Free Standard AU & NZ Shipping For All Book Orders Over $80!
Register      Login
Environmental Chemistry Environmental Chemistry Society
Environmental problems - Chemical approaches
RESEARCH ARTICLE

Degradation of oxytetracycline in the aquatic environment: a proposed steady state kinetic model that takes into account hydrolysis, photolysis, microbial degradation and adsorption by colloidal and sediment particles

Mark F. Zaranyika A B , Pamhidzai Dzomba A and Jameson Kugara A
+ Author Affiliations
- Author Affiliations

A Chemistry Department, University of Zimbabwe, PO Box MP167, Mount Pleasant, Harare, Zimbabwe.

B Corresponding author. Email: zaranyika@science.uz.ac.zw

Environmental Chemistry 12(2) 174-188 https://doi.org/10.1071/EN14116
Submitted: 30 April 2014  Accepted: 1 September 2014   Published: 27 January 2015

Environmental context. Pollution of the aquatic environment by oxytetracycline can lead to microbial resistance thereby compromising the efficacy of current medication regimes. Adsorption by colloidal and sediment particles reduces the rate at which oxytetracycline degrades, whereas the longer the antimicrobial remains in the aquatic environment, the greater the danger of microbial resistance. There is need therefore for a fuller understanding of the kinetics of degradation of oxytetracycline in aquatic ecosystems before measures for mitigating pollution by the antimicrobial can be designed.

Abstract. The persistence of oxytetracycline in an aquatic microcosm and distilled water control experiments, was studied over a period of 90 days. An immediate 35 % loss as a result of adsorption by the sediment was observed in the microcosm experiment soon after charging. Subsequently triphasic linear rates of oxytetracycline degradation were observed for both the water phase (3.1 × 10–2, 5.8 × 10–3 and 1 × 10–3 µg g–1 day–1) and sediment phase (4.8 × 10–2, 6.5 × 10–3 and 2 × 10–4 µg g–1 day–1). Degradation is attributed to photolysis and microbial degradation of the free oxytetracycline in solution, and microbial degradation of the colloidal and sediment particle adsorbed speciation forms. The distilled water control exhibited biphasic zero order kinetics attributed to hydrolysis (2 × 10–6 µg g–1 day–1) and microbial degradation (2.7 × 10–3 µg g–1 day–1) under dark conditions, and monophasic zero order kinetics attributed to photolysis (6.9 × 10–3 µg g–1 day–1) under sunlight exposure. A kinetic model that takes into account hydrolysis, photolysis, microbial degradation and adsorption of the antibiotic by colloidal and sediment particles, is presented to account for the monophasic, biphasic and triphasic zero order kinetics observed in the control and microcosm experiments. Possible remediation strategies for mitigating aquatic environments polluted by the antimicrobial are discussed.

Additional keywords: antibiotic, colloidal particles, persistence, photochemical degradation, zero order kinetics.


References

[1]  J. F. Yang, G. G. Ying, J. L. Zhao, R. Tao, H. C. Su, Y. S. Liu, Spatial and seasonal trends of selected antibiotics in Pearl Rivers, South China. J. Environ. Sci. Health B 2011, 46, 272.
Spatial and seasonal trends of selected antibiotics in Pearl Rivers, South China.Crossref | GoogleScholarGoogle Scholar | 21462055PubMed |

[2]  K. R. Izbicki, E. A. Quinn, Investigation of Antibiotic Levels and Antibiotic Resistance in Water and Bacterial Samples from the Pennsylvania Lake Erie Watershed, Proceedings of The National Conference On Undergraduate Research (NCUR), 2011, pp. 914–1920 (Ithaca College: New York).

[3]  Y. Luo, L. Xu, M. Rysz, Y. Q. Wang, H. Zhang, P. J. J. Alvarez, Occurrence and transport of tetracycline, sulfonamide, quinolone, and macrolide antibiotics in the Haihe River Basin, China. Environ. Sci. Technol. 2011, 45, 1827.
Occurrence and transport of tetracycline, sulfonamide, quinolone, and macrolide antibiotics in the Haihe River Basin, China.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhslyhsLs%3D&md5=5fb413b25dd77267f7339158a8065563CAS | 21309601PubMed |

[4]  L.-J. Zhou, G.-G. Ying, S. Liu, J.-L. Zhao, B. Yang, Z.-F. Chen, H.-J. Lai, Occurrence and fate of eleven classes of antibiotics in two typical wastewater treatment plants in South China. Sci. Total Environ. 2013, 452–453, 365.
Occurrence and fate of eleven classes of antibiotics in two typical wastewater treatment plants in South China.Crossref | GoogleScholarGoogle Scholar | 23538107PubMed |

[5]  K. Kümmerer, Antibiotics in the aquatic environment- a review- Part I. Chemosphere 2009, 75, 417.
Antibiotics in the aquatic environment- a review- Part I.Crossref | GoogleScholarGoogle Scholar | 19185900PubMed |

