Harmful chemicals are commonplace in many different industries. Volatile organic compounds – or ‘VOCs’ – represent one such type of chemicals, which are particularly prevalent in industries that require spraying of paints and coatings. Unfortunately, VOCs can readily evaporate into the air, potentially harming people’s health through inhalation. Some VOCs are also environmental pollutants and can even contribute to climate change. Read More
Many industries use post-combustion systems to destroy VOCs before they escape the factory. However, such systems require extremely high temperatures and typically involve the combustion of fossil fuels. Therefore, researchers are attempting to find new ways to remove VOCs in an inexpensive, efficient and environmentally friendly manner.
Dr Sabine Grüner-Lempart, Julian Eckert, and their team at the Weihenstephan-Triesdorf University of Applied Sciences, Germany, have been developing a biotrickling filter technology that can do just that. The team came up with a plan to design a ‘living filter’ that can naturally remove VOCs from a mixture of exhaust gases, using helpful bacteria.
They began by examining five strains of bacteria that have the ability to break down common organic pollutants. They cultivated these bacteria in the laboratory, and performed tests on them to explore how they responded to various VOCs. Then, they transferred these bacteria into a reactor to generate a new microbial community, called biofilm.
Exhaust gases containing VOCs were passed through the reactor, giving the bacteria in the biofilm a chance to interact with them. The team then analysed the output gases to determine how well the VOCs were being broken down by the bacteria.
The team found that their new biotrickling filter was able to efficiently break down VOCs at around 20 degrees Celsius without the need for any fuel. They found a significant drop in the carbon content of the air that had passed through their system, meaning that a substantial amount of the VOC content had been consumed by the bacteria.
This result reveals the true beauty behind this method of air filtration: These types of bacteria need a source of carbon in order to survive. Carbon is one of the main elements in VOCs, and acts as a source of ‘food’ for the bacteria. The team’s new biotrickling filter thus represents a promising new way to remove VOCs from exhaust gases produced by factories.
However, their research doesn’t stop there. In a recent study, the researchers applied a similar biotrickling technology to help remove the ammonia produced in poultry farms. This irritating gas can cause respiratory problems in poultry, and ammonia emissions from farming lead to environmental pollution. By implementing their biotrickling technology in agriculture, Grüner-Lempart and Eckert hope to make animal farming cleaner and greener, for the benefit of humans, animals, and the planet.
