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These thoughts were prompted by a reading of Al Gore’s interactive book, Our Choice, reissued as an interactive app for Apple iPads, iPhones and iPods earlier this year. You can download the Our Choice app right now.

It’s certainly a thought-provoking read and presents some pretty stark choices. One statement caught my eye: “Modern agriculture is one of the largest sources of global warming pollution.” This is quite some statement because, if it’s true, it really condemns us to extinction. The world population is growing at a rate of about 1.3% a year, which means it doubles in 54 years.

Added to that, a greater proportion of that growing population is emerging into the middle class. Think of the Asian economies (China in particular), Eastern Europe and Latin America. More people eating more food. It’s not only quantity: affluent people want food from all around the world, and more meat, which is very wasteful to produce. In fact, the Food and Agriculture Organisation of the United Nations estimated that the meat industry contributes 18% of all greenhouse gases.

Gore estimates that industrial agriculture uses 10 calories of energy from fossil fuels to produce one calorie of food. This is wasteful enough, you might think, but even more wasteful when you consider that a lot of that food is fed to meat animals, thus further reducing the yield.

In response to the growing world population, agricultural productivity has also increased. For example, US farm output has risen annually by 1.58% per year for the last 50 years, so that 2008’s output was 158% higher than that of 1948. A major factor in this rise in productivity has been the increasing use of nitrogen-based fertilisers. These fertilisers are largely synthetic and to make them requires the burning of enough natural gas to release 1.25 tons of carbon (or 4.6 tonnes of carbon dioxide) into the atmosphere.

Another unwanted by-product of nitrogen-based fertilisers is that they drain into rivers and dams and stimulate the growth of algae in them, and in the ocean. When alive, these algae tend to block out the sun thus affecting the growth of other water-borne organisms; when they die, their decomposition consumes the oxygen dissolved in the water. Fish and other plants die, creating what scientists call “dead zones”.

I’m reminded of nothing so much as an athlete who takes steroids. The results are quite excellent but the muscles (and the body in general) are degraded in ways that are not obvious at the time, but are cumulatively very damaging.

This is a serious problem and clearly it’s only getting worse. However, there is at least a partial solution. Even better, it also offers a partial solution to one of other seemingly intractable problems we just don’t like to face, namely the treatment of human waste.

Current methods of treating sewage are actually as wasteful as the modern methods used to create the food in the first place. Here in South Africa, a water-scarce country, we are particularly sensitive to the fact that treating sewage uses up a lot of water that was costly to obtain and purify in the first place. Haven’t we just signed another agreement to harvest more of Lesotho’s water at vast cost, for example?

In addition, overloaded sewage plants are simply discharging raw sewage into our riverine systems.

A very workable solution for developments such as housing estates (especially golf courses), shopping centres, intensive farming, rural hotels, game lodges, remote clinics, schools and others, is simply to divert all the waste water and sewage into a closed purification system that uses natural bacteria and ozone to purify the water. Once the system is purchased, it is relatively maintenance-free, requires minimal human intervention (no horrible solids to clear!) and produces water that is ideal for irrigating crops or gardens. Clients who use it for that purpose rave about the results. This way of thinking not only saves water, as you can see, it minimises the need for polluting fertilisers.

There’s also a nice symmetry about the whole process.

Within 16 years of its discovery in 1840, ozone was already being used to disinfect operating rooms and sterilise surgical instruments. Today, various forms of ozone therapy are used to assist in the treatment of a wide variety of ailments.

Ozone can even be effective in a spa bath but only as a means of assisting in killing bacteria in the water, thus reducing the amount of chlorine required. For ozone to be effectively absorbed through the skin and into the blood of people using such a bath, the ozone would have to be thoroughly-mixed with warm water. This can only be achieved by utilising a very sophisticated, industrial-type mixing device.

Better methods

The use of an ozone steam cabinet offers a much more effective treatment. In this instance, the patient sits in an enclosed capsule for 20 to 30 minutes, while steam and ozone are introduced into the cabinet. As the body warms up, so the skin’s pores open up, allowing the ozone gas easier access into the body and the bloodstream.

Since the majority of toxins are held in the lymph and the fat, this treatment is a very effective way to eliminate them from the body. Moreover, as the skin is the largest organ of elimination, the majority of the toxins are sweated out, sparing the liver and the kidneys most of the work.

In medical practice another effective method of introducing ozone into the body is to remove around 100ml litres of blood from a patient. Ozone is then injected into this blood, after which it is reintroduced to the patient. Furthermore, ozone can be directed directly at a tumour or ulcer, helping to reduce its size and ultimately assisting in healing the wound.

A wide range of health benefits associated with the use of ozone therapy have been reported by patients, whether they have been using steam, insufflation, drinking ozonated water or applying ozone topically with ozonated olive oil or gel.

Ozone gel, for example, has been shown to assist the skin to promote healing in respect of a variety of skin conditions, including acne, athlete's foot, blisters and boils, cold sores, haemorrhoids, insect bites, recent scarring and ulcers, along with many others.

History of ozone use

The ozone steam cabinet was originally used by Dr Kellogg as far back as 1881, and by the end of the 19th century, ozone was being effectively used to disinfect drinking water of bacteria and viruses across much of mainland Europe.

During the First World War, many doctors that were by then familiar with the healing properties of ozone applied it topically to infected wounds. This not only remedied infection, it also had hemodynamic and anti-inflammatory properties.

Today ozone therapy is recognised and utilised in Germany, Italy, France, Russia, Romania, Poland, Czech Republic, Slovakia, Austria, Hungary, Bulgaria, Yugoslavia, Greece, Spain, Portugal, Israel, Dubai, Japan, Singapore, Cuba, Mexico and 14 US states.

However, despite the fact that ozone therapy has been used to treat several million people in Europe, for a variety of medical conditions from eczema and gangrene to strokes, hepatitis and herpes, it remains illegal in the majority of US states and also in Canada. In fact, the Federal Drug Administration (FDA) has publicly condemned ozone therapy in front of a Capitol Hill sub-committee, citing it as an example of medical fraud.

