Dr. Xu and her students, The Environmental Interfacial Chemistry (EIC) Group, are interested in improving the fundamental understanding of the environmental interfacial chemical processes, with the goal of applying them to both natural and engineered systems to address today’s environmental challenges. The group is investigating the surface reactivity of pyrogenic carbon and other novel materials with the ultimate goal of transforming the fundamental knowledge into solutions for safe drinking water provision, sustainable environmental remediation, and nutrient recovery. The main areas of research are summarized below:
Harness the synergy between naturally existing pyrogenic carbon matter and other environmental reagents for sustainable in situ remediation for contaminated soils and sediments
The immense use of chemicals in agriculture, industry, and by the military over the past century has resulted in significant harmful impact to the environment, especially in estuarine and coastal waters where the population is most dense. Sorption to black carbons is an important sink for these contaminants in soil and sediment. Previous studies by the PI and others have demonstrated that there is a synergy between black carbon and sulfide in facilitating contaminants degradation. However, the involvement of other environmental reagents and the biotic processes require further investigation.
Develop Effective yet Low-Cost Strategies to Mitigate the Formation of DBPs during Water Treatment
As a result of our rapid population growth and limited pristine water supply, providing safe drinking water is becoming a grand challenge for this century. Recent studies suggest that a suite of toxic chemicals can be produced during the disinfection process. These chemicals, collectively referred to as disinfection byproducts (DBPs), pose human health concerns due to their potential link with increased rates for bladder cancer, reproductive and developmental effects. Over 600 emerging DBPs have been discovered over the past twenty years.
Reinvent Wastewater Treatment using Biochar as Attachment Surface for One-step Nutrient Removal
The conventional nutrient removal technologies in wastewater treatment use enormous quantities of energy to aerate wastewater, oxidizing ammonia (NH4+) to nitrate (NO3-) and then reduce it back to nitrogen gas (N2). As an alternative, the recent discovered anammox process could avoid costly aeration by oxidizing ammonia to nitrogen in one step. However, the long doubling time of anammox (i.e., 7-11 days) hinders its application in wastewater treatment. Recent research suggests that biochar, a charcoal- like, organic carbon-rich solid residue from biomass pyrolysis under oxygen-limited conditions, has electron donating and accepting capacity. Moreover, biochar shows the ability to enhance microbial activities and promote the abiotic transformation of certain contaminants. Here, we are investigating the redox properties of biochar in promoting the activity of anammox and reduce its doubling time for wastewater treatment applications. The project is currently pursued through a collaborative effort with Drs. Metin Duran (CEE), Amanda Grannas (Chemistry), and James Wilson (Biology).