A team of researchers has explored the promising role of aquatic creatures, including worms, non-biting midge larvae, and mussels, in enhancing the efficiency of wastewater treatment plants. Investigating their ability to degrade sludge, reduce greenhouse gas emissions, and eliminate excess nutrients, the study reveals a potential natural solution for the challenges faced by wastewater treatment facilities.
In conventional wastewater treatment processes, excess sludge is a notable byproduct, posing economic challenges due to the high cost of processing. However, the research, part of the Aquafarm project, demonstrates that invertebrates thriving in streams and ditches can play a pivotal role in breaking down this sludge, primarily composed of organic material.
Tom van der Meer, a researcher at Wageningen Environmental Research and a participant in the Aquafarm project, conducted a Ph.D. study to analyze the efficiency of various aquatic species in consuming excess sludge. The non-biting midge larvae emerged as particularly effective, accelerating sludge degradation up to five times compared to sludge without them. The introduction of different species further improved sludge degradation, and their burrowing activities introduced oxygen, mitigating the formation of the potent greenhouse gas methane.
The European Union’s Water Framework Directive mandates the improvement of water quality in member states by 2027. To achieve this, the directive emphasizes the reduction of nutrient levels, such as nitrogen and phosphorus, in surface water. Aquatic invertebrates, as highlighted in the research, can contribute to this goal by addressing excess nutrients and preventing the growth of harmful cyanobacteria.
Additionally, the study explored the combined efforts of algae, mussels, and floating plants like duckweed ferns in removing nutrients from water after the wastewater treatment process. The promising results suggest a nature-based approach for further enhancing water quality.
In a practical application of the findings, two Dutch water authorities are set to develop a pilot treatment facility capable of purifying approximately 75 cubic meters of wastewater per day. This marks a step toward implementing natural, cost-efficient solutions that could significantly contribute to improving water quality in Dutch nature.
Van der Meer envisions a future where sewage plants widely adopt these nature-based solutions, potentially revolutionizing wastewater purification processes in the next decade.
Source: Phys.org
