Updated on 2022/01/28


TEAH, Heng Yi
Faculty of Science and Engineering, Waseda Research Institute for Science and Engineering
Job title
Junior Researcher(Assistant Professor)
Mail Address

Concurrent Post

  • Faculty of Science and Engineering   School of Advanced Science and Engineering


  • 2014.10

    The University of Tokyo   Graduate Program in Sustainability Science, Division of Environmental Studies   Doctoral degree  

  • 2012.09

    National Cheng Kung University   Department of Environmental Engineering   Master degree  

  • 2009.09

    National Cheng Kung University   Department of Environmental Engineering   Bachelor degree  


  • Sustainability Science   PhD

  • Environmental Engineering   MSc


Research Areas

  • Environmental load and risk assessment

Research Interests

  • Life cycle assessment (LCA), Sustainability assessment, Interdisciplinary study


  • Redox reactions between chromium(VI) and hydroquinone: Alternative pathways for polymerization of organic molecules

    Tzou, Y.-M., Chen, K.-Y., Cheng, C.-Y., Lee, W.-Z., Teah, H.Y., Liu, Y.-T.

    Environmental Pollution   261  2020


  • Molecular mechanisms for Pb removal by Cyanidiales: a potential biomaterial applied in thermo-acidic conditions

    Cho, Y.-L., Lee, Y.-C., Hsu, L.-C., Wang, C.-C., Chen, P.-C., Liu, S.-L., Teah, H.-Y., Liu, Y.-T., Tzou, Y.-M.

    Chemical Engineering Journal   401  2020


  • Modeling the time-lag effect of sea surface temperatures on ciguatera poisoning in the South Pacific: Implications for surveillance and response

    Zheng, L., Gatti, C.M.I., Garrido Gamarro, E., Suzuki, A., Teah, H.Y.

    Toxicon   182   21 - 29  2020


  • Life Cycle Greenhouse Gas Emissions of Long and Pure Carbon Nanotubes Synthesized via On-Substrate and Fluidized-Bed Chemical Vapor Deposition

    Teah, H.Y., Sato, T., Namiki, K., Asaka, M., Feng, K., Noda, S.

    ACS Sustainable Chemistry and Engineering   8 ( 4 )  2020


  • Incorporating external effects into project sustainability assessments: The case of a green campus initiative based on a solar PV system

    Teah, H.S., Yang, Q., Onuki, M., Teah, H.Y.

    Sustainability (Switzerland)   11 ( 20 )  2019  [Refereed]

     View Summary

    We demonstrated that a green campus initiative can reduce the carbon footprint of a university and improve the disaster resilience of the local community. A project sustainability assessment framework was structured to support the initiative. First, an on-campus solar photovoltaic (PV) system was designed. The project performance in terms of financial cost and greenhouse gas (GHG) emissions was assessed using life cycle cost analysis (LCC) and a life cycle assessment (LCA), respectively. Then, we explored the incorporation of positive social impacts on the local community in the context of natural disaster-prone Japan. Indicators for improving the disaster resilience of the residents were defined based on the Sendai Framework. Our results showed that the proposed solar PV system could provide an electricity self-sufficiency rate of 31% for the campus. Greenhouse gas emissions of 0.0811 kg CO2-eq/kWh would decrease the annual emissions from campus electricity use by 27%. Considering the substituted daytime electricity purchase, a payback period of 12.9 years was achievable. This solar PV system could serve as an emergency power source to 4666-8454 nearby residents and 8532 smart city residents. This external effect would encourage stakeholders like local government and developers to participate in the project.


  • Removal and simultaneous reduction of Cr(VI)by organo-Fe(III)composites produced during coprecipitation and coagulation processes

    Chen, K.-Y., Tzou, Y.-M., Chan, Y.-T., Wu, J.-J., Teah, H.-Y., Liu, Y.-T.

