Water quality assessments using hydroxyl radical probes in gamma irradia7ons

Transcription

1 Water quality assessments using hydroxyl radical probes in gamma irradia7ons in Water Quality Monitoring Through Cross Disciplinary Approaches Illinois Water Conference 2012 Dr. Julie R Peller Department of Chemistry Indiana University orthwest Dr. Stephen P Mezyk Department of Chemistry California State University, Long Beach

2 Wastewater treatment problems and challenges 1. PPCPs and others require advanced treatment 2. Infrastructure 3. Combined Sewer Overflows 4. 2 o treated wastewater quality - variable CSOs: Combined Sewer Overflows

3 Present Day Wastewater Treatment Approximately 70% of WWTF in United States treat through the secondary treatment. Many dissolved substances remain: Dissolved anions: nitrate, nitrite, sulfate, bicarbonate, etc. Dissolved metal ions: iron, magnesium, sodium, nickel, potassium, etc. Dissolved organic nitrogen compounds (ie,: DMA), ammonium compounds Dissolved organic compounds (emerging contaminants; chemicals of concern)

4 For water treatment challenges and reclama8on/reuse, implement ADVACED WasteWater TREATMETS Can we PREDICT or determine advanced treatment EFFECTIVEESS of secondary treated WW? Some Major Factors to consider in advanced treatment: 1) Water quality of the secondary treated wastewater. 2) Type of advanced treatment 3) Problema7c contaminants

5 How can we assess the quality of 2 o treated wastewater? WEST COAST 2 different locations MIDWEST GREAT LAKES

6 OH produc8on using Radiolysis Radiolysis: Use of ionizing radia:on (ie.: gamma rays) to induce chemical changes. H 2 O ^^^ OH, H, e - (aq), H +, H 2 O 2, H 2 Oxidizing or reducing condi7ons can be established. Condi7ons for oxida7on: e - aq + 2 O(g) + H 2 O 2 + OH + OH - H + 2 O 2 + OH

7 Removal Constant and Efficiency of OH The Removal Constant represents the change in concentra7on of the chemical contaminant (CC) due to reac7on with the radia7on- generated radical species, OH, with radia7on dose, kgy. The Removal Constant is the ini7al slope of the curve of Δ[CC] vs Dose (kgy). Focus is on the early stages of the radical transforma7ons, MAJOR rxn: OH + CC. Can compute the % efficiency since the OH radical yield is known, 0.59 µm/gy.

8 O Varia8ons in hydroxyl radical reac8on efficiencies in pure water SOME compounds are 100% efficient in their reac7ons with the hydroxyl radical, while others are not. O 1,3,7-trimethylxanthine (caffeine) Caffeine: stimulant; Human marker ~ 100% Efficient 100 DEET: Personal care product HO ~75% Efficient CH 3 CH 3 ~50% Efficient Sulfa Drugs, Sulfamethoxazole: Pharmaceuticals OH BPA: Endocrine disruptor; Industrial Chemical for production of polymers (BPA-polycarbonate )

9 Removal Constants afford a way to determine the efficiencies of hydroxyl radical reac7ons in Advanced Oxida7on Technologies [COTAMIAT] + OH Individual dissolved organic components show wide varia7ons in OH efficiencies Mixtures of dissolved organics show dependency on concentra7on and rate constant; more work needs to be done to bejer understand the complexity of contaminant mixtures COTAMIAT + OH + other dissolved substances Can Removal Constants be used to determine the general quality of treated wastewaters?

