Abstract
The widespread use of hazardous organophosphate ester (OPE) flame retardants has led to the contamination of groundwater and drinking water sources. Given the negative impact of OPEs on environmental and human health, there is a critical need to identify effective remediation processes. This study reports that ultrasonic irradiation at 640 kHz leads to effective degradation of tris(2-chloroethyl) phosphate (TCEP), a model organophosphate flame retardant. The concentration of TCEP in an irradiated aqueous solution was monitored by a gas chromatography- nitrogen phosphorus detector (GC-NPD) technique. TCEP has a half-life of less than 1 h under the used experimental conditions. The degradation follows pseudo-first-order kinetics with rate constants varying from 0.09 to depending on initial concentrations ranging from 3.1 to 84 μM. The observed rate constant decreases with the increase in initial TCEP concentration, implying the process likely involves a heterogeneous process controlled by partitioning at the gas–liquid interface during ultrasonic cavitation. The degradation fits the heterogeneous Langmuir-Hinshelwood model, further suggesting the degradation occurs at the gas–liquid interface. Detailed product studies using liquid chromatography orbitrap high-resolution mass spectrometry confirm the primary degradation products are the mono and diester adducts of TCEP, specifically 2-chloroethyl dihydrogen phosphate and bis(2-chloroethyl) hydrogen phosphate. Mineralization of TCEP to chloride and phosphate was monitored by ion chromatography, yielding mass balances of 48% and 32% for chloride and phosphate, respectively, after 6 h of treatment. The results demonstrate that ultrasonic irradiation is effective for the degradation of the halogenated flame retardant TCEP. The results suggest ultrasonic treatment can be used alone or in combination with other methods for the remediation of problematic organophosphorus flame retardants.
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Data Availability Statement
All data, models, and code generated or used during the study appear in the published article.
Acknowledgments
Kevin O’Shea acknowledges partial support received from the National Science Foundation (NSF) under Award No. CHE-1710111. The authors also would like to acknowledge the Southeast Environment Research Center of Institute of Environment in the Florida International University. A M Abdullah is thankful for the dissertation year fellowship from Florida International University.
References
Abdullah, A. M., and K. E. O’Shea. 2019. “ photocatalytic degradation of the flame retardant tris (2-chloroethyl) phosphate (TCEP) in aqueous solution: A detailed kinetic and mechanistic study.” J. Photochem. Photobiol. A 377 (May): 130–137. https://doi.org/10.1016/j.jphotochem.2019.03.026.
Antonopoulou, M., P. Karagianni, and I. K. Konstantinou. 2016. “Kinetic and mechanistic study of photocatalytic degradation of flame retardant tris (1-chloro-2-propyl) phosphate (TCPP).” Appl. Catal., B 192 (Sep): 152–160. https://doi.org/10.1016/j.apcatb.2016.03.039.
Cristale, J., D. D. Ramos, R. F. Dantas, A. Machulek Jr., S. Lacorte, C. Sans, and S. Esplugas. 2016. “Can activated sludge treatments and advanced oxidation processes remove organophosphorus flame retardants?” Environ. Res. 144 (Jan): 11–18. https://doi.org/10.1016/j.envres.2015.10.008.
Crump, D., S. Chiu, and S. W. Kennedy. 2012. “Effects of tris(1,3-dichloro-2-propyl) phosphate and tris(1-chloropropyl) phosphate on cytotoxicity and mRNA expression in primary cultures of avian hepatocytes and neuronal cells.” Toxicol. Sci. 126 (1): 140–148. https://doi.org/10.1093/toxsci/kfs015.
Cui, D., A. M. Mebel, L. E. Arroyo-Mora, C. Zhao, A. De Caprio, and K. O’Shea. 2018. “Fundamental study of the ultrasonic induced degradation of the popular antihistamine, diphenhydramine (DPH).” Water Res. 144 (Nov): 265–273. https://doi.org/10.1016/j.watres.2018.07.032.
Czili, H., and A. Horváth. 2008. “Applicability of coumarin for detecting and measuring hydroxyl radicals generated by photoexcitation of nanoparticles.” Appl. Catal., B 81 (3–4): 295–302. https://doi.org/10.1016/j.apcatb.2008.01.001.
