How to save the world with Leerdammer cheese: Engineering nanoporous materials for clean water

Water is the single most important substance on Earth, it is vital for all known forms of life. Water scarcity however, means that one in five people on this planet lack access to clean, safe drinking water. Water scarcity is not just caused by an uneven distribution of water resources, but also a severe decrease in water quality. Declining water quality has been recognised by the United Nations as a rapidly emerging issue, one that will have a large impact on both developing and developed countries, including the United Kingdom. The decline in water quality is due to an increase in the number of chemicals, including pharmaceuticals and pesticides, entering the water supply. Research is now focusing on cheaper and more efficient methods to remove these contaminants. One potential solution is to use a class of materials which have a lot in common with Leerdammer cheese. These so-called nanoporous materials are not usually bright yellow, and neither are they really edible. They are however full of thousands of nano-scale sized holes or pores (a nanometre is one millionth of a millimetre), and it is this property which makes them potentially world-saving. Molecules are able to stick to the surface of nanoporous materials, by a process known as adsorption. On passing untreated water through this type of material, undesirable molecules can be stored on the materials surface, and removed from the water supply. One type of nanoporous material is known as activated carbon, and it is already used in water treatment. These materials are one of the oldest known and most efficient water treatment methods. Despite this, current activated carbon materials are unable to completely remove all contaminants from the water supply. Only a limited amount of certain contaminants, such as the pesticide metaldehyde, are removed using current activated carbon materials. Our research focuses on the development of novel activated carbon materials, which will be able to remove these challenging contaminants from the water supply. The performance of nanoporous materials is affected by several factors. We are investigating the optimal pore size and shape for our Leerdammer cheese-like materials. Our research focuses on upgrading a waste product, called lignin, into an activated carbon. Lignin is a component in biomass, and is produced in large quantities by the paper pulping industry. The wide-spread availability and low cost of lignin makes this a promising feedstock for industrial-scale production of novel activated carbons. Uniquely the structure of lignin depends on the type of plant it is extracted from. This leads to the exciting possibility we will be able to tune the activated carbon structure, including the size and shape of its pores, simply by adjusting the feedstock. Further, this could enable us to selectively remove some of the more challenging contaminants from the water supply, by producing this type of tailored activated carbon. Severely declining water quality is fast becoming an urgent problem. Our research is working towards the producing more efficient Leerdammer cheese-like materials to help save the world.