The Bioenergy and Environment Research Group in the Department of Molecular Biosciences and Bioengineering at The University of Hawaii at Manoa, Honolulu, HI, USA has immediate opening for graduate student (M.S./Ph.D.) starting Fall 2022. The selected candidate will conduct research on the use of biochar and nano-bubble technology in aquaculture and aquaponics. The candidate should have prior research experience in biological wastewater treatment, mass transfer, water chemistry, nitrogen transformations, and techno-economic analysis. The research project will develop a state-of-the-art aquaponics/aquaculture prototype integrating biochar with nano-bubble technology and conduct the overall cost/benefit analysis of the proposed prototype. We prefer candidates with strong environmental engineering background, analytical/lab skill, capability of designing (hands-on) and operating an scalable system with nano-bubble technology. B.S./M.S. in environmental engineering or a closely related engineering field is required. The candidate must have superior academic and excellent research temperament. The position requires excellent written and oral English skill including ability to prepare refereed journal articles/progress report. The Graduate Research Assistantship is highly competitive and commensurate with experience. The M.S./Ph.D. candidate will also receive full tuition waiver along with fund for attending/presenting at national/international conference. For consideration, please e-mail CV (with GRE, TOEFL or IELTS scores (if applicable) and GPA), short write-up on research experience, names of two referees and publications if any in a single PDF file to Dr. Samir Kumar Khanal at For any question regarding this opening, please contact Dr. Surendra KC at

Starting 2022 with a bang! Congratulation to Dr. Khanal! He has been promoted to Editor of Bioresource Technology, where he was previously an Associate Editor. He exclaims that this was not possible without the love and support of his research team and extended colleagues. Godspeed, Sir!

Updated: Dec 6, 2021

As we close out 2021, we would like to take the time to recognize the achievements made thus far. Twenty-three publications have been authored by our research group, including five review papers! A summary of these works are listed below:

Wongkiew, S., Polprasert, C., Koottatep, T., Limpiyakorn, T., Surendra, K.C. and Khanal, S.K., 2022. Chicken manure-based bioponics: Effects of acetic acid supplementation on nitrogen and phosphorus recoveries and microbial communities. Waste Management, 137, pp.264-274.

One of our first publication on this very subject.

Cruz, I.A., Chuenchart, W., Long, F., Surendra, K.C., Andrade, L.R.S., Bilal, M., Liu, H., Figueiredo, R.T., Khanal, S.K. and Ferreira, L.F.R., 2021. Application of machine learning in anaerobic digestion: Perspectives and challenges. Bioresource Technology, p.126433.

A comprehensive review on machine learning to anaerobic digestion.

Karki, R., Chuenchart, W., Surendra, K.C., Sung, S., Raskin, L. and Khanal, S.K., 2022. Anaerobic co-digestion of various organic wastes: Kinetic modeling and synergistic impact evaluation. Bioresource Technology, 343, p.126063.

Our first publication on co-digestion

Wongkiew, S., Koottatep, T., Polprasert, C., Prombutara, P., Jinsart, W. and Khanal, S.K., 2021. Bioponic system for nitrogen and phosphorus recovery from chicken manure: Evaluation of manure loading and microbial communities. Waste Management, 125, pp.67-76.

One of our first publication on this very subject.

Karki, R., Chuenchart, W., Surendra, K.C., Shrestha, S., Raskin, L., Sung, S., Hashimoto, A. and Khanal, S.K., 2021. Anaerobic co-digestion: Current status and perspectives. Bioresource Technology, p.125001.

An updated review on anaerobic co-digestion.

Chuenchart, W., Karki, R., Shitanaka, T., Marcelino, K.R., Lu, H. and Khanal, S.K., 2021. Nanobubble technology in anaerobic digestion: A review. Bioresource Technology, p.124916.

The first review regarding nanobubble technology to anaerobic digestion

Wongkiew, S., Hu, Z., Lee, J.W., Chandran, K., Nhan, H.T., Marcelino, K.R. and Khanal, S.K., 2021. Nitrogen Recovery via Aquaponics–Bioponics: Engineering Considerations and Perspectives. ACS ES&T Engineering, 1(3), pp.326-339.

The first review regarding bioponics, it's applications and design considerations.

Wu, Z., Nguyen, D., Lam, T.Y., Zhuang, H., Shrestha, S., Raskin, L., Khanal, S.K. and Lee, P.H., 2021. Synergistic association between cytochrome bd-encoded Proteiniphilum and reactive oxygen species (ROS)-scavenging methanogens in microaerobic-anaerobic digestion of lignocellulosic biomass. Water Research, 190, p.116721.

A recent publication on microaeration to anaerobic digestion.

Fonoll, X., Shrestha, S., Khanal, S.K., Dosta, J., Mata-Alvarez, J. and Raskin, L., 2021. Understanding the Anaerobic Digestibility of Lignocellulosic Substrates Using Rumen Content as a Cosubstrate and an Inoculum. ACS ES&T Engineering, 1(3), pp.424-435.

One of the first publications on ACS ES&T ENG.

Surendra, K.C., Tomberlin, J.K., van Huis, A., Cammack, J.A., Heckmann, L.H.L. and Khanal, S.K., 2020. Rethinking organic wastes bioconversion: Evaluating the potential of the black soldier fly (Hermetia illucens (L.))(Diptera: Stratiomyidae)(BSF). Waste Management, 117, pp.58-80.

A comprehensive review on black soldier fly and the challenges and opportunities.

