Date of Award
Doctor of Philosophy
Environmental Science and Engineering
Wen Y. Lee
Polybrominated diphenyl ethers (PBDEs) are a group of brominated compounds widely used as flame retardants. PBDEs are structurally similar to polychlorinated biphenyls (PCBs), and appear to act similarly in the environment. Due to their persistence and lipophilicity, PBDEs are found to be bioaccumulated and biomagnified in the food chain. Current research in PBDEs is focused on their occurrences, concentration, fate and transport in the environment, and the impact in the ecosystem and human health. Since PBDEs are not regulated in the USA, large amounts of these harmful chemicals are being dumped indiscriminately into the drainage system. As a result, these PBDEs still persist after wastewater treatment process. In addition, these PBDEs are then released into the aquifers.
In this research, an innovated and environmentally friendly sample preparation technique called Stir Bar Sorptive Extraction (SBSE) was used. This technique is coupled with thermal desorption, Gas Chromatography and Mass Spectrometry for detection of organic compounds in several matrices. The methodology has the advantage of detecting PBDEs at low concentrations, i.e. ng/L (parts per trillion) range. The principal target compounds for this study are BDE #47, BDE #99, BDE #100, which are commonly found in wastewater, and are the most concerned in terms of their toxicity to both the environment and health.
This research studied the contamination of PBDEs in our region. Specifically, the objectives of this study include:
1. Identify the most common PBDEs in wastewater and water bodies at the border region (El Paso, TX, US and Cd. Juarez, Mexico).
2. Evaluate profile, removal per plant and influence of seasonal temperature on PBDEs levels in wastewater and sewage sludge.
3. Establish the first baseline assessment for PBDEs presence in water, wastewater and sewage sludge, in the border region.
4. Identify the sources of pollution.
A total of 163 samples were collected and analyzed. Collection sites included six Waste Water treatment Plants (WWTPs), water and sediments from a wetland, and tap water. Wastewater and sewage sludge samples were studied by season. Statistical analysis were performed using StatisticaTM version 9.0
The principal findings for this research are the following:
1) The most dominant PBDEs in wastewater treatment plants are BDE-47, BDE-99, and BDE-100
2) PBDEs concentrations in waste water and sludge were not significantly affected by seasonal changes.
3) Treatment processes at the WWTPs in the US (El Paso, TX) are more efficient than the implemented procedures at Mexico (Cd. Juarez, Chih.) WWTP in the border region studied.
4) Possible sources of PBDEs in El Paso, TX include effluents from hospitals, paperboard packaging producers, electric and electronic appliances manufacturers, and laundries discharging in the different WWTPs.
Results from this study will provide valuable information on water resources to El Paso Water Utilities, research community, environmental agencies and policy makers.
Received from ProQuest
Beatriz Adriana Rocha-Gutierrez
Rocha-Gutierrez, Beatriz Adriana, "Study Of PBDES In Wastewater, Water And Sludge Of El Paso Del Norte Border Region Using SBSE TD/GC-MS" (2010). Open Access Theses & Dissertations. 2574.