About Dryden Aqua Dryden Aqua is a Scottish based Marine Biological company formed in 1980 and specialising in water quality and water treatment. As marine biologists our focus has been with the aquaculture and environmental business sectors. We have a strong research and development background and have been conducting research for the European Commission and UK Government under a Life Environment program. Our R&D is reported on European Commission web site click here . Dryden Aqua R&D program on water treatment is summarised click here  Dryden Aqua manufacture a range of unique products , environmental chemical products and systems which we distribute through our dealer network. The combination of a strong skills base and manufacturing capacity have allowed us to developed innovative systems for the treatment of water and waste water which offer unrivalled performance and costs benefits. The systems, products and technology developed by Dryden Aqua are now being adopted by many industrial sectors and we are experiencing a period of exponential growth, turnover has doubled over the last 12 month despite the recession. Presently in excess of 80% of the business conducted by Dryden Aqua is out-with the UK with a strong focus on Europe, the Middle East & SE Asia.
Public and Environmental Health...important "Water and Sanitation is one of the primary drivers of public health. I often refer to it as “Health 101”, which means that once we can secure access to clean water and to adequate sanitation facilities for all people, irrespective of the difference in their living conditions, a huge battle against all kinds of diseases will be won." Dr LEE Jong-wook, Director-General, World Health Organization. Also from WHO, 6% of all disease in Europe is from drinking water, of these infections 50% is due to Cryptosporidiosis. Dryden Aqua technology has the potential to eliminate the disease and at the same time reduce the operating cost of treating drinking water. We are able to achieve this task because Dryden Aqua are perhaps the only biological based company that have examined and understand media bed filtration systems. The approach taken by most of the water industry is from a chemical or engineering perspective.
Industrial Sector Reports Swimming pools 
Swimming is one the best possible excises you can undertake, as long as the water quality and atmospheric conditions in the pool are safe. If you can enter a swimming pool and you can still smell the chlorine after 2 minutes, then do not enter. If you go swimming and your eyes sting, then we recommend that you leave the pool. The characteristic swimming pool smell and sore eyes is not caused by chlorine but by a chlorine reaction product called trichloramine. AFM® ( Activated Filter Media) is a key product to Dryden Aqua. In the European swimming pool industry, the design of the systems are such that high levels of trichloramines and THM`s can be produced and discharged into the atmosphere. Reports published by the European Respiratory Society claim that children that go swimming experience the same lung damage as an adult smoker as measured by biochemical indicators. We also know that trichloramines strips off the mucous lining from your lungs and predispose children (and adults) to infection. Trichloramines can also initiated a sensitised reaction to dust, pollen or virtually any chemical which can develop into to asthma or respiratory problems latter in life. In addition to trichloramines, UVc disinfection and ozone are being promoted to the swimming pool industry, however both processes increase the chlorine demand by up to 500% and increase not only the trichloramine level in the atmosphere but a second chemical called THM`s (trihalomethane) which are highly carcinogenic. The use of UVc and ozone should not be permitted in chlorinated systems. The problems in swimming pools are caused by the use of sand in the sand filters, UVc and Ozone, there are other factors such as water flow rates and operational procedures. However at Dryden Aqua we were the first company to determine the mechanism for he production of trichloramines. Once you understand how something works, it then gives you the tools to solve the problem. At Dryden Aqua we have almost eliminated the production of trichloramines and reduced THM`s by 80% and this is achieved by designing proper water filtration systems, and replacing the sand in the sand filters with AFM® . We have advised the authorities around Europe of our findings and a copy of the report is available (click here) In Scotland, Germany, Switzerland and Spain AFM® is being implemented rapidly, however the authorities and industry in the England are still actively promoting the use chemicals, ozone and UVc systems. click here for swimming pool section of web site. By using AFM® and adopting Dryden Aqua procedures for running swimming pool water treatment systems, there will be on average an 80% reduction in chemical consumption, and production of chlorine reaction products. We do not know the long term health implications or chlorine reaction products but it can only be good for the public as well as the environment if we can reduce or eliminate the use of chemicals.
