf Conclusion The technology studied in this experiment is shown to have incredible benefits to not only water treatment methods of the future, but also in prevention of respiratory disorders as a result of excess chlorine exposure. Possible areas for improvement in future experiments include number of tests, higher grade equipment, or a more focused study of a specific treatment system. Future experiments could test with larger bodies of water to mirror the aspects of a public swimming pool such as loading rate in relation to swimmers and fulfillment of capacity requirements. Another aspect to consider is the uncontrollable facets of wildlife such as animal and human contamination (Brix,1994) over an extended period of time. These improvements could lead to implementation of naturally filtered pool systems thus making chemically enhanced pool additives obsolete. Through the treatment methods aforementioned, there was a significant decrease in the pollutants present in the source water. The source water was shown to have a turbidity of 20, TSS of 220, nitrite of 0.026, nitrate of 0.56 and ammonia of 0.153 all measured in mg/L. The data taken compared the water purity and filtration efficiency at various turnover rates (5 gal/hr, 10 gal/hr, and 15 gal/hr. The upflow treatment system (Graph 3) at a rate of 15 gallons per hour proved to have the highest overall nutrient removal. The other control experiments (Graphs 1 and 2) clearly indicate decreases in the presence of TSS, turbidity, nitrite, nitrate, and ammonia levels but due to the varying direction the influent was propelled, the upflow method proved most efficient. Through analysis by logistic regression, the data collected shows a correlation between filtration rate and nutrient removal; the quicker the filtration rate, the higher the percentage of nutrient removal. Materials and Methods (cont’d) Figure 1. CAD generated diagram of the setup of the suspended growth treatment system. Figure 2. CAD generated diagram of the setup of the gravitational feed treatment system. Figure 3. CAD generated diagram of the setup of the upflow treatment system. Pea Pebbles River Gravel Volcanic Rock 0 2 4 6 8 10 TSS Turbidity Nitrite Nitrate Ammonia mg/L Suspended Growth Treatment System Subsurface (5 gal/hr) Subsurface (10gal/hr) Subsurface (15 gal/hr) 0 5 10 15 20 25 30 TSS Turbidity Nitrite Nitrate Ammonia mg/L Gravitational Feed Treatment System Trickling (5 gal/hr) Trickling (10 gal/hr) Trickling (15 gal/hr) 0 2 4 6 8 TSS Turbidity Nitrite Nitrate Ammonia mg/L Upflow Treatment System Upflow (5 gal/hr) Upflow (10 gal/hr) Upflow (15 gal/hr) Pea Pebbles
Transcript of Biological processes for recreational water quality improvement€¦ · Biological processes for...
Biological processes for recreational water quality improvement Emma Boyson
Mentored by Bruce McMillin
Today, most swimming pools require intense chemical treatment in order to prevent the spread of disease and eliminate any contaminants as well as maintain clinical standards. Typical chemical pool additives such as chlorine (Cl) and bromine (Br) can cause lifelong respiratory ailments including asthma and irritation of the mucous lining in the nose and throat. In order to combat these effects, scientists have worked to create a new definition of “pool”, thus the natural swimming pool was born. The basic principle of a “swimming pond” is to use the natural purifying properties of plants and micro-organisms to sustain clean, clear and healthy water. Natural swimming ponds consist of a “regeneration zone” separate of the “swimming zone.” The regeneration zone serves as a large biological filtration system that utilizes the metabolic processes of aquatic substrates and plants in order to create properly filtered effluent. A biological filter consists of a non-corrosive material such as ceramic, rock, fiberglass, or plastic with a significant amount of surface area for the bacteria to colonize. This bacterium then consumes potentially harmful debris creating clear water suitable for swimming. Despite the accessibility and inventiveness of this technology it has yet to be implemented in the United States. The purpose of this study was to construct and evaluate three treatment systems that could possibly be utilized in oncoming years.
