NEWS
2023.11.10
【Report】 The AJI International Workshop: “New Challenges in Constructed Wetlands for Sustainable Wastewater Treatment: Intensification Strategies Based on Asian Experiences”
On July 16, 2022, International Workshop on “New Challenges in Constructed Wetlands for Sustainable Wastewater Treatment: Intensification Strategies Based on Asian Experiences” was held in hybrid way and hosted by Asian-Japan Research Institute (AJI), Ritsumeikan University.
The main purpose of the workshop was to share information and knowledge on the management and use of constructed wetlands for wastewater decontamination, review the strategies and techniques for enhanced wastewater treatment, and discuss solutions/challenges for future improvements in this field. Eight presenters from Asian Universities/Institutes, Bangladesh, China, India, Japan, Sri Lanka, and Vietnam, and many audiences both online and onsite participated in this workshop. The workshop was divided into two sessions and moderated by Dr. Dan A (Associate Professor, Zhongkai University of Agriculture and Engineering, China) and Dr. Nguyen Thi Thuong (Senior researcher, Asian-Japan Research Institute, Ritsumeikan University).
Professor Yasushi Kosugi (Director of the AJI) introduced the workshop and welcomed all speakers and participants from both Japan and abroad. While doing so, he drew attention to the global water crisis and Asian water quality challenges. He emphasized the importance of protecting water sources and the urgent need to use green technologies for wastewater treatment. At the end of his speech, he wished the participants great success and hoped that through this workshop researchers could build a good relationship and continue to strengthen collaboration in the future.
The first session opened with a presentation by Dr. Dan with the title “Removal Optimization and Material Balance of Antibiotics from Freshwater and Seawater Aquaculture Tail Water in Constructed Wetlands.” She introduced the antibiotic-contaminated water and wastewater, and the use of constructed wetlands for antibiotics decontamination in China and around the world. In the case study, she used pilot-scale constructed wetlands to remove antibiotics from aquaculture wastewater in Guangzhou, Guangdong province, China. The fate of antibiotics and their microbial response mechanism in constructed wetlands was examined. Her findings indicated that antibiotic-contaminated aquaculture wastewater was treated effectively by constructed wetlands. The removal mechanism, the role of microbes, and the effect of configurations on antibiotic removal were clarified in her research. From these findings, she proposed a practical scale constructed wetland for removing antibiotics from wastewater in her conclusion. After delivering her informative presentation, participants both online and onsite gave her several comments and questions.
Dr. Dan delivering her presentation
In the second presentation, Dr. Vo Thi Dieu Hien (Vice Dean, Faculty of Environmental and Food Engineering, Nguyen Tat Thanh University, Vietnam) presented her research named “Shallow-Bed Constructed Wetland System: A Promising Innovative Nature-Based Solution Towards Circular and Resilient Cities.” The main purpose of her research was to discuss the potential applications of shallow-bed constructed wetlands on roofs as a constructing a wetland roof. In addition, the factors affecting performance, benefits, and challenges of wetland roofs were also discussed. Her results showed that the wetland roof was a promising green technology that needed to be investigated and scaled up in the future. Her presentation received many positive reactions from participants. Also, she answered in detail two questions from participants.
Dr. Thi Dieu Hien making her presentation
Next, Dr. Saurabh Singh, an assistant professor from Swami Keshvanand Institute of Technology, Management and Gramothan, India made his presentation under the title “Design and Performance Assessment of Subsurface Constructed Wetlands for Pollutant Removal.” His research focused on the investigation of design optimization (introducing Machine Learning analysis) through constructed wetlands and maximizing the removal efficacy of pollutants by utilizing the full potential capacity of this technology. He found out that the design of the deeper horizontal flow constructed wetland systems could be beneficial for the combined organics and nutrient removal. In addition, he proposed that this design would help to avoid the design of under-loaded constructed wetlands, resulting in conserving land area, and would help in design customization based on the required pollutant removals. At the end of his presentation, he showed his achievements and publications related to this research to the participants.
Dr. Singh providing his presentation
The last presentation in the first session was made by Professor Nehreen Majed from the University of Asia Pacific, Bangladesh, named “Towards Multifaceted Mitigation of Climate Change Impacts: Ensuring Sustainable Treatment Solutions with Constructed Wetlands.” She began her presentation by mentioning our duty to protect the earth, particularly protecting water bodies, and then she emphasized the use of constructed wetlands as sustainable treatment solutions for mitigating climate change impacts globally, with particular relevance to South Asia countries. During her presentation, she presented the use of many types of constructed wetlands for treating various pollutants such as heavy metals, nutrients, suspended solids, organic matter, etc. She found out that constructed wetlands generally were effective in removing suspended solids, nutrients, and heavy metals with a minimum environmental damage and also, they had the potential to mitigate climate change by sequestering 1 to 10 tons of carbon per hectare per year and creating biodiversity. She concluded that the utilization of constructed wetlands has become a very useful strategy in tackling industrial expansion and the effects of climate change, especially in developing nations.
