RemTech Surface Water Remediation and Waste Water Treatment Using Circulators.

Transcription

1 RemTech 2006 Surface Water Remediation and Waste Water Treatment Using Circulators. Author: Kathleen Cameron (M.Sc., PAg) Manager and Senior Environmental Director, Dagaz Environmental Inc. Who is Sunset Solar Systems Ltd. and Dagaz Environmental Inc.? Sunset Solar Systems Ltd. is the manufacturer of the Little River Pond Mill circulators and Dagaz Environmental (formerly the environmental management division of Sunset Solar Systems Ltd.) conducts marketing activities and environmental consulting (primarily surface water remediation and waste water treatment) for the Little River Pond Mill circulators and other environmental technologies and services. After 23+ years and 5,000+ energy efficient and renewable energy circulators in operation world wide, Sunset Solar Systems Ltd. and Dagaz Environmental Inc. are the world leaders in providing renewable energy (wind, solar) and low energy consuming circulators to remediate and treat surface waters and waste waters. This remediation is achieved by enhancing both biological and natural chemical processes in aquatic (water based) environments. Circulators For over 23 years Little River Pond Mill circulators have provided a unique in-situ processing technology that facilitates biologically active filtration (BAF) and biogeochemical remediation (BGCR) in surface water remediation and waste water treatment while enhancing aquatic species diversity essentially you are creating an insitu bioreactor. The Little River Pond Mill is a circulator, not an aerator (air injection), although circulators do promote significant aeration via re-aeration at the surface. Surface reaeration is upwards of 99% efficient for oxygen transfer (OTE) whereas air injection OTE is significantly below this at about 40% max for micro-bubble air injection systems.

2 Aerator Circulator Figure 1.0 Comparison of a circulator with an aerator All circulators are not created equal; their efficiency, which includes the ability of the circulator to effectively circulate the liquid contents of a containment system (to the surface for exposure to the elements, i.e. oxygen, UV rays, etc. as well as internal circulation) is based on machine design characteristics such as the floatation system, machine aerodynamics, impeller design, and impediments to fluid flow tubes, pontoons, legs, etc. all of which interact with fluid dynamics. Figure 1.1 Comparison of circulator design characteristics The most efficient Little River Pond Mill circulator comes in a number of designs and efficiency ratings and its specially designed impeller has a strong and effective recirculating, toroidal vortex circulation pattern and flow rate of more than 9 m 3 s -1 (7.1 million Imperial gph) (Bugg, J. D. 1997).

3 There are thousands of Little River Pond Mill circulators in operation globally in chemical and other waste water ponds (hydrocarbon and chemicals contamination, livestock, municipal, food processing, etc.) and surface water bodies (lakes and ponds - municipal, recreational, private). The circulators are used for reversing eutrophication and control of undesirable or nuisance aquatic species, increasing dissolved oxygen to sustain fish and other aquatic species populations in lakes and water reservoirs; and for odour control, solids digestion, chemistry alteration and element stabilization in lagoons and waste water ponds. The aquatic environments that circulators are used in can be altered through a variety of techniques (chemical addition, specialty microbial mixes, exposure to UV, exposure to oxygen, etc.) to a desired outcome and the circulator doesn t necessarily need to be a stand-a-lone piece of equipment. Circulator action promotes: 1. The growth of desirable microorganisms that promote: a. A reduction of solids/sludge; b. Creation of beneficial enzymes and other metabolites, and when land applied can: i. Improve plant performance; ii. Improve soil tilth; iii. Improve soil health; c. Sequestration of carbon (organic matter) into microbial bodies; 2. An increase in aquatic species diversity; 3. An increase in dissolved oxygen that promotes: a. A reduction in biological and chemical oxygen demands; b. Mineralization, oxidation, and alteration of nutrients and other elements when exposed to oxygen thereby reducing pollution loading e.g. N, S, P, Mn; c. Fish and aquatic organism survival; 4. An increase in exposure to UV rays, its damaging effects on chemical bonds, and eventually the degradation of various pollutants including PCB s, hydrocarbons, etc. as well as its effects on living organisms such as UV sensitive microbes; 5. A reduction of odorous and non-odorous gases (methane, hydrogen sulfide, ammonia, etc.) a. Greenhouse gases; b. Acid rain gases; c. Other; 6. A reduction of undesirable and nuisance organisms including pathogens (e.coli), vegetation (Eurasian water milfoil, algae, Duck Weed), mosquitoes, etc.; 7. Reduce lake eutrophication: a. Reduce availability of nutrient elements such as N and P; b. Control nuisance aquatic plants and harmful pest organisms (algae and coliform bacteria); 8. A potential reduction for chemical requirement: a. Circulation enhances chemical exposure; b. Circulation reduces organic load thereby improving the effectiveness of many chemical treatments;

