Watch an interview with the authors of this article to learn even more! (Video 1).

Sustainable Development Goal 12

Sustainable Development Goal 12 (SDG 12) is all about responsible consumption (use of resources) and production (creation of materials). The aim of SDG 12 is for all the world’s countries to promise to take care of our planet. Reducing the amount of waste materials humans produce is good for the environment and also helps to save important resources, like plants, food, and energy. If we do not conserve them, resources will be used up and will not be available for future generations. This is where SDG 12 comes in, to help us find sustainable materials such as wood and solar energy, which can help us to keep the planet beautiful and healthy for the future.

There are several important ways to achieve SDG 12 (Figure 1) [1]. Recycling is perhaps the best-known way. For example, we can dispose of recyclable materials in special bins instead of throwing them into the trash. These materials then go to a factory where they are destroyed and made into new versions of the same (or very similar) material. For example, glass bottles can be made into new bottles or glass jars. Other factories use even more science to transform waste materials into goods that are quite different from the original material, which is called upcycling. In upcycling, a material that is not needed anymore is used to create something useful, with higher value than the original material. For example, if you take a t-shirt you no longer need and turn it into a tote bag, this is upcycling—you have completely changed the t-shirt into something new and useful! Both recycling and upcycling help to achieve SDG 12, as things that we are throwing away become usable products.

Materials That Break Down Naturally

Have you noticed that shopping bags used to be made from harmful plastic, but some shops have replaced these bags with paper bags or with new kinds of plastics that can break down naturally in the environment? When the older type of plastic bags are thrown in the trash, they pollute the land and the oceans, and they stick around for centuries. But new bags are made of a natural material called biomass, and they biodegrade. Biodegrading means that these bags are part of a natural cycle—they break down in the environment and become part of new plants.

Biodegrading is a good method of breaking down materials. The way we currently handle most of our trash is not very good for the environment. Landfills are getting full because there is so much waste, and as landfills grow, they have negative effects on the people and animals nearby. Scientists are looking at ways to manage all the trash better. They are trying to create products in ways that use less energy and make less mess, to protect our planet and continue to work toward SDG 12 and other environmental goals [2].

What is Biomass?

Biomass is a very cool mix of materials made by living organisms, such as plants and animals. For example, farming waste, including the leaves of corn plants or date palms, and animal waste, such as bones or fat, are types of biomass. These materials will always be available because they are constantly produced, and they are compatible with natural cycles. A material that will never run out is called renewable. It is sustainable because we can get more of it like a gift that will never run out, so it will also be available for the people of the future.

Biomass is a big deal in science and engineering because of its good properties. It is available worldwide and it does not produce any chemical waste, which is great for nature. When we finish using products made from biomass, we can easily get rid of them because they do not contain any harmful stuff that will harm the environment when they break down.

Membranes are one class of useful things that can be made of biomass. A membrane is a thin layer that can act as a wall to separate objects according to their sizes. Figure 2 shows examples of membranes, some of which are useful in our everyday lives. Currently, many membranes are made from fossil-based chemicals.

Membranes with extremely small holes can be used to separate things that are not visible by your eyes, for example, to remove poisonous chemicals from water or medicines. To do so, scientists make membranes with tiny holes, called nanofiltration membranes. These membranes are often built from microscopic building blocks, similar to Lego^® pieces. Can you think of other membranes that you have seen at home or school?

Membrane Applications

Our team, called the Sustainable Separation Engineering Research Group, focuses on using stuff in nature to make membranes that can be used to make our everyday lives more convenient and enjoyable. Figure 3 shows three examples of biomass that we successfully upcycled into nanofiltration membranes.

Saudi Arabia and the Middle East are known for their very delicious dates. When you eat a date, there is a seed in the middle that is generally thrown away. Our research at KAUST uses these seeds to make membranes. The process involves grinding the seeds into a powdery material that it is then cleaned and processed. Finally, the material goes through a machine that forms the powdered date seeds into a flat, thin layer of membrane. This is a very interesting process and it helps to work toward SDG 12, as it is an example of upcycling [3].

Another interesting membrane-making method uses the shells of shrimp. When people eat shrimp, they usually get rid of the shells. Our team of scientists removes a special substance called chitin from shrimp shells. Chitin can be used for many things including bandages, medicines, and as a nutritional supplement. Membranes made with chitin as well.

Algae are another interesting biomass source that can be used to make membranes. Algae are plant-like organisms that range in size from microscopic to giant seaweeds, living mostly in water and using sunlight to make their food, similar to land plants. A chemical inside the algae is recovered and mixed with liquid, then it goes through a machine in which a thin layer of membrane is produced. Imagine growing a vegetable in your garden and, once it grows, you harvest it and clean it to make your dinner. Well, this is the same idea but, with the help of science, algae are used to make membranes [4].

Making membranes from date seeds, shrimp shells and algae are all examples of upcycling waste materials and helping the world to achieve SDG 12.

Trash to Treasure

Now you have seen how things from nature, such as biomass, can be used to make membranes—potentially replacing the unsustainable materials that are currently used. SDG 12 aims to make us mindful of how we create and use materials and how we get rid of materials after use. By finding creative ways of using biomass, we can create materials that are less toxic and reduce the amount of harmful chemicals needed to produce useful things. Further, using biomass can reduce the total amount of waste we create. Science is making great strides toward helping our planet by reducing the amount of waste that ends up in landfills. You can help too, by doing things like recycling at home, continuing to learn how to make the world better by reducing waste, and sharing your knowledge about upcycling biomass with the people you know. Remember, all these actions help us to meet SDG 12—and we can all play a part.

Glossary

Sustainability: ↑ It is a common goal for people to be able to co-exist on Earth over a long time. It takes into account the needs of future generations.

Recycling: ↑ Taking waste material, such as empty water bottles, to be processed, cleaned, and fixed to be used again.

Upcycling: ↑ Transforming old materials to make new and exciting things of higher value. For example, turning an old, unsafe ladder into a fancy bookshelf.

Biomass: ↑ Waste parts from plants and animals that can be renewed or regrown. Biomass can be used to make new and useful things.

Biodegrade: ↑ When waste materials, often made from biomass, are broken down in nature.

Renewable: ↑ Renewable resources replenish themselves at similar rate they are used, while a non-renewable resources continuously deplete and have limited supply.

Membrane: ↑ A thin sheet with holes in it that allows some things to go through but not others, often dependent on size.

Nanofiltration: ↑ The process of separating very small molecules that cannot be seen by the naked eye.

Conflict of Interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Acknowledgments

We would like to thank Nicki Talbot at KAUST for her invaluable support during the review process, without which this collection would not have been possible. We would also like to extend our gratitude to the Office of Sustainability and UNDP-Saudi Arabia team for their dedication to raising awareness of the importance of the UN SDGs in our journey toward fight for a more sustainable world. The figures were created by Ana Bigio, scientific illustrator at KAUST.