DIVISION OF ENVIRONMENTAL CHEMISTRY
236th ACS National Meeting
August 17-21, 2008
Processing of Organic Pollutants in Aquatic Systems: From Micropollutants to Industrial Contaminants
Cosponsored by AEESP
P. J. Vikesland, Organizer
W. A. Arnold, Organizer, Presiding
1:30 — Introductory Remarks.
1:35 —96. Hydroxylated polybrominated diphenyl ether photolysis quantum yields and product identification. P. O. Steen, M. Grandbois, W. A. Arnold, K. McNeill
1:55 —97. Photolytic degradation pathways of emerging agrochemicals. A. Nienow, R.
Espy, E. Pelton, M. Richards, A. Staker
2:15 —98. Absolute rate constant measurement for ?OH reaction with effluent organic matter. S. P. Mezyk, D. F. R. Doud, M. K. Singh, F. L. Rosario-Ortiz, S. A. Snyder
2:35 —99. Sunlight induced degradation of ciprofloxacin and metolachlor in natural and constructed wetlands. Z. He, C. A. Marron, L. K. Weavers, Y. P. Chin
2:55 — Intermission.
3:10 —100. Inadvertent co-oxidation of selected dissolved organics during the oxidation of aqueous Fe(II). J. M. Burns, P. S. Craig, T. J. Shaw, J. L. Ferry
3:30 —101. Sonochemical degradation of pharmaceuticals exemplified by ibuprofen and ciprofloxacin. Z. He, G. Y. Pee, L. K. Weavers
3:50 —102. Predicting NOM Photosensitized reaction rates using spectroscopic correlations. A. Carfagno, C. M. Sharpless
4:10 —103. Mechanistic investigation of sulfur–doped TiO–mediated photocatalytic 2
degradation of organic molecules as models for pollutants. E. M. Rockafellow, L. K.
Stewart, W. S. Jenks
4:30 —104. Removing common antibiotics from contaminanted waters using radical reactions. M. K. Dail, S. P. Mezyk
Hydroxylated polybrominated diphenyl ether photolysis quantum yields and product identification
12Peter O. Steen, email@example.com, Matthew Grandbois, firstname.lastname@example.org, 32William A. Arnold, email@example.com, and Kristopher McNeill. (1) Water
Resources Science Program, University of Minnesota, 1985 Buford Ave, Saint Paul, MN 55108, (2) Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, (3) Department of Civil Engineering, University of Minnesota, Minneapolis, MN 55455
Hydroxylated analogues of the ubiquitous polybrominated diphenyl ethers (PBDEs) have recently been found in surface waters, snow, rain, and wastewater/sewage treatment plant effluent. In addition to being natural products and known metabolites of PBDEs, OH-PBDEs are potentially produced during the wastewater treatment process. This study investigated the photolysis of 6-OH-BDE47 and three chlorinated derivatives, 3-Cl-6-OH-BDE47, 5-Cl-6-OH-BDE47 and 3,5-Cl-6-OH-BDE47, which are hypothesized to be produced upon disinfection with chlorine. Quantum yields were determined for both the protonated and deprotonated species, and photoproducts were identified.
Photolytic degradation pathways of emerging agrochemicals
Amanda Nienow, Ryan Espy, Emily Pelton, Mallory Richards, and Amanda Staker, Department of Chemistry, Gustavus Adolphus College, 800 W College Ave, Saint Peter, MN 56082
Sulfonylurea, imidazolinone, and organophosphate pesticides are being used on a variety of crops in the Midwest. Although many of them (e.g., flumetsulam) are relatively
new in terms of application, they have already been detected in Midwestern surface water samples by the USGS. Relatively little is known about the photodegradation, hydrolysis, occurrence, long-term fate, water transport in surface or ground water environments, and toxicology of many of these compounds. The work presented here is a first step at understanding these factors for the compounds flumetsulam, nicosulfuron, and imazethapyr, and focuses on the photolytic and hydrolytic degradation pathways of the compounds in deionized water, as well as in Mississippi and Minnesota River water.
