Tag Archives: wastewater reuse

Effluent and Waste Water Management Conference, Nairobi, Kenya, 22-23 November 2011

This conference assesses recent developments and approaches to industrial wastewater management in the African region.There are speakers from UN agencies (Wold Bank, UNEP), universities, industry and government.

The conference is being organised by  Aidem Business Solution (ABS) and is sponsored by the Kenyan National Environment Management Authority (NEMA) and Cuss Environmental System Technology and Service GmbH.

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Safe use of wastewater in agriculture offers multiple benefits

Recycling urban wastewater and using it to grow food crops can help mitigate water scarcity problems and reduce water pollution, but the practice is not being as widely implemented as it should, according to a new UN food and agriculture organization (FAO) report [1]. The FAO has called for governments to increase the amount of treated wastewater being used for irrigation purposes as this will reduce costs for farmers and cities and improved water quality.

FAO report coverThe FAO report used case studies from Spain and Mexico to test methodologies for cost-benefit and cost-effective analyses of wastewater reuse projects. The Mexico case studies were drawn from three regions:

  • Mexico City & Tula Valley
  • Guanajuato City & La Purísima irrigation module
  • Durango City & Guadalupe Victoria irrigation module

“The case studies in this report show that safely harnessing wastewater for food production can offer a way to mitigate competition between cities and agriculture for water in regions of growing water scarcity,” said Pasquale Steduto, Deputy Director of FAO’s Land and Water Division. “In the right settings, it can also help to deal with urban wastewater effluent and downstream pollution.”

[1] Winpenny, J. … [et al.] (2010). The wealth of waste : the economics of wastewater use in agriculture. (FAO water reports ; 35). Rome, Italy, Food and Agriculture Organization of the United Nations (FAO). xv, 129 p. Download full report

See also: Mexico: farmers fear loss of “free fertilizer” when wastewater treatment plant is built, Sanitation Updates, 02 Aug 2010

Source: FAO, 06 Sep 2010

Japan: selling sewage to Australia

Japan has an unlikely new export product:  the sewage it normally dumps into rivers or the sea. The first buyer is the Australian mining industry. Could this also become a new money earner for developing countries? Well, no. The “export quality” sewage in question is effluent from high-tech Japanese wastewater treatment plants.

An innovative trade experiment will take place in the autumn of 2010. Australian ships with iron ore for Japan, will return, not with seawater in their ballast tanks, but with highly treated sewage water.

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Vacancy: Post Doctoral Fellow Microeconomics of Sanitation and Wastewater Reuse in Agriculture, IWMI, Ghana (with some travel) [deadline 30 September]

If you have recently completed your PhD in economics or sanitation but have sound understanding of both, then this could be just the assignment for you. The International Water Management Institute (IWMI) seeks the right person to analyze problems relating to human waste, as used in agriculture, then form policy recommendations to enhance livelihoods in the rural/urban interface.

Requirements include:

  • A recent PhD in agricultural or natural resources or environmental economics or environmental or civil engineering and
  • A good understanding of agriculture and microeconomics
  • Knowledge of sanitation challenges in developing countries: solid waste, fecal sludge and wastewater management (with on-site sanitation systems)
  • Excellent written and spoken English

Read the full job description and application details

Online application form

Complete Application Form + attach résumé + attach letter which addresses IWMI’s requirements listed in job description with names and email addresses of 3 professional referees, to be contacted if you are short-listed

Contact: work-at-iwmi@cgiar.org

Application deadline: 30 September 2010

Please do send requests for information or applications to Sanitation Updares

Mexico: farmers fear loss of “free fertilizer” when wastewater treatment plant is built

For over 100 years farmers in Hidalgo State use “the black waters” (wastewater) from Mexico City to irrigate their land.

So when word got out that the government was finally going to build a giant wastewater treatment plant, one might have expected the farmers around here to be excited. Instead, they were suspicious.

“Without that water, there is no life, “ said Gregorio Cruz Alamilla, 60, who has worked his family’s 12-acre farm since he was a boy.

Mr. Cruz knows the water is loaded with toxic substances, including chemicals dumped by factories, and he tires of clearing his field of plastic bottles and wrappings every time he irrigates.

But like many others here, he worries that treating the water, though it may remove harmful contaminants, will also strip away some of the natural fertilizers that even the authorities here say have helped make this valley so productive. And despite the government’s assurances, the farmers here suspect the worst: that once the water is treated, it will be pumped back to Mexico City, leaving the farms dry.

Farmer using “the black waters” for irrigation in Mezquital Valley. Photo: Janet Jarman, New York Times. Janet Jarman, New : :

Wastewater reuse for irrigation is common throughout the developing world, but nowhere on the scale of Mezquital Valley with its 350 square miles (906 square kilometres) of irrigated fields.

But now, Mexico City (pop. 20 million) is building a stormwater drainage system and treatment plant to deal with the growing problem of flooding during the rainy season.

