Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Where there’s muck . . . there’s compost and irrigation water

09.06.2004


Waste is a life and death issue in less-developed countries, where poor rubbish collection and sanitation affects life expectancy. Expertise from the University of Leeds’ civil engineering department is helping transform lives by transferring knowledge on low-cost public sanitation.



Every year 1.8 million people die from diarrhoea, 90% of them children under five, according to the World Health Organization. The WHO says improved sanitation could bring these cases down by 37.5%. Translate that into real lives and bringing sanitation to the less-developed world can make a big difference.

That’s the specialism of Leeds civil engineering professors Ed Stentiford and Duncan Mara. This year they are engaged in EU-funded projects in Viet-nam, Thailand, Bangladesh, Nepal and Colombia helping to clean up towns and cities lacking the infrastructure we take for granted.


The key in these cash-strapped economies is to sidestep high-tech solutions and use locally-available technology and resources, processing waste safely and recycling it or turning it into compost and producing irrigation water from sewage where possible.

These principles are illustrated by Professor Mara’s specialism – low-cost sewers – which are currently being implemented in the city of Cali in Colombia. He said: “Often engineers in developing countries want hi-tech water treatment systems, but these are high-cost too. They depend on unreliable electricity and equipment that can break down, needing expensive spares. We try to convince them that they should make the most of the resources they have to hand like cheap land, plentiful labour and sunshine.”

The concrete sewers of western cities, which run under roads and require large-scale construction are out of the question in places like Cali. Instead, low-cost sewerage can bring sanitation to poor districts at 20% of the cost. Small diameter pipes run through back yards of houses and carry away sewage that usually runs in open ditches.

Treating the sewage highlights another example of the low-cost ethos advocated by the Leeds team. Human waste is treated by aerating it to help bacteria break it down. In our cities this is done with equipment that stirs the sewage slowly. In the developing world, where capital is short and electricity unreliable, the Leeds team recommends a different approach – waste stabilisation ponds.

These are large ponds where the sewage is allowed to collect and green algae carries out the aeration. The set-up costs are 10-30% of western treatment systems and when the waste water has been treated it can be used for irrigation or fish farming. “Land is cheap and there’s plenty of sunshine so the message is to capitalise on what they have plenty of,” said Professor Mara.

Rubbish is the other half of the equation. Even in the least developed countries each person produces half a kilogram every day. Poor or inadequate collection results in dumping in streets, clogged sewers and drainage systems, contamination of water sources and a profusion of rats, insects and disease.

Professor Stentiford advises on ways of tackling the problem. These include changing popular attitudes, organising effective collection and sorting of waste to enable recycling where possible.

On the Tan Hoa-Lo Gom canal project in Ho Chi Minh City, Viet-nam, these ideas have been put into practice. In the tightly-packed district, rubbish collection was patchy and much ended up in the waterways. Rubbish collected was taken away in imported compactor trucks to landfill, which made things difficult and hazardous for the waste pickers who make a living combing tips for recyclable material.

The district now has an efficient collection system and recycling has been made easier and safer. Locally built tricycles carry away rubbish to a transfer station. The garbage is not densely packed and tables have been built to aid the waste pickers.

“We’ve improved waste collection and removed the health risk. They’re handling waste better now and getting it out of the city.

“Where rubbish was thrown into the canal, it is now going to the transfer station and landfill. With sorting they can get back 75% of the value of plastic, for example, but the next stage is to use organic material by composting it,” said Professor Stentiford.

“The secret is to achieve the same performance as the developed-world but not using the same technology, as this would be too costly. In many less-developed countries, labour is cheap, so where material sorting is done by machine in Europe it is a labour-intensive process in these countries.”

According to the UN, one-in-six of the world’s population lacks adequate safe water supplies and another 2.4 billion do not have adequate sanitation. The Leeds team is making a small difference to some of those lives.

“We use local staff and build on indigenous skills by providing education and training for the local people. We’re fighting a losing battle against population growth so hopefully we are making a difference by getting expertise into these countries,” said Professor Stentiford.

Vanessa Bridge | University of Leeds
Further information:
http://reporter.leeds.ac.uk/499/index.html

More articles from Ecology, The Environment and Conservation:

nachricht Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht Understanding animal social networks can aid wildlife conservation
23.06.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

New 3-D model predicts best planting practices for farmers

26.06.2017 | Agricultural and Forestry Science

New research reveals impact of seismic surveys on zooplankton

26.06.2017 | Life Sciences

Correct connections are crucial

26.06.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>