Effective against ALL microbes, including Cryptosporidium and Giardia
Flexible disinfection performance at lowest cost
Nearly four centuries to understand the need for disinfection of drinking water
The Dutch tradesman and scientist Antoni van Leeuwenhoek (1632-1723) is considered to be the first microbiologist and is generally known as “the Father of Microbiology”. He is famous for the construction of microscopes as well as for his observations of micro-organisms. He is the first to report a potential relation between drinking water (which was untreated surface water in his days) and diseases, by recognizing the similarities in the micro-organisms found in water and in his own diarrhoea. In fact, he most probably was describing Giardia centuries before it’s effects were fully recognized.
However, it was not until 1855 that the health impact of water became really clear: John Snow’s investigation of the Broad Street Cholera Outbreak proved that the outbreak was caused by contamination of the Broad Street public water pump. This initiated centralized water treatment, to provide bacteriological safe drinking water using disinfection. Initially, this was achieved using slow sand filtration. However, due to population growth as well as an increase of prosperity, water consumption rapidly increased. This required large scale drinking water treatment and chlorine was introduced as primary disinfectant.
In the early seventies, Dr. Joop Rook, a Dutch water scientist, discovered the presence of trihalomethanes in chlorinated drinking water. These are carcinogenic compounds that are by-products of disinfection, formed as a result of chlorination of natural organic matter. This revolutionized the Dutch drinking water industry: chlorination was banned and alternatives were developed. It is no coincidence that Dutch entrepreneur Hans Berson successfully started his UV business in 1972: the water industry needed alternatives for chlorine. Furthermore, Rook’s observations raised awareness on disinfection by-products, which in the early nineties lead to the discovery of bromate formation when water containing bromides is disinfected.
A large part of the global drinking water community however kept relying on chlorine for disinfection. In 1993 this approach proved to be fatal: in Milwaukee over 400,000 people became ill with stomach cramps, fever, dehydration and diarrhoea, at least 54 people died. Cryptosporidium oocysts that passed through the filtration system of one of the city´s water-treatment plant proved to be the cause. Cryptosporidium is extremely chlorine resistant, hence the disinfection strategy failed. This lead to a second revolution in water treatment, acknowledging that chlorine could no longer be the sole disinfection barrier for drinking water. As UV disinfection is very effective for cryptosporidium this boosted its application for drinking water further.
New challenges ahead: organic micro-pollutants
The industrial growth as well as the intensifying of agriculture has had a strong influence of the quality of surface water. Even though measures have been taken to avoid and minimize industrial pollution from the early seventies, the level of pesticides in surface water is a concern that needs to be addressed. Additionally, probably the most challenging issue is the removal of endocrine disruptors (EDC), these are medicine and hormone residuals that enter our surface waters by discharge of secondary or tertiary municipal effluent discharge. Currently the water industry is identifying methods to remove these compounds from surface water and to prevent these compounds from entering surface waters in the first place. Advanced oxidation processes (AOP), which apply a combination of hydrogenperoxide dosing and UV are solutions for both point of discharge removal of EDC and EDC conversion in drinking water processes.
The value of ‘waste’ water
In the new millennium the value of water is not limited to drinking water only. There is an ever growing understanding of the impact of human activities on the world around us. Water is a high value, low priced commodity that we need for drinking, washing, production of food, industrial activities, and certainly leisure from our activities as well. Therefore we recognize the need for extensive waste water treatment before discharge. Disinfection of waste water effluent is an important step, both for safe recreation in surface water as well as for safe intake of that surface water for drinking water purposes. Importantly, re-use of municipal effluent for industrial applications, irrigation and district cooling, is much more efficient than using drinking water, especially when the drinking water is produced by desalination. UV disinfection of effluent is highly effective, ensuring both safe discharge and re-use. Bersons InLine system was the first closed vessel UV to receive NWRI approval for application in water re-use.
Rely on the Masters
Berson provides UV based water disinfection solutions for applications in drinking water production, waste water treatment and effluent re-use. We work closely with our customers to provide the best solution for them. Our systems are available with DVGW, USEPA and NWRI validations.