Eren, Z., and K. O’Shea. 2019. “Hydroxyl radical generation and partitioning in degradation of methylene blue and DEET by dual-frequency ultrasonic irradiation.” J. Environ. Eng. 145 (10): 04019070. https://doi.org/10.1061/(ASCE)EE.1943-7870.0001593.
Evgenidou, E., I. Konstantinou, K. Fytianos, and T. Albanis. 2006. “Study of the removal of dichlorvos and dimethoate in a titanium dioxide mediated photocatalytic process through the examination of intermediates and the reaction mechanism.” J. Hazard. Mater. 137 (2): 1056–1064. https://doi.org/10.1016/j.jhazmat.2006.03.042.
Flint, E. B., and K. S. Suslick. 1991. “The temperature of cavitation.” Science 253 (5026): 1397–1399. https://doi.org/10.1126/science.253.5026.1397.
Garcia-Lopez, M., I. Rodriguez, and R. Cela. 2007. “Development of a dispersive liquid-liquid microextraction method for organophosphorus flame retardants and plasticizers determination in water samples.” J. Chromatogr. A 1166 (1–2): 9–15. https://doi.org/10.1016/j.chroma.2007.08.006.
González-García, J., V. Sáez, I. Tudela, M. I. Díez-Garcia, M. D. Esclapez, and O. Louisnard. 2010. “Sonochemical treatment of water polluted by chlorinated organocompounds: A review.” Water 2 (1): 28–74. https://doi.org/10.3390/w2010028.
Grieco, S. A., and B. V. Ramarao. 2013. “Removal of TCEP from aqueous solutions by adsorption with zeolites.” Colloids Surf. A 434 (Oct): 329–338. https://doi.org/10.1016/j.colsurfa.2013.04.042.
Hoffmann, M. R., I. Hua, and R. Höchemer. 1996. “Application of ultrasonic irradiation for the degradation of chemical contaminants in water.” Ultrason. Sonochem. 3 (3): 163–172. https://doi.org/10.1016/S1350-4177(96)00022-3.
Kim, D. K., Y. He, J. Jeon, and K. E. O’Shea. 2016. “Irradiation of ultrasound to 5-methylbenzotriazole in aqueous phase: Degradation kinetics and mechanisms.” Ultrason. Sonochem. 31 (Jul): 227–236. https://doi.org/10.1016/j.ultsonch.2016.01.006.
Kim, S. D., J. Cho, I. S. Kim, B. J. Vanderford, and S. A. Snyder. 2007. “Occurrence and removal of pharmaceuticals and endocrine disruptors in South Korean surface, drinking, and waste waters.” Water Res. 41 (5): 1013–1021. https://doi.org/10.1016/j.watres.2006.06.034.
Kyllönen, H., P. Pirkonen, M. Nyström, J. Nuortila-Jokinen, and A. Grönroos. 2006. “Experimental aspects of ultrasonically enhanced cross-flow membrane filtration of industrial wastewater.” Ultrason. Sonochem. 13 (4): 295–302. https://doi.org/10.1016/j.ultsonch.2005.04.006.
Li, J., J. P. Giesy, L. Yu, G. Li, and C. Liu. 2015. “Effects of tris (1,3-dichloro-2- propyl) phosphate (TDCPP) in Tetrahymena Thermophila: Targeting the ribosome.” Sci. Rep. 5 (1): 1–9. https://doi.org/10.1038/srep10562.
Löning, J. M., C. Horst, and U. Hoffmann. 2002. “Investigations on the energy conversion in sonochemical processes.” Ultrason. Sonochem. 9 (3): 169–179. https://doi.org/10.1016/S1350-4177(01)00113-4.
Mahamuni, N. N., and Y. G. Adewuyi. 2010. “Advanced oxidation processes (AOPs) involving ultrasound for waste water treatment: A review with emphasis on cost estimation.” Ultrason. Sonochem. 17 (6): 990–1003. https://doi.org/10.1016/j.ultsonch.2009.09.005.
Marklund, A., B. Andersson, and P. Haglund. 2005. “Organophosphorus flame retardants and plasticizers in Swedish sewage treatment plants.” Environ. Sci. Technol. 39 (19): 7423–7429. https://doi.org/10.1021/es051013l.