This attitude has been exacerbated by certain marketers of ozone generators and other ozone-based products. These entities make fantastic promotional claims that suggest that ozone is a miraculous cure for all disease, including cancer and AIDS.

The ozone reality

Nonetheless, proponents of ozone therapy suggest that while it is an effective treatment for many health issues, their claims in this regard are more modest. These people say that the use of ozone by injection or steam cabinet simply promotes the body's own mechanisms for healing.

Nonetheless, ozone has recently been scientifically proven to selectively attack viruses as well as cancer cells without harming healthy cells. The Canadian Military, in association with the International Red Cross, recently completed a 100% successful study with monkeys proving ozone can safely sterilise blood that is infected with viruses. Monkeys injected with blood plasma contaminated with SIV (the monkey equivalent of the AIDS-related virus) died within 12 to 14 days, while all the monkeys receiving injections that had been treated with ozone remained uninfected and healthy.

Locally, the Ozone Association of Southern Africa (OASA) has been established with the purpose of encouraging members to further their studies and to create a network of people doing ozone therapy, as well as providing a support base for members. The association has created self-regulating guidelines with regards to protocols, machine specifications and any additional education required.

While not implying that ozone is a cure for anything and everything, OASA points out that ozone can help assist the body in such a way that its own mechanisms can promote a healthier lifestyle. Ozone, along with diet and exercise, are the best and most effective ways to assist the body’s own natural defences.

For more information please see:

• http://video.google.com/videosearch?q=oxygen+mccabe
• http://www.familyhealthnews.com/articles-politics-medical-ozone.html
• http://www.o3center.org/Articles/OzoneandthePoliticsofMedicine.html
• http://www.ozoneassociationsa.co.za/

Additional information can be obtained from the following contacts:

• Shawn Stewart
  Enviroglobe
  e-mail: stewies@mad.scientist.com
  Cell: 083-484-0401
  Work: 011-435-5777

• Peter Essex Clarke
  Doctor, Centre For Homeopathy
  e-mail: essex@netactive.co.za
  Cell: 082-446-9244
  Work: 011-706-3280

• Ozone Association of South Africa
  Michelle Nicolopulos
  e-mail: talisman1@telkomsa.net
  Cell: 082-600-8908

By now, everybody in the HVAC industry will be aware that the draft regulations concerning the phasing out and management of ozone depleting substances in South Africa were published in the government gazette on 14th January this year. The fact that South Africa is accepting its share of responsibility for ensuring the continuing self-regeneration of the damaged ozone layer is commendable. Ground-based and satellite monitoring continue to measure the steady progress of the ozone layer with precision as it recovers from the damages caused by ozone depleting substances, particularly chlorinated fluorocarbon chemicals [CFCs] which were first manufactured commercially way back in the 1930s. By the early 1980s, recognition of the potentially catastrophic global consequences of the ozone layer becoming ineffective focussed attention on ozone itself which had, for nearly 100 years been applied to various processes with only limited and sporadic successes. If ozone was succeeding so well in protecting our existence on earth why was it not showing more successes in other applications? To answer this question many researchers began to look again at ozone itself.

What is ozone?

Chemists say that oxygen forms “allotropes”, which is just a way of saying that oxygen can exist in different forms. Normal oxygen gas [or liquid under high pressure] is the familiar stable O2; two atoms of oxygen joined together; the 20% of the atmosphere which reacts with [oxidises] iron, copper and other metals. Single atoms of oxygen, O1, called “nascent” or “atomic” oxygen, exist but only very briefly. A good example illustrating this is when water, which always contains small amounts of dissolved oxygen, heats up and releases atoms of O1 from solution which immediately either combine with each other making O2 or oxidise any metals they come into contact with causing an extremely rapid form of corrosion known as “oxygen corrosion”. Under the influence of UV radiation or electrical arcs, O2 will react to form the ozone allotrope, O3, which is also not stable but changes back to O2 more slowly than O1 does. Incoming UV radiation from the sun causes two different effects in the ozone layer around the earth. Shorter wavelength UV creates two O3 atoms from three O2 atoms whilst longer wavelength UV is the energy absorbed by O3 atoms when cracking them back to become O2 atoms again. The balance between these two UV effects maintains the total amount of ozone in the layer which serves as a barrier absorbing much of the UV from the sun which would otherwise be severely damaging to life on the surface of the earth.

In the atmosphere, ozone is slightly heavier than oxygen so it tends to sink slowly towards the ground. However, because ozone is inherently unstable, by the time it reaches ground level its concentration in the atmosphere is generally less than 1 part per million which is below the normal odour detection threshold of people. Similar small amounts of ozone are formed at ground level by residual solar UV causing reactions between nitrates and sulphates in the air and hydrocarbons of animal and plant origin. During the second half of the twentieth century, due to the build-up of nitrate and sulphate airborne pollutants in urban industrial areas prior to legislation limiting polluting emissions, ozone concentration increased to a level where its odour became noticed and was erroneously labelled as the odour of “pollution” resulting in a perception that ozone was the main culprit in smog formation. In reality, ozone has a characteristically “clean” aroma when it is formed in nature by lightening, or is artificially manufactured in an unpolluted environment. It is theoretically possible but not practical to store ozone in very high pressure cylinders. Consequently, ozone is manufactured on site either by specific UV lamps, water electrolysis or the now widely used method of corona discharge. Electrolysis is not an energy-efficient process so the two most common methods for ozone production are UV for small amounts, mainly used for air purification, and corona discharge when larger quantities are required. Figure 1 is a schematic of a corona discharge unit which is fed either by air in which the 20% oxygen content is sufficient for the amount of ozone needed, or, if higher amounts of ozone are required then pure oxygen is supplied to the corona unit.

Figure 1. Schematic of a corona discharge unit for manufacturing Ozone. Picture courtesy of Ozone Service Industries Pty Ltd

Alternating electrical potentials measured in kV are applied between the high voltage and earth electrodes at kHz frequencies. Total electrical power demand varies from small fractional kilowatt units, increasing for larger units according to rates of ozone production required. Corona discharge systems using air produce ozone in gas phase concentrations of 1 - 5% by weight and up to 14% by weight if using high purity oxygen instead of air.