4 c. Enhanced pre-treatment with circulators can improve water quality such that it may not be necessary or may only be required in a lower dose level; 9. Financial & Environmental costs associated with treatment of surface water and waste water (industrial, commercial, municipal and livestock) such as project costs, reduced environmental impact when compared with other treatments; 10. Social costs (legal, neighbour relations) due to use of eco-economic waste management & environmentally friendly management practices; 11. Energy consumption when compared with other circulators and aerators (Winter saved a swine producer $12,000 CDN in electricity charges) Surface Water Management Little River Pond Mill circulators have been used in surface water remediation for over 23 years with global surface water markets including France, Australia, the United States and Canada. The circulators are used to control Eurasian water milfoil, algae, Water Lettuce, Duck Weed, and other undesirable/uncontrolled vegetative growth, control of undesirable organisms including coliform bacteria, and reduction of hydrogen sulfide gas. Figure 2.0 Reversing lake eutrophication in Australia using Little River Pond Mill circulators 2005

5 One month after circulator installation At time of circulator installation Figure 2.1 Duck weed control in southern Saskatchewan using Little River Pond Mill circulators A study conducted on the Super Aqua Club lake (35 ha) in Quebec, Canada (Boudrias, D., 1997) using Little River Pond Mill circulators, reduced the required harvesting of Eurasian water milfoil by upwards of 500% without the use of chemicals, eradicated the requirement for weed harvesting, and reversed the signs of eutrophication. The level of oxygen at the 4.3 m depth rose from a low of 2.6 mg/l to 7.7 mg/l in only 2 months and circulation of the lake had altered the lake s super saturation oxygen values at the surface, and facultative to anaerobic conditions near the bottom to create an even temperature and oxygen profile. This change enabled indigenous organisms to compete more effectively, resulting in an increase in the lakes natural diversity and a reduction in fecal coliforms. Prior to installation of the circulators, fecal coliform counts were 300 cfu/100ml and within a short time period they were reduced to < 2 cfu/100ml well within provincial guidelines. Table 1.0 Increasing dissolved oxygen (DO) in a lake hypolimnion while using Little River Pond Mill circulators. Depth (m) June 1997 DO before circulators installation (mg/l) July 1997 DO one month after circulators installation (mg/l)

6 Figure 2.2 Reversing lake eutrophication at the Super Aqua Club using Little River Pond Mill circulators In a 25 ha lake in Quebec, Canada, (Boudrias, D., 1999), a study was done and in only four days time the anoxic hypolimnion (10-14 m depth) had been positively affected with a significant rise in oxygen observed in the upper regions of the hypolimnion and thermocline. Significant oxygen increases were also observed at the thermocline and hypolimnion at 150 m radius from the circulator within the four day time period. Table 1.1 Dissolved oxygen (DO) values of a lake in Quebec, Canada using Little River Pond Mill circulators. Depth (m) Control DO near circulator at time of installation (mg/l) Test 1 DO near circulator at 4 days after installation (mg/l) Test 2 DO at 150 m radius from circulator 4 days after installation (mg/l) n/a n/a

