Hospital and Energy-Related Wastewater Impacts on Drinking Water Disinfection By-Products

Oral Presentation

Prepared by H. Liberatore1, M. Plewa2, D. Westerman1, C. Granger1, A. Cuthbertson1, J. Allen1, S. Richardson1
1 - University of South Carolina, 631 Sumter St, Columbia, SC, 29208, United States
2 - University of Illinois, , , United States


Contact Information: hkl@email.sc.edu; 336-253-9947


ABSTRACT

Many drinking water treatment facilities are located downstream of wastewater treatment plants, meaning that what is not effectively removed from waste makes its way into the drinking water. In this research, we focus on wastewater components that themselves are not highly toxic, but are transformed during drinking water disinfection to form bromine-/iodine-/nitrogen-containing disinfection by-products (DBPs), which are much more toxic than their chlorine-containing carbonaceous analogs. In particular, we focus on: (a) high-bromide and -iodide wastes from energy extraction (hydraulic fracturing [HF]) and utilization (coal-fired power plants [CFPPs]) and (b) medical wastes with high levels of iodinated medical imaging compounds (e.g. iopamidol).
In addition to quantifying ~50 priority DBPs by GC-MS(/MS), comprehensive broadscreen analyses were conducted for the determination of unknown DBPs by high resolution MS via GC-TOF-MS, LC-QTOF-MS, and 21T FT-ICR-MS.
Iopamidolís impact on DBP formation during chlorination was studied at both wastewater-like and surface water-like concentrations. The presence of iopamidol at both concentrations led to significantly higher formation of iodo- and nitrogenous DBPs. GC-high resolution-TOF-MS analyses of un-quenched, high concentration iopamidol reactors led to a tentative identification of N,2,2-trichloroacetamide, which has provided insight into potential formation mechanisms of nitrogenous DBPs from iopamidol.
Controlled laboratory chlor(am)ination reactions were performed for HF wastewater to assess the impact of halides and organics on DBP formation and mammalian cell toxicity. Similar reactions were conducted for river water with and without CFPP wastewater. Three classes of iodo-phenolic-DBPs were identified by GC-high resolution-TOF in chloraminated HF wastewater, many of which proved to be of similar toxicity to commonly-reported, toxic iodo-DBPs. In addition, a series of Br-/Cl-/I-sulfur-containing DBPs were discovered by LC-QTOF-MS, with further structural elucidation by MS3 21T FT-ICR analyses. In both cases, chlorination of waste-impacted water led to elevated Br-DBP levels over unimpacted water, while chloramination enhanced I-DBP levels. Toxicity data revealed that chlor(am)inated HF wastewaters were extremely more toxic than undisinfected, with chloraminated being the most toxic.