The Electrochemical Oxidation Potential [EOP] of a substance, measured in volts, is a good indicator of how strongly and how quickly the substance will act as a disinfectant. Figure 2 shows 9 of the highest EOP values of disinfectant substances. Fluorine has the highest EOP but is very costly and difficult to use within current technology. The next highest EOP substance, the Hydroxyl-radical is not a substance by itself but is produced when air contacts the surfaces of a titanium grid under specific wavelength UV radiation. Disinfecting activity of the Hydroxyl-radical is rapid but confined to micro-organisms coming into contact with the titanium grid surfaces. Next comes Oxygen [atomic], the O1 previously noted which, in practice, reverts back to the O2 form too rapidly to provide practical disinfection. Only slightly below Oxygen [atomic] is Ozone with an EOP value of 2.08V which is almost twice the EOP of normal O2 at 1.23V. [As a disinfectant, O2 oxygen is poisonous only to anaerobic bacteria which limits its use to a few specialised applications.]

Figure 2. Provided by Ozone Service Industries Pty Ltd.

A more accurate way to assess the disinfecting power of ozone is to compare its EOP with that of chlorine which is still the most commonly used disinfectant worldwide. The EOP of ozone at 2.42V is nearly twice the 1.36 EOP of chlorine indicating that ozone has almost twice the oxidising power of chlorine. Furthermore, many direct practical tests have shown that ozone disinfects by oxidation at a faster rate than chlorine. Also, ozone oxidises the organic debris resulting from dead bacteria and other micro-organisms as well as any other organic and inorganic substances with which it comes into contact. When all this happens in an aqueous environment then ozone delivers another benefit. It acts as a micro-flocculent, coagulating non-soluble particles which sink down leaving the bulk of the water with a clean appearance. The widely shown pictures of ozone treated Olympic swimming pool water in television coverage of the 1984 Olympic Games in Los Angeles showed pool water that was not only brilliantly clean but also had to comply with the stringent disinfection specifications of the International Olympic Committee.

Objectionable odours are associated with air and vapour from volatile liquids but they also emanate from non-volatile liquids such as water. The oxidation and coagulation abilities of ozone in water occur in a similar manner in air as well, either removing offending odour-producing particles completely or altering them to larger flocculated forms which are much easier to remove with electrostatic scrubbers or filters. In other words, ozone removes odours, not by masking them but by reacting with and coagulating the substances producing the odours. In this respect, ozone is again superior to chlorine which does remove some odours but may, in fact, add to odour problems by reacting with dissolved metals such as iron commonly occurring in aqueous solutions.

Chlorine does have practical handling and application advantages over ozone. Chlorine can be stored as solid calcium hypochlorite [HTH] granules, in liquid form as sodium hypochlorite or as a gas in cylinders under pressure. A functional advantage which chlorine also has is its stability in water and air which prolongs its disinfection activity into days, weeks or even months. By comparison, the half life time of ozone in air is generally a maximum of about 30 minutes and in water solutions open to atmosphere even shorter unless water circuits are specifically designed to ensure longer ozone contact times. One of the important research areas into disinfecting and purifying water supplied by municipalities and other water authorities has been to determine optimum methods of applying ozone to do the initial purifying and then adding chlorine in amounts small enough not to adversely affect the taste of the water but enough to protect the water against re-infection and growth of micro-organisms during storage and reticulation.

The progress of ozone application since the beginning of the twentieth century has, in similar fashion to many other practical technologies, been reliant on advances in other technical fields. UV lamps designed to produce ozone did not become commercially viable until the 1990s. Now special UV lamps are even available purely for breaking down any excess ozone emitted from treatment vessels. Like other strong oxidising agents, ozone corrodes non-stainless steel as well as other metals commonly used in water circuits. Therefore, the advent of plastic and reinforced fibreglass pipes and vessels allowed ozone solutions, as well as many other astringent liquids, to be far more widely and safely used.

Recent developments in metallurgy and dielectric materials have also greatly advanced the efficiency and reliability of corona discharge ozone manufacturing units. In the past a serious drawback of corona units was their short life due to dielectric breakdown causing arcing and corrosion across the electrodes. This electrode corrosion was exacerbated by low capacity desiccants which did not remove water vapour efficiently from air fed into the unit with the result that high voltage between the electrodes created nitric acid from airborne nitrogen oxides and water vapour. As these problems were overcome with improved designs and materials, successful ozone disinfection and purifying applications increased to the extent that the US Food and Drug Administration [FDA] the Department of Agriculture [USDA] and Environmental Protection Agency [EPA] issued successive Ozone Use Regulations during the period shown in Figure 3 covering a relatively recent 22 year period from 1982 to 2004.

Figure 3. Provided by Ozone Service Industries Pty Ltd.

Since 2004 many more advances have been made in both the technology and technique of manufacturing ozone and getting the best results from its powerful oxidising, coagulating and cleaning properties. Ozone is rapidly becoming the product of choice for the primary treatment of potable water, disinfecting and sanitising air, removing all sorts of odours, for example after fire damage, and cost-effectively achieving these results without leaving any sort of residue. A highly versatile tool indeed with 100% green credentials [except for needing small amounts of electrical power]. It has taken time to learn how to utilise ozone correctly and safely. The next article details the latest ozone production units available and recommendations by Ian Wright, the CEO of Ozone Service Industries Pty Ltd, as to how they can be optimally applied in HVAC systems, either alone or in combination with chlorine, other halogens such as bromine, or various types of UV radiation.

Where one really scores is when a totally new innovation comes about that actually alters the process permanently. For example imagine that you have to wash towels or dishes in very hot water to kill bacteria like in a hospital. Imagine that instead of killing the bacteria using heat you can do it using ozone gas. Then you can wash the items in ordinary warm water instead of piping hot, then treat them with ozone for the purpose of the sterilisation. Now that will save you the electricity used for heating the hot water, and that is permanent. Recently I happened to meet Ian Wright the CEO of Ozone Services Industries (OSI) and his company is in the business of supplying a whole range of ozone systems. That is all most interesting. The ozone is used in sewage treatments and water treatments and Wright has been installing systems in places like game lodges, hotels, hospitals, municipalities and a host of others where they have a direct and immediate water or sewage issue that needs attention.