“It was a predictable problem, but we never paid enough attention to it,” said Ernesto E. Espino de la O, who manages the treatment and water supply project for the National Water Commission. A collapse of the crumbling system, warned one study from Mexico’s National Autonomous University of Mexico, would be catastrophic, flooding large parts of the city.

Engineers have started to construct a 38.5-mile (62 km) drainage tunnel that will transport stormwater to the town of Atotonilco, where a wastewater treatment is plant is planned.

The plant, which is budgeted to cost $1 billion and will begin operating in 2012, will clean 60 percent of the city’s wastewater. The water commission’s measurements show that the water is laced with heavy metals like lead and arsenic, filled with high levels of pathogens and parasites, and weighed down by grease.

But the farmers “are worried that the treatment plant will take out the nutrients, that the water will go back to Mexico City and that it will be privatized,” said Filemón Rodríguez Castillo, the director of the main irrigation district here. “The water is very much appreciated here, independent of the fact that it smells so ugly, that it stinks.”

One of his jobs is to persuade local residents that even though the residents of Mexico City will have to pay to have their water treated, they will not get it back.

The main benefit of irrigating with clean water, he has told them, is that they will be able to grow many kinds of vegetables, which are now restricted to protect consumers from illness.

Officials here now direct farmers not to grow crops in which the edible part comes into contact with the irrigation water and is eaten raw, ruling out vegetables like lettuce, carrots or beets. Alfalfa is permitted because it is used as animal feed. But enforcement is spotty and the farmers abide by an elastic interpretation of the regulations, planting broccoli and cauliflower, for example.

To the farmers here, whose sturdy opinions match their surprisingly good health, the proof that their water is good is in what they see around them. “Plants won’t absorb poison; they would die,” said Jesús Aldana Ángeles, a 75-year-old fifth-generation farmer, who was watching his small flock of sheep munch on the remains of his harvested alfalfa field. “There is no better laboratory than the ground. The earth absorbs everything. It purifies it, it treats it.”

Read more about wastewater irrigation read “Wastewater irrigation and health : assessing and mitigating risk in low-income countries”.

Related web site: WHO – Safe use of wastewater, excreta and greywater

Source: Elisabeth Malkin, New York Times, 04 May 2010

Research project on safe wastewater reuse for urban poor concludes

The WHO/IDRC/FAO research project on non-treatment options for safe wastewater use in poor urban communities was concluded on 30 April 2010. The report of the final workshop in Amman, Jordan (7-10 March 2010) has now been published.

The objective of the project was to test the applicability of the third edition of the WHO Guidelines for the Safe Use of Wastewater, Excreta and Greywater in Agriculture and Aquaculture (WHO, 2006). For this purpose the following four field studies were conducted:

  • Ghana Kumasi: Evaluation of non-treatment options for maximizing public health benefits of WHO guidelines governing the use of wastewater in urban vegetable production in Ghana.
  • Ghana/Tamale: Minimizing health risks from using excreta and grey water by poor urban and peri-urban farmers in the Tamale municipality, Ghana.
  • Jordan: Safe use of greywater for agriculture in Jerash Refugee Camp: focus on technical, institutional and managerial aspects of non-treatment options.
  • Senegal: Proposition d’étude en vue de l’intégration et de l’application des normes de la réutilization des eaux usées et excréta dans l’agriculture.

The research team is now working on the final product, a Guidance Document/Manual for Sanitation Safety Plans to assist national and municipal authorities and other users of the WHO guidelines in their application.

During the 2010 Stockholm Water Week, WHO will launch the second edition of the information kit for the WHO safe use of wastewater guidelines (Sunday 5 September 17:45-18:45).

Project documents and the 2006 WHO guidelines are available on the WHO web page on Safe use of wastewater, excreta and greywater.

Scientists find low-tech way to recycle H2O

Love that dirty water – Scientists find low-tech way to recycle H2O

Horticulturists at Pennsylvania State University have come up with a low-cost, green method for recycling so-called “gray” water – the stuff from sinks, showers and washing machines that would otherwise go down the drain.

They filter the water through some plant roots and layers of crushed stone, peat moss and waste materials – making it clean enough to reuse for growing vegetables or flushing toilets – but not for drinking.

Using gray water is generally not allowed in the United States, but some states have explored the idea. The Penn State researchers hope their data – which show such biofilters can remove almost all suspended solids, nitrogen compounds and other pollutants from gray water – might lead to greater acceptance.

Meanwhile, such filters could be used in poor nations that lack adequate water for sanitation and irrigation, said Robert D. Berghage, associate professor of horticulture.

Robert Cameron

Robert Cameron, the doctoral student on the project, presented the research this month at a sustainable-farming meeting in Cuba.

The system consists of two plastic pipes filled with layers of porous rocks, soil, crumbs from discarded tires, composted cow manure and peat moss. Vegetables and other plants are planted in holes along the sides of the pipes.

The pipes stand in a basin with still more plants – papyrus and horsetail reed – whose roots support microbes that remove pollutants.

Each material in the pipes removes different contaminants, though the tire crumbs are there mainly as filler. Tire crumbs also contain contaminants, but tests showed they are not released into the water, Berghage says.

