Benefits of Seair Golf Course Water Treatment

Seair is a leading developer of patent protected diffusion and sterilization technologies which allow for the efficient diffusion of gases into liquids, thereby facilitating numerous applications in a wide variety of industries. Seair’s primary focus is developing and selling equipment that diffuses gases, such as oxygen, ozone or carbon dioxide, into a liquid, resulting in a supersaturate solution. The major difference between Seair and other diffusion technologies is Seair’s ability to achieve extremely small bubble size, which in turn allows for the mass transfer of gas to fluid. The result is a stable condition where gases remain in solution for extended periods of time, leading to increased productivity and lower operating costs. Seair’s diffusion systems promote healthy pond and irrigation water, which in turn leads to superior turf condition in a highly environmentally friendly manner. The Seair solutions are ideal for situations where golf courses rely on recycled water.

Seair’s diffusion system produces micro-bubbles of gas which, at 5 microns in diameter, are 1,000 times smaller than those produced by traditional fine-bubble diffusers. The gas micro-bubbles provide for an extremely efficient transfer of gas into irrigation water. This efficiency will not only increase dissolved oxygen levels (decrease pH, chelate metals, disinfect water) and thereby enhance irrigation water quality, but in doing so require a fraction of the energy used in other diffusion systems.

Seair has a unique background in agriculture horticulture, and aquaculture, collecting data on the benefits of adding oxygen, ozone, and CO2 to irrigation water. Using this data, Seair has adapted this unique diffusion technology to the golf course industry. Several years of studying the effects of diffused gasses in irrigation water is the basis for a specialized diffusion unit specifically designed for the golf courses. The SA 300PB-120 is specifically designed to address the most demanding soil and water treatment issues on golf courses.

Golf courses are increasingly required to use effluent as their source for irrigation water. The SA 300PB-120 system is a stand-alone portable treatment solution that allows golf courses to use ozone gas to improve the quality of their pond and irrigation water. Ozone is used to eliminate harmful contaminants, bacteria, and create an aerobic environment that facilitates the decomposition of unwanted organic materials. With legislation forcing golf courses to use reclaimed wastewater as their source, the need for enriched bacteria free water is becoming more important for the health and well being of golf courses and golfers alike. For example, the SA 300PB-120 system is being used at Castle Pines Golf and Country Club in Castle Pines, Colorado.

Carbon Dioxide

Along with oxygen and nutrients, pH plays a significant role in turf health. High pH soils promote unfavourable bacterial growth, whereas excessively low pH promotes fungal growth10. Ideal turf pH should remain within 6.5-7.0 range (depending on the golf course). For turf to fend off disease and promote healthy growth, and to maintain a proper soil structure, a constant pH, suited to the region, should be employed. Upsets in the pH adversely affects all organisms, including grass10. For most golf courses, water is one of the largest contributing factors for pH. For some courses it is necessary for the addition of acid or base to increase the pH of the soil10. Seair has the ability to dissolve CO2 gas, a very inexpensive product to purchase into the irrigation water at very high efficiency.

Addition of carbon dioxide has been used in industry for many years to neutralize high pH waters. When dissolving CO2 into water it reacts with the water using the following reaction scheme:

H2O + CO2à H2CO3

Carbonic Acid formation

When in solution the carbonic acid dissociates as a weak acid, releasing a proton and forming bicarbonate:

H2CO3à H++ HCO3-

Carbonic acid first dissociation

HCO3- à H++ CO32-

Carbonic acid first dissociation

Carbonic acid is a diprotic acid, which means that has the capacity to release two protons. The first dissociation indicated as above is a weak acid with a pKa of 6.352. The pKa of the second dissociation is at 10.329, indicating bicarbonate as a weak base. The titration curve for carbonic acid is typical for a diprotic acid with two equivalence points9.

Titration of carbonate with a strong acid

When carbonic acid (Carbon dioxide injection) is used to reduce high pH water, a similar curve forms, the deprotonation steps are not as pronounced, however it provides an excellent picture of the buffering capacity a of carbonic acid/bicarbonate.