The ozone does not only act as a sterilising agent but also precipitates minerals such as iron out of contaminated water. So the ozone can be used to clean impurities out of water as well as sterilising it.

Let me briefly explain the ozone. We humans need to breathe oxygen. Our atmosphere is about 20% oxygen and many people think that the more oxygen in the air the better. Not so! Too much oxygen is poisonous to people. Too much oxygen causes rust acceleration. So the 20% is just right. Oxygen in the air is found as the oxygen molecule O2 which is two oxygen atoms combined. Two oxygen atoms together are more stable than single oxygen atoms alone. It is like two friends with their arms wrapped around each other, the arms are occupied, as compared to a single person standing with arms outstretched waiting to grab something.

The ozone molecule is composed of three oxygen atoms O3. This molecule is much more reactive than ordinary O2 the third oxygen atom is just waiting to start a reaction with anything it can gel its hands on.

As a result ozone in small doses is poisonous to bacteria. They react so fast with ozone that the process kills them.

As far as impurities in water are concerned like iron, manganese they too react rapidly with the ozone and then turn into chemicals that deposit out of the water.

The ozone can also be used to sterilise and purify air. The ozone acts in a similar fashion as it does in water and removes odours and smoke as well as harmful bacteria.

OSI produces a range of products for treating air and water, these include air purification units, sewage and water processing plants plus a range of other products.

I found it most interesting to talk to lan Wright because he was bursting with ideas. That is the sort of approach that appeals to me. Wright is supplying many systems to all sorts of customers. I even met a farmer who arrived to collect his new machine to kill bacteria on his agricultural produce after harvesting. He enthusiastically said that he had tried one of the machines a while ago and it performed way better than specification, so he was back for another one. He had to guarantee a low bacteria count when selling his produce to a distributor, and he had found the answer. OSI even has a simple unit with which you can wash fruit with ozone rich water to kill bacteria and so extends shelf life of the produce.

Wright spoke to me about a number of new ideas and they all appealed to me. The ozone solution is good chemistry and physics, and that appeals to my scientific instinct. OSI is a rapidly growing company that seems poised to grow even faster. They are also keen to talk to anybody with any problem that they think could be addressed using ozone treatment. So call them if you have any ideas.

Ozone is not new, it has been around for years, but let me caution about a distinction between the really scientific use of ozone like OSI does, and other folks who sell all sorts of home ozone therapy and such like. That is not the same thing. I am not supporting the 'home ozone foot bath' to get your feet sparkling fit by next week. There are all sorts of black magic 'do-it-yourself' ozone products available. They are all trading on the mystique of the word 'ozone' just like the 'detox yourself' craze.

The real scientific application of ozone in air and water applications I believe will advance significantly. The ozone really works for correct scientific reasons, and is not harmful to any workers or maintenance people. Ozone systems do not need highly skilled people for general maintenance and daily operations, so they can be installed in game lodges, sports stadiums and any place that is not connected to a major municipal system to which you pay rates for the service. Within the cities air cleaning systems in restaurants, conference venues, or even hospital operating theatres can also use ozone devices.

Cunning applications of good science are always a move in the right direction, and as they gain attention more and more uses tend to be found for them. I am sure that there are another dozen smart ideas just waiting for an ozone solution.

-- Dr. K. Kemm

They offer an extensive range of products and services which provide the industry with proven solutions and capabilities.

Wendy van der Merwe, Principal Scientist in the Measurement and Control division of Mintek has been working on Ozone treatment for some time, and in mid 2010 installed equipment in order to research the feasibility of using Ozone for cyanide destruction, regeneration, and pre-oxidation.

"I wanted to look at feasibility of commercialising Ozone as a cyanide destruction technique” she comments. “Ozone has been used in the past but there has been little understanding of the chemistry and how to optimise the process. That’s how I became involved. We needed Ozone generators to produce the Ozone required for our tests, and Ozone Service Industries were forthcoming and demonstrated a strong competence in this area.” I dealt with both the MD Ian Wright and Plants and Projects Manager Jaco Coetzee who worked with me on the installation and operating of the Ozone product”.

Coetzee comments: “For the trials Mintek are using an Aquazone CD 2000 ozone generator capable of supplying 30 grams of ozone per hour. Bottled oxygen is being used as the feed gas and Mintek utilised their own mixing and dosing system for the trials. OSI also supplied a BMT ozone analyser for the trials to measure differing concentration of ozone levels”

Mintek funded the labour costs of the research as the output of the project is aimed at having a direct positive impact on the environment and the minerals industry, and OSI provided the ozone generator. “This is why we were able to do the Ozone feasibility project for cyanide destruction” explains van der Merwe. “I had old equipment in the past, but OSI were able to provide modern equipment in order to conduct the research. The equipment was installed mid last year, and has been used under test until now. We have written a paper where Ozone was used for pre-oxidation of gold ore. Gold mining companies are now mining refractory gold ore which requires pre-treatment to liberate ‘locked’ gold”.

Van der Merwe wanted to look at a three pronged approach for ozone use which would make commercialising the process more feasible; these being pre-oxidation, cyanide destruction and the potential complex procedure of the re-generation of free cyanide. “Cyanide is expensive - so regeneration is definitely beneficial” continued van der Merwe. “Water treatment is becoming increasingly important and topical. Environmental regulations are becoming stricter, and mining companies are being put under more pressure to treat their waste water. Ozone is a very strong oxidant and is environmentally friendly - most other cyanide destruction processes add something to the system, which can necessitate further treatment but Ozone does not. It also assists with the treatment of arsenic for example”.

There will be a paper detailing all the research conducted by Mintek scientists regarding their use of Ozone later this year.
 

The equipment produces ozone from oxygen and is supplied by Swiss company Ozonia through its South African agents, Ozone Services Industries (Pty) Ltd (OSI). It is a key component of the process upgrade for the Roodeplaat treatment plant and will be used to improve the quality of water supplied to citizens, says Mike Hughes, a director of PCI Africa, a member of the joint venture providing the solution. The new equipment was manufactured in Switzerland and tested in the United States before being shipped to South Africa. PCI Africa expects to have completed the installation in the first quarter of 2012.

