Sustainable solution: Microalgae to treat contaminated water

Microalgae, a sustainable solution for water treatment, has been highlighted as an efficient alternative in the fight against antibiotic contamination.

Water contamination by antibiotics is a problem environmental and public health growing. Medicines discarded incorrectly or disposed of by patients, as well as effluents from hospitals and pharmaceutical industries, end up reaching rivers, lakes and even supply reservoirs.

Conventional sewage treatment plants are not designed to remove this type of chemical residue, which makes its presence recurrent in water bodies. In addition, the continued presence of antibiotics in water can have serious consequences, such as the development of resistant bacteria, one of the biggest challenges facing modern medicine.

Therefore, residues of these drugs can also negatively affect aquatic fauna, alter ecosystems and make it difficult to reuse water for agricultural or industrial purposes.

Microalgae as a sustainable solution

Faced with this challenge, scientists have been looking for natural and low-cost methods to eliminate these contaminants. One of the most promising solutions is the use of microalgae - single-celled organisms that grow in water and have the ability to capture pollutants.

A study published in Biochemical Engineering Journal highlighted the action of Phaeodactylum tricornutum, a marine microalgae capable of almost completely removing oxytetracycline, an antibiotic widely used in agriculture.

Results of the microalgae study

The researchers tested different forms of the microalgae, active and inactive, to analyze their efficiency in absorbing antibiotic residues. The results were surprising due to the high removal rate, for example:

• The active microalgae adsorbed up to 29.18 mg of oxytetracycline per gram of biomass.
• Even inactive, the microalgae managed to retain 4.54 mg/g of the antibiotic.
• In tests with a concentration of 2.5 mg/L, the removal efficiency was approximately 97%.

Sustainable benefits of using microalgae in treatment systems

Before implementing an environmental technology on a large scale, it is important to understand its real advantages over other methods. For this reason, microalgae offer a combination of efficiency, economic viability and sustainability.

The main advantages of microalgae in removing antibiotics:

The use of microalgae in water treatment has emerged as an innovative and sustainable solution to tackle antibiotic contamination. For this reason, this biotechnology stands out not only for its efficiency, but also for the environmental and economic benefits it offers. Here are the main advantages of this promising method for conserving water resources:

• High efficiency rate, even at high contaminant concentrations.
• Reduced production costs compared to more complex chemical or physical techniques.
• Environmentally friendly application, without generating toxic waste.
• Possibility of reusing algal biomass, including as a source of energy or fertilizer.

In addition, the technique can be incorporated as a complementary stage to traditional effluent treatment, raising the quality of the final water without major changes to the structure of the treatment plants.

Challenges and future prospects

Despite positive results in the laboratory, the implementation of microalgae as a sustainable solution in real environments still presents obstacles. Adapting a biological solution for urban or industrial effluents requires caution and technical adjustments.

The main challenges to expanding this technology are:

• Adaptation to different types of effluents, which contain complex mixtures of contaminants.
• Stability of microalgae cultivation, which depends on factors such as light, temperature and nutrients.
• Biomass harvesting process, which still needs to be optimized in terms of cost-benefit.
• Guaranteed continuous effectiveness, even with seasonal or operational variations in the treatment plants.

As a result, studies continue to evolve, with a focus on the automation of microalgae cultivation as a sustainable solution, integration with water reuse technologies and energy use of residual biomass.

Environmental and health importance of this discovery

The use of microalgae as a sustainable solution is not just a scientific innovation: it is a strategic tool in the fight against water pollution and bacterial resistance.

This type of solution is especially relevant in contexts of water crisis, such as the one that often occurs in the Southeast region of Brazil. With water quality at risk, technologies that promote safe reuse are even more important.

Furthermore, it is an advance in line with the principles of the circular economy and environmental sustainability, taking advantage of natural resources to mitigate negative impacts on the environment.

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