Crop irrigation with untreated wastewater


Photo credit: IWMI

Basudev Mondal irrigates a farm near the busy EM Bypass road of Calcutta, India growing brinjal or egg plant. Photo: Chhandak Pradhan / IWMI

Crop irrigation with untreated wastewater

A major health and environmental menace

The use of wastewater to irrigate crops is far more widespread than previously estimated, according to a new study, exposing hundreds of millions of people to health risks and posing a major environmental hazard.

Study results, based on on advanced modeling methods, show that 65% of all irrigated areas within 40 kilometers downstream from urban centers – amounting to about 35.9 million hectares (Mha) worldwide – are affected by wastewater flows to a large degree. Of this total area, 29.3 Mha are in countries where wastewater treatment is very limited, exposing 885 million urban consumers as well as farmers and food vendors to serious health risks.

Five countries – China, India, Pakistan, Mexico and Iran – account for most of this cropland. The new findings supersede a widely cited 2004 estimate, based on case studies in some 70 countries and expert opinion, which had put the cropland area irrigated with wastewater at a maximum of 20 million hectares.

Read the full article: IWMI


Possibilities to eliminate the issues relating to wastewater.


Photo credit: AZO Cleantech

Caution, no drinking water. Only 0.3 % of the water on the Earth�s surface is suited for use as drinking water. KIT scientists study possibilities of improving wastewater use. (Photo: KIT)

KIT Researchers Propose New Ways to Utilize Wastewater

Written by AZoCleantech

A team of researchers from the “Water-Energy Group” of Karlsruhe Institute of Technology (KIT) are studying possibilities to eliminate the issues relating to wastewater.

Wastewater is considered to be of no use. Washing water is said to an average temperature of 30 °C. Toilet water can be used not only for producing fertilizers or biogas but also as valuable resources that otherwise is dumped in the sewer system unused. What is worse is that annually, over 2 million people die from diarrheal diseases because of the wrong use of wastewater.

Although water covers around 72% of the Earth’s surface, only 0.3% can be utilized as drinking water.

Read the full article: AZO Cleantech

With that in mind, wastewater is no waste. It contains thermal energy, chemical energy in the form of carbon compounds, and valuable plant nutrients. Now, we have to develop processes for the use of these resources.

Helmut Lehn, Institute for Technology Assessment and Systems Analysis (ITAS)

Wastewater, once treated, can help meet the needs for freshwater as well as energy and agriculture.


Photo credit: UN News Centre

A wastewater treatment facility in Manila, the Philippines. Photo: Danilo Pinzon / World Bank

Wastewater should be recognized as a valuable resource, UN says on World Water Day

In a world where the demand for water continues to grow and the resource is finite, a new United Nations report argues that wastewater, discarded into the environment every day, once treated, can help meet the needs for freshwater as well as for raw materials for energy and agriculture.

Needless to mention, treating wastewater and removing pollutants can also remarkably reduce the impact on the environment as well as on health.

“Improved wastewater management is as much about reducing pollution at the source, as removing contaminants from wastewater flows, reusing reclaimed water and recovering useful by-products [as it is about increasing] social acceptance of the use of wastewater,” noted Irina Bokova, the Director-General of the UN Educational, Scientific and Cultural Organization (UNESCO) Director-General in her foreword to the World Water Development Report 2017 – Wastewater: An untapped resource.

The report, launched today in Durban, South Africa, on the occasion of World Water Day, also highlights that improved management of wastewater is essential in achieving the 2030 Agenda for Sustainable Development.

“It’s all about carefully managing and recycling the water that runs through our homes, factories, farms and cities,” said Guy Ryder, the Director-General of the UN International Labour Organization (ILO) and the Chair of UN-Water, urging for reducing and safely reusing more wastewater.

“Everyone can do their bit to achieve the Sustainable Development Goal target to halve the proportion of untreated wastewater and increase safe water reuse by 2030.”

Sustainable Development Goal 6 (SDG6) has specific targets on halving the proportion of untreated wastewater and substantially increasing recycling and safe reuse globally (target 6.3) as well as supporting countries in wastewater treatment, recycling and reuse technologies (target 6.a).

Read the full article: UN News Centre


Reforestation on sewage effluent




In an innovative forestry project known as the Serapium forest, Egypt has found a solution to desertification – when fertile land becomes deserts with the persistent degradation of dryland.

