Addressing the Water Shortage with Electron Beam Wastewater Treatment
The Global Crisis of Water
As the population of the world continues to grow, so does industrialization and urbanization, creating a global community that relies on enormous amounts of water and resulting in waste water containing a variety of contaminants. Nature alone used to be able to clean the water, but not anymore. The steady discharge of toxic substances into the world’s ecosystems has made it impossible for water to be naturally recycled in rivers and aquifers. With a lack of clean, accessible water in both arid and semi-arid climates, we are now facing a global crisis of water supply.
When contaminated, wastewaters can carry many different types of harmful chemicals, such as heavy metals, organic pollutants, pesticides and dyes. Biological treatment processes—which for a long time were the standard—are no longer capable of treating many of the complex organic chemicals founds in wastewaters. In addition, there has been a recent increase in the presence of pharmaceuticals and endocrine disruptors compounds found in municipal wastewater, which remain untreated by conventional treatment processes.
From forests and plains to cities and villages, water plays a vital role for the proper functioning of the Earth’s ecosystems. It is also an important resource for all human activity. The negative effects of pollution impact the use of water for drinking, household needs, recreation, fishing, transportation and commerce. In order to support increasingly large and complex civilizations, it is essential that we ensure water now and for the future.
How Electron Beams Can Treat Water
The IAEA, under its Radioisotopes Production and Radiation Technology progamme, works to strengthen the ability of Member States to use radiation technology for treatment of polluted water, wastewater and sewage sludge, for their safe disposal or re-use. Radiation technology that utilizes electron beams treats different organic pollutants in combination with existing treatment techniques, transforming them into less harmful substances or reducing them to levels below the permissible concentrations.
Unlike other technologies that have come to the forefront in recent years, electron beam technology is an attractive approach because it treats water without using any chemicals that could further pollute downstream. Electron beam treatment is also advantageous in it operates at ambient temperatures and pressures and its performance is not affected by solids since the electron beam can easily penetrate them.
Following a Drop of Water
Discharge – Water is discharged from the Earth’s rivers and aquifers where it is received by and animals in their natural eco-systems.
Industrial and Household Use – To support the growth of human civilization, water is collected and brought to communities around the world for its use in households and industries. It comes out of our faucets, runs through our sewage systems and cleans our streets.
Wastewater/Sludge Treatment Plants – Wastewater and sludge treatment plants collect water that has been used for industrial and household purposes. By using traditional treatment techniques along with electron beams, the water is then treated in order to remove harmful industrial waste and organic pollutants. The new water is then able to be re-used for a variety of purposes, such as irrigation, industrial cooling and street washing. Moreover, the sewage sludge that is the end product of the conventional sewage treatment plants still contains a high microbial load and its disposal poses serious challenge to the municipal authorities. Electron beam radiation has the unique capability of producing highly reactive ions or radical species that can inactivate the pathogens present in the sludge in a simple and effective manner for disposal or reuse for land applications.
Success Stories from the Field
Through its technical cooperation programmes and coordinated research projects, the IAEA has aided in the development and transfer of important new technologies to Member States. In the Republic of Korea, a plant using electron beams at a relatively low dose in combination with biological treatment for wastewater has successfully been applied on an industrial scale to water re-use. The electron accelerator, called the 1 MeV 400kW, is able treat more than 10000 cubic m of wastewater per day. Now available on the market, this latest technology is evidence that radiation processing for wastewater treatment will become a reality very soon.
Despite its clear advantage over existing methods for municipal wastewater disinfection, at present there is only one large scale radiation treatment plants for industrial wastewater treatment. It is therefore critical that the public be informed of the environmental and societal benefits offered by this radiation technology. Many projects involving radiation processing have already shown to successfully clean fuel gases.
In fact, radiation technology is also a commercially well-established technology for radiation sterilization of medical products and for enhancing the safety of food supplies. In wastewater treatment, electron beam radiation can provide clean, reusable water without using chemicals or producing any radioactive material. With the global water crisis just over the horizon, the use of electron beams for wastewater treatment—in combination with existing treatment facilities—warrants greater public support.