Dr Mias van der Walt, from Temba Roodeplaat Consulting Consortium, the consulting engineers on this project, says that the new system will complement existing conventional water treatment techniques. “Ozone treatment will be used when necessary at Roodeplaat to provide advanced disinfection, help control taste and odour, and remove colour,” he says.

“South Africa is one the world’s most water-stressed countries and our municipalities have a challenge on their hands when it comes to providing drinking water of an acceptable standard,” says Ian Wright of OSI. “This system uses the natural power of oxygen to improve the quality of drinking water dramatically without generating any unpleasant or harmful by-products.”

The state-of-the-art treatment kit is the very latest incarnation of Ozone technology that is already proving its worth in a country with limited water resources and high pollution levels, especially of iron and manganese. Other municipalities and water treatment plants using ozone to treat drinking water include Rietvlei, Vaalkops, Midvaal Water Company, Delmas and Plettenberg Bay.

Midvaal’s Marina Krüger says that they originally commissioned the system to remove dissolved manganese and iron. “We then realised that ozone acts like a broad-spectrum antibiotic for water so, aside from manganese and iron we use it to remove colour, tastes and odour, micro-organisms and algae as well,” she explains. “I wouldn’t want to use water from the Middle Vaal without ozone.”

Midvaal’s raw water is drawn from the highly polluted section of the Vaal River between the Barrage and the Bloemhof Dam, and ozone treatment is used to boost conventional processes to provide the potable water this growing area needs. Krüger adds that since 1985 she has noticed that the availability of the specialist skills needed to keep the ozone plants optimised and maintained has improved considerably. “Everything used to be totally imported, but now local skills are available, which is a huge benefit,” she says.

OSI’s Wright adds that the company recently launched its homegrown Biozone Nokak Sewage Treatment Plant to provide an affordable, compact way for South Africa to combat its growing water shortage. “Our physical product is 100% South African and uses a completely natural process that requires no chemicals or regular emptying to treat sewage,” explains Wright.

A single Biozone Nokak Sewage Treatment unit can process up to 300 cubic metres of sewage daily. “This is a way for a medium-sized hotel, a cluster of small houses or a large game farm to deal with waste without polluting scarce water resources or putting further strain on conventional treatment resources which themselves are heavy users of water,” says Wright. “We need innovative solutions to this problem.”
UShaka Marine World also uses ozone to disinfect its water, as do most aquariums worldwide, while the process is well established in leading global municipalities like London, Paris and Los Angeles.

9th June 2011, Johannesburg - Ozone Services Industries (OSI), a South African water, air and sewage treatment specialist, has commercially launched its Biozone Nokak Sewage Treatment Plant, a compact and affordable alternative to septic tanks and French Drain sewers aimed at golf estates, housing developments, game lodges, shopping centres, and mining villages.

The Biozone Nokak Sewage Treatment Plant is designed to recycle sewage effluent into water that can be reused in toilet flushing systems, irrigation systems and even as drinking water for livestock.

Ozone Services Industries says that it is targeting the estimated R1.26bn South African water treatment and waste water treatment market (2008), which, according to business research & consulting firm Frost and Sullivan, is forecast to grow by 69% to R2.13 billion by 2014.

This growth comes as a result of increased legislative and environmental pressures, a historical lack of investment in water treatment and the fact that demand for clean water is outstretching its supply in South Africa.

According to Ian Wright, Managing Director at OSI, the Biozone Nokak Sewage Treatment Plant is a 100% South African designed and developed product, utilising a completely natural process that requires no chemicals or regular emptying to treat sewage.

“The process involves utilising a series of tanks and a combination of oxygen, naturally-occurring bacteria and an Ozone generator, to quickly and effectively eliminate effluent from sewer water and purify the water to within government standards that can be reused indoors and out,” he says.

Sewage makes its way into a collection tank where non-biodegradable solids are separated from the rest of the effluent. Then, through a series of subsequent tanks, bacteria and other micro-organisms – which occur naturally in the effluent – are fed oxygen to promote their growth and multiplication and feed off the biodegradable solid waste in the water.

The process is accelerated in the final stages of treatment as the bacteria are then starved of oxygen and sent into a „feeding frenzy‟ to eliminate the final solid waste in the water.

Any residual solids are then collected and sent back to the first collection tank to start the process again along with any new effluent that is collected, while the recycled water is sterilised with Ozone and then pumped back into the water system for reuse.

The recycled water meets strict industry and government standards for reuse, and an additional optional purification plant can ensure that the water is of a drinking standard.

“The system itself has very little effect on the environment because the entire process is contained within the recycling tanks and the only by-product of the system is usable water. This means that the system has no unpleasant smells and does not attract flies or other nuisances normally associated with sewage treatment,” explains Wright.

While septic tanks do offer an alternative to traditional sewage systems, they still require a significant amount of maintenance, which is both unpleasant and costly.

The Biozone Nokak Sewage Treatment Plant is ideally suited to rural use, mines, agricultural land, game lodges, golf estates and housing developments where traditional sewage collection and treatment is either non-existent or expensive to install.

In addition, these sites are very heavy water users and can utilise millions of litres of municipal drinking water on what are considered business-critical applications, like keeping lawns and crops irrigated, or cleaning equipment.

Grey water treatment methods are well known in SA but Wright asks the question as to “why not treat all of the water and sewage out of the home and utilise this rather than the washing and bathing water alone?”

A single plant can treat up to 300 cubic metres of sewage daily and can comfortably handle a medium-sized hotel, a cluster of small houses or a large game farm. Depending on its size and capacity, a plant can cost between R50,000 and R1.8 million.

Water: The next potential crisis

A combination of polluted water sources and poor management of sewage works and treatment plants within South Africa has led to a situation where the country is amongst the most water stressed nations in the world.

“It is estimated that a mere 3% of South Africa‟s water treatment systems operate to an acceptable standard, placing water firmly in line to be the next major utility crisis after electricity,” says Wright.