Mason, T. J. 1999. “Sonochemistry: Current uses and future prospects in the chemical and processing industries.” Philos. Trans. R. Soc. London, Ser. A 357 (1751): 355–369. https://doi.org/10.1098/rsta.1999.0331.
Matthews, R. W., and S. R. McEvoy. 1992. “A comparison of 254 nm and 350 nm excitation of in simple photocatalytic reactors.” J. Photochem. Photobiol., A 66 (3): 355–366. https://doi.org/10.1016/1010-6030(92)80008-J.
Meeker, J. D., E. M. Cooper, H. M. Stapleton, and R. Hauser. 2013. “Urinary metabolites of organophosphate flame retardants: Temporal variability and correlations with house dust concentrations.” Environ. Health Perspect. 121 (5): 580–585. https://doi.org/10.1289/ehp.1205907.
Morozov, I., S. Gligorovski, P. Barzaghi, D. Hoffmann, Y. G. Lazarou, E. Vasiliev, and H. Herrmann. 2008. “Hydroxyl radical reactions with halogenated ethanols in aqueous solution: Kinetics and thermochemistry.” Int. J. Chem. Kinet. 40 (4): 174–188. https://doi.org/10.1002/kin.20301.
Morris, P. J., D. Medina-Cleghorn, A. Heslin, S. M. King, J. Orr, M. M. Mulvihill, R. M. Krauss, and D. K. Nomura. 2014. “Organophosphorus flame retardants inhibit specific liver carboxylesterases and cause serum hypertriglyceridemia.” ACS Chem. Biol. 9 (5): 1097–1103. https://doi.org/10.1021/cb500014r.
Oncescu, T., M. I. Stefan, and P. Oancea. 2010. “Photocatalytic degradation of dichlorvos in aqueous suspensions.” Environ. Sci. Pollut. Res. 17 (5): 1158–1166. https://doi.org/10.1007/s11356-009-0292-4.
O’Shea, K. E. 2003. “Titanium dioxide-photocatalyzed reactions of organophosphorus compounds in aqueous media.” Semicond. Photochem. Photophys. 10 (Feb): 231–247.
O’Shea, K. E., A. Aguila, K. Vinodgopal, and P. V. Kamat. 1998. “Reaction pathways and kinetics parameters of sonolytically induced oxidation of dimethyl methylphosphonate in air-saturated aqueous solutions.” Res. Chem. Intermed. 24 (6): 695–705. https://doi.org/10.1163/156856798X00591.
O’Shea, K. E., S. Beightol, I. Garcia, M. Aguilar, D. V. Kalen, and W. J. Cooper. 1997a. “Photocatalytic decomposition of organophosphonates in irradiated suspensions.” J. Photochem. Photobiol., A 107 (1–3): 221–226. https://doi.org/10.1016/S1010-6030(96)04420-6.
O’Shea, K. E., I. Garcia, and M. Aguilar. 1997b. “ photocatalytic degradation of dimethyl- and diethyl-methylphosphonate, effects of catalyst and environmental factors.” Res. Chem. Intermed. 23 (4): 325–339. https://doi.org/10.1163/156856797X00556.
Page, S. E., W. A. Arnold, and K. McNeill. 2010. “Terephthalate as a probe for photochemically generated hydroxyl radical.” J. Environ. Monit. 12 (9): 1658–1665. https://doi.org/10.1039/c0em00160k.
Ruan, X. C., R. Ai, X. Jin, Q. F. Zeng, and Z. Y. Yang. 2014. “Photodegradation of tris (2-chloroethyl) phosphate in aqueous solution by .” Water Air Soil Pollut. 225 (8): 1405–1414. https://doi.org/10.1016/j.chemosphere.2017.07.090.
Salamova, A., Y. Ma, M. Venier, and R. A. Hites. 2014. “High levels of organophosphate flame retardants in the Great Lakes atmosphere.” Environ. Sci. Technol. Lett. 1 (1): 8–14. https://doi.org/10.1021/ez400034n.
Schramm, J. D., and I. Hua. 2001. “Ultrasonic irradiation of dichlorvos: Decomposition mechanism.” Water Res. 35 (3): 665–674. https://doi.org/10.1016/S0043-1354(00)00304-3.
