Waste activated sludge management is a critical yet complex issue for wastewater treatment plants worldwide. Its high moisture content complicates dewatering, increasing operational costs and limiting the efficiency of processes like anaerobic digestion and composting. Current techniques for measuring moisture—ranging from thermal drying to infrared methods—are either too slow, inaccurate, or costly for real-time application. This gap has led to a pressing need for faster, more accurate moisture monitoring. Recognizing this challenge, researchers have developed a cutting-edge system that captures sludge jet images, enabling deep learning models to predict moisture content swiftly, thus addressing a significant research need in sludge management.
Published (DOI: 10.1016/j.ese.2025.100614) on August 28, 2025, in Environmental Science and Ecotechnology, this groundbreaking study from researchers at Heilongjiang University and Heilongjiang Academy of Sciences presents an innovative approach to real-time sludge moisture monitoring. The team has developed a system that captures high-speed jet expansion images of activated sludge and uses deep learning to predict moisture content in under 20 seconds. This method breaks away from traditional techniques, offering an accurate, efficient solution to a pressing challenge faced by wastewater treatment plants globally.
The study introduces an ingenious laboratory-scale system, known as instantaneous capturing of activated sludge jet expansion images (iCASJEI), that captures real-time sludge jet images at 260 frames per second. By examining over 11,000 images of activated sludge, the researchers utilized deep learning models to establish correlations between the non-Newtonian fluid behavior of sludge and its moisture content. The convolutional neural network (CNN) model VGG-16 emerged as the most effective for moisture prediction, surpassing other models like AlexNet and LeNet in both accuracy and efficiency. The team achieved impressive validation results—93.5% accuracy at 2% precision and 87.6% at 1% precision. The study further explored various experimental conditions, including jet pressures and nozzle diameters, optimizing them to ensure the highest predictive accuracy. This combination of deep learning and high-speed imaging not only drastically reduces the testing time but also provides a reliable method for moisture monitoring, even in challenging real-world conditions.
Dr. Guotao Wang, a key contributor to the research, explains: "Our approach represents a significant leap forward in sludge moisture monitoring. By merging high-speed jet imaging with deep learning, we've developed a system that dramatically improves both the speed and precision of moisture content detection. This method not only optimizes wastewater treatment but also holds potential for broader applications in industries where accurate moisture control is essential. The future of sludge management looks much brighter with this innovative technology."
This innovative technology has the potential to revolutionize wastewater treatment, where real-time monitoring of sludge moisture can optimize processes like anaerobic digestion and composting, ultimately reducing costs and enhancing resource recovery. Beyond wastewater management, the methodology could be applied across industries handling viscous fluids, such as food production, chemical processing, and pharmaceuticals, where moisture content is crucial. With plans to refine the system and expand its capabilities, this deep learning-powered jet imaging approach promises to offer faster, more efficient solutions for moisture detection, ultimately transforming how industries manage fluid-based materials.
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References
DOI
10.1016/j.ese.2025.100614
Original Source URL
https://doi.org/10.1016/j.ese.2025.100614
Funding information
This work was supported by Heilongjiang Provincial Natural Science Foundation of China (LH2024E111); the Higher Education Institutions' Collaborative Innovation Achievement Project of Heilongjiang Province (LJGXCG2023-077, LJGXCG2024-P08), Outstanding Youth Science Fund of Heilongjiang University for the Year 2022 (JCL202204); Special Fund Project of Heilongjiang University (2023-KYYWF-1433).
About Environmental Science and Ecotechnology
Environmental Science and Ecotechnology (ISSN 2666-4984) is an international, peer-reviewed, and open-access journal published by Elsevier. The journal publishes significant views and research across the full spectrum of ecology and environmental sciences, such as climate change, sustainability, biodiversity conservation, environment & health, green catalysis/processing for pollution control, and AI-driven environmental engineering. The latest impact factor of ESE is 14.3, according to the Journal Citation ReportsTM 2024.