Unprecedented bioreactor system monitors composting processes in the laboratory

Agricultural research has developed a system of interconnected benchtop bioreactors that allows the efficiency of composting processes, the main method for producing organic fertilizers, to be quickly and accurately analyzed. The prototype has already been validated in the bioreactors and bioprocesses laboratory at Embrapa Solos (RJ) with very satisfactory results, and now the technological asset is available for partnership with companies interested in developing a more functional and attractive interface and design to offer it to the production sector   

One of the equipment's differences is the ability to perform rapid laboratory tests on the mixture being prepared for composting. With 1 kg of a combination of waste, it is possible to know, in a matter of hours, its potential for bioprocesses.

The report shows the potential for the material to reach temperatures between 50 and 65 degrees Celsius, ideal for the composting process, as well as the aeration rate (oxygen supply) required by the biodegradation activity. According to the researchers, even the most complex experiments can be evaluated in less than two months. 

“Bioreactors like these exist in other projects and models, but, in our case, we achieved the unprecedented feat of having 12 reactors operating at the same time and in line, with oxygen and carbon dioxide sensors and temperature control, all integrated. One of the differences of this system is that, with a maximum volume of 50 liters of waste mixture, it is possible to carry out a complete experiment, with combinations, treatments and repetitions, something that would be impossible in the field”, explains researcher Caio Teves Inácio, project leader who created the system at Embrapa Solos. 

Inácio emphasizes that the generation of waste in agriculture and agroindustry grows at the same rate as production in these sectors. Therefore, reusing this waste for the composting process, for example, is important for the environment and brings profits to producers. “It’s a question of sustainability. In this scenario, benchtop bioreactor technology gains even more relevance,” he adds.

These systems also offer greater control over all experimental development, making it possible to more safely and quickly research topics such as pesticide degradation, nitrogen loss and the efficiency of using microbial inoculants during composting.

Technological advances expand the use of bioreactors

Bioreactors are equipment widely used in research and development in the areas of biomedicine, biopharmaceuticals, bioenergy, waste bioremediation and other bioprocesses. 

Inácio points out that advances in biotechnology, in connection with digital technologies and equipment engineering, have allowed important innovations in the technological field of bioreactors in recent years, driven by the trend towards using biological, organic, renewable and recyclable sources to replace raw materials. of non-renewable origin, such as those coming from fossil and inorganic matrices, which have a high potential for negative impacts on the environment.

The greater use of biological resources and bioactive molecules of animal and plant origin has represented important innovation potential for agriculture. In the case of reusing rural waste and agro-industry for the production of fertilizers, for example, industry and agriculture have been integrated into a production chain of bio-based and renewable inputs. 

“The use of organic matter, as a fertilizer input and soil conditioner, although it corresponds to a traditional practice in agriculture, has demanded innovations to meet the growing interest of industry, farmers and end consumers in obtaining products with improved effects on terms of nutrition and performance”, highlights the researcher.

The most effective use of organic waste from agriculture and agro-industry now requires biotransformation processes to produce plant nutrients with greater protein and energy value, as well as being proven to be safe for the environment and human health. As a result, the use of aerobic and anaerobic bioreactors in so-called bioprocesses has increased, whether industrial-sized or pilot- and bench-scale equipment, as is the case with the asset developed by Embrapa. 

Teves explains that bioreactors on a scale suitable for research and experimentation enable the simulation of bioprocesses – such as aerobic composting of organic waste – that occur in large windrows (beds) arranged in the environment. Using bench-scale equipment, it is possible to simulate, in a controlled laboratory environment, the repetition of a complex system of factors comprising temperature, oxygen levels, biological activity and degree of acidity or alkalinity – hydrogen potential (pH).

“Laboratory-scale equipment also allows us to establish methods of evaluating and monitoring the generation of by-products, with the aim of improving, on an industrial scale, the quality and energy and environmental efficiency of organic and biological-based compounds”, adds the researcher. .

Brazilian production of special fertilizers on the rise

Benchtop bioreactor technology can bring important gains to innovation in composting processes and, consequently, to the production of organic fertilizers, which is on the rise in Brazil.

According to data released by the 2022 Yearbook of the Brazilian Association of Plant Nutrition Technology Industries (Abisolo), sales in the special fertilizer sector (which include special minerals, organominerals and organics) reached R$16,6 billion in 2021, showing a growth of 65% over the 2020 result. 

The three categories had robust growth, with sales of organic fertilizers showing the highest percentage change (131%), followed by organominerals (68%) and special minerals (58%). 

In 2021, sales of special mineral fertilizers reached R$11,943 billion, compared to R$3,298 billion for organominerals and R$1,419 billion for organic fertilizers.