[6]  A. Jia, X. Yang, H. Jianying, M. Asami, K. Shoichi, Simultaneous determination of tetracyclines and their degradation products in environmental waters by liquid chromatography–electrospray tandem mass spectrometry. J. Chromatogr. A 2009, 1216, 4655.
Simultaneous determination of tetracyclines and their degradation products in environmental waters by liquid chromatography–electrospray tandem mass spectrometry.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXlslWksr8%3D&md5=f73588e30b221249a091fe930b3ea8c5CAS | 19368929PubMed |

[7]  P. Navratilova, I. Borkovcova, M. Dračkova, B. Janštova, L. Vorlova, Occurrence of tetracycline, chlortetracycline, and oxytetracycline residues in raw cow’s milk. Czech Journal Food Science 2009, 27, 379.
| 1:CAS:528:DC%2BD1MXhtlyis7fI&md5=10da916461d84f3e57486f91029ac75dCAS |

[8]  R. P. Deo, R. U. Halden, Pharmaceuticals in the built and natural water environment of the United States. Water 2013, 5, 1346.
Pharmaceuticals in the built and natural water environment of the United States.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2cXktFSmtbg%3D&md5=4b34335a4adf8ec4e8a33859700b8dd1CAS |

[9]  S. A. Snyder, Occurrence of pharmaceuticals in US drinking water. ACS Symposium Series, 2010, 1048, 69.

[10]  A. M. Doi, M. K. Stoskopf, The kinetics of oxytetracycline degradation in deionized water under varying temperature, pH, light, substrate, and organic matter. J. Aquat. Anim. Health 2000, 12, 246.
The kinetics of oxytetracycline degradation in deionized water under varying temperature, pH, light, substrate, and organic matter.Crossref | GoogleScholarGoogle Scholar |

[11]  J. J. Werner, W. A. Arnold, K. McNeill, Water hardness as a photochemical parameter: tetracycline photolysis as a function of calcium concentration, magnesium concentration, and pH. Environ. Sci. Technol. 2006, 40, 7236.
Water hardness as a photochemical parameter: tetracycline photolysis as a function of calcium concentration, magnesium concentration, and pH.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XmtVygsrY%3D&md5=e0075a99b0d37da7b9fc8cc5a46e8069CAS | 17180972PubMed |

[12]  R. Xuan, L. Arisi, Q. Wang, S. R. Yates, K. C. Biswas, Hydrolysis and photolysis of oxytetracycline in aqueous solution. J. Environ. Sci. Health B 2009, 45, 73.
Hydrolysis and photolysis of oxytetracycline in aqueous solution.Crossref | GoogleScholarGoogle Scholar |

[13]  J. J. López-Peñalver, M. Sánchez-Polo, C. V. Gómez-Pacheco, J. Rivera-Utrilla, Photodegradtion of tetracyclines in aqueous solution by using UV and UV/H2O2 oxidation processes. J. Chem. Technol. Biotechnol. 2010, 85, 1325.
Photodegradtion of tetracyclines in aqueous solution by using UV and UV/H2O2 oxidation processes.Crossref | GoogleScholarGoogle Scholar |

[14]  Y. Chen, H. Li, Z. Wang, T. Tao, C. Hu, Photoproducts of tetracycline and oxytetracycline involving self-sensitized oxidation in aqueous solutions: Effects of Ca2+ and Mg2+. J. Environ. Sci. 2011, 23, 1634.
Photoproducts of tetracycline and oxytetracycline involving self-sensitized oxidation in aqueous solutions: Effects of Ca2+ and Mg2+.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhsVCls7nO&md5=d15f98901a166013579807acdee78c47CAS |

[15]  H. Xu, W. J. Coopers, J. Jung, W. Song, Photosensitized degradation of amoxicillin in natural organic matter isolate solutions. Water Res. 2011, 45, 632.
Photosensitized degradation of amoxicillin in natural organic matter isolate solutions.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXhs1Sqsr%2FK&md5=9e9bc56b6d2d0f92d7bede00ab4e1c30CAS | 20813393PubMed |

[16]  S. Canonica, H. U. Laubschen, Inhibitory effect of dissolved organic matter on triplet-induced oxidation of aquatic contaminants. Photochem. Photobiol. Sci. 2008, 7, 547.
Inhibitory effect of dissolved organic matter on triplet-induced oxidation of aquatic contaminants.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXls1Shs7s%3D&md5=52262bac3ce3f6c5a2f48971d510106aCAS | 18465010PubMed |

[17]  J. Wenk, U. von Gunten, S. Canonica, Effect of dissolved organic matter on the transformation of contaminants induced by excited triplet states and the hydroxyl radical. Environ. Sci. Technol. 2011, 45, 1334.
Effect of dissolved organic matter on the transformation of contaminants induced by excited triplet states and the hydroxyl radical.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhtFOgsbk%3D&md5=4332e64baeeb2a35546088