Titration Curve of a weak base with carbonic acid addition

Carbonic acid addition to water that includes weak bases such as ammonia, carbonate, acetate and other organic acids form a flatter curve with a very strong buffering capacity at around a pH of 6. The buffering capacity is of importance because it allows resistance for high and low pH upsets9. With resistance to pH upsets, soil micro organisms and grass can maintain healthy long term growth.

If too much CO2 is added a low pH situation is formed. If the pH is still too low after the soil-water interaction, carbon dioxide will be released (similar to gas release from carbonated beverages). This will release to a point when the pH balances near the pKa.

Other acids that are also used to decrease pH of golf course water, such as HCl, H2SO4, and CH3COOH do not provide a buffer against upsets in the water pH and also are very hazardous to handle due to their corrosive nature. Carbon dioxide is applied using compressed gas cylinders, however if there is ever a leak, the gas will be released to the atmosphere with no hazardous effects. Also, the cost of carbon dioxide is very inexpensive, particularly when applied with the extremely efficient Seair diffusion system. The Seair diffusion system allow for total reaction of carbon dioxide with water, and can be performed in an inline process, without any other specialized equipment.

It is to be noted that carbonic acid should be used when the total pH of the soil and water remain below 8.5. If the pH is allowed to increase higher than 8.5, carbonate ions will begin to form. This is not beneficial to turf growth, as carbonate will react with calcium and magnesium to form precipitates, leaving the sodium ion as the dominant cation in the soil. However, if the pH is maintained in the soil this should not occur. It should be advised, as with using any acid to remove alkalinity, to properly inspect the soil for salinity build up or calcium deficiency in the irrigated soil. Carbonic acid injection may not be suitable for all soils and hence should be tested accordingly.

Oxygen

The Seair Diffusion System has the ability to dissolve oxygen into water to create a stable oxygenated state which can be used for golf course irrigation systems. This is accomplished by the use of a relatively small oxygen generator that conveniently concentrates oxygen on site. The Seair system very effectively increases the dissolved oxygen (D.O.) content in irrigation water. In doing so, the system ensures that oxygen is readily available in the soil/turf profile and prevents soil oxygen levels from becoming depleted by actively growing turf roots or soil microbes 1.

The resulting elevated D.O. levels in irrigation water lead to higher D.O. levels within the soil pore water. This additional oxygen in the root-zone environment is then available for use by turf grass roots and soil micro-organisms.

Soil micro-organisms are an essential part of the soil system since they are the main force driving nutrient movement in soils 2. Providing an aerobic environment for soil microbes to flourish is essential in any turf management system. Seair’s oxygen diffusion system can accomplish this by increasing irrigation water D.O. levels to well above the approximately 5mg/L needed in order to maintain an aerobic environment 3.

By increasing the amount of oxygen available in soil pore space, Seair’s diffusion system effectively supports critical soil microbial activity. Elevated oxygen levels within the soil pore space aids microbes in the mineralization of organic matter to useful forms of nutrients required for plant growth 4. Maintaining an aerobic environment not only helps break down organic matter, but also reduces the potential for formation of H2S and CH4 that prevail in anaerobic conditions.

Soil microbes also aid in the aggregation of root-adhering soil at the soil-root interface. This is the physical environment where roots take up O2, water, and nutrients 5. Since soil productivity is dependent on aggregate formation, soil microbes have a direct influence on both soil fertility and productivity 6. By facilitating root growth and aerobic microbial activity, Seair’s oxygen diffusion system helps maintain a balanced turf/soil system and has the potential to reduce fertilizer requirements in the long run.

Ozone

Ozone is a triatomic form of oxygen that naturally forms in our environment. It is the major gas responsible for blocking harmful electromagnetic radiation. However, it is also formed during a thunderstorm at the ground level. Due to Ozone’s structure it is a very powerful Oxidant with an oxidation potential of 2.07V7.