7 A significant alteration of the eutrophication parameters was observed in a lake in Quebec with decreases in available phosphorous and chlorophyll a, and increases in dissolved oxygen and transparency (Boudrias, D., 1999). Table 1.2 Decreasing eutrophication parameters in a lake in Quebec, Canada while using Little River Pond Mill circulators. Parameters July 1998 July 1999 Total Phosphorous (mg/l) Chlorophyll a (mg/l) Transparency (m) DO (mg/l) 2 m depth DO (mg/l) 4 m depth DO (mg/l) 6 m depth DO (mg/l) 8 m depth DO (mg/l) 10 m depth A household water reservoir at Congress, SK, Canada ( ) observed a significant reduction in turbidity within a couple months of installing a circulator on July 28, Table 1.3 Turbidity reduction in a household water reservoir at Congress Saskatchewan, Canada ( ) while using a Little River Pond Mill circulator. Date Turbidity (mg/l) January 05, May 05, July 05, August 05, October 17, January 09, May 01, July 10, An increase was observed in the dissolved oxygen levels of a 30,000 m 3 stocked fish pond near Kerrobert, SK, Canada during the winter of such that for the first time in five years there was not a winter fish kill; water clarity went from 1.8 to 3 m in depth. Table 1.4 Dissolved oxygen maintenance in a stocked fish pond in Saskatchewan, Canada using a Little River Pond Mill circulator. Date Oxygen (mg/l) October 15, November 13, November 29, February 13, February 22, March 07,

8 Waste Water Treatment Little River Pond Mill circulators have been used in waste water treatment for over 20 years with global waste water markets including Australia, New Zealand, China, Panama, the United States and Canada. The circulators are used in municipal, livestock, industrial and commercial waste water operations for odour abatement, gas emissions reduction, solids, BOD and COD reduction. In 2004, circulators were installed in the solid cell of a two stage dairy lagoon near Bassano, Alberta, Canada in 4.3 m of solids a backhoe was required to dig a hole to install the circulators. In five months the solids had been digested down and the producer was able to pump directly out through his irrigation pivot for a land application. 2 months after circulators installation 5 months after circulators installation Figure 3.0 Dairy waste treatment using Little River Pond Mill circulators 2004 Significant reduction of solids/sludge was observed in a livestock/poultry manure lagoon in Nebraska, USA in Table 2.0 Solids reduction in a livestock and poultry manure lagoon using a Little River Pond Mill circulator. Date Solids/sludge depth (m) Installation February 24, months 1 week after installation June 01,

9 3 months after circulators installation At time of circulators installation Figure 3.1 Swine waste treatment using Little River Pond Mill circulators Significant solids reduction has been observed in many municipal systems. In a municipal lagoon in Nebraska, USA (1995), solids reduction was observed in only 12 days from time of circulator installation (May 25, 1995) where the solids were reduced from an even 0.3 m depth to m (June 06, 1995). In two separate municipal systems in Ontario, Canada, significant improvements were observed in many test parameters. Table 2.1 Improving municipal waste water quality using Little River Pond Mill circulators. Test Parameter Municipal Lagoon A (1991) Municipal Lagoon B (1994) Biological Oxygen Demand (mg/l) Influent: Effluent: Influent: Effluent: Ammonia (mg/l) Influent: Effluent: Influent: Suspended solids (mg/l) Influent: Effluent: Influent: Effluent: TKN (mg/l) Influent: Effluent: n/a Phosphorus (mg/l) n/a Influent: Effluent: ph n/a Influent: Effluent:

10 A major meat processor in the Midwest United States (processes 16,000+ swine daily) utilizes wind driven Little River Pond Mill circulators for alteration of its ammonia levels into ammonium on its secondary and finishing waste water lagoons (30 surface acres each). Ammonia emissions prior to circulators installation averaged ppm and the circulators were able to promote the conversion of the ammonia to ammonium and final ammonia emissions were reduced to less than 2 ppm. The final waste water is used to irrigate crop land. Figure 3.2 Swine processing waste water treatment using Little River Pond Mill circulators Municipal lagoon system (with carrot & potato processor) Bassano, Alberta, Canada Before After Figure 3.3 Municipal waste water treatment using Little River Pond Mill circulators