All other 2021 works are listed below. A comprehensive list of all of our research can be found at:

  1. Siddiqui, M. A., Biswal, B. K., Saleem, M., Guan, D., Iqbal, A., Wu, D., ... & Chen, G. (2021). Anaerobic self-forming dynamic membrane bioreactors (AnSFDMBRs) for wastewater treatment–recent advances, process optimization and perspectives. Bioresource Technology, 125101.

  2. Kim, S.H., Kumar, G., Chen, W.H. and Khanal, S.K., 2021. Renewable hydrogen production from biomass and wastes (ReBioH2-2020).

  3. Jamison, J., Khanal, S.K., Nguyen, N.H. and Deenik, J.L., 2021. Assessing the Effects of Digestates and Combinations of Digestates and Fertilizer on Yield and Nutrient Use of Brassica juncea (Kai Choy). Agronomy, 11(3), p.509.

  4. Oberoi, A. S., Huang, H., Khanal, S. K., Sun, L., & Lu, H. (2021). Electron distribution in sulfur-driven autotrophic denitrification under different electron donor and acceptor feeding schemes. Chemical Engineering Journal, 404, 126486.

  5. Fang, H., Oberoi, A.S., He, Z., Khanal, S.K. and Lu, H., 2021. Ciprofloxacin-degrading Paraclostridium sp. isolated from sulfate-reducing bacteria-enriched sludge: Optimization and mechanism. Water Research, 191, p.116808.

  6. Jia, Y., Khanal, S.K., Yin, L., Sun, L. and Lu, H., 2021. Influence of ibuprofen and its biotransformation products on different biological sludge systems and ecosystem. Environment International, 146, p.106265.

  7. Sebayuana, K., Nindhia, T.G.T., Surata, I.W., Nindhia, T.S., Shukla, S.K. and Khanal, S.K., 2021. Performance of 500 Liter Stainless Steel Portable Biogas Anaerobic Digester with Agitator Designed for the Tropical Developing Country. In Key Engineering Materials (Vol. 877, pp. 160-165). Trans Tech Publications Ltd.

  8. He, M., Zhu, X., Dutta, S., Khanal, S.K., Lee, K.T., Masek, O. and Tsang, D.C., 2021. Catalytic co-hydrothermal carbonization of food waste digestate and yard waste for energy application and nutrient recovery. Bioresource Technology, p.126395.

  9. Zeng, Q., Zan, F., Hao, T., Khanal, S.K. and Chen, G., 2021. Sewage sludge digestion beyond biogas: Electrochemical pretreatment for biochemicals. Water Research, p.117839.

  10. Sharma, P., Ngo, H.H., Khanal, S., Larroche, C., Kim, S.H. and Pandey, A., 2021. Efficiency of transporter genes and proteins in hyperaccumulator plants for metals tolerance in wastewater treatment: Sustainable technique for metal detoxification. Environmental Technology & Innovation, p.101725.

  11. Zeng, Q., Wang, Y., Zan, F., Khanal, S.K. and Hao, T., 2021. Biogenic Sulfide for Azo Dye Decolorization from Textile Dyeing Wastewater. Chemosphere, p.131158.

  12. Khanal, S.K., Lü, F., Wong, J.W., Wu, D. and Oechsner, H., 2021. Anaerobic Digestion Beyond Biogas.

  13. Wells, J.M., Crow, S.E., Khanal, S.K., Turn, S., Hashimoto, A., Kiniry, J. and Meki, N., 2021. Anaerobic Digestion and Hot Water Pretreatment of Tropically Grown C4 Energy Grasses: Mass, Carbon, and Energy Conversions from Field Biomass to Fuels. Agronomy, 11(5), p.838.


In our commitment to helping our undergraduates, we are please to announce that two UROP projects mentored by our research group were approved! Waste Management and Resource Recovery

Ruby Anne Polintang & April Vidad

This project aims to improve the waste management and resource recovery at the University of Hawaii by reducing the volume of aluminum cans and non-food waste. It includes a pneumatic can compactor to compact aluminum cans. It also consists of sensors that determine the current level of waste of each bin and once it is detected full, there is an alert system to notify those in charge to empty out the waste bin(s). This can reduce the amount of time trash bins need to be changed out and checked on. Lastly, it encourages students and staff to separate their leftover food waste from their takeout containers to prevent leftover food waste from going to a landfill as it releases methane gas into the environment.

Small Scale Soldier Fly Farm and the Effect of Substrates on Larvae Nutritional Value

Tavish McGreevy

The proposed project concentrates and provides valuable data on two main focuses. The project's first focus is to better understand how different food waste substrates (sourced from UH cafeterias) affect the carbohydrate, lipid and protein profiles of soldier fly larvae. This data can be used to then formulate substrate mixtures that can ensure optimal nutritive values for animal and human consumption. The second focus is to build a robust prototype farm. Although outputs may be lower than a commercial setup, the prototype will serve as a blueprint for a much larger operation.


Furthermore, congratulations to Renisha Karki on a successful defense of her thesis entitled Anaerobic Co-Digestion of Coffee Pulp and Cattle Manure: Evaluation of Process Stability. You have left a mark on this lab group; we hope nothing but the best at Umich!

We would also like recognize Dr. Lut Raskin's induction into the National Academy of Engineering


In addition, congratulations to Dr. Khanal! He was featured as an 2021 outstanding alumni at his alma mater: The Hong Kong University of Science and Technology.


Lastly, the lab group was feature in several news outlets within the university!

  1. Phew! That $$$ Sure Helps

  2. The Long Way Round

  3. CEE MS Student Kyle Marcelino Won Outstanding Postgraduate Researcher at International Sustainable Biowaste Management Conference

  4. Nanobubble tech could revolutionize aquaculture, aquaponics


As we beginning the new year, our lab group wishes you happy holidays! Mahalo

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