Absolute rate constant measurement for ?OH reaction with effluent organic matter
11, firstname.lastname@example.org, Devin F. R. Doud, email@example.com, Stephen P. Mezyk12Manu K. Singh, firstname.lastname@example.org, Fernando L. Rosario-Ortiz, email@example.com, and Shane A. Snyder, firstname.lastname@example.org. (1)
Department of Chemistry and Biochemistry, California State University at Long Beach, 1250 Bellflower Blvd, Long Beach, CA 90840, Fax: 562-985-8557, (2) Southern Nevada Water Authority, Henderson, NV 89015, (3) Water Quality Research and Development, Southern Nevada Water Authority, Las Vegas, NV 89193-9954
Advanced oxidation processes (AOPs) are water treatment technologies based on the •in situ production of hydroxyl radicals (OH) for non-selective removal of chemical •contaminants. To optimize these AOPs, and therefore reduce cost, the total OH
scavenging potential of the water is required. The most important component of the scavenging potential is organic carbon, referred to as effluent organic matter (EfOM). •We have measured EfOM-OH reaction rate constants from eight different waters
collected and characterized from seven wastewater and reuse treatment plants across 9-1-1the United States. Values ranged from 0.27–1.15 x 10 M s, some 3-5 times faster
than previously reported values using isolates. These widely separated rate constants indicate that no single value can be assumed when optimizing AOPs. A model that correlated the measured rate constants with bulk properties, including the EfOM polarity, organic nitrogen content, and fluorescence index, was constructed. The effects of EfOM ozone exposure are also reported.
Sunlight induced degradation of ciprofloxacin and metolachlor in natural and constructed wetlands
121Ziqi He, email@example.com, Corin A. Marron, firstname.lastname@example.org, Linda K. Weavers, email@example.com, and Yu Ping Chin. (1) Department of Civil and Environmental
Engineering and Geodetic Science, The Ohio State University, 470 Hitchcock Hall, 2070 Neil Avenue, Columbus, OH 43210, (2) Department of Food, Agricultural, and Biological Engineering, The Ohio State University, Columbus, OH 43210, (3) School of Earth Sciences, The Ohio State University, Columbus, OH 43210
Sunlight-induced photodegradation of ciprofloxacin and metolachlor was studied in one natural and three constructed wetland waters (Old Woman Creek, Olentangy River Research Park, Waterman Farm Wetland, and Defiance County Wetland) to examine the effects of natural photosensitizers (DOM, nitrate and iron) on the photofate of organic micropollutants. Ciprofloxacin degraded rapidly through direct photolysis with -1pH dependence (0.9353 and 33.71 hr at pH 4 and pH 8, respectively), whereas
metolachlor underwent relatively slow degradation. Compared to direct photolysis, wetland waters decreased ciprofloxacin degradation due to light screening, while metolachlor degradation was enhanced 2-15 times in wetland waters. The addition of a -, significantly decreased metolachlor degradation, strong iron complexing ligand, F
indicating iron played an important role in photosensitized degradation. The addition of additional iron into wetland waters increased metolachlor degradation. But the effect and the amount of Fe added were dependent on wetland raw water properties.
Inadvertent co-oxidation of selected dissolved organics during the oxidation of aqueous Fe(II)
Justina M. Burns, Preston S. Craig, Timothy J. Shaw, and John L. Ferry, Department
of Chemistry and Biochemistry, University of South Carolina, 631 Sumter St, Columbia, SC 29208, Fax: 803-777-9521
Anoxic groundwaters are known to be significant sources of reduced Fe species and organic contaminants to estuaries and to the coastal ocean. The subsequent oxidation of Fe(II) in oxic sediments and the water column leads to the production of a variety of reactive oxidants, including hydrogen peroxide, superoxide, hydroxyl radical, etc. These species could potentially serve to attenuate the signature of co-dissolved organic pollutants. A multivariate, microscale, high throughput experimental approach is described for evaluating the extent of attenuation initiated by the oxidation of Fe(II) in the presence of varying concentrations of fluoride, sulfate, dissolved organic matter, chloride and carbonate. Oxidation rates were then compared to determine the accessibility of the molecule to different transients (i.e., hydrogen peroxide, hydroxyl
radical, superoxide, etc.). A QSAR was built based on the oxidation rate and the K of ow
the organics investigated. The implications for the selective removal of different types of organics are discussed.
