In two experimental aquarium rooms at the Faculty of Agronomy, for example, rainbow trout or African catfish are kept. The water in the tanks is constantly circulated and purified thanks to pumps. Biological filtration removes ammonia from the water, while mechanical filtration separates large quantities of waste sludge and fish faeces, which are rich in nitrogen or phosphorus due to the composition of the food.
“I like it when something can be saved or reused. That’s why I thought it was a shame that all the sludge is being dumped away and not used in any way. The waste is an excellent source of nutrients that are important for plant growth,” explained Harabiš, who is a PhD student at the Department of Fisheries and Hydrobiology at MENDEL.
The student’s aim is to convert the waste produced by aerobic digestion into a liquid fertiliser that could be used in hydroponic plant cultivation. “Aerobic digestion is essentially a process in which different groups of heterotrophic organisms break down fish feces into individual minerals,” Harabiš explained. According to the PhD student, the nutrients obtained in this way could find application in the production of lettuce, for example. “I would like to create a fertiliser that is comparable to commonly available chemical mineral fertilisers, which require minerals to be extracted. But that won’t be the solution forever, so I am offering a renewable alternative,” said the student.
Harabiš would like to test the quality of the product directly with colleagues at MENDELU who specialize in plant cultivation. “Of course, depending on the composition of the waste and how much nutrients we can mineralise, we will adjust the fertiliser. I expect that it will be necessary, for example, to dilute it so that we don’t burn the plant,” he explained. However, he expects it to be more of a supplementary fertiliser to ensure that the crop gets enough nitrogen, phosphorus and other minerals.
With his research, the PhD student is aiming at practice, and he is even already in contact with some breeders. “The simplicity of the process is important to us. Farmers could either process the waste themselves or offer it to fertiliser manufacturers,” Harabiš described. But anything is better than dumping the waste outside, he said. “There is generally a lot of phosphorus in surface water today. It comes from the farm, industry, and it also gets into the water from households, for example from washing gels and so on. In summer, it is a breeding ground for cyanobacteria in ponds. Any way of reducing phosphorus in nature therefore seems to me to be a good thing,” he reflected.
In general, the number of recirculating fish farms is increasing worldwide. According to Harabiš, the advantage compared to conventional fish farming is that it is easier to comply with hygiene conditions and the farming is more efficient. “You have the tanks somewhere under the shed, so you are less likely to introduce diseases into the farm, there is no way for predators to get in, you use very little water. Plus, if the population is going to continue to grow in the future, we need to feed people in some sensible way,” Harabiš said.
Contact for more information. Lukáš Harabiš, +420 733 280 506, lukas.harabis@mendelu.cz, Institute of Zoology, Fisheries, Hydrobiology and Apiculture AF MENDELU
More news
-
The third edition of the MENDELU Ph.D. Talent competition for supplementary talent scholarships for doctoral students has announced its winners. Ten talented students advanced to the second round of the MENDELU Ph.D. Talent competition, where they…2. 4. 2024
-
This year’s Water days at MENDELU were devoted to the revitalization of…
On the occasion of World Water Day, a weekly Water Days event was held at MENDELU, which serves to educate on the topis of water in forest, agricultural and urban landscapes. This international event is organized by the PoVE center of excellence in…22. 3. 2024 -
First joint conference of the Alpine and the Carpathian Conventions on large…
A transboundary character of wildlife populations, such as large carnivores, require enhanced international collaboration for successful conservation and management solutions. As large carnivore populations are recovering in Europe, this is even…8. 3. 2024 -
MENDELU experts focus on digital water
The team of experts from Mendel University in Brno is developing new methods within the framework of the European project WATERLINE under HORIZONT WIDERA call, focused on digital water. This action will bring the processes related to water in the…29. 2. 2024 -
MENDELU focuses on prevention as part of safety
Mendel University in Brno is implementing a number of security measures in connection with the December event at the Faculty of Arts of Charles University. It wants to focus primarily on prevention, i.e. on informing employees and students how to…16. 2. 2024 -
Water management problems were solved by student teams from all over the country
A total of eighty high school and university students gathered at the Impact Hub for the "Water for the Future" Hackathon. Its aim was to increase interest in water management and to expand and share key knowledge with the younger generation. Teams…30. 1. 2024 -
Unique method to show how micro and nanoplastics are deposited in agriculture
Micro and nanoplastics have increasingly come into the sights of world leaders in recent years. According to UN data, there are over 50 trillion microplastic particles in the seas alone, 500 times more than the number of stars in our galaxy. While…9. 1. 2024 -
Student MENDELU won the international ArcGIS StoryMaps competition
The StoryMap "Wind Erosion," authored by Petr Zálešák a first-year Ph.D. student in the Applied and Landscape Ecology program at Mendel University in Brno, has captivated and emerged victorious in the international ArcGIS StoryMaps Competition 2023,…12. 12. 2023 -
Czech scientists create energy from mango pellets in Cambodia
Experts from the Faculty of Forestry and Wood Technology at MENDELU are helping to make use of waste from fruit processing while reducing the consumption of firewood in Cambodia. They use the mango pellets to produce fuel briquettes, which are then…15. 11. 2023 -
World experts in agroforestry are going to meet in Brno
European agriculture struggles with climate change, the decline of insects and birds in the landscape, pollution and the desire to improve human health. Agroforestry, the growing of trees together with crop or livestock production, is a proven way…1. 11. 2023