Scientists have shown that using mud from waste water treatment plants as a partial alternative fuel can enable cement factories to reduce their CO2 emissions and comply with the Kyoto Protocol, as well as posing no risk to human health and being profitable. These are the results of an environmental impact assessment.
Dependency on oil and coal could be coming to an end. Researchers from the Rovira i Virgili University (URV) have analysed the environmental and human health impacts of an alternative fuel that solves various problems simultaneously. This is the solid waste from the water treatment plants of large cities.
The scientists have carried out the first study into this method at a cement plant in Vallcarca (Catalonia), which has been producing cement for more than 100 years, and they confirm in the latest issue of the journal Environmental Science and Pollution Research that it is “the best option for getting rid of mud that would have had to be dumped elsewhere, while also powering the plant”.
[...] Up to 20% of the fossil fuel energy used at the Catalan plant has now been substituted for the fuel from waste water treatment plant mud.
One of the most important issues for the URV scientists is the reduction in environmental impact, and consequently the health risks for people living near the plants. The experiment with the mud has led to a 140,000 tonne reduction in CO2 emissions between 2003 and 2006, and will have limited the potential deaths from exposure to chemical pollutants. In addition, the study shows that using this green fuel would reduce the cancer rate by 4.56 per million inhabitants.
The researchers say it is essential to carry out separate studies for each plant because “we still don’t know whether this will be positive for the whole cement industry”, according to Domingo. However, if the conditions are right, using mud from waste water treatment plants in cement factories is “a very good solution”, he concludes
Source: Plataforma SINC, ScienceDaily, 23 Jun 2009
PWN, the water supply utility for North Holland, The Netherlands, launched PWN Technologies, a new international company for the commercial exploitation of their expertise and advanced water treatment solution designs. PWN has provided technology and services across Europe, as well as in Asia, Africa and the Americas, also providing emergency water services following catastrophes like the 2004 Indian Ocean Tsunami.
Specifically for developing countries, PWN Technologies has developed the Perfector series of water treatment solutions to produce drinking from surface water through coagulation, flocculation, separation, filtration and disinfection. Perfector units have been installed in Indonesia and Viet Nam.
The Perfector-R is a water treatment plant for the production of drinking water for communities of 50,000
to 250,000 people, and overall net production capacities of 60, 120 or 240 l/s. The modular design consists of:
raw water intake on floating pontoons, process units, chemicals preparation and dosing systems, clear water reservoirs, distribution pumping station, electrical infrastructure and various other facilities such as emergency generator, laboratory, offices, work shop, etc.
optional waste water storage and pumping
The Perfector-P is a purification installation with a production capacity of 10 l/sec.
The Japan International Cooperation Agency (JICA) has produced a multimedia-based learning package “Slow sand filtration: creating clean, safe water” in English and Japanese, consisting of a video and reference materials. There are examples of the use of slow sand filtration technology in Japan and in a project in Sierra Leone.
WaterAid has produced a new poster resource that rates different water supply technology options in relation to their relative capital cost, operational cost, water quantity supplied and water quality supplied.
The poster also provides information on the situations in which certain water supply technologies are most applicable.
Levels of appropriateness are colour coded based on different combinations of the above variables.
The resource can be printed as a poster on A4, A3 or A2. You can download it here:
Chilean natural gas distributor Metrogas and water utility Aguas Andinas started up operations at the country’s first biogas plant installed at the Farfana water treatment complex on the outskirts of Santiago. The plant will produce 24Mm3/y of biogas and replace about 14Mm3/y of natural gas. “This is the only place in the world where biogas produced by a water treatment facility ends up being used directly in homes,” Metrogas president Matías Pérez Cruz said, adding that the biogas plant is the largest in South America. Investment in the project totaled 3bn pesos (US$5.3mn).
Source: BNamericas [subscription site], 14 May 2009
Meanwhile in Brazil, officials from the Japan International Cooperation Agency (JICA) and Paraná state water utility Sanepar [have met] to discuss projects to expand power generation sewage treatment plants. [...] Since 2008, Sanepar has been producing electric power from its [Ouro Verde sewage treatment plant in Foz do Iguaçu]. The plant produces energy for its own operations and the surplus is sold to power company Copel. [Sanepar wants to] extend the successful experience of Foz do Iguaçu to all [its] sewage treatment plants.
Source: BNamericas [subscription site], 25 May 2009
Scientists at IBM Research, together with collaborators from Tokyo-based Central Glass, the King Abdul Aziz City for Science and Technology (KACST) and the University of Texas, Austin have created a new membrane that filters out salts as well as potentially harmful toxins in water such as arsenic while using less energy than other forms of water purification.
[...] Membrane filtration is currently one of the most energy efficient techniques for removing salt and improving water quality. But, conventional membranes used today are easily damaged by chlorine, which is commonly added to water to prevent bacterial growth that can cause health problems. Now, the collaborative research team has designed a new concept in membrane materials that combines resistance to chlorine damage and high performance separation behavior in mildly basic conditions, making it suitable for arsenic removal in addition to water desalination.
[...] Because of its unique chemistry, the membrane contains ionizable hydrophobes that undergo a dramatic change when they encounter mildly basic conditions – they become substantially hydrophilic. In short, the membrane, which is made with fluorine materials, transforms from a low water transporting filter to a high water transporting state in a basic environment – what the researchers call a “water superhighway.” Fortuitously, high pH also causes arsenic to become ionic resulting in a relatively easy separation by desalination membranes. Because of these conditions and reactions, when contaminated water is forced through the membrane, the arsenic is filtered out.
See also: IBM Unveils Smart Technologies, Services to Help Combat Mounting Global Water Issues, IBM, 16 Mar 2009
