July 15, 2020
Meet our students: Peng Zhang profile
Peng Zhang is a University of Regina PhD student in the Institute for Energy, Environment and Sustainable Communities.
1. When did you start your PhD studies at the University of Regina?
2. How did you know that you wanted to attend graduate school?
I had an opportunity to meet Dr. Gordon Huang in China in 2014. His excellent expertise in the field of environmental engineering was what attracted me to attend graduate school at the University of Regina.
3. Tell us about your research.
The topic of my PhD research is the development and assessment of nanomaterial enhanced wastewater treatment technology for rural areas.
There are three main components to my research. The first is the nanoparticle modified sponge/fiber developed to enhance the separation of oil and grease from wastewater. The second is the integrated wastewater treatment process, which includes an anaerobic unit, multi-soil layers unit, constructed wetland unit, and lagoon unit. This process was developed to adapt wastewater treatment requirements for communities that discharge sewage directly into the environment. The third component looks at the toxic mechanisms and risk assessment of nanoparticles in the wastewater treatment process on aquatic organisms; these were studied using the synchrotron beamline technologies at the Canadian Light Source in Saskatoon.
This research is important because it developed a wastewater treatment technology that integrates nano-material science and environmental engineering to help solve pollution issues in rural areas. Often rural areas do not have an effective drainage pipeline network that is connected to a municipal wastewater treatment plant. This technology provides a safe option for small communities where sewage is discharged into the environment due to a lack of, or aging, wastewater treatment infrastructure. The outcome of my study is the design of a high-performance and low-cost eco-wastewater treatment system with low greenhouse gas emissions.
4. What do you find most interesting about your research?
(1) The nano zinc oxide array fabricated sponge exhibits a superhydrophobicity to separate oil from oily wastewater. An array of nano size zinc oxide pillars was fabricated to create a superhydrophobic surface on the sponge – this is when water drops stay on the surface and oil drops diffuse as a film on the sponge’s surface. Generally, the sponge adsorbs liquid. After modification, the sponge can suck oil and repel water when placed into oily wastewater.
(2) Multi-layer assembled wetland displays an efficient performance for pollutant removal. The wetland is a land-based wastewater treatment. However, it requires a large area to treat high loading wastewater (high concentration pollutants, such as COD, BOD and nutrients). The developed multi-layer assembled wetland consists of a mixed soil unit and a permeable unit. The mixed soil unit contains soil, biochar, sand, and iron to enhance the organic pollutants’ removal capacities through physical, chemical and microbiological processes. The permeable unit has a higher permeability than the mixed soil unit, which could potentially reduce inner blockages. The two units are assembled alternatively like a brick wall for efficient performance.
(3) When a nanoparticle modified sponge is used in a wastewater treatment system, it poses a risk to the environment because nanoparticles are toxic to algae and affect aquatic organisms’ health. So, it is important to study the toxic effects of nanoparticles on aquatic organisms. The exposure pathway is critical to triggering toxic effects, and the toxic response and mechanism are different with exposure pathways, such as inhalation, ingestion, or direct contact. Therefore, it was necessary to study the exposure pathways of nanoparticles when enhancing wastewater treatment technology to make it safe for aquatic organisms.
5. Tell us about your experience with IEESC. What have you learned that is most valuable?
I have learned how to apply knowledge to solving real world problems and pursuing discoveries during the research process.
6. What advice would you give to a student considering a visit to IEESC?
(1) Assign a target, arrange a schedule, and achieve a highlight
(2) Communicate with all colleagues, listen to suggestions, and share skills
(3) Meet with a supervisor and cooperate with members
7. Where do you find your inspiration?
(1) When moisture touches the surface of a beetle, it forms a water drop due to the tiny pillars on the surface. This gave me an idea to create a nanopillar array on the sponge to separate oil depending on the superhydrophobic surface.
(2) A brick wall consists of alternating brick and cement layers, which inspired me to apply this configuration to subsurface flow wetlands to treat wastewater and avoid an inner blockage of the system.
8. What are your next goals/future plans?
Develop more reliable and safe materials to treat wastewater and adapt to harsh environmental conditions.
Thanks Peng and best wishes for your research!
To learn more about Peng’s research, see the following publication:
Peng Zhang, Guohe Huang, Chunjiang An, Haiyan Fu, Panfeng Gao, Yao Yao, Xiujuan Chen, An integrated gravity-driven ecological bed for wastewater treatment in subtropical regions: process design, performance analysis, and greenhouse gas emissions assessment, Journal of cleaner production, 212, 2019, 1143-1153.