    Journal of Hazardous Materials   376   12 - 20  2019  [Refereed]


  • Adsorption mechanisms of chromate and phosphate on hydrotalcite: A combination of macroscopic and spectroscopic studies

    Hsu, L.-C., Tzou, Y.-M., Chiang, P.-N., Fu, W.-M., Wang, M.-K., Teah, H.Y., Liu, Y.-T.

    Environmental Pollution   247   180 - 187  2019  [Refereed]


  • Use 3-D tomography to reveal structural modification of bentonite-enriched clay by nonionic surfactants: Application of organo-clay composites to detoxify aflatoxin B1 in chickens

    Tzou, Y.-M., Chan, Y.-T., Chen, S.-E., Wang, C.-C., Chiang, P.-N., Teah, H.Y., Hung, J.-T., Wu, J.-J., Liu, Y.-T.

    Journal of Hazardous Materials   375   312 - 319  2019  [Refereed]


  • Capacity and recycling of polyoxometalate applied in As(III) oxidation by Fe(II)-Amended zero-valent aluminum

    Hsu, L.-C., Cho, Y.-L., Liu, Y.-T., Tzou, Y.-M., Teah, H.Y.

    Chemosphere   200   1 - 7  2018  [Refereed]

     View Summary

    Arsenic remediation is often initiated by oxidizing As(III) to As(V) to alleviate its toxicity and mobility. Due to the easy availability, zero-valent Al (ZVAl) like Al can was considered as potential alternatives to facilitate As(III) oxidation. This study determined the capability and recycling of polyoxometalate (POM) to catalyze As(III) oxidation in Fe(II)-amended ZVAl systems. POM acquired electrons from ZVAl more effectively at pH 1 than at pH 2. While 76% of the reduced POM [POM(e−)] reacted with O2(g) to generate H2O2 at pH 1, only 60% of POM(e−) was used to produce H2O2 at pH 2. The remaining POM(e−) was oxidized by the generated H2O2. Such additional consumption of POM(e−) and H2O2 led to the incomplete As(III) oxidation in the system without residual ZVAl and emphasized the need for a continuous electron supply from ZVAl to compensate the depletion of POM(e−). After the hydrolyzation at pH 6.0, the XANES data evidenced that not only As(V) but WO4 released from the POM retained on surfaces of Al/Fe hydroxides. The competition for sorption sites on Al/Fe hydroxides between As(V) and WO4 led to the incomplete As removal. Despite the loss of WO4, the POM re-polymerized at pH 1 still showed the comparable capability to catalyze As(III) oxidation with original POM. This study revealed electron transfer pathways from ZVAl to As(III) as catalyzed by POM and evidenced the effective POM recycling after As removal, which lowers the cost of POM application and turns the ZVAl/Fe(II)/POM/O2 system into a practical strategy for As remediation.

    DOI PubMed

  • Adsorption of tetracycline on Fe (Hydr)oxides: Effects of pH and metal cation (Cu2+, Zn2+ and Al3+) addition in various molar ratios

    Hsu, L.-C., Liu, Y.-T., Syu, C.-H., Huang, M.-H., Tzou, Y.-M., Teah, H.Y.

    Royal Society Open Science   5 ( 3 )  2018  [Refereed]

     View Summary

    Iron (Fe) (hydr)oxides control the mobility and bioavailability of tetracycline (TC) in waters and soils. Adsorption of TC on Fe (hydr)oxides is greatly affected by polyvalent metals
    however, impacts of molar metal/TC ratios on TC adsorptive behaviours on Fe (hydr)oxides remain unclear. Results showed that maximum TC adsorption on ferrihydrite and goethite occurred at pH 5–6. Such TC adsorption was generally promoted by the addition of Cu2+, Zn2+ and Al3+. The greatest increase in TC adsorption was found in the system with molar Cu/TC ratio of 3 due to the formation of Fe hydr(oxide)– Cu–TC ternary complexes. Functional groups on TC that were responsible for the complexation with Cu2+ shifted from phenolic diketone groups at Cu/TC molar ratio &lt
    1 to amide groups at Cu/TC molar ratio ≥ 1. For the addition of Al3+, the complexation only took place with phenolic diketone groups, resulting in the enhanced TC adsorption at a molar Al/TC ratio of 1. However, TC adsorption decreased for Al/TC molar ratio &gt
    1 as excess Al3+ led to the competitive adsorption with Al/TC complexes. For the Zn2+ addition, no significant correlation was found between TC adsorption capacity and molar Zn/TC ratios.


