Environmental Engineering
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Characterizing the Settlement of Activated Sludge Based on AI-Assisted Analysis of Moving and Still Images
In the final process of wastewater treatment, the settleability of activated sludge, a mass of microorganisms responsible for the adsorption and decomposition of pollutants, is important. In order to contribute to the improvement of the efficiency of wastewater treatment plants in rural areas and developing countries, which have problems in terms of economical human resources, this study proposed a low-cost settleability diagnosis method that uses AI-based technology to analyze still images of activated sludge using inexpensive digital microscopes and moving images of activated sludge settling using smartphone camera functions.
Yuki Nakaya, Kai Sugino, Shota Ishizaki, Reiko Hirano, Shuhei Noda, Shinobu Moniwa, Yukio Hiraoka, and Hisashi Satoh
Evaluation of Phosphorus Release from Lake Sediments Using Passive Sampling and Phosphate Oxygen Isotope Analysis
In eutrophic lakes, the persistent high phosphorus concentration in lake water poses a significant problem. This study employs passive sampling techniques and phosphorus oxygen isotope analysis to identify the sources supplying phosphorus to the lake water. This approach will also reveal contributions from lake sediments, which have not been evaluated previously. This research is expected to contribute to the assessment and conservation of lake water environments.
Akira Hafuka, Takuya Ishida, and Kazuto Sano
The Sumitomo Foundation, Grant for Environmental Research Projects 2025.11.01～2026.11.30
Green Conversion of Palm Oil Wastes into Bio-Compressed Natural Gas (Bio-CNG) for Renewable Energy Diversification in Malaysia
This collaborative research aims to enhance the production and upgrading of bio-compressed natural gas (Bio-CNG) by effectively utilizing two major byproducts generated from Malaysia’s palm oil industry: palm oil mill effluent (POME) and empty fruit bunches (EFB). Specifically, the Japanese team will develop and support the operation of anaerobic digestion processes, conduct microbial community analyses, and apply machine-learning-based data-driven modelling to improve process stability and enable rapid and precise optimization of CO2 adsorbent performance. The Malaysian team will optimize pretreatment and fermentation conditions for EFB and lead the development and evaluation of gas separation technologies using EFB-derived biochar. Through collaborative research between the two countries, the project is expected to contribute to establishing a renewable energy technology platform that supports Malaysia’s transition toward a decarbonized energy society
Mamoru Oshiki, and Adeline Seak May CHUA
Networked Exchange, United Strength for Stronger Partnerships between Japan and ASEAN (NEXUS) 2026.1〜2028.12
Solid-phase fluorescence excitation-emission matrix spectroscopy of soil, fulvic acid fractions, and clay mineral complexes: Evidence from red shift of fluorescence maxima associated with aggregation
Most of the analysis of natural organic matter (humic substances) in soil is carried out in a solution state by an alkali extraction operation. However, this approach addresses concerns regarding the potential alteration of humic substances during alkaline extraction, which may cause these substances to lose their original structure. In this study, as a non-extraction and non-destructive method, solid-phase fluorescence (excitation-emission matrix) spectroscopy (SPF-EEM) was applied for the first time to a standard humic substance and its complex with clay. It was found that the excitation-emission wavelength could shift according to the state of solution, complex, aggregate, etc.
Yuki Nakaya, Takashi Hirose, Ryuichi Tamori, Nobuhide Fujitake, Satoru Nakashima, Hiroshi Yamamura, and Hisashi Satoh
Creation of a Novel Evaluation Method for Assessing the Efficacy of Water Treatment Processes on Hard-to-Culture Viruses Without Relying on Conventional Cell Culture Approaches
This study aims to elucidate the removability of “non-culturable” viruses, such as norovirus, in water treatment processes—whose behavior in such treatments remains completely unknown. In this study, virus-like particles (VLPs) composed of viral capsid proteins will be produced using genetic engineering techniques. By incorporating foreign genes into these VLPs using non-viral vector construction methods and applying them to water treatment experiments, we seek to establish a novel evaluation method for viral removability that does not rely on cultivation.
Taku MATSUSHITA, and Nobutaka SHIRASAKI
Grant-in-Aid for Scientific Research(A) 2025.4.1～2028.3.31