Materials and Methods Three treatment systems were created; a suspended-growth filter, a gravitational feed filter, and an upflow filter. Data for each system was collected as the influent was filtered at three rates of 5 gal/hr, 10 gal/hr, and 15 gal/hr respectively; for week long periods. The filtration media was chosen based on available microbial action. The suspended growth system (Figure 1) consisted of a layer of volcanic rock, river gravel, and pea pebbles, as well as floating Lemnaceae (duckweed) and Eichhornia (water hyacinth). Biologically aerated filtration processes (BAF) are what encompasses the gravitational feed technique (Figure 2); the filter was comprised of three layers of filtration media each 8 cm in depth; volcanic rock, river gravel, and pea pebbles all separated by uniformly needle-punched coir fiber 0.5 in (12.5 mm) thick. The upflow filter (Figure 3) consisted of the same separate layers of filtration media but the influent was forced upwards rather than falling downward through the treatment system. Overall filtration performance was determined based on the treatment rate in comparison to the nutrient removal levels of total suspended solids (TSS), ammonia, nitrate, nitrite, and turbidity in the source water (Beagle & Justin, 1993). With the lab setups shown, measurements were taken on these various aspects of water pollution.
Results
Graph 1. Change in purity of water in mg/L in the Suspended Growth Filtration System for TSS, turbidity, nitrite, nitrate, and ammonia.
Graph 2. Change in purity of water in mg/L in the Gravitational Feed Filtration System for TSS, turbidity, nitrite, nitrate, and ammonia.
Introduction Results (cont’d)
Graph 3. Change in purity of water in mg/L in the Upflow Treatment System for TSS, turbidity, nitrite, nitrate, and ammonia.
Acknowledgements I would like to thank my advisor Mrs. McDonough, my mentor, Mr. Bruce McMillin, as well as Donna Geiger for her help throughout.
References Beagle, G., & Justin, J. (1993). Using a constructed wetland to treat waste water and propagate wetland species. Tree Planters' Notes, 44(3), 93-97. Retrieved from http://www.rngr.net/publications/tpn/44 3/44_3_93_97.pdf/at_download/file Brix, H. (1994). Functions of macrophytes in constructed wetlands. Wat. Sci. Tech., 29(4), 71-78. Retrieved from http://mit.biology.au.dk/ ~biohbn/cv/pdf_files/Wat_Sci_Tech_29 (1994) 71-78.pdf
Conclusion The technology studied in this experiment is shown to have incredible benefits to not only water treatment methods of the future, but also in prevention of respiratory disorders as a result of excess chlorine exposure. Possible areas for improvement in future experiments include number of tests, higher grade equipment, or a more focused study of a specific treatment system. Future experiments could test with larger bodies of water to mirror the aspects of a public swimming pool such as loading rate in relation to swimmers and fulfillment of capacity requirements. Another aspect to consider is the uncontrollable facets of wildlife such as animal and human contamination (Brix,1994) over an extended period of time. These improvements could lead to implementation of naturally filtered pool systems thus making chemically enhanced pool additives obsolete.
Through the treatment methods aforementioned, there was a significant decrease in the pollutants present in the source water. The source water was shown to have a turbidity of 20, TSS of 220, nitrite of 0.026, nitrate of 0.56 and ammonia of 0.153 all measured in mg/L. The data taken compared the water purity and filtration efficiency at various turnover rates (5 gal/hr, 10 gal/hr, and 15 gal/hr. The upflow treatment system (Graph 3) at a rate of 15 gallons per hour proved to have the highest overall nutrient removal. The other control experiments (Graphs 1 and 2) clearly indicate decreases in the presence of TSS, turbidity, nitrite, nitrate, and ammonia levels but due to the varying direction the influent was propelled, the upflow method proved most efficient. Through analysis by logistic regression, the data collected shows a correlation between filtration rate and nutrient removal; the quicker the filtration rate, the higher the percentage of nutrient removal.
Materials and Methods (cont’d)
Figure 1. CAD generated diagram of the setup of the suspended growth treatment system.
Figure 2. CAD generated diagram of the setup of the gravitational feed treatment system.
Figure 3. CAD generated diagram of the setup of the upflow treatment system.
Pea Pebbles River Gravel Volcanic Rock
02468
10
TSS Turbidity Nitrite Nitrate Ammonia
mg/
L
Suspended Growth Treatment System Subsurface(5 gal/hr)
Subsurface(10gal/hr)
Subsurface(15 gal/hr)
05
1015202530
TSS Turbidity Nitrite Nitrate Ammonia
mg/
L
Gravitational Feed Treatment System Trickling(5 gal/hr)
Trickling(10 gal/hr)
Trickling(15 gal/hr)
0
2
4
6
8
TSS Turbidity Nitrite Nitrate Ammonia
mg/
L
Upflow Treatment System Upflow(5 gal/hr)
Upflow(10 gal/hr)
Upflow(15 gal/hr)
Pea Pebbles