  • Life cycle assessment of small-scale horizontal axis wind turbines in Taiwan

    Wang, W.-C., Teah, H.-Y.

    Journal of Cleaner Production   141   492 - 501  2017  [Refereed]

     View Summary

    Small-scale horizontal axis wind turbines (HAWTs) are a promising alternative energy resource for the off-grid generation of household electricity. In this study, we conducted a life-cycle assessment (LCA) of greenhouse gas (GHG) emissions and energy consumption pertaining to the environmental impact of a Taiwanese-built 600 W HAWT. This investigation was divided into five phases: (1) materials; (2) production; (3) transport; (4) disposal; (5) recycling. Four main components of a HAWT were focused on: (a) rotor; (b) generators; (c) electronic components; (d) tower. Based on the evaluation, the production phase and the fabrication of generator make the highest contribution to GHG emissions, whereas the phase of materials and the fabrication of generator are responsible for the most energy consumption. Based on estimations of the power generated by the HAWT under the local wind conditions in Tainan, Taiwan, it is estimated that the HAWT would require 160.9 years to return the energy used in the production and disposal of the devices and 100.1 years to counter-balance the production of GHGs. (C) 2016 Elsevier Ltd. All rights reserved.


  • Life cycle assessment of palm-derived biodiesel in Taiwan

    Maharjan, S., Wang, W.-C., Teah, H.Y.

    Clean Technologies and Environmental Policy   19 ( 4 ) 959 - 969  2017  [Refereed]

     View Summary

    In Taiwan, due to the limited capacity of waste cooking oil, palm oil has been viewed as the potential low-cost imported feedstock for producing biodiesel, in the way of obtaining oil feedstock in Malaysia and producing biodiesel in Taiwan. This study aims to evaluate the cradle-to-grave life cycle environmental performance of palm biodiesel within two different Asian countries, Malaysia and Taiwan. The phases of the life cycle such as direct land-use-change impact, plantation and milling are investigated based on the Malaysia case and those of refining, and fuel production as well as engine combustion is based on Taiwan case. The greenhouse gas (GHG) emission and energy consumption for the whole life cycle were calculated as -28.29 kg CO2-equiv. and +23.71 MJ/kg of palm-derived biodiesel. We also analyze the impacts of global warming potential (GWP) and the payback time for recovering the GHG emissions when producing and using biodiesel. Various scenarios include (1) clearing rainforest or peat-forest; (2) treating or discharging palm-oil-milling effluent (POME) are further developed to examine the effectiveness of improving the environmental impacts.


  • Support phosphorus recycling policy with social life cycle assessment: A case of Japan

    Teah, H.Y., Onuki, M.

    Sustainability (Switzerland)   9 ( 7 )  2017  [Refereed]

     View Summary

    Producing phosphorus (P) fertilizers with recycled P is desirable for efficient use of P resource. However, the current cost of P recycling facilities in Japan strongly discourages the government from adopting this practice. To expand consideration for a P recycling policy, the concept of social externality was introduced. Social issues, such as the violation of human rights in P mining in the Western Sahara, have been identified in recent studies; nevertheless, a systematic approach towards accountability was lacking. Therefore, the purpose of this study was to support a P recycling policy with a social life cycle assessment (SLCA) by contrasting the social impacts associated with mineral and recycled P fertilizers using the case study of Japan. We developed a framework based on the UNEP-SETAC SLCA Guidelines with a supplementary set of P-specific social indicators. The results showed that the marginal social impact associated with recycled P was much less relative to mineral P; however, even if we factored in the maximum recycling capacity, a mandate of P recycling policy in Japan would not mitigate the impacts significantly relative to the current situation because only 15% of P rocks could be substituted. In short, we showed that a semi-quantitative SLCA framework would be useful to communicate the wide spectrum of social impacts to policymakers.


