Dr Alison Parker
define clean water and wastewater? How do people gain access to clean water? Dr Parker: We use the WHO( World Health Organization) / UNICEF( United Nations Children ' s Fund) definition of‘ improved water source’ and‘ improved sanitation’. Many communities, governments, non-governmental organisations( NGOs) and other agencies are working towards providing clean water. However, providing good sanitation is also important so that water sources do not become contaminated with human waste.
THE MACRO LEVEL OF THE WORLD’ S WATER
TECHNOLOGY GN: Where are we today? What is the current situation of clean water and wastewater? What are the latest water technologies today? Dr Parker: UNICEF and the WHO provide regular updates on the progress towards universal water and sani-tation coverage. There are still some technological changes to achieving universal coverage, including finding a hygienic way to empty existing pit latrines and finding alternatives to pit latrines.
THE MICRO LEVEL GN: What are the initiatives / projects that you are doing( or have done) that will provide clean water to third world countries? Dr Parker: Cranfield University is developing the Nano Membrane Toilet which will be able to treat human waste onsite without external energy or water. The Cranfield toilet is designed for single-household use( equivalent to 10 people) and will accept urine and faeces as a mixture. It is still under development but this is the vision of how it will work. The Cranfield toilet flush uses a unique rotating mechanism to transport the mixture into the toilet without using any water while simultaneously blocking odour and the user’ s view of the waste. Solids separation( faeces) is principally accomplished through sedimentation. Loosely bound water( mostly from urine) is separated using low glass transition temperature hollow-fibre membranes. The unique nanostructured membrane wall facilitates water transport in the vapour state rather than as a liquid state which yields high rejection of pathogens and some odorous volatile compounds. The water will be collected for reuse at the household level in washing or irrigation applications. Following release of unbound water, the residual solids are transported by mechanical screw into a gasifier which will convert them into ash and energy. The energy will power the membrane processes, and there may be extra energy for charging mobile phones or other low voltage items. The Cranfield toilet will be rented by the households and maintenance will be undertaken with a trained operative responsible for the franchised area.
ADVICE TO THE YOUNG
ENGINEERS GN: Please give advice and words of wisdom about the clean water campaign to our young global audience. What would you like to tell to the millennials? Any inspiring words that you can share? Dr Parker: The water sector has many challenges that need solving – not only technical challenges but social, political and institutional challenges as well. We need well-trained scientists, engineers, designers and social scientists who have a good understanding of these challenges and who aren’ t afraid to propose radical new solutions.
SEPTEMBER 2016 Clean Water Technologies
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