Schreder, E. D., and M. J. La Guardia. 2014. “Flame retardant transfers from US households (dust and laundry wastewater) to the aquatic environment.” Environ. Sci. Technol. 48 (19): 11575–11583. https://doi.org/10.1021/es502227h.
Stackelberg, P. E., J. Gibs, E. T. Furlong, M. T. Meyer, S. D. Zaugg, and R. L. Lippincott. 2007. “Efficiency of conventional drinking-water-treatment processes in removal of pharmaceuticals and other organic compounds.” Sci. Total Environ. 377 (2–3): 255–272. https://doi.org/10.1016/j.scitotenv.2007.01.095.
Sundkvist, A. M., U. Olofsson, and P. Haglund. 2010. “Organophosphorus flame retardants and plasticizers in marine and fresh water biota and in human milk.” J. Environ. Monit. 12 (4): 943–951. https://doi.org/10.1039/B921910B.
Suslick, K. S. 1990. “Sonochemistry.” Science 247 (4949): 1439–1445. https://doi.org/10.1126/science.247.4949.1439.
Suslick, K. S., D. A. Hammerton, and R. E. Cline. 1986. “The sonochemical hot spot.” J. Am. Chem. Soc. 108 (18): 5641–5642. https://doi.org/10.1021/ja00278a055.
van der Veen, I., and J. de Boer. 2012. “Phosphorus flame retardants: Properties, production, environmental occurrence, toxicity and analysis.” Chemosphere 88 (10): 1119–1153. https://doi.org/10.1016/j.chemosphere.2012.03.067.
Wang, W., S. Deng, D. Li, L. Ren, D. Shan, B. Wang, J. Huang, Y. Wang, and G. Yu. 2018. “Sorption behavior and mechanism of organophosphate flame retardants on activated carbons.” Chem. Eng. J. 332 (Sep): 286–292. https://doi.org/10.1016/j.cej.2017.09.085.
Watts, M. J., and K. G. Linden. 2009. “Advanced oxidation kinetics of aqueous trialkyl phosphate flame retardants and plasticizers.” Environ. Sci. Technol. 43 (8): 2937–2942. https://doi.org/10.1021/es8031659.
Wei, G. L., D. Q. Li, M. N. Zhuo, Y. S. Liao, Z. Y. Xie, T. L. Guo, J. J. Li, S. Y. Zhang, and Z. Q. Liang. 2015. “Organophosphorus flame retardants and plasticizers: Sources, occurrence, toxicity and human exposure.” Environ. Pollut. 196 (Jan): 29–46. https://doi.org/10.1016/j.envpol.2014.09.012.
Wei, Z., R. Spinney, R. Ke, Z. Yang, and R. Xiao. 2016. “Effect of pH on the sonochemical degradation of organic pollutants.” Environ. Chem. Lett. 14 (2): 163–182. https://doi.org/10.1007/s10311-016-0557-3.
Yao, J. J., N. Y. Gao, C. Li, L. Li, and B. Xu. 2010. “Mechanism and kinetics of parathion degradation under ultrasonic irradiation.” J. Hazard. Mater. 175 (1–3): 138–145. https://doi.org/10.1016/j.jhazmat.2009.09.140.
Ye, J., J. Liu, C. Li, P. Zhou, S. Wu, and H. Ou. 2017. “Heterogeneous photocatalysis of tris(2-chloroethyl) phosphate by : Degradation products and impacts on bacterial proteome.” Water Res. 124 (Nov): 29–38. https://doi.org/10.1016/j.watres.2017.07.034.
Yuan, X., S. Lacorte, J. Cristale, R. F. Dantas, C. Sans, S. Esplugas, and Z. Qiang. 2015. “Removal of organophosphate esters from municipal secondary effluent by ozone and treatments.” Sep. Purif. Technol. 156 (Dec): 1028–1034. https://doi.org/10.1016/j.seppur.2015.09.052.
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Published In
Journal of Environmental Engineering
Volume 146 • Issue 10 • October 2020
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© 2020 American Society of Civil Engineers.
History
Received: Feb 26, 2020
Accepted: May 21, 2020
Published online: Jul 28, 2020
Published in print: Oct 1, 2020
Discussion open until: Dec 28, 2020
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