  • Molecular Structures of Al/Si and Fe/Si Coprecipitates and the Implication for Selenite Removal

    Chan, Y.-T., Kuan, W.-H., Tzou, Y.-M., Chen, T.-Y., Liu, Y.-T., Wang, M.-K., Teah, H.-Y.

    Scientific Reports   6  2016  [Refereed]

     View Summary

    Aluminum and iron oxides have been often used in the coagulation processes during water purification due to their unique surface properties toward anions. In the presence of silica, the coprecipitation of Al/Si or Fe/Si might decrease the efficiency of wastewater purification and reuse. In this study, surface properties and molecular structures of Al/Si and Fe/Si coprecipitates were characterized using spectroscopic techniques. Also, the selenite removal efficiency of Al/Si and Fe/Si coprecipitates in relation to their surface and structural properties was investigated. While dissolved silicate increased with increasing pH from Fe/Si coprecipitates, less than 7% of silicate was discernible from Al/Si samples over the range from acidic to alkaline conditions. Our spectroscopic results showed that the associations between Al and Si were relatively stronger than that between Fe and Si in coprecipitates. In Al/Si coprecipitates, core-shell structures were developed with AlO6/AlO4 domains as the shells and Si frameworks polymerized from the SiO2 as the cores. However, Si framework remained relatively unchanged upon coprecipitation with Fe hydroxides in Fe/Si samples. The Si core with Al shell structure of Al/Si coprecipitates shielded the negative charges from SiO2 and thereby resulted in a higher adsorption capacity of selenite than Fe/Si coprecipitates.


  • Accumulation of heavy metals and trace elements in fluvial sediments received effluents from traditional and semiconductor industries

    Hsu, L.-C., Huang, C.-Y., Chuang, Y.-H., Chen, H.-W., Chan, Y.-T., Teah, H.Y., Chen, T.-Y., Chang, C.-F., Liu, Y.-T., Tzou, Y.-M.

    Scientific Reports   6  2016  [Refereed]

     View Summary

    Metal accumulation in sediments threatens adjacent ecosystems due to the potential of metal mobilization and the subsequent uptake into food webs. Here, contents of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn) and trace elements (Ga, In, Mo, and Se) were determined for river waters and bed sediments that received sewage discharged from traditional and semiconductor industries. We used principal component analysis (PCA) to determine the metal distribution in relation to environmental factors such as pH, EC, and organic matter (OM) contents in the river basin. While water PCA categorized discharged metals into three groups that implied potential origins of contamination, sediment PCA only indicated a correlation between metal accumulation and OM contents. Such discrepancy in metal distribution between river water and bed sediment highlighted the significance of physical-chemical properties of sediment, especially OM, in metal retention. Moreover, we used Se XANES as an example to test the species transformation during metal transportation from effluent outlets to bed sediments and found a portion of Se inventory shifted from less soluble elemental Se to the high soluble and toxic selenite and selenate. The consideration of environmental factors is required to develop pollution managements and assess environmental risks for bed sediments.


  • Assessment of downscaling planetary boundaries to semi-arid ecosystems with a local perception: A case study in the middle reaches of Heihe River

    Teah, H.Y., Akiyama, T., Carlos, R.S., Rayo, O.V., Khew, Y.T.J., Zhao, S., Zheng, L., Onuki, M.