Professor Nehreen Majed making her presentation
The second session started with a presentation named “Constructed Wetlands Planted with Iris for Mine Drainage Treatment: Effects of Domestic Wastewater-Feeding on Removal of Multiple Heavy Metals” from Dr. Nguyen Thi Thuong. She introduced the use of constructed wetlands for heavy metal removal from acid mine wastewater mixed with domestic wastewater. The objectives of her present research were (1) to evaluate the treatment performance these systems for heavy metal decontamination, (2) to compare the use of cattail and iris on removing heavy metal, and (3) to clarify the pathway of heavy metal removal in constructed wetlands. Her results showed that constructed wetlands were effective in enhancing effluent pH and removing dissolved metals, sulfate, and organic/nutrient pollutants. Additionally, using ornamental flowering plants such as iris in constructed wetlands could create beautiful landscapes and economic values. In the lively Q&A, the participants raised several comments on her presentation. Also, she clarified some questions from other speakers.
Dr. Thuong delivering her presentation
Dr. Obey Gotore (Research Fellow, Akita Prefectural University, Japan) continued the 2nd session with a presentation titled “The Applications and Performances of Biochar in Constructed Wetlands for Sustainable Wastewater Treatment”. He started his presentation by introducing wastewater treatment technologies, then, emphasized the advantage of using constructed wetlands for wastewater treatment. He evaluated the recycling of agricultural by-products (corncobs) as substrates in constructed wetlands for mine wastewater treatment. Results showed that the use of biochar corncob in constructed wetlands significantly enhanced nutrients and organic removal. He concluded that the biochar corncob-based constructed wetland was a cost-effective, environmentally friendly method for wastewater decontamination, and suitable for remote areas in least-developed countries. Dr. Obey also proposed using this corncob-based system for mine drainage treatment in the near future.
Dr. Obey giving his presentation
Next, Dr. Dissanayaka Mudiyanselage Shiromi Himalika Dissanayaka (Associate Professor, Department of Agricultural Engineering and Soil Science, Rajarata University of Sri Lanka, Sri Lanka) delivered her presentation with the title “Constructed Wetlands’ – An Environmentally Friendly Approach to Treating Wastewater: A Review.” Her research reviewed the phytoremediation of constructed wetlands using different combinations of wetland plants and the bioremediation of pollutants using microbes. The findings indicated that the wetland vegetation was considered a massive biofilm that provides a large surface area for the growth of various microbes responsible for phyto-microbial processors in wastewater. Further studies are needed to understand the interactions of microbes and their symbiotic effects on wastewater treatment. After her interesting presentation, participants enthusiastically discussed her topic research and gave her their comments.
Dr. Dissanayaka making her presentation
The last presentation in second session was given by Dr. Tang Van Tai, a lecturer from Faculty of Safety Engineering, School of Engineering and Technology, Van Lang University, Vietnam. The title of his presentation was “Novel Advanced Porous Concrete in Constructed Wetlands: Preparation, Characterization and Application in Urban Storm Runoff Treatment.” In this research, he investigated the common porous concrete templates and advanced porous concrete templates as filter media in constructed wetlands for pollutant removal from storm runoff. He found out that wetland plants grew very well on the porous concrete. The advanced porous concrete template-based constructed wetland showed better treatment performance than the common porous concrete template-based constructed wetland. He concluded that the advanced porous concrete template in constructed wetlands was a promising alternative technology for removing pollutants from urban stormwater runoff. In the Q&A, he received comments and questions from participants.
Dr. Tang Van Tai making his presentation
After the two sessions, all invited speakers and audience members moved to the closing discussion. Here, the invited speakers had a productive discussion and continued to receive many interesting questions and comments from the audience. In addition, all the researchers promised to promote international academic research-sharing platforms and strengthen collaboration in the future.
All panelists for this workshop
In his closing remarks, Professor Soda Satoshi from the Graduate School of Science and Engineering, Ritsumeikan University, expressed his gratitude to all invited speakers, participants, and organizers for the success of this workshop. He also once again emphasized the importance of wastewater treatment and the challenges in polluted water treatment in developing countries. He confirmed his belief that such international collaborations as this workshop could drive innovation and solve global water pollution issues. Finally, he wished all the participants success in their scientific research careers.