RESEARCH
BIOFILMS IN DRINKING WATER PIPELINES
Image: Gomez-Smith and Aggarwal S. (2019). Encyclopedia of Water: Sci., Tech., & Society,1-17. 10.1002/9781119300762.wsts0193
Biofilms are routinely formed in water treatment systems (e.g., GAC filters, ultrafiltration membranes) and water distribution pipelines. In wastewater treatment biofilms are formed on trickiling filters, rotating biological contactors, and also membrane biofilm reactors. Biofilms can aid in biodegradation of contaminants as well as hinder performance (e.g. in ultrafiltration membranes) via biofouling. Traditionally, biofilm processes have not received significant attention in overall function and performance of water and wastewater systems. We are interested in investigating the role of biofilms in natural and engineered environmental systems.
MECHANICAL PROPERTIES OF BIOFILMS
Biofilms are communities of microorganisms attached to a solid surface in a self-secreted slime comprising extra-cellular polymeric substances (EPS). Biofilms are ubiquitously present on all moist surfaces of the world. To attain better biofilm control (attachment or removal from surfaces), it is important to understand the factors which control biofilm detachment -- which in turn, is dependent upon the mechanical properties of biofilms. We are interested in experimental and modeling approaches to measure biofilm mechanical properties and understand the role in biofilm process in natural and engineered systems.
Image: Micro-cantilever test platform for laboratory measurement of biofilm mechanical properties.
[Aggarwal et al. 2010 Biotechnol. Bioeng., 105(5): 924-934]
WATER TREATMENT TECHNOLOGIES
There is a pressing need for preserving and expanding our water supplies by innovative approaches in water treatment, recycling, desalination. Recovery and recycling of used domestic, agricultural or industrial waste water for human and/or agricultural use presents challenges in terms of removal of organic contamination and several micro-pollutants to ensure food safety and public health. Thus it is required to develop innovative solutions for meeting the needs of next generation water supplies.
Image: Adsorptive Removal of Se(IV) by Citrus Peels. https://doi.org/10.1021/acsomega.0c01347
PARTICULATE MATTER IMPACTS ON AIR QUALITY
With increasing fraction of world population residing in fast-expanding urban areas of the world, ambient air quality issues are on a rise. Specifically, exposure to fine and ultrafine particulate matter (PM2.5 and PM0.1) have been correlated with adverse human health impacts. It is important to, therefore, understand the factors which impact the spatio-temporal variability of air quality parameters which can help mitigate human exposure.
Image: Modeling of ultrafine particulate matter (UFP) on Minnesota freeways. [Aggarwal et al., 2012, Environ. Sci. & Technol., 46(4): 2234-41]
ENVIRONMENTAL IMPACTS OF OIL SPILL RESPONSE
According to USGS estimates the Arctic contains vast oil and natural gas reserves, and thus witnesses considerable oil exploration especially on the North Slope of Alaska. In the wake of 2010 Deepwater Horizon incident, additional measures for emergency response and containment requirements are needed to address a possible oil release in the Arctic. Many oil spill response technologies which are applicable in warm regions need to be re-assessed and re-designed for the Arctic application. There is also increased interest in the environmental fate and transport of oil spill response chemicals and any associated environmental impacts they may cause in Alaskan -off shore waters and marine wildlife. Our specific research interests include a) environmental fate of oil spill response chemicals, and, b) air quality impacts of in-situ burning of spilled oil.
Image: Experiments for assessing environmental fate and air quality impacts of chemical herder-mediated in-situ burning at UAF fire facility.
[Bullock et al., Journal of Env. Management, 190, 266-273 ]
Image: Aerial application of herding agents to advance in-situ burning for oil spill response in the Arctic
[Aggarwal et al., Cold Region. Sci. Technol., 135, 97-104]