    Sustainability (Switzerland)   8 ( 12 )  2016  [Refereed]

     View Summary

    The middle reaches of Heihe River are located in the oasis of the Gobi Desert where limited freshwater supply supports more than 1.5 million inhabitants. The intense agricultural activities are depleting the groundwater reserve. Consequently, natural landscapes and habitats are degraded. Though such development improves the livelihood of the local community, long-term sustainability of the ecosystem is at risk. Local authorities must be informed holistically to prepare for adapting to the changes and/or mitigating the impacts. The purpose of this study was to perform a regional sustainability assessment based on downscaling the planetary boundaries (PBs). We proposed a regional safe operating space framework that applied a top-down approach using the environmental monitoring data, and a bottom-up approach using knowledge from the local perception about environmental disaster. We conducted on-site samplings and interviews of residents to demonstrate the method. Overall, we showed that the middle reaches had transgressed the safe operating space, particularly on the freshwater use and biogeochemical flow dimensions. We found that the local perception acquired from interviews complemented the insufficiency of the monitoring data and provided the insightful social implications of transgressing the safe operating space, i.e., the anticipated impacts on local livelihood, for policy support.


  • Stabilization of natural organic matter by short-range-order Iron hydroxides

    Chen, K.-Y., Chen, T.-Y., Chan, Y.-T., Cheng, C.-Y., Tzou, Y.-M., Liu, Y.-T., Teah, H.-Y.

    Environmental Science and Technology   50 ( 23 ) 12612 - 12620  2016  [Refereed]

     View Summary

    Dissolved organic matter (DOM) is capable of modifying the surfaces of soil minerals (e.g., Fe hydroxides) or even forming stable co-precipitates with Fe(III) in a neutral environment. The DOM/Fe co-precipitation may alter biogeochemical carbon cycling in soils if the relatively mobile DOM is sorbed by soil minerals against leaching, runoff, and biodegradation. In this study, we aimed to determine the structural development of DOM/Fe co-precipitates in relation to changes in pH and C/(C + Fe) ratios using XRD, XPS, Fe K-edge XAS, FTIR, and C-NEXAFS techniques. The results showed that in the system with bulk C/(C + Fe) molar ratios <= 0.65, the ferrihydrite-like Fe domains were precipitated as the core and covered by the C shells. When the C/(C + Fe) molar ratio ranged between 0.71 and 0.89, the emerging Fe-C bonding suggested a more substantial association between Fe domains including edge- and corner-sharing FeO6 octahedra and DOM. With C/(C + Fe) bulk molar ratios >= 0.92, only corner-sharing FeO6 octahedra along with Fe-C bonding were found. The homogeneously distributed C and Fe domains caused the enhancement of Fe and C solubilization from co-precipitates. The C/(C + Fe) ratios dominated structural compositions and stabilities of C/Fe co-precipitates and may directly affect the Fe and C cycles in soils.


  • Drawing lessons from the Minamata incident for the general public: Exercise on resilience, Minamata unit AY2014

    Amasawa, E., Teah, H.Y., Khew, J.Y.T., Ikeda, I., Onuki, M.

    Sustainability Science: Field Methods and Exercises     93 - 113  2016  [Refereed]

     View Summary

    This chapter introduces the Minamata Unit, a GPSS-GLI Exercise on Resilience conducted around Minamata City, Kumamoto Prefecture, in Japan. The disruption caused by Minamata mercury pollution persists even 60 years after the incidents. Such a long history of development can provide invaluable insights into the study of the impact of industrial pollution to a society, which includes the significance of identifying new pollutants, the intricate social tension between victims and local community, and the urge to heal the strained bonds. Drawing lessons from the Minamata incident can prevent and mitigate similar incidents in developing countries, where environmental regulation is typically less stringent than in developed countries. In the present chapter, the authors describe the outcomes of a week-long field exercise in Minamata, designed for students of sustainability science. The aims of the unit were for participants to understand the complexities of the Minamata incident, not only the causal relationship between the pollutant and its impact on human health, but also the impacts the disease had on the society. Also, it attempted to examine the responsibility of scientists and the government, especially when certain issues regarding the case remain scientifically uncertain, by redefining the issue in the contemporary context. In order to facilitate learning by the participants of the unit presented in this chapter and students of future units, the exercise organisers requested the production of educational materials as the final output. Students were divided into three working groups, each tasked with the development of a different type of media material, namely blog posting, video production, and game development. The prearranged field activities included stakeholder interviews, site visits, and an intensive group work. Overall, the student groups completed the production of the tangible outputs, though their effectiveness in reaching the target audience and helping future sustainability science students require further analysis.