“And while acid mine water is rightly getting the majority of the headlines in national newspapers as a major crisis waiting to happen, the threat of sewage water entering the drinking water systems has been largely ignored to-date and presents as much of a danger.”

This, he says, is where systems such as the Biozone Nokak Sewage Treatment Plant can help solve one part of a larger problem.

“The beauty of the system,” explains Wright, “is that with no toxic by-products, water can be recycled to acceptable standards, cutting costs and reducing the overall demand on South Africa‟s already-stressed water utilities.”

Ozone Services Industries is seeing a significant increase in demand by the likes of the hospitality, construction, and mining industries to find alternative sewage treatment methods, where water treatment is considered business critical or where water comes at steep a premium.

“We‟ve already rolled out plants in South Africa, Botswana and Mozambique and are currently in negotiations with various mines, hotel groups and government departments for large-scale rollouts across sub-Saharan Africa in the near future,” he adds.

For more information on Ozone Services Industries and the Biozone Nokak Sewage Treatment Plant, please visit http://www.ozonize.co.za.

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Tribeca Public Relations
Nicola Weiner / Cian Mac Eochaidh

Since the late 1970.s, there have been many small and large outbreaks of Legionnaires. disease. Most of these outbreaks have been traced to either cooling tower water systems or potable water systems. Although the bacteria most often associated with Legionnair.s disease, Legionella pneumophila, is present in many waater systems, outbreaks are usually a result of large concentrations of Legionella pneumpohila.

This paper is a report of the work conducted in association with the Centers for Disease Control at their facility in Atlanta, GA. A model cooling tower was constructed that recirculated water and rejected heat through evaporation. This model system was inoculated with know concentrations of bacteria and amoebae. It was allowed to reach equilibrium and then biocides, such as ozone chlorine, chlorine dioxide, and monochloramine, were applied to determine their efficacy in controlling the total bacteria and the legionella in particular. The results of this study are summarized in this paper.

Introduction

The focus of this research is to determine the relative efficacy of different biocides in controlling panktonic Legionella pneumophila in a simulated cooling tower environment. These same biocides will also be used to establish their efficacy in eliminating fully developed biofilms, like those found in potable and cooling water plumbing systems.

Background

Since its initial isolation in 1977, Legionella pnuemophila has been found to be associated with sporadic and large scale outbreaks of Legionnaires. Disease. It is estimated that there are between 10,000 and 20,000 cases of Legionnaires Disease annually in the United States.

The genus of bacteria which cause the disease have proven to be unusual pathogens in many respects. The legionellae were originally considered

*The author conducted much of the research while employed by TriOx

transitory contaminants of the environment, but have since been recognized as natural components of freshwater ecosystems. These bacteria are known to survive as intracellular pathogens of freshwater protozoa and multiply in these cells in a manner analogous to their infection of human alveolar macrophages. Studies have shown that multiplication within these freshwater protozoa can protect the bacteria from the effects of biocides. In addition these protozoa exist as part of a complex microbialbiofilm in these aquatic environments, that serve as physical barriers to biocides.

Because reservoirs of legionellae have been implicated in outbreaks of Legionnaires Disease in cooling towers, evaporative condensers, and
plumbing systems, the effectiveness of various biocides, both common and novel, with respect to the prevention of legionnaires and related respiratory diseases needs to be evaluated..

There are many biocides available. Some of these contain heavy metals, organic molecules, or amine structures. Historically, the most common biocide used in comfort cooling towers and similar equipment have been halogenated compounds that contain chlorine and/or Bromine. Recent research has also shown that ozone is an acceptable biocide when used in these systems.

Several studies of the effectiveness of biocides for the control of Legionella p. have been published in the past. All of the studies were performed in the laboratory and used pure cultures of the bacteria in sterile water. Although these simplified systems of testing biocides were easy to perform, they have little relevance to applications in cooling towers or plumbing systems (England, A.C.,et al. Failure of Legionella pneumophila sensitivities to predict results from disinfectant treated air conditioning cooling towers. 1982. Appl. Envion. Microbiol. 43:240-244). In this project we will develop a model cooling tower and cooling tower basin in which legionellae grow in conjuction with other naturally occurring aquatic organisms.

Cooling towers have been used for reducing the temperature of liquids for the past century. By evaporating a percentage of the water that recirculates through the system, the remainder of the water is cooled. These systems are used alone or with compressive chillers and/or heat exchangers to cool a wide variety of gas or liquid systems.

Comfort cooling, especially in drier climates, has made extensive use of cooling towers. Commercial, industrial, and medial office buildings use cooling towers to reduce their air conditioning bill.

To operate efficiently cooling tower need a variety of water treatment. Corrosion and scal inhibitors are often used to control the natural tendencies of the water to corrode or precipitate. Over the years there has been intensive research into these areas. Many chemical treatments have been discontinued for environmental reasons. Some chemical treatments have been replaced by newer or superior chemicals or groups of chemicals.

Cooling towers, because they are west and warm, are ideal locations for biological growth. Most treatment systems include a biocide. Lately there have been several epidemics which have been closely associated with bacteria, known to be in cooling towers. This has caused the acceptable level of bacteria in cooling towers to be reconsidered.

In the recent past a cooling tower was considered to be in acceptable biological control with bacterial populations of under 100,000 colony forming units per milliliter (cfu/mL). With planktonic bacteria populations in this region, the drift leaving a cooling tower could contain billions of potentially harmful bacteria.

Often this was the best that could been done without using dangerous chemicals or inducing excessive corrosion. The danger associated with
immune suppressed people at a hospital and cooling tower drift became quite clear.

The majority of cooling towers are currently treated with chlorine in various forms. Chlorine is very inexpensive and easy to use. Unfortunately
many organism become immune to high levels of chlorine and bacteria levels can build. Shock treatments are then used, either with extremely high concentrations of chlorine or another biocide.

Among the new generation of biocides ozone has demonstrated the ability to be a candidate to replace most biocides in cooling tower applications.

Ozone is a gas which has to be generated on site. This prevents problems with storage and handling. Ozone is also be thousands of time more effective than chlorine, chlorine dioxide, and hypochlorous acid for control of spores, bacteria, and virus.

