(3b) Resource Recovery for Sustainable Development at the Water-Energy-Food-Carbon Nexus

Recover resources from waste can lead to sustainable development to address water, nutrient, energy, and climate challenges. My research over the past six years focuses on designing technologies for reclaiming wastewater and waste CO₂ to address water scarcity, depleting phosphorus supply, and chemical intensive water treatments. My Ph.D. work developed a low-energy CO₂-driven platform using selective ion exchange adsorbents to desalinate and decontaminate wastewater for reuse, recover phosphate from wastewater for fertilizer supplement, and sequestrate CO₂ for climate change mitigation. My postdoc work developed a chemical-free phosphate and water recovery process by combining selective ion exchange adsorbents with electrochemical techniques. To transfer technologies into practice, I have developed and field validated a hybrid ion exchange adsorbent with nitrate and phosphate/fluoride selectivity. In China and USA, I have led field validations of two waste-driven ion exchange systems to enhance water recovery of reverse osmosis (RO): a CO₂ driven system for impaired surface water reuse (Wuhu, China), and a waste brine-driven system for brackish groundwater desalination (National Desalination Research Facility, New Mexico). Using waste CO₂ as a driving force for recovering water and nutrient from wastewater exemplifies resource-efficient processes that facilitate sustainable development.

Future Direction:

I envision a research group focusing on designing novel process technologies for reclaiming waste to address sustainability challenges, developing new materials to advance recovery process efficacy, and collaborating with practitioners to translate lab technologies to breakthrough solutions. I have gained skills for conducting cross-scale researches at molecular, process, and system levels, and had experiences of seeking funding to support my research.

Research Interests:

• Design processes to recover resources from liquid and gases waste streams using sustainable driving forces (e.g., CO₂, electricity, and solar energy)
• develop novel materials with enhanced selectivity and regenerability to advance recovery process efficacy
• diffuse technologies into practical solutions via field tests and global collaborations.

Teaching Interests:

With teaching experiences at both Lehigh and Stanford, I am well prepared for teaching fundamental engineering classes. My teaching interests include Environmental Engineering Science, Water Chemistry, and Water and Wastewater Treatment Processes. I am also greatly interested in developing courses on my specialties of Separation and Control Technologies, and Ion Exchange in Environmental Engineering Processes.

Selected Publications:

• Dong, H., Wei, L., & Tarpeh, W. A. (2020). Electro-assisted regeneration of pH-sensitive ion exchangers for sustainable phosphate removal and recovery. Water Research, 116167. DOI: 10.1016/j.watres.2020.116167.
• Dong, H., German, M., Tian, L., & SenGupta, A. K. (2020). Multifunctional ion exchange pretreatment driven by carbon dioxide for enhancing reverse osmosis recovery during impaired water reuse. Desalination, 485, 114459. DOI: 1016/j.desal.2020.114459
• Dong, H., Tian, L., & SenGupta, A.K. (2020). Field validation of multifunctional ion exchange process for reverse osmosis pretreatment and phosphate recovery during impaired water reuse. Journal of Water Process Engineering, 36,101347. DOI: https://doi.org/10.1016/j.jwpe.2020.101347
• Dong, H., Shepsko, C. S., German, M., & SenGupta, A. K. (2020). Hybrid nitrate selective resin (NSR-NanoZr) for simultaneous selective removal of nitrate and phosphate (or fluoride) from impaired water sources. Journal of Environmental Chemical Engineering, 103846. DOI: 1016/j.jece.2020.103846
• Dong, H., Shepsko, C. S., German, M., & SenGupta, A. K. (2018). Hybrid ion exchange desalination (HIX-Desal) of impaired brackish water using pressurized carbon dioxide (CO₂) as the source of energy and regenerant. Environmental Science & Technology Letters, 5(11), 701-706. DOI: 1021/acs.estlett.8b00487