  • Designing field exercises with the integral approach for sustainability science: A case study of the Heihe river Basin, China

    San Carlos, R.O., Teah, H.Y., Akiyama, T., Li, J.

    Sustainability Science: Field Methods and Exercises     23 - 39  2016  [Refereed]

     View Summary

    This chapter introduces one of the GPSS-GLI exercises, the Oasis Unit, which has been conducted annually in northwestern China. The unit aims to equip the students who take it with a wide knowledge base and leadership competency, and is thus strongly field-oriented. The Integral Approach proposed by Ken Wilber is applied when designing this unit, which provides an interdisciplinary and transdisciplinary framework for synthesizing the complex problems of sustainability, as well as allowing the inclusion of methodologies from different academic fields. In the present chapter a practical implementation of the approach is showed and discussed, using as a case study the 2015 Oasis Unit within two contexts-(1) as a holistic framework for addressing sustainability problems, and (2) as a design approach for educational field exercises. Finally, the authors summarize the usefulness of the integral approach in designing field exercises based on the seven year long experience of the University of Tokyo in organizing the Oasis Unit.


  • Experiential knowledge complements an LCA-based decision support framework

    Teah, H.Y., Fukushima, Y., Onuki, M.

    Sustainability (Switzerland)   7 ( 9 ) 12386 - 12401  2015  [Refereed]

     View Summary

    A shrimp farmer in Taiwan practices innovation through trial-and-error for better income and a better environment, but such farmer-based innovation sometimes fails because the biological mechanism is unclear. Systematic field experimentation and laboratory research are often too costly, and simulating ground conditions is often too challenging. To solve this dilemma, we propose a decision support framework that explicitly utilizes farmer experiential knowledge through a participatory approach to alternatively estimate prospective change in shrimp farming productivity, and to co-design options for improvement. Data obtained from the farmer enable us to quantitatively analyze the production cost and greenhouse gas (GHG) emission with a life cycle assessment (LCA) methodology. We used semi-quantitative graphical representations of indifference curves and mixing triangles to compare and show better options for the farmer. Our results empower the farmer to make decisions more systematically and reliably based on the frequency of heterotrophic bacteria application and the revision of feed input. We argue that experiential knowledge may be less accurate due to its dependence on varying levels of farmer experience, but this knowledge is a reasonable alternative for immediate decision-making. More importantly, our developed framework advances the scope of LCA application to support practically important yet scientifically uncertain cases.


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Research Projects

  • Early-Stage Sustainability Assessment of Carbon-Nanotubes-Enabled Renewable Energy Technologies using Ex-Ante LCA and Sound Material-Cycle Index

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Early-Career Scientists

    Project Year :


  • Concurrent development and assessment of emerging technology: a case study on carbon nanotube production

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Research Activity Start-up

    Project Year :


    Teah Heng Yi

     View Summary

    Improvement in chemical vapor deposition (CVD) methods to efficiently synthesize high-quality carbon nanotubes (CNTs) is critical to commercialization of CNTs. Methods with less environmental impacts are preferable for sustainable chemistry. However, in the field of material sciences, the environmental impacts are rarely quantified. Here we provide a systematic investigation on the life cycle greenhouse gases (GHGs) emission of two emerging CNT synthesis methods: on-substrate and fluidized-bed CVD. Based on years-long experiments, we show the impacts of important configurations. We find that the life cycle GHGs of CNT production ranged from 28.55 (on-substrate) to 0.48 (fluidized-bed) kg CO2e/g CNTs. Considering the scale-up effects to industrialized levels, CNT production can be as low as to present carbon fiber (0.02 kg CO2e/g materials).

  • Life Cycle Sustainability Assessment (LCSA) of Phosphorus Recycling Policy of Japan

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for JSPS Fellows

    Project Year :




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