10 Model Compounds as Water Quality Probes for secondary treated wastewater CAFFEIE (100%) AD SULFAMETHOXAZOLE (50%) ASSUMPTIO: the lower the experimentally determined % efficiency, the lower the water quality (more dissolved substances as hydroxyl radical compe7tors) Treated wastewater supplied from: Orange County, CA (pop = 2.4 million; 350 square miles) & Portage, I (pop = 50,000; 35 square miles) Probe Solu7on concentra7ons : 10µM

11 Caffeine - An OH Probe I PURE WATER: O OH + O 100% efficient 1,3,7-trimethylxanthine (caffeine) I 2 o treated WASTEWATER OH + O O 1,3,7-trimethylxanthine (caffeine) + Dissolved ions Dissolved organics Dissolved metals Value will 1) offer a measure of water quality 2) indicate the effectiveness of OH in remediation

12 Sulfamethoxazole - An OH Probe I PURE WATER: OH + 50% efficient I 2 o treated WASTEWATER OH + + Dissolved ions Dissolved organics Dissolved metals Value will 1) offer a measure of water quality 2) indicate the effectiveness of OH in remediation

13 Rate Constants and Efficiencies for organic contaminants with OH in DI water and in secondary treated wastewater Solution / Contaminant Caffeine Sulfamethoxazole Rate Constant DI Water, M -1 s -1 OH EFFICIECY in Deionized Water Adjusted Rate Constant DI Water, M -1 s -1 EFFICIECY in Q1, 50µM, (2 o treated wastewater) 6.9 (± 0.4) x (± 0.8) x ± 8 % 56 ± 7 % 6.3 (± 0.4) x (± 0.8) x ± 4 % 29 ± 7 % Peller, Julie R., Mezyk, Stephen P., Cooper, William J., Ishida, Kenneth, P. Evaluation of parameters influencing removal efficiencies for organic contaminant degradation in advanced oxidation processes, AQUA Journal of Water Supply: Research and Technology, 2011, 60, Average of ~50-60% drop in removal efficiency in 2 o treated wastewater

14 Selected secondary treated wastewater data from Orange Co, CA Organic ph TOC Turbidity Total Alkalinity (as CaCO 3 ) 0.7 mg/l mg/l 1.4 TU 171 mg/l Sulfate Chloride Calcium magnesium Sodium 223 mg/l 215 mg/l 80.7 mg/l 28.1 mg/l 190 mg/l

15 Caffeine in secondary treated wastewater Rate constant: 6.9 (± 0.4) x 10 9 M -1 s -1 Removal efficiency: 92 ± 8 % month IDIAA CA Removal constant Efficiency Removal constant OV % % DEC % JA % APRIL % MAY % % JULY % % AVERAGE % % Efficiency

16 Sulfamethoxazole in secondary treated wastewater Rate constant: 8.3 (± 0.8) x 10 9 Removal efficiency: 56 ± 7 % month IDIAA CA Removal constant Efficiency Removal constant OV % % DEC % JA % % APRIL % MAY % % JULY % % AVERAGE % % Efficiency

17 Probe compound comparison: OH reac8on efficiencies in Indiana 2 o treated wastewater Caffeine = 100% efficiency in pure water. Rate constant: 6.9 (± 0.4) x 10 9 M -1 s -1 Sulfamethoxazole = 56% efficiency in pure water. Rate constant: 8.3 (± 0.8) x 10 9 month IDIAA CAFFEIE Removal constant OH efficiency OV % DEC 11 JA % APRIL MAY % JULY % IDIAA SX Removal constant OH efficiency % % % % AVERAGE % %

18 Conclusions Ø Hydroxyl Radical Probes can be used for the general assessment of treated wastewater quality. Ø The OH efficiencies, calculated from the removal constants, also indicate the effec7veness of advanced oxida7on processes for secondary treated wastewater. Ø Different radical probes can be used. Ø From our experiments, the secondary treated wastewater in Portage Indiana contains less dissolved substances (cleaner!) than the Orange County, CA secondary wastewater. Ø Ø Ø Ø H is nonselec7ve and remediates the vast majority of known contaminants. Advanced oxida7on can be an effec7ve component of water treatment to ensure high water quality. For effec7ve, economical implementa7on of advanced oxida7on methods, the efficiency of the oxidant must be known. Probe compounds can be used to determine the number of oxidant species needed to remediate contaminants.

19 Acknowledgements: University of otre Dame RadiaFon Laboratory Dr. Ken Ishida, Orange County Water District Fountain Valley, CA Portage, I ReclamaFon Facility IU Student: Emily Watson CSULB Student: GarreQ McKay

20 Thank you!