Improving Sugar Beet Waste Breakdown with Controlled Oxygen Levels

Jenn Hoskins
6th July, 2024

Improving Sugar Beet Waste Breakdown with Controlled Oxygen Levels

Image Source: Natural Science News, 2024

Key Findings

  • The study by Wroclaw University of Economics and Business focused on treating sugar beet distillery wastewater using Bacillus bacteria under controlled oxygen conditions
  • The efficiency of pollutant removal (COD, BOD5, TOC) was high and consistent across different oxygen levels, with reductions of 78.6-78.7%, 97.3-98.0%, and 75.0-76.4%, respectively
  • Lower oxygen levels improved the removal of nitrogen and phosphorus, achieving reductions of 54% and 67.8%, respectively, at the lowest oxygen setpoint
The treatment of industrial wastewater is a significant challenge due to the presence of both organic and inorganic pollutants that can harm the environment and human health. Traditional methods often fall short due to high energy consumption and the production of secondary pollutants. A recent study conducted by the Wroclaw University of Economics and Business aimed to address this issue by examining the aerobic biodegradation of sugar beet distillery stillage using Bacillus bacteria under controlled dissolved oxygen tension (DOT) conditions[1]. The study utilized a 2-L Biostat®B stirred-tank reactor (STR) to conduct the biodegradation processes at a constant temperature of 36°C and an initial pH of 8.0. The experiments were performed with different DOT setpoints: 75%, 65%, and 55% saturation, controlled by adjusting the stirrer rotational speed. The goal was to determine the impact of DOT on the efficiency of pollutant load removal, measured in terms of Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD5), and Total Organic Carbon (TOC). Remarkably, the study found that the DOT setpoint did not significantly influence the overall efficiency of pollutant removal. The reduction values for COD, BOD5, and TOC were comparable across all three DOT setpoints, falling within narrow ranges of 78.6-78.7%, 97.3-98.0%, and 75.0-76.4%, respectively. However, the rate of biodegradation did vary with different DOT setpoints. The highest removal rate of COD was observed at a DOT setpoint of 65% (0.55 g O2/(L•h)), while the lowest was at 55% (0.48 g O2/(L•h)). Additionally, the study found that lower DOT setpoints had a beneficial effect on the removal of biogenic elements like nitrogen and phosphorus. At the lowest DOT setpoint of 55%, the maximum removal of total nitrogen and total phosphorus was achieved, with reductions of 54% and 67.8%, respectively. These findings suggest that a lower DOT setpoint can enhance the removal of certain pollutants while maintaining high overall efficiency, potentially reducing the process cost. These results align with earlier studies that have explored various methods for wastewater treatment. For instance, electrochemical processes such as electrochemical oxidation/reduction (EOR) and electrocoagulation (EC) have been shown to effectively remove organic matter, nitrates, ammonia, and phosphates from agri-food wastewaters[2]. However, these methods often come with high energy consumption and the generation of secondary pollutants. Combining electrochemical and biological treatments has been suggested to overcome these disadvantages and improve removal performance while reducing operational costs[3]. Microalgae-based bioremediation has also been studied as an eco-friendly alternative to traditional methods. Microalgae can degrade complex organic compounds into simpler, non-toxic substances and even use some pollutants as a carbon source[4]. Although effective, challenges such as high harvesting costs and the need for genetic engineering to improve tolerance against higher pollutant concentrations remain. The study by the Wroclaw University of Economics and Business contributes to this body of research by demonstrating that controlled DOT conditions can optimize the aerobic biodegradation of distillery wastewater. By achieving high pollutant load removal efficiency at lower DOT setpoints, this method could offer a cost-effective and environmentally friendly solution for industrial wastewater treatment. This approach could potentially be integrated with other treatment methods to further enhance overall efficiency and sustainability.

AgricultureEnvironmentBiotech

References

Main Study

1) Efficiency of aerobic biodegradation of sugar beet distillery stillage under dissolved oxygen tension-controlled conditions.

Published 5th July, 2024

https://doi.org/10.1371/journal.pone.0306330


Related Studies

2) Comparative study of electrochemical hybrid systems for the treatment of real wastewaters from agri-food activities.

https://doi.org/10.1016/j.scitotenv.2018.08.023


3) Comprehensive understanding of electrochemical treatment systems combined with biological processes for wastewater remediation.

https://doi.org/10.1016/j.envpol.2023.121680


4) Microalgal-induced remediation of wastewaters loaded with organic and inorganic pollutants: An overview.

https://doi.org/10.1016/j.chemosphere.2023.137921



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