The solution was planting forests. This is easier said than done as 96% of Egypt is consumed by deserts and Egyptian deserts have virtually no rain falls. But researchers in Egpyt have found a way to repurpose wastewater instead of tapping into the sparse fresh water supply. The result? A thriving tree plantation in the middle of the Egyptian desert.

According to Deutsche Welle (DW), the Serapium forest project is a research programme that was initiated by the Egyptian government in the 1990s with the aim to green 36 different desert locations. An array of native tree species were planted alongside commercially valuable non-native species including Eucalyptus and Mahogany.

The source of wastewater is based in northern Egypt, an approximate two hours car ride from Cairo. The body of waastewater is the drainage basin with sewage effluent produced by the inhabitants of the nearby town, Ismailia.

The individual trees in the 200-acre of the 500-acre plantation are given five litres of the repurposed water twice a day without the necessity of extra fertilizer as the effulent water delivers the nutrients needed. Regular tests have also shown that there was no contamination in the soil with the effluent, DW reported.

In fact, with oxygen and microbes added into the effluent, results showed a high concentration of phosphates and nitrogen compounds to deliver quality fertilizers found in powder form at gardening shops.

Read the full article: Panels Furniture Asia


How to grow forests in the desert with sewage


Photo credit: Inhabitat

Located about two hours from Cairo, the Serapium forest is part of a program initiated by the Egyptian government in the 90s. The 200-hectare plantation is home to a variety of native and non-native trees, including commercially valuable species like eucalyptus and mahogany. Though the soil in this area would normally be too devoid of nutrients to support new tree growth, researchers have found that by watering the trees with sewage effluent, the plants are able to flourish. The wastewater provides so many nutrients that additional fertilizer isn’t even necessary.

Egyptian researchers discover a way to grow forests in the desert with sewage


Desertification is a major issue throughout Africa, but there’s a simple way to stop the spread of deserts into fertile land: planting forests. The problem is that in the regions hardest hit by the phenomenon, there simply isn’t enough clean water to properly nurture the trees and keep them healthy. But an innovative project in Egypt proves that it can be done using repurposed wastewaterinstead of tapping into the sparse fresh water supply. The trees grown in the forest are thriving, and in fact, the eucalyptus trees have been found to produce wood at four times the rate of pine plantations in Germany.

Read the full article: Inhabitat

Namibia’s innovative water system


Photo credit: SciDevNet

Copyright: Danilo Pinzon/World Bank

Lessons from Namibia’s innovative water system

When you have no other options, people will accept anything you put on the table.” : Pierre van Rensburg, City of Windhoek

by Sipho Kings

Speed read

  • In Namibia, municipal wastewater has been turn it into drinking water
  • The technology resulted from water scarcity in the country
  • A similar project in South Africa did not materialise because of fears

A convoy of fuel trucks blocks the single-lane road, moving in a close herd. Warm air floods through the window. The scenery drags past mountains and thorny acacia.

A gravel road leads to the S Von Bach dam. It is one of three dams supplying Windhoek with water, and it is nearly empty.

Windhoek’s water problem

For Windhoek, home to Namibia’s industry and 20 per cent of its 2.3 million people, this is an intractable problem. The national utility, NamWater, says the city has six months of water left. After that, it will be up to people’s ingenuity to keep the taps dripping.

But drought is nothing new in Namibia. The only consistent rivers form the country’s northern and southern borders. Its ephemeral rivers only flow when it floods, looking like lazy brown snakes with full bellies lounging on a parched and cracked countryside.

South of Von Bach dam lies Windhoek, encased in a lumpy basket of hills.

 Read the full article: SciDevNet


This “living wagon” cleans greywater for reuse with marsh plants

Photo credit: Treehugger

© Wohnwagon

Green-roofed, off-grid Austrian microhome filters greywater for reuse

Kimberley Mok

by Kimberley Mok

© Wohnwagon -
© Wohnwagon –

We don’t see many tiny houses with green roofs, but Austria’s Wohnwagon (translated as “living wagon”) demonstrates that it can be done. Outfitted with distinctive, rounded ends and round porthole windows, the solar-powered tiny home also boasts its own water filtration system that cleans greywater for reuse — using marsh plants on its roof.

Read the full article: Treehugger

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