26 No. 5
Chemistry For Water—ChemRAWN XV Conference
by Alan Smith
The 15th ChemRAWN Conference, titled “Chemistry for Water,” was held in Paris at the Maison de la Chimie Foundation from 21-23 June 2004. In keeping with the concept of Chemical Research Applied to World Needs, the aim of this conference was to address the issue of unsafe water. Following are some of the alarming statistics from the World Health Organisation (WHO) related to water supplies throughout the world:
• There are 1.7 million deaths each year related to unsafe water, mostly among children under five.
• It is estimated that there are 4 billion cases of diarrhea annually, which represents 4.5% of the global burden of disease.
• One sixth of humanity currently lacks access to any form of improved water supply within one kilometer of their homes.
The Millennium Declaration Goal was to halve the proportion of people unable to reach or afford safe drinking water by 2015. To achieve this would require at least 125 000 unserved people to be connected to safe water supplies each day before the 2015 target!
|Photo (L to R): Pierre Fillet (France) President of the Organizing Committee and Member of the Program Committee, also member of de l’Académie des Technologies; Raymond Hamelin (France), Member of the Program Committee and coordinator of the corresponding IUPAC Chemrawn Project; and Bill Carroll (USA), President of the International Scientific Committee and president-elect of the American Chemical Society.
Professor Pierre Potier, a leading government advisor and member of the French Academy of Science opened the IUPAC conference, which also received the high patronage of the President of the French Republic, Jacques Chirac. Speakers and attendees from five continents spent three days hearing about new developments in chemistry and chemical engineering that are helping purify and provide water more efficiently in order to reach the Millennium Declaration Goal. A series of workshops enabled delegates to look at specific problems and share their views.
The industrial and municipal demands for water supplies, and its quality, vary from country to country. For example, the electronics industry requires ultra-pure water that contains only a few parts per trillion of impurities for computer chip manufacturing. On the other hand, people in poor countries often drink untreated water from sources also used for bathing and care of animals.
|IUPAC is currently involved in a project to help solve the problems caused by arsenic occurring naturally in drinking water in various parts of the world. Read More
Three main areas for development were considered at the conference. Separation science is particularly important for chemists and chemical engineers. It focuses on coagulants, flocculants, and dispersants that enable reuse of wastewater and the purification of supplies. Some elegant chemistry was presented on multifunctional and tagged polymers for water treatment applications. The leading idea nowadays is that all new water treatment chemicals should be biodegradable and should not add to the environmental burden. Twenty years ago a new treatment chemical was judged simply on performance, but now, in addition to performance, toxicity, environmental impact, and water conservation are also crucial. Clearly, companies need to be encouraged to use less water and to recycle wastewater.
Development of new membranes, which will provide higher-quality water, was highlighted. Cheaper desalination processes, though, remain an ambition for many countries since it is estimated that 97.2% of the world’s water is contained in the oceans. China’s “thirst” for water, both potable and for its booming industry, is likely to come from desalination plants in the future. More specific separation processes were also considered, and the delegates looked at the problems of natural contaminants in water supplies. Moldovan representatives spoke about the problems of excessive fluoride ions in their water supplies, and other speakers told of the arsenic contaminants, in particular, found in water supplies in Bangladesh.
Another aspect of separation science that was included in the conference was soil remediation, an area in which the French have specific expertise. In Europe, this has become an increasingly important area for new development.
Disinfection science is the second main area where chemists and chemical engineers can make an impact on potable water supplies. Again, improved processes are being developed, and ultraviolet light is gaining more ground now, often in combination with other disinfection routes. Bio-film fouling in pipes used to supply water is a problem that is being addressed by many companies. As for chemicals used in water separation processes, any anti-microbial chemicals must degrade to acceptable by-products and not cause increased problems.
|The Nymphea Company has developed a way of using the fresh water that comes from fissures in certain sea beds. Read More
Analytical science is another important aspect of water purification. There is a great deal of research underway on advanced monitoring techniques, and some emphasis on developing biomarkers to track certain pollutants. Computational analysis is being examined in the developed countries to model flow of water and effluent with a view to minimizing usage and waste. Risk analysis was also a subject talked about at the conference.
For the less developed countries, the difficulties are simply getting water to where the people are and purifying it to a quality that is adequate, in an economically sustainable way. Education on the benefits of disinfected water is essential, but is currently lacking in many areas. For some, the answer may be to copy what Uruguay has achieved with small, skid-mounted treatment plants, which are placed in isolated areas either for local industry to treat their water or for the supply of potable water. For others, a low-tech chlorination unit metering dry disinfectant into a community’s water tank offers a possible remedy. There is also a need for test kits so that people know to what they are being exposed. For the benefit of all, research needs to be coordinated. Solutions to problems, especially in developing countries, must be
economically sustainable; otherwise money will simply be wasted.
Another key point stressed at the conference was the need to keep contamination away from water in the first place. Lake Baikal, for example, has plenty of fresh water, but there the efforts are directed at keeping pollution out. In addition, water treatment processes need to minimize energy use. The first action of the Future Actions Committee for the conference will be to encourage smaller conferences to work on specific problems in certain countries.
The IUPAC conference was a considerable success, attracting many leaders from the chemical and water industries. The French Minister of Foreign Trade, François Loos, was one of the final speakers, clearly voicing the theme of the ChemRAWN conference—providing chemical and chemical engineering solutions to supplying water for world needs.
Alan Smith <[email protected]> chaired one workshop during the Chemrawn conference on "Chemistry, Industry and Water;" he is a member of the IUPAC Bureau and former chairman of the Industrial Affairs Division of the Royal Society of Chemistry.
last modified 16 September 2004.
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