As a cooling tower treatment ozone has only recently become a viable option. The combination of ozone generators with computers has made a system which is highly reliable. The ozone residual in the water is controlled on a feed back loop. This maximizes biological control yet minimizes corrosion. Well controlled ozone systems have bacteria populations well under 1,000 cfu.s and often less than the makeup water to the cooling tower.

The research in this paper is a comparison of well maintained and controlled chlorine and ozone systems. Concentrations necessary for effective bacterial and especially Legionella p. control are considered.

Experimental

Bacterial cultures and amoeba, which are known to reside in cooling tower and potable water systems with Legionella pneumophila, were grown to simulate a typical cooling tower environment. These included:

1. Legiionella pneumophila serogroup 1, Rl-243
2. Acinetobacter
3. P.Stutzeri
4. Comamonas testosteroni
5. P.paucimobillis
6. A hydophila
7. Alcaligenes
8. P.aeroginosa
9. P.climinuta
10. P. vesicularis
11. P.methylobacterium extorquens
12. Hartmannella veriformis

These bacteria, initially frozen, were thawed. The Rl-243 was plated on Buffered Charcoal Yeast Extract (BCYE) agar and the other bacteria were plated on blood agar. Cultures were incubated for 24 hours at 35°C. To 10 mL of steriale buffered saline solution, bacteria samples, excluding RI-243, were added to produce a suspension with an absorbance of 0.955 using a Beckman spectrophotometer at 540 nanometers with 1 cm path length. The Rl 243 was suspended in sterile endotoxin free water. This absorbance indicated a bacterial concentration of 1 x 109 cfu/mL.

1.8 X 107 Hartmannella veriformis amoebas were suspended in 10 milliliters of buffered saline solution to achieve a concentration of 1.8 X 106. To produce an environment conducive to the production of a consistent, large quality of bacteia and amoeba, a biological growth reactor or chemostat was used. The suspensions of amoeba and bacteria were added to the chemostat.

The Chemostat

The chemostat used in these experiments was a 12 liter carboy. It was equipped with an air sparger, nutrient feed, stirrer, and located in a temperature controlled room. The chemostat was connected to a pump and the liquid from the chemostat was pumped through a biological sampling devise made by Calgon Corp. The biological sampling devise contains stainless steel substrate which develop a biofilm. The biofilm is thought to be an integral part in the sustained, continuous development of the biological population in the chemostat.

Liqid in the chemostat was withdrawn under vacuum and added to the cooling tower before each experiment. This controlled, defined bacterial population make the quantification of individual biocides more evenly attained.

R2A nutrient is pumped into the chemostat at a rate of 10 gallons per 14 days. The R2A concentration is 2.2 grams per 12 liters of sterile water.

The Cooling Tower

The model cooling tower was filled with water and allowed to operated overnight. The tap water used had a conductivity of 75 microsiemens per centimeter.

After one day of operation a 1.3 liters sample from the chemostat was used to provide a level of biological activity in the model cooling tower. The tower continued to run for 24 hours before the introduction of the biocide. This time helped the microbes acclimatize to the cooling tower.

The fully functional model cooling tower is pictured in Figure 1. It is a forced draft style system with PVC nozzles and fill. It is equipped with a recirculating pump in the basin and a heat source to facilitate evaporation. A separate recirculation system has locations for a sampling port, and ORP probe. The system has a total volume of 12 liters. A supply of potable water was used to replenish water lost by evaporation. A water analysis of the supply water is in Figure 2. The cooling tower was located in a biosafety cabinet.

Sodium Hypochlorite

Commercially available 5.25% sodium hypochlorite wa diluted to keep a residual of 1.0 free chlorine during the experiment. Before the experiment started a biological sample was taken. Before and after each sample was taken, the sample port was swabbed with alcohol and dried, a 10 mL sample was taken at each time interval for bacterial examination.

Another sample was taken in one hour, after which the chlorine concentration was again adjusted to 1.0 parts per million (ppm). The final sample was taken at 2 hours, after which the experiment was stopped. Free chlorine was determined with a Hach test kit.

After the experiment was concluded the water feed to the basin was turned off and the basin water was emptied into a glass carboy and autociaved for disinfection. The model cooling tower was allowed to run empty with the fans on to dry the system.

Ozone

The Oxidation Reduction Potential (ORP) of the tap water was initially at 200 mv. After being stripped of residual chlorine for a day the ORP was reduced to 175 mv. After the sample from the fermentor was added to the model cooling tower, the ORP was reduced to 150 mv. Ozone was added at a rate of 100 on the Aalborg rotameter, or 288 mL/min, at 1.5% weight ozone from an ozone generator1. The ozone concentration reached 0.1 ppm within 10 minutes. The ORP was stable st 250 mv.

Again samples were taken at 0, 1, and 2 hours. Ozone concentration was determined using a spectrophotometer2 and Potasium Indigo Trisulfonate dye. After the experiment the water to the cooling tower was turned off, the cooling tower fans, pump, and heater turned off, the ORP probes removed and stored for future use and the cooling tower drained and dried. The water from the cooling tower was autoclaved and discarded.

Sample Preparation

One milliliter of sample was diluted with 9 mL of sterile endotoxin free water and shaken to ensure homogeneity. From that solution one milliliter was removed and added to another 9 mL of sterile endotoxin free water. In this way the sample was serially dilted four more times to produce six samples, diluted one through six logs.

At time zero, one hour, and two hours a sample was taken to determine the quanity of Legionellap. and total bacteria in the cooling tower. These

microbes were serially dilated and plated on BCYE agar and BCYE with antibodies to reduce bacteria otheer than Legionella. The samples that were to be plated on BCYE with antibodies were acidified for 15 minutes with a KCI solution. These samples were then neutralized with KOH solution and serially diluted. This technique also reduces the number of total bacteria and makes the Legionellap. colonies more detectable.

100 microliters of sample were pipetted from each dilution onto the different culture medium. The solutions were plated using the spread-plate
technique to ensure an even distribution and incubated for 48 hours. To accurately read the bacterial colonies on the plates, a total of 3 to 300
colonies are necessary. When the plates are within this number, they can be read, multiplied by the dilution factor and recorded.

