This book consists of the peer-reviewed and revised papers from the 2024 9th Asia Conference on Environment and Sustainable Development, which was held in Osaka, Japan, November 9–11, 2024. The conference provided an ideal platform for communication among experts and scholars working in a wide variety of scientific areas with a common interest in improving environment and sustainable development related techniques. The book covers highly diverse topics, including environmental pollution monitoring and pollutant treatment, greenhouse gas emissions, air pollution monitoring and emission reduction, solid waste management, environmental sustainability, sustainable development, resource management and ecosystem protection. The book serves as a useful reference for researchers and engineers working in the field of environmental science and sustainable development.