Sonochemical degradation of pharmaceuticals exemplified by ibuprofen and ciprofloxacin
Ziqi He, Gim Y. Pee, and Linda K. Weavers, Department of Civil and Environmental
Engineering and Geodetic Science, The Ohio State University, 470 Hitchcock Hall, 2070 Neil Avenue, Columbus, OH 43210, Fax: 614-292-3780
As one important class of emerging organic contaminants, pharmaceuticals and personal care products (PPCPs) have been detected at trace levels in aquatic systems and water supplies. The application of sonochemistry for the degradation of selected PPCPs (ibuprofen, an anti-inflammatory, and ciprofloxacin, an antibiotic) was
investigated in this study. Results showed rapid degradation of ibuprofen and ciprofloxacin at micromolar levels by sonolysis. For example, at an initial concentration -1, 80-90% degradation was
achieved within 5 and 10 min at 620 and 20 kHz, respectively. The first order rates for each compound under different conditions showed that the degradation was dependent on pH, ultrasonic frequency and compound concentration. Bulk solution hydroxyl radical scavenging experiments and pH dependent degradation indicated that sonolytic degradation occurred in both the bulk solution and the interfacial areas of cavitation bubbles.
Predicting NOM Photosensitized reaction rates using spectroscopic correlations
Amy Carfagno and Charles M. Sharpless, Department of Chemistry, University of Mary Washington, 1301 College Ave, Jepson Science Center, Fredericksburg, VA 22401
Reactions photosensitized by aquatic natural organic matter (NOM) are an important fate pathway for organic pollutants. We are examining ways to accurately predict the rates at which photooxidants are produced in natural waters with attention to singlet 11oxygen (O) and HO. Quantum yields for O in aerated, buffered solutions range 2222
from 0.50 to 5.0% for several NOM samples at different pH. We find that these yields linearly correlate with the E2/E3 ratio (A/A). This correlation provides a way to 2543651quantitatively predict O production rates. For HO, quantum yields range from 222-4approximately 0.6 to 3 x 10. The yields increase with pH, roughly doubling over the pH range 5-9. This trend with pH gives rise to an inverse correlation between the HO 22
quantum yield and E2/E3. These results can be interpreted in terms of a charge-transfer model for NOM absorption.
Mechanistic investigation of sulfur–doped TiO–mediated photocatalytic 2
degradation of organic molecules as models for pollutants
Erin M. Rockafellow, Laine K. Stewart, and William S. Jenks, Department of Chemistry, Iowa State University, 3801 Gilman Hall, Ames, IA 50011, Fax: 515-294-0105
Titanium dioxide is a useful photocatalyst for the complete mineralization of organic pollutants in water. Unfortunately, TiO is able to use less than 5% of the terrestrial solar 2
irradiation as an excitation source due to its wide band gap. Doping titania with main group elements increases the visible light absorbance by introducing a localized band of orbitals within the band gap. The effects of this mid–gap state on the oxidizing power of
the photocatalyst are not understood. Although a wavelength dependence has been
reported by other groups, the actual organic mechanism(s) of degradation mediated by main group doped titania remains ambiguous.
Our group and others have previously employed various organic molecules to mechanistically probe the two major photooxidative degradation pathways: hydroxyl radical addition and single electron transfer. In the current study, well–known probe
is an effective molecules are used to help determine whether sulfur–doped TiO2
photocatalyst for remediation.
Removing common antibiotics from contaminanted waters using radical
Michelle K. Dail and Stephen P. Mezyk, Department of Chemistry and Biochemistry, California State University at Long Beach, 1250 Bellflower Blvd, Long Beach, CA 90840, Fax: 562-985-8557
Of the many groups of pharmaceutical drugs that have recently been found in aquatic environments, β-lactam antibiotics are some of the most prevalent. Their presence, even at trace levels, may adversely affect aquatic ecosystems and contribute to the production of strains of bacteria that are resistant to antibiotics. Therefore, active removal of antibiotics may be necessary under some water use, or reuse, applications. Radical-based advanced oxidation processes (AOPs) continue to gain interest as the technology of choice for removing trace levels of contaminant chemicals in different quality waters. However, to ensure that AOP treatment occurs efficiently and quantitatively, a full understanding of the kinetics and mechanisms of all the chemical reactions involved under the conditions of use is necessary. In this study, we report on our kinetic measurements involving the oxidation and reduction of three representative β-lactam drugs in aqueous solution at ambient temperature: Carbenicillin, Cephalothin, and Cefatoxime.