11 Significant ammonia emissions reduction was observed in a municipal effluent lagoon in a trailer park in Nebraska, USA (1995). Ammonia emissions were 10.6 mg/l at time of circulator installation (March 09, 1995) and only 2.2 mg/l at the second test period only 27 days later (June 21, 1995). A research project conducted in Ontario (Toombs, Michael R., 1997) showed significant reductions in VFA s, total phenolics and odour potential regardless of continued manure inputs to a test tank every 7-10 days the control tank only had one input of manure at the start of the test. Although there are not significant changes in methane and hydrogen sulfide production, the circulator was able to maintain control tank values regardless of regular inputs to the test tank. It should be noted that this study did not utilize the recommended quantity of circulators (2) and was still able to achieve significantly positive odour and gas reduction. Table 2.2 Odour reduction in a liquid livestock manure storage using a Little River Pond Mill circulator. Test Parameter Control Tank Test Tank VFA s (mg/l) 7, Total Phenolics (mg/l) Odour Potential (ou/l) 143,199 44,263 Methane Hydrogen Sulfide (mg/l) Liquid Significant BOD reductions have been observed in many municipal systems. A municipal system in Quebec, Canada (August 1998) reported a BOD reduction from 167 mg/l in the influent to 1.1 mg/l in the effluent. Figure 3.4 Municipal waste water treatment in Australia using Little River Pond Mill circulators

12 Significant increases in dissolved oxygen have been reported in many municipal systems. A municipal system in Nebraska, USA (1995) reported a rise from 2.3 ppm at time of circulator installation (May 25, 1995) to 8.9 ppm only 2 months later (July 29, 2005). The DO test was taken at 1 metre from the surface. Figure 3.5 Winery waste water treatment in Australia using a Little River Pond Mill circulator More Than Just Odour Control Little River Pond Mill circulators are used for more than just odour control. They can be used to: Create a homogenous nutrient solution throughout a lagoon When a lagoon is circulated, its contents become homogenous and testing and pumping practices are enhanced. Create an in-situ bioreactor, i.e. use the sump, lagoon, lake or pond as the containment cell Circulation is a key component of any bioreactor and the technology can be applied to almost any containment cell. Through monitoring of various test parameters including temperature, ph, nutrients, etc., many pollutants can be effectively remediated/treated through use of circulators. Promote conversion of sulfur and nitrogen into bioavailable and stable forms thereby decreasing volatile nutrient losses to the atmosphere Elements such as sulfur and nitrogen, when in an oxygen rich environment become bioavailable and stable thereby decreasing the incidence of their loss to the environment and improving environmental conditions through proper land application. Promote precipitation of iron, manganese, and phosphorous thereby improving water and waste water quality

13 Elements such as iron, manganese and phosphorous precipitate out of water when in an aerated environment. Through circulated aeration, these elements can be promoted to precipitate out of water and waste water thereby improving the quality. Promote water re-use and water conservation through reclamation of waste water Circulator remediated/treated waste water (livestock, municipal, industrial and commercial) has he potential to be re-used for a variety of applications e.g. flushing barns, gas storage, etc. Promote energy conservation through use of low power or renewable energy powered circulators Many applications that presently use high hsp circulators and aerators can effectively switch to lower hsp or renewable energy powered (solar and wind) circulators and assist in reversing Canada s poor standing under the Kyoto agreement. In 2004, by switching from their conventional aeration system to Little River Pond Mill circulators, a Hutterite Colony near Bassano, Alberta, saved $12,000 in one year. Provide producers with a saleable commodity fertigation liquid and carbon credits Fertigation liquid is achieved when livestock waste is remediated with circulators. The effluent becomes a liquid bio-fertilizer solution full of nutrients, enzymes and useful microorganisms. Some producers may wish to sell excess fertigation liquid since it has been found to be very beneficial in plant production and land rejuvenation. Carbon credits may also be attainable based on both aerobic remediation of waste waters (prevention of methane production) and the conversion of carbon into microbial bodies. Besides the added benefit of reducing potentially harmful organisms such as coliform bacteria, significant increases in aerobic bacteria have been observed. The town of Assiniboia (1991), with a population of 3,000 persons, and utilizing ¼ of the recommended circulators, significantly reduced it coliform bacterial count in its municipal lagoon in only 3 months from 9,300 mpn orgs/ml (prior to installation March 14, 1991) to 40 mpn orgs/ml on June 11, A study conducted in a swine lagoon in 2001 in central Alberta, Canada showed how significantly both the coliform bacterial reduction can be, and the potential for using circulators to use microorganisms for carbon sequestration and ultimately for the sale of carbon credits. Table 3.0 Microbial growth in a swine lagoon in Alberta using Little River Pond Mill circulators. Total Coliforms (cfu/ml) Fecal Coliforms (cfu/ml) Aerobic Plate Count (cfu/ml) Installation 700, ,000 5,700 Pump Out <1 <1 26 zillion

