The title may have been slightly misleading. The sesame seeds on hamburger buns might actually contaminate water, but Mucuna sloanei, common name, hamburger seed, has recently been explored as a possible sustainable source of water purification.
Essentially, a common way that water is purified is by using activated charcoal (AC) being an adsorbing material for pollutants. Adsorbing essentially just means “sticking” to. In the past, the production of activated charcoal has been explored using agricultural waste. Food waste is a huge problem worldwide, with food being thrown out at every step between the growing of the crop to the consumer’s homes. Agricultural waste is a cheap, accessible, and sustainable way to create AC’s that can be used to purify water, while at the same time reducing the amount of food waste. Past crops that have been confirmed to be used as a source for AC’s are things like coconut shells, chickpeas, acorn shells, rice husks, and a variety of other crops.
Recently, researchers in Nigeria published a paper analyzing the effectiveness of hamburger seed being used to produce AC’s. Hamburger seed is a very common soup condiment in Nigeria, but the coat of the seed is non-edible and as a result, often thrown out. When thrown out, it can cause soil pollution, and when burned (the common way it is disposed of), it causes a large amount of air pollution. Therefore, these scientists are looking to optimize this waste so another source for water purification is present, and the environment is not negatively affected.
To run the experiments, researchers collected hamburger seed waste from a processing plant at Abakaliki, Nigeria. After being purified using deionized water, it was carbonized. After converting the hamburger seed coat to activated charcoal, the scientists could then test the effectiveness of the AC on contaminated water.
Essentially, they treated contaminated water with both the lab generated FHAC (Hamburger-Seed Activated Charcoal) and commercially available AC. They found that both acted similarly, in that they were able to turn yellowy odorful water into clear odorless water. Another metric they used to measure effectiveness was TDS, the amount of non-filterable solids in the water. Water containing large amounts of TDS are not safe for bathing, drinking, or industrial applications. But, the FHAC was able to decrease the amount of TDS in contaminated water by 67.6%. The resulting amount of TDS was well below the recommended level for safe water. They did find something problematic when testing for the alkalinity of the purified water, which was higher than the recommended amount. High alkalinity can be toxic for surrounding aquatic life, but should not have any impact on humans who consume the water. Further testing needs to be done, but these AC’s probably need to be kept away from liquids containing life.
This is just a small sample of the research that is going to change the world, little by little. Much of the discourse around environmental problems is pessimistic, with good reason too - public policy is lagged a little. But, researchers are finding more and more creative ways to change how we as humans interact with the world’s resources, and that is something to be hopeful about.