Among other goals to achieve sustainable development, the United Nations listed following three goals: Goal 6 – Ensure availability and sustainable management of water and sanitation for all; Goal 11 – Make cities and human settlements inclusive, safe, resilient and sustainable; Goal 12 – Ensure sustainable consumption and production patterns. I conduct research studies to meet these goals.
More than half of the world’s population now lives in urban areas, and this figure is expected to exceed 70% by 2050. That is, nearly 3.2 billion new urban residents will be added to some of the densely populated cities throughout the world (detail here). While urbanization provides many socioeconomic benefits, it creates many environmental issues. For instance, impervious surfaces during urban development not only reduce natural infiltration of rainwater and natural replenishment of groundwater (a major source of drinking water) but also increase surface runoff, flooding, land erosion, contamination of water resources, greenhouse gas emission and the loss of biodiversity. In particular, bacteria or pathogens in stormwater cause widespread contamination of surface waters and groundwater. My research on stormwater capture, treatment, and reuse focuses on sustainable treatment of stormwater for nonpotable reuse.
Furthermore, climate change is expected to exacerbate some of these issues. Thus, providing adequate resources such as clean water without depleting the water resources and managing wastes without degrading the environment have been few challenges that must be addressed in order to build sustainable cities. During my doctoral study, I examined how changes in weather pattern affect the net export of colloids and contaminants from the subsurface soil to water resources. My postdoctoral research study examined how to create resources out of traditional wastes (e.g., clean water from contaminated stormwater, biochar from organic waste). Minimizing the generation of wastes, their transport from the source, and transforming the wastes into resources save energy while protecting the environment. Because biochar is expected to last for decades, increasing use of biochar in stormwater management systems has potentials to alleviate water contamination in urban areas, provide an alternative source for non-portable water, increase carbon sequestration on the ground while minimizing organic waste in the landfill. Overall, these studies highlight the needs for a coordinated effort to manage resources and wastes to achieve the sustainable development goals in the urban environment.
Specific research areas that I work include the following:
- Develop methods to create resources (e.g., compost) from biowaste generated from a house or community and use them in rain gardens to treat stormwater and maintain the urban ecosystem.
- Use solar-powered electrochemical cells to enhance contaminant removal in stormwater bioinfiltration system.
- In-situ regeneration of reactive surface properties of geomedia (e.g., biochar, iron or manganese-based geomedia) for sustainable removal of contaminants from stormwater.
- Improve the design of rainwater harvesting technologies.
- Life cycle assessment of the materials and resources used in the urban development, particularly in the water sector.