14 Benefits Summing up what has been discussed, there are many environmental, economic and social benefits that can be achieved through use of circulators. Circulators promote the natural process of biogeochemical remediation in surface waters and waste waters an in-situ bioreactor. By promoting a natural process and by tweaking the natural process to fit the desired end result, an operator can achieve many other side benefits such as cost savings, energy savings, assisting Canada in meeting Kyoto requirements, and reducing pollution loading on the environment. Circulators promote a reduction of both odorous and non-odorous gases when used aerobically. Specialized tweaking of the process to achieve a desired reduction at just the right point in the remediation process however involves a trained operator. Circulators could be used for the creation of carbon credits by eliminating the production of such gases as methane and by conversion of carbon into microbial bodies rather than emitting carbon to the atmosphere. Circulators can be used to reverse eutrophication in lakes and other surface water bodies thereby increasing recreational potential, enhancing fish survival/fisheries industry, enhancing species diversity and the return of indigenous species, and improving water quality through the alteration of elements and the control of nuisance/pest/harmful plants and organisms. Circulators can be used to reduce the financial and environmental costs associated with front end treatment for municipal potable water and waste water. Circulators can be used to reduce the environmental and financial costs associated with the oil and gas and mining industries. Waste water can be reclaimed and re-used within these industries instead of new fresh sources being used for pumping, collection, processing, and other practices. Circulators can be used to mineralize and stabilize nutrient elements thereby enhancing fertilizer value in the livestock industry and in return potentially reducing pollution loading on the environment (preventing losses to the atmosphere and through leaching). The final fertigation liquid is homogenous, easy to test and easy to manage (place within a manure management plan and apply to the land). Overall, circulators can provide a reduction to environment, economic and social costs associated with surface water management and waste water treatment. Conclusion Through use of circulators, you are creating a man-made solution to a man-made environmental challenge using Mother Nature s natural processing techniques using manmade equipment.

15 The Little River Pond Mill circulator is an effective ecosystem enhancement tool that can be used to tailor-make management solutions in aquatic environments such as waste water ponds and tanks, sewage lagoons, and various surface water bodies. Whether your desire is to reduce or eliminate odours and solids in waste water or sewage, reduce hydrocarbons in a sump, reduce environmental liabilities, promote environmentally friendly waste water management practices, improve your corporate image and reduce costs, or reduce the signs of eutrophication in a lake, circulators are an effective tool in the management and treatment of aquatic based environments. Remember that not all circulators are created equal and it is important to know the design challenges and benefits of each circulator type and how it interacts with the fluid dynamics and challenges of your remediation/treatment project, and equally important is knowing the knowledge base and background of the manufacturer and distributor/dealer/consultant that you choose. A properly functioning in-situ bioreactor is only as good as the product gong in and its operator. References Bugg, J. D 1996 Flow in a recirculating pond agitated by a Little River Pond Mill Department of Mechanical Engineering, University of Saskatchewan May 17, 1996 Michael R. Toombs 1997 Final Report May 20, Evaluation of a wind powered aerator to control odours from a liquid manure storage Ontario Ministry of Agriculture, Food and Rural Affairs, Ontario, Canada Various unpublished reports were obtained from dealers, previous dealers (e.g. D. Boudrias) and clients. Photos are courtesy of Kathleen Cameron Dagaz Environmental Inc. and Chris Hilder Windhill Pty. Contact Information Dagaz Environmental Inc. (formerly the environmental management division of Sunset Solar Systems Ltd.) #2, rd St. E. Saskatoon, SK S7N 1Z1 Canada P , , F Web: info@pondmill.com