Drinking Water by RGF (rapid gravity) & pressure filters Dryden Aqua manufacture the only filter media certified under Regulation 31 in the UK that is permitted to be used for the treatment of Drinking Water In the UK and the rest of Europe, most of our drinking water supplies are treated by adding a coagulant such as Aluminium Sulphate, or PAC ( poly aluminium chloride), polyelectrolytes may also be used, but the predominant coagulant is PAC because it is effective and a low cost. The water is then passed through sand filters, after which chlorine may be added. It is now also becoming common place to add ammonium to the water. The reason for adding ammonium is that in around 25% of the water treatment systems can not comply with the European Directives with regards to the concentration of THM`s. The water industry therefore adds ammonium to the water to form mono-chloramine with chlorine, which then prevents the chlorine reacting with dissolved organics to form THM`s. This is a ridiculous situation. It is impossible to prevent bacterial fouling of the sand in a sand filter, the bacteria excrete a muco-saccharide alginate which eventually start to glue to sand grains together which leads to the development of stable channels down through the filter bed. Most sand filters used for the treatment of drinking water will experience channelling from time to time. This means that there is a conduit through which untreated water will pass, carrying bacteria and parasites. However the situation is worse than un-treated water because the water will also contain aluminium (which may be linked to Alzheimer's disease), the high level of organics will also increase the concentration of toxic chlorine reaction products. The graph opposites shows that there is 30% more solids discharged during a back-wash from AFM® as opposed to a parallel system using sand. The system had only be running for 10 weeks. AFM® performance stays the same , however sand filtration performance gradually deteriorates, after 24 months AFM® can be removing as much as 80% more matter from the water than sand. This data was obtained from trials conducted by Lyonnaise des Eau in Norfolk. Slow bed sand filter depend upon a healthy population of bacteria and other organisms growing on the sand, these filters operate at flow rates as low as 0.1 m/hr, slow bed sand filter work well and provide excellent water quality. However rapid gravity and pressure sand filters operate at flow rates 50 to 100 times faster and the high flow rates the bacteria can not establish a stable ecosystem, instead the bacteria totally disrupted the mechanical flow characteristics of the sand. It is therefore absolutely essential to minimise biofouling in rapid filters, however many of the water companies and consultants have not appreciate the implications of biofouling on rapid filtration performance, and as such they still think that bacteria are required in the sand filter. There is therefore a risk from treated Drinking Water, from bacteria and parasitic disease, chronic aluminium toxicity and possibly dementia, and a cancer risk from THMs. While the risk is small, at Dryden Aqua we believe that it is significant. We are all living longer, and as biologists we know that if you are exposed to a chemical or a virus then it may take 10, 20 or 50 years before there is an impact from the exposure. From WHO 6% of all disease in Europe is caused by our drinking water, and of these infections 50% is due to the protozoan parasite Cryptosporidium, this tells us that there is a problem. Most of the problems with the water treatment systems are linked to bacterial fouling of the sand and channelling of water through the filter bed. Dryden Aqua AFM® water filtration media is certified to replace the sand in sand filters. Indeed AFM® is the only water filtration media certified under Reg31 for the treatment of Drinking Water. Simply by changing the sand in the water filters to AFM® media, we will eliminate most of the water treatment problems described above. However in the UK there is huge inertia in the water industry to change, consequently most of our work with drinking water treatment has been out-with the UK. click here for a report | click here for drinking water section. The situation will eventually change because AFM® provides major life cycle cost benefits, chemical consumption will be reduced by up to 80% and the public will have much safer and cleaner water.
Wastewater treatment The principal source of environmental water pollution is effluent for sewage works. The Royal Commission Standards were set in the UK over 100 years ago, however very few treatment works are actually in compliance with a 100 year old standard. Prior to the 1960`s, waste water comprised mainly of organic matter, nitrogen and phosphates. The waste matter would cause pollution and eutrophication of the environment. In addition to the nutrient load there were also disease issues, however there were few persistent chemical problems. Since the 1960`s there has been a huge explosion in the number and type of chemicals used by the public and by industry. Some of these chemicals, referred to as List 1 chemicals, are persistent and will bio-accumulate in the environment. Sewage works are not permitted to discharge list 1 chemicals, however if they are discharging solids, then there will also be list 1 chemicals, albeit at a very low level. The concentration of list 1 chemicals discharged does not matter, even if it is below detection levels by the analytical procedures used, the levels will still be too high. By way of example, PCB`s ( polychlorinated biphenyl's) enter the waste water, the chemical gets adsorbed by bacteria in the effluent treatment system. A small proportion of the bacteria are then discharge to a river or the marine environment. Protozoa eat the bacteria, zooplankton eat the protozoa, fish eat the zooplankton and people catch the fish. At each stage the concentration of the list 1 chemicals may increase by an order of magnitude. The fish may be consumed directly, and in the UK the Government issued a public health warning, that you should not eat any more than 2 oily fish from the North Sea each week. Pregnant women should restrict intake to one fish per week. We know the health benefits of omega 3 & 6 fatty acids from fish, however if you eat fish high in these oils, your intake of list 1 carcinogenic chemicals may be too high. Fish are also caught and turned into fish meal and then fed to chickens and cattle etc, so it is difficult to escape from consuming list 1 chemicals. At Dryden Aqua we consider the discharge of bio-accumulated list 1 chemicals to be the greatest threat to the environment and public health. Also, we must remember that probably in excess of 90% of carbon dioxide (greenhouse gas) absorption and oxygen production is by the sea. Trees, rain forest and terrestrial plants are of course very important but the main driver is the plant and animal life in our seas and oceans. List 1 chemicals don't go away, they will always be recycled back into the food chain, it may take decades but it will happen. We therefore feel very strongly that sewage effluent should be treated to a very high standard and that tertiary filters must be installed. Special moving bed sand filters are sometimes used on sewage effluent, however they are expensive and can be problematic. Rapid gravity sand filters are also used, but in most cases they do not work effectively. Sewage effluent is the perfect environment to grow bacteria, and considering that heterotrophic bacterial can double in population biomass every 15 to 30 minutes, it makes it very difficult to run sand filters. AFM® however rejects biofouling, so it can and is being used in regular low cost pressure filters and RGF filters to achieve really good sewage effluent water quality. We have not completely solved the problem, however the photo on the right shows a typical example of sewage effluent before and after AFM® filtration.
Global Warming ?? we may have a solution to the problem. For a pdf file covering the main points click here
|
| Ozone | Membrane filtration | Swimming Pools | Leachate Treatment | 
