This report, written for the Meridian Institute by a team of scientists from South Africa and Sri Lanka, describes the general issues facing projects aimed at improving access to clean water in the developing world, as well as the specific challenges facing nano-based projects.

The authors describe a number of water treatment devices that incorporate nanotechnology, including nanofiltration membranes, attapulgite clays and zeolites, nanocatalysts, magnetic nanoparticles and nanosensors. More importantly, they outline potential opportunities associated with these technologies, and possible risks.

The paper includes two case studies of projects designed to improve access to clean water — one in Bangladesh based on a conventional approach using sari cloth to remove cholera from water, and one in South Africa that incorporates a nanofiltration membrane.

This paper from the Meridian Institute describes a range of well-known and field-tested conventional approaches to removing contaminants from water as well as the current crop of nanotechnologies that could enhance existing — or develop new — water treatment technologies.

For each approach or potential product the authors give a short description of what it is and who has developed it, and report on the product's effectiveness in removing contaminants, the amount of water it can treat, and its cost and ease of use. They also include summary comparative charts of conventional versus nano-based treatments.

Conventional approaches covered include various types of filters, ultraviolet radiation, chemical treatment and desalination. Nano-based water treatments covered include carbon nanotube-based technologies, nanofiltration membranes and devices, nanoporous materials and clays, zeolites, nanocatalysts and magnetic nanoparticles.

This scientific article, written by researchers at Rice University in the United States, describes how magnetite (iron) nanocrystals — or 'nanorust' — can be used to remove arsenic from contaminated water. The authors describe the discovery of unexpected magnetic interactions between nanoparticles of rust that mean they can be easily extracted from water using a hand-held magnet.

Iron is well known for its ability to bind arsenic and the researchers' experiments show that by suspending the nanoparticles of rust in arsenic-contaminated water, arsenic levels were reduced to well below accepted standards for drinking water.

This feature article from Nanowerk, written in collaboration with scientists, provides a short introduction to the role nanotechnology could play in resolving water shortage and quality issues.

The authors describe how nanotechnologies are being used in water filtration, especially nanotechnology membranes incorporating carbon nanotubes and dendrimers. They also examine how nanotechnologies and materials such as zeolites, carbon nanotubes and biopolymers can be used to remove, reduce or neutralise heavy metals and other contaminants that pose a threat to human health. And they briefly discuss the issue of using nanotechnology to develop water disinfectants.

This commentary, by South African scientists Thembela Hillie and Mbhuti Hlophe, examines nanoscience's potential to solve the technical challenges associated with removing pollutants from water. The authors describe a range of nano-based water treatment technologies already in the marketplace and discuss how nanofiltration membranes can be used in low-cost methods to produce safe drinking water. They highlight a case study in South Africa where such membranes were used to treat brackish groundwater.

The authors emphasise the importance of technology transfer in getting nano-based solutions to the countries that need them, arguing that direct transfer does not often work. Rather, what developing countries need are approaches that combine technology transfer with technology adaptation and adoption — involving local stakeholders in establishing water treatment devices and developing local capacity to use them.

This report, prepared by the World Water Assessment Programme under UNESCO (UN Educational, Scientific and Cultural Organization), assesses global freshwater resources including what drives the pressures facing them, how water is used, climate change's future effects on water supplies and options for improving water management for sustainable development.

The authors highlight the increasing demand for water, outlining the demographic, economic and social factors — such as population growth, international trade and changing lifestyles. They argue that climate change will undoubtedly affect water resources, impacting water quality and the frequency of extreme events such as droughts or flooding.

Investment in the water sector is important, say the authors — to improve access to clean water as well as decrease pollution from untreated sewage discharge. International donors must play a part in improving water infrastructure in the developing world, they add.

But how individual countries respond will depend on their own development objectives, capacity and political framework. The authors outline options for policymakers to increase supply, manage demand, reduce losses and reallocate resources.

This report, published by the Meridian Institute describes the growing interest that developing countries, including Brazil, China, India and South Africa are showing for nanotechnology. It describes the ways in which nanotechnology applications could solve problems of health, sanitation, and pollution and provide faster, cheaper information and communication technologies.

The report also reviews the challenges of using nanotechnology for and in developing nations. Finally, it outlines the roles and responsibilities of different stakeholders in ensuring that nanotechnology moves forward responsibly.

The Meridian Institute says nanotechnology could play a role in achieving the UN Millennium Development Goals — a set of quantified development objectives to be achieved by 2015. As a result, governments of rich nations should dedicate a "reasonable" portion of their overseas development assistance to nanotechnology.

To access the report, users must create a free login name and password.

This detailed overview by CMP Cientifica, one of Europe's largest information providers on nanotechnology, aims to introduce the wide variety of technologies falling under the nanotech umbrella and lay them out in a way that shows the scope and timing of their impacts. Intended for governments, venture capitalists, large corporations and scientists working in relevant disciplines, the paper looks at the field as a whole, current financing, and possible future directions.

The authors point out nanotechnology's tremendous diversity and applicability, emphasising that it is not just about miniaturisation, but also about rendering materials atomically exact. They show how developments are already being seen in drug delivery, solar energy, catalysts, coatings, bioanalysis tools and much more. As a result, the discipline already attracts funding approaching some US$4 billion a year from public and private sources.

Casting an eye over the technology's future, the authors see molecular nanotechnology — the manufacture of robotic machines on a molecular scale — as potentially hugely important. The possible problems thrown up by the self-replication of these machines are also briefly examined. The paper ends with a detailed summary of applications and an appendix listing milestones in the field.