Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sunlight plus lime juice makes drinking water safer

18.04.2012
Looking for an inexpensive and effective way to quickly improve the quality of your drinking water?

According to a team of researchers from the Johns Hopkins Bloomberg School of Public Health and the Johns Hopkins School of Medicine, sunlight and a twist of lime might do the trick. Researchers found that adding lime juice to water that is treated with a solar disinfection method removed detectable levels of harmful bacteria such as Escherichia coli (E. coli) significantly faster than solar disinfection alone. The results are featured in the April 2012 issue of American Journal of Tropical Medicine and Hygiene.

"For many countries, access to clean drinking water is still a major concern. Previous studies estimate that globally, half of all hospital beds are occupied by people suffering from a water-related illness," said Kellogg Schwab, PhD, MS, senior author of the study, director of the Johns Hopkins University Global Water Program and a professor with the Bloomberg School's Department of Environmental Health Sciences. "The preliminary results of this study show solar disinfection of water combined with citrus could be effective at greatly reducing E. coli levels in just 30 minutes, a treatment time on par with boiling and other household water treatment methods. In addition, the 30 milliliters of juice per 2 liters of water amounts to about one-half Persian lime per bottle, a quantity that will likely not be prohibitively expensive or create an unpleasant flavor."

In low-income regions, solar disinfection of water is one of several household water treatment methods to effectively reduce the incidence of diarrheal illness. One method of using sunlight to disinfect water that is recommended by the United Nations Children's Fund (UNICEF) is known as SODIS (Solar water Disinfection). The SODIS method requires filling 1 or 2 L polyethylene terephthalate (PET plastic) bottles with water and then exposing them to sunlight for at least 6 hours. In cloudy weather, longer exposure times of up to 48 hours may be necessary to achieve adequate disinfection. To determine if one of the active constituents in limes known as psoralenes could enhance solar disinfection of water, Schwab and Alexander Harding, lead author of the study and a medical student at the Johns Hopkins School of Medicine, looked at microbial reductions after exposure to both sunlight and simulated sunlight. The researchers filled PET plastic bottles with dechlorinated tap water and then added lime juice, lime slurry, or synthetic psoralen and either E. coli, MS2 bacteriophage or murine norovirus. Researchers found that lower levels of both E. coli and MS2 bacteriophage were statistically significant following solar disinfection when either lime juice or lime slurry was added to the water compared to solar disinfection alone. They did find however, that noroviruses were not dramatically reduced using this technique, indicating it is not a perfect solution.

"Many cultures already practice treatment with citrus juice, perhaps indicating that this treatment method will be more appealing to potential SODIS users than other additives such as TiO2 [titanium dioxide] or H2O2[hydrogen peroxide]," suggest the authors of the study. However, they caution, "additional research should be done to evaluate the use of lemon or other acidic fruits, as Persian limes may be difficult to obtain in certain regions."

"Using Limes and Synthetic Psoralens to Enhance Solar Disinfection of Water (SODIS): A Laboratory Evaluation with Norovirus, Escherichia coli and MS2," was written by Alexander S. Harding and Kellogg J. Schwab.

The research was supported in part by the Osprey Foundation of Maryland, The Johns Hopkins University Global Water Program, the Johns Hopkins University School of Medicine Dean's Funding for Summer Research and the Johns Hopkins University School of Medicine Scholarly Concentrations.

Natalie Wood-Wright | EurekAlert!
Further information:
http://www.jhsph.edu

More articles from Health and Medicine:

nachricht The end of pneumonia? New vaccine offers hope
23.10.2017 | University at Buffalo

nachricht Scientists track ovarian cancers to site of origin: Fallopian tubes
23.10.2017 | Johns Hopkins Medicine

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017 | Life Sciences

Gamma rays will reach beyond the limits of light

23.10.2017 | Physics and Astronomy

The end of pneumonia? New vaccine offers hope

23.10.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>