25 March 2009

Zimbabwe: Researchers Developing New Ways to Purify Water

Bulawayo — Scientists at Bulawayo's National University of Science and Technology (NUST) have embarked on research to develop simple and affordable water purification methods, as more than a billion people live without safe drinking water in developing countries.

Water and sanitation experts are currently investigating if a powder made from the seeds of the Moringa Oleifera, commonly known as the drumstick or horseradish tree, can be used as a filter to purify water.

In Sub-Saharan Africa, only a third of the population has access to clean drinking water, according to United Nations Children's Fund, UNICEF. Water-borne diseases kill an estimated five million people a year, many of them children.

The situation is particularly dire in Zimbabwe, where the economic meltdown has led to a breakdown in water service provision and infrastructure. Resulting water contamination and poor water treatment have caused major health issues.

A cholera outbreak, first reported in mid-2008, has claimed the lives of more than 3,000 people to date, with more than 80,000 reported cholera cases countrywide, according to World Health Organisation (WHO).

Without access to safe drinking water, WHO says Zimbabwe is highly unlikely to meet the Millennium Development Goal (MDG) 1 of halving the number of people suffering from poverty and hunger by 2015, due to a combination of factors linked to poor infrastructure, poor sanitation and lack of investment in water treatment systems.

Poor water quality and sanitation will also make it difficult for the country to reach MDG3, reducing child mortality, and MDG4, increasing maternal health.

A combination of chemical and bacteriological pollution of water resources presents a particular problem in Zimbabwe, explained Theresa Mkandawire, researcher at the University of Malawi and regional water expert. "Deep wells and boreholes are often subjected to chemical contamination, whilst in shallow wells bacteriological and physical contamination dominates," she told IPS.

"The level of pollution that goes unmonitored is quite high and people living downstream [of rivers] are particularly affected," agreed executive director of the Harare-based Institute of Water and Sanitation Development (IWSD), Noma Neseni. "Pollution within the [SADC] region and in Zimbabwe is caused by industry, domestic users, agriculture, and at the moment fines for pollution are quite low in Zimbabwe." â-¨ Neseni further noted that, in Zimbabwe, the national rural water supplies and sanitation programme has not effectively promoted household water treatment, although researchers found this could be an important entry point to increase water quality.

"Although there have been fears that water is contaminated through transportation and storage, we have failed to invest into developing appropriate technologies for water treatment at household level until now," she said.

Preventing water pollution is a cornerstone in the Southern African Development Community (SADC) regional water policy of 2005, which aims to address weak regulatory and legal frameworks, inadequate institutional capacity of national water authorities, poor water resource management as well as lack of participation and infrastructure.

To make clean water more accessible and affordable to Zimbabweans in urban as well as in rural areas, the National University of Science and Technology (NUST) in Bulawayo has embarked on a research project to develop low-cost water treatment methods, such as the use of Moringa seed powder.

"Water quality is a problem in Zimbabwe, and this is not only confined to urban areas but happens in rural areas too," explained NUST civil engineer Ellen Mangore.

She told IPS the research project is modelled on water treatment practices in Sudan, where the seed is used pounded or whole to purify water. Moringa Oleifera is a small tree whose leaves are popularly used to make salad, while its elongated fruit is eaten as a vegetable.

Researchers place their hopes in the Moringa tree seed for water purification, as the tree is widely found in Zimbabwe. In addition, it is drought tolerant and grows in locations with as little as 500 millimetres of annual rainfall.

In addition, NUST investigates other simple water treatment methods, such as purification with household bleach and sand filtration columns.

So far, the treatment of water with Moringa seed powder has proven to be an effective method of reducing water-borne diseases and correct pH, said Mangore, as have the other tested methods.

"Our test results also showed that household bleach is a very strong disinfectant and raised the levels of free and total chlorine in the water, while the simple filtration columns resulted in almost 85 percent reduction in total suspended solids," she explained.

Mangore said the research project is ongoing, as different purification scenarios still need to be investigated, for example dosages and contact times. She explained the results of the study are still under wraps pending verification of the potential toxicity of the Moringa powder and household bleach.

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