With enough treatment, you could even drink water that goes through such filters, Berghage says. He admits that this wouldn’t gain wide acceptance, even though drinking-water plants already treat water from rivers that receive treated waste.

“Most of us have this sort of aversion to drinking treated wastewater,” he says, “even though much of the time we’re doing it anyway.”

Source – http://www.philly.com/philly/living/green/93911854.html

South Africa: wastewater is a resource

South Africa faces chronic water shortages, yet billions of litres are flushed away every year. Being one of the driest countries in the world, the conservation of water resources and managing wastewater should be a top priority for government. [According to] the World Wide Fund for Nature (WWF) [...] water shortage is a genuine threat as 98 percent of the country’s water resources are already fully utilised. [...] WWF estimates that by the year 2025 South Africa will have a water deficit of 1.7 percent.

[...] One of the ways to protect and conserve water is to focus on the recycling of waste water, according to water experts gathered in Cape Town for a water seminar in May [2009]. The event was attended by water experts from Europe and South Africa and formed part of an economic and political mission of the Dutch governmental delegation comprising of minister of Development Cooperation Bert Koenders and deputy minister of Foreign Trade Frank Heemskerk.

“We should change our mindsets about wastewater,” said Brendon Meulman, project manager at Landustrie, a Dutch company that specialises in wastewater management. “We should stop seeing it as waste and a burden, but rather as a resource”.

“Toilet water for instance, is rich in organic material,” he explained. “If the concentration of this so-called black water is high enough, you can create energy out of this organic material. You can also turn it into compost and fertiliser.”

[...] Apart from reducing the amount of wastewater and waste, the system does not require water to flush excrement. Similar systems are already in operation in South Africa, for instance in Durban were thousands of dry toilets have been installed. “We work with so-called vacuum toilets that are already used on cruise ships,” he told IPS. “”According to our calculations, a vacuum toilet saves 36 litres of water per person per day,” said Meulman. “That is over 25 percent of your daily total water consumption.”

According to Meulman, this technology is not applicable only in high-income countries. “We have developed a low tech version which is specifically meant to service informal settlements and squatter camps,” he explained. “It is a self-contained system that is not dependent on energy sources. It basically comprises of a container that is equipped with toilets and urinals, which are vandalism proof, hygienic and clean.”

[...] The chances of the vacuum toilet system solving South Africa’s water problems are slim, as government figures show that domestic consumption accounts for just 12 percent of all water used in South Africa. Industry, mining, and power generation together consume another 12.5 percent and agricultural irrigation accounts for around 52 percent the country’s water use.

[...] Koenders emphasised that it is not only toilet water that needs to be looked at. “The country’s water problems are further impacted by the fact that mines are contaminating rivers and other water bodies,” he told IPS.

[...] The problems mentioned by Koenders were key focal points of a 2008 report presented by South Africa’s National Nuclear Regulator. The publication predicted serious problems with the country’s water supply, including radioactive pollution and waste dumping. It also suggested that wastewater from mines was seeping into the country’s groundwater.

The water and forestry department however, denied a looming water crisis. In a statement, forestry and water affairs minister Lindiwe Hendricks said that South Africa’s drinking water quality was rated among the best in the world. [...] “Indeed, due to mining and other human activities, the water quality is affected in some parts of the country,” Marius Keet, Director of Water Quality Management of Forestry and Water Affairs of the Gauteng province, said. “But it is not a crisis. It is a challenge, that needs to be addressed.”

Source: Miriam Mannak, IPS, 08 Jun 2009

Peru, Lima: Sedapal to build wastewater treatment plant for irrigation

Peru’s state water and sewerage utility Sedapal, serving Lima and neighboring Callao, will sign an agreement with the Pueblo Libre district to build a wastewater treatment plant [that will] irrigate the district’s green areas with treated water instead of polluted water from the Surco river.

“Pueblo Libre will be the first ecological district in the city and its parks and gardens will be 100% watered by treated water,” [utility president Guillermo León said].

Source: BNamericas [subscription site], 27 Jan 2009

Singapore NEWater: From Sewage to Safe

Singapore has taken recycling to a whole new level, in the process, securing safe, drinking water for its citizens for centuries to come.

The world can learn a thing or two on water recycling from Singapore. Faced with diminishing freshwater sources, its national water agency, the Public Utilities Board (PUB), has tapped an unlikely resource-used, dirty, down-the-toilet-bowl, sewage water.

Using a combination of microfiltration, reverse osmosis technology and ultraviolet disinfection, Singapore’s scientists have perfected the process of transforming sewage water into new, clean, safe drinking water. And since every corner of this bustling city is connected to a single sewerage system, Singapore will never run out of sewage water as long as its residents keep flushing.

Aptly branded NEWater, this reclaimed or recycled water is one of Singapore’s “four national taps” or freshwater sources providing 7% of the country’s water demands.

Related Links

Read more: Cezar Tigno, ADB, Dec 2008