Results

Samples were tested for the presence of amoeba. Amoeba were found in the samples taken from the chemostat. No amoeba were found in samples taken from the cooling tower. This indicated all amoeba were attached to the cooling tower surfaces.

No biofilm was detected inside the biofilm sampling devise. This prevented testing the biocides against the fully developed biofilm. There was a noticeable biofilm in the tygon tubing which connected the chemostat to the biological sampling devise.

The data that were recorded fro the two experiments follow.

Conclusions

The chemostat was run over three months sustaining a population of bacteria and amoeba.

Both biocides reduced the amount of Legionellap. substantially. The continuously controlled Ozone removed the Legionellap. completely and was three orders of magnitude more effective in killing the total bacteria than chlorine.

The amount of ozone used was one tenth the amount of chlorine used. In work done by Nalco, this concentration of ozone would be no more
corrosive than oxygenated water itself.

Endnote

1TriOx model 400 Ozone generator
2Hach Dr2000

Table 1
Time
0
DisinfectantChlorine
Total Bacteria
4,650,000
Legionella P.
58,000
1 hour Chlorine 3,880,000 30,000
2 hour Chlorine 3,110,000 2,600
0 Ozone 14,000,000 29,000
1 hour Ozone 19,000 0
2 hour Ozone 6,000 0

WATERTECH .94

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OZONE……THE STORY

The Ozone layer is well known, where the lack of it causes enormous problems in our living environment. What is not known however is that Ozone can be produced at ground level to tremendous advantage?

Ozone is a gas that is generated by ultraviolet rays or corona discharge by splitting the oxygen molecule in to 2 individual atoms which then attach themselves to another oxygen molecule thus forming an O3 molecule.

This molecule is very unstable with a short half life where it will revert back to oxygen in a short period of time. It therefore has unique capabilities for sanitation and sterilisation.

Ozone is second only to fluorine as an oxidant and has been used in Municipal water treatment plants and in the medical field since the late 20th Century. Because of its short half life and its tremendous oxidising capabilities, it can be used in situations where residual chemicals are undesirable. For example in food preparation or water purification, where chlorine is used to kill bacteria the use of ozone to replace chlorine will result in no residual damage or contamination.

Ozone works 3000 times quicker and is 2.5 times stronger than chlorine as an oxidant.

In water purification and effluent treatment it is used to disinfect the water, remove algae, improve flocculation, oxidise iron and manganese and remove colour and odour.

These contaminants are common in South African waters and the effect of Ozone can be judged by the number of Municipal Water Treatment plants upgrading to ozone disinfection and oxidation. (Plettenberg Bay, Midvaal Water Treatment, Vaalkops, Delmas, Rietvlei, Roodeplaat ,to name a few).

In air treatment ozone is used to eliminate odours, sterilise the air and ducting and remove pollutants such as cigarette smoke and carbon monoxide.

In food sterilisation, thermal based sterilisation and pasteurisation accounts for about 55-60% of the processes used and chemical sterilisation, accounts for about 30%. Thermal processes adversely affect the physiological, nutritional, sensory and functional properties of food products and we all know the problems associated with chemical treatment. Even where eco friendly chemicals are offered, when investigated in depth, it is found that the manufacturing process required is, more often than not, damaging to the environment resulting in no advantage to the environment instead of conventional chemicals.

Within water sterilisation, chemical-based treatments has been the dominant sterilisation technique, accounting for about 60% of the market, followed by ultraviolet based water sterilisation (~28%).

Apart from the genetics controversy these are probably the main reasons that organically grown and processed food is becoming such a large Industry.

Consumers are demanding less-altered taste, non-thermal methods that preserve the flavour, nutrients, colour and texture.
Furthermore retailers list shortened shelf life of fresh food as a major cost and wastage is of major concern.

Increasing prohibitive regulations and demand for chemical-free food is increasing usage of alternative chemical free solutions.
Food Manufacturers are adopting preservation methods such as high pressure systems, ozone, pulsed electric field, ultraviolet and bacteriophage to reduce the amount of chemicals used during food and water sterilisation. Also with the high cost of water in the Processing plant where ozonised water can be recycled, the resultant savings in capital cost pays for the equipment in a short period of time.

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Ultraviolet, being chemical free, is the key competing technology for ozone based sterilization but irradiation suffers from unfavourable consumer perception as a sterilisation method and this has adversely affected the demand for UV and irradiation products. (Recently in USA, new irradiation facilities have faced significant local opposition and by way of example, citizens in Illinois, US, successfully pressured state officials to force a new e-beam facility to apply for an air pollution permit.)

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1. Water treatment
2. Waste water treatment and recycling
3. Rinsing of fresh food with ozonated water to eliminate surface bacteria and pesticides.
4. Exposing fresh produce to Ozone gas if water rinsing is not possible.
5. Using Ozone or UV in Cold or rooms to maintain clean bacteria free environment and prevent mould growth (increase shelf life).
6. Using Ozone in Storage areas to eliminate ethylene.
7. Ozone gas to treat packaging before packing such as in vacuum packs.
8. Bottling plants to rinse containers before filling.
9. Refrigerated transport to prevent cross contamination of spores and airborne pathogens in transit food.

In today’s world, the high cost and shortages of water and energy necessitate the provision for effective treatment of own water resources (such as on a Mine). Recycling of waste water using appropriate technology instead of discarding in to overloaded Municipal Sewer systems, septic tanks, drains and rivers is necessary, cost effective and safe. The use of septic tanks for sewer treatment is no longer condoned especially in built up areas and the use of chlorine as a disinfectant is definitely disallowed. In areas with high clay content soils, a high water table or sensitive groundwater areas, septic tank soak-away systems are inefficient, out of date, often fail and contribute to surface or groundwater pollution.

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FEATURES

The Biozone NoKak system uses a biological process where bacteria colonies are grown on a submersed fixed film media where they feed on organic nutrients (sewerage). Oxygen is introduced at the correct levels in to the treatment tank (bioreactor) to encourage and promote bacteria growth. In so doing COD levels are reduced, nitrification and de-nitrification
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