Ozone Resonance structure

Golf course irrigation water is not always pure, clean water, and may sit in holding ponds for days before it is used on the course. These ponds are breeding grounds for bacteria, viruses, cysts and fungus8. When this water is applied to turf it will affect the health of grass, as well as the golfers. Ozone applied to the irrigation water using the Seair diffusion system reduces or removes the pathogens and unwanted organic matter that may enter the system. This is possible as an inline process because the Seair system create a very stable 5 micron bubble which allows for the total utilization of ozone. If excess ozone is added, other beneficial effects will occur as well. The effect on metals will be discussed later in this report. If there is an existing algal, fungal or bacterial problem occurring on the course, ozonated water will help to alleviate this problem as well. Ozone has minimal effect on larger organisms such as grass or trees; however it is detrimental to small organisms. Ozonated water will slowly kill algae or fungus, while having a little or no impact on the grass. Persistent algal or fungal growths on turf grass will involve addition of algaecides or fungicides that are not very environmentally friendly, and may also be harmful to the golfers. Adding ozone to irrigation water may reduce or eliminate the need to use or store chemicals.

Chemical fertilizers added to the golf course are a very large expense. In some areas the soils are lacking metals or the soil conditions do not allow for easy metal uptake. Metals present in the irrigation water ozone will also indirectly chelate metals. For metals such as iron and manganese, this makes them more biologically available. For heavy metals such as mercury or arsenic, the metals are reacted to their irreversible hydroxide form, making them not biologically available.

When ozone is added to any system there is always a corresponding amount of oxygen that is added. The ozone is incorporated at only a few percent by gas volume. The majority of gas added is oxygen, therefore when ozone is added to the system, oxygen is added as well. Furthermore, in some ozone reaction mechanisms oxygen is reformed after it has reacted with the organic molecules in solution.

The benefits of ozonation extend beyond sterilization and chelation, ozone will remove unpleasant odours from the irrigation water or pond, by oxidizing volatile organics and removing H2S. There is no residual odour after use as compared to chlorine. All ozone and oxygen gasses are generated on site, and therefore eliminate the need for chemical storage and transport.

The Seair system can incorporate a single gas, two gasses or all three gasses in a single step. Each golf course is unique and as such the solution for each will be different. The addition of each gas can be dosed to meet specific concentration in a system. The SA300 PB 120 will deliver oxygen and ozone in one port, while the second port can inject ambient air, carbon dioxide, or more ozone if desired. Seair technology is adaptable and can be customized to meet the needs of the golf course.

 Bibliography

1. Pillar, Dean.Soil. Physical Properties Monitoring Oxygen for Success. Green Master, August 2006. (pp 8)

2. Papli, Gail et al. Biological Approaches to Sustainable Soil systems. Taylor & Francis Group, LLC, 2006 (pp 606)

3. Skorulski, Jim. Pond aeration, USGA Green Section Record, Vol 38, Number 1, January/February 2000. Turf Line News June/July 2000

4. Papli, Gail et al. Biological Approaches to Sustainable Soil systems. Taylor & Francis Group, LLC, 2006 (pp 612)

5. Papli, Gail et al. Biological Approaches to Sustainable Soil systems. Taylor & Francis Group, LLC, 2006 (pp 609)

6. Papli, Gail et al. Biological Approaches to Sustainable Soil systems. Taylor & Francis Group, LLC, 2006 (pp 610)

7. Beltran, Fernando J. Ozone Reaction Kinetics for water and Wastewater Systems. CRC Press LLC, 2004 (pp 119)

8. Spellman, Frank R. Choosing Disinfection Alternatives for Water/Wastewater Treatment. CRC Press LLC, 1999.

9. Zumdahl, M. Zumdahl Chemistry, Hughton Mifflin, 2000

10. Sachs, Paul C, et al. Ecological Golf Course Management. Wiley, 2002.

Submitted by Guy Scott  info@seairaustralia.com.au