Available REU Projects
As human activity from tourism or urban expansion increases, so does the potential for contamination of groundwater. Groundwater in the Yucatán is more susceptible to pollution because of the karst geology, which allows for pollution dumped on the surface to rapidly transport into the groundwater with little attenuation.
This research project will examine groundwater for organic pollution that is associated with tourism and urban expansion. The outcome of this research will be the ability to pinpoint the source of the pollution so that it can be prevented in the future. Pharmaceutical and personal care products (PPCP) such as caffeine, antibiotics, female hormones, DEET, and sunscreen all enter the groundwater either through swimming in the water or by wastewater disposal. These compounds have been shown to have a detrimental impact on human or ecosystem health. Pesticides, especially 2,4-D, are used near the edges of cenotes or in urban areas to control weeds. 2,4-D is a known carcinogen and recalcitrant in the environment. Gasoline (benzene, toluene, ethylene benzene, and xylenes) is ubiquitous in urban areas and enters waterways through leaking storage tanks, cars, and other engines.
The student involved in this project will learn how to detect these compounds in water through use of gas chromatography (GC) and liquid chromatography (LC). Water samples will be collected throughout all the field sites to determine the source of pollution in the water.
The main geology of the peninsula is karst. The karst is evident on the surface with collapse features and cenotes throughout the whole area. The lack of soil and the surface conduits allow contaminant releases at the surface to spread into the freshwater. Drinking water comes from an unconfined aquifer located 10-50 m below the surface with a saline water interface below that. This unconfined and coastal aquifer gradient is influenced by increased pumping for freshwater supplies and by diurnal tidal action.
As tourism increases so does the need for fresh water. The well field for southern Cancún and Puerto Morelos is just west of the Cancún International Airport along the Ruta de los Cenotes. This well field contains over 75 wells, each pumping fresh water out of the aquifer. Without the pumping, the aquifer flows into the ocean. The research questions are: Does the pumping at the well field reverse the hydraulic gradient so water flows into the well field? How large is the cone of depression? What is the zone of influence of the well field? Is the coast aquifer elevation influenced by the diurnal tidal action? Do major rain events change the direction of flow?
This project will use the elevation of groundwater around the well field to model the groundwater flow. Elevation will be determined by surveying the water levels in cenotes throughout the region. Pressure transducers will be used to monitor water levels over the month. The data will be used to generate groundwater flow models using GFlow or Modflow. The outcomes from this research will allow for better planning and management of the limited freshwater resources in the Yucatán Peninsula.
The Yucatan Peninsula has some unique geological features called sinkholes (locally called cenotes), which are natural windows where groundwater communicates with the surface of the earth. This connection between the surface and the groundwater allows for activities on the surface (e.g. wastewater treatment and discharge, surface runoff) to directly impact the aquifer below. Through the examination of the chemistry of the groundwater, we hope to be able to determine if nutrient pollution is occurring and what the cause is and to provide insight into how the different parts of the aquifer system are connected.
This project has two parts. One part aims to examine the concentrations of nutrients and other chemical parameters in these systems: nitrogen (NO2-, NO3-, NH4+), phosphorous (PO4-3), dissolved oxygen (O2, aq). The second part will focus on the major ion chemistry of the groundwater to determine how the areas sampled connect to the other large scales aquifer systems in the area. Both parts will involve field and laboratory work.
This project will consist of one faculty mentor and two student researchers, working closely together in the field and in the laboratory to accomplish the goals of characterizing the chemistry of the groundwater system. You will learn to create a sampling plan, collect and preserve water samples from cenotes and analyze the water samples at the lab in Mexico, and bring other samples back to Illinois to complete their analyses. With the results obtained, we will try to recreate the story of the most probable chemical processes in the cenotes, how the nutrients are introduced and behave in the aquifer, and what our results mean for these aquifers in the Yucatán.
While candidates are suggested to have general chemistry and biology knowledge, and interest in hydrogeology and water chemistry, all interested students are welcome.
Tourism is the primary industry in the Riviera Maya of Mexico, and although it is economically important to the region it has also degraded the natural environment, including negatively affecting water quality. Beaches are the most visited attraction by tourists to the region, but in the couple years an unusually large amount of sargassum seaweed has washed up on the region’s beaches, impacting touristic activities. In 2019, we found that as a result of the seaweed, tourists were shifting towards other touristic activities, primarily visiting cenotes (sinkholes) as alternate sites for swimming and recreation.
Previous studies of cenotes in this region have found clear evidence of human-related contamination, including human pathogenic bacteria, and antibiotics. The karst geology of the region makes cenotes particularly sensitive to contamination concerns. It is likely that cenotes may continue to see increased tourism due to the seaweed problem, so it is worth understanding the impact of increased tourism in this region.
The purpose of this project is two-fold:
- To determine the relationship between the number of visitors to different cenotes and potential contamination of water in the cenotes
- To understand how cenote operators, government officials and conservationists in the region are approaching the management of these cenotes in light of increased tourism.
This will be a mixed-methods study that will combine qualitative data (e.g. participant observation at cenotes, interviews with cenote operators and government officials, etc.) with water chemistry data on potential contamination as related to levels of tourist activity. Results from this research will aid in making policy recommendations related to the capacity of cenotes to handle increased tourist activity.
This project will consist of one faculty mentor and two student researchers. While candidates are suggested to have a general knowledge of biology, chemistry or environmental conservation, all interested students are welcome. Advanced or native fluency in Spanish will be particularly helpful for the qualitative portion of the project.
Microplastics are a type of water pollution that continues to receive increased attention from the public and the scientific community. Measurements of microplastics in bodies of water are indicative of anthropogenic pollution that is occurring on a large scale in some regions. This project will focus on:
- Testing of laboratory methods for the measurement of microplastics
- Applying those methods to different bodies of water in our study area in the Yucatán.
As this is an exploratory project, we will be looking at a wide variety of potential areas (e.g. ocean, cenotes, well-water) to generate a baseline for microplastic pollution and to validate the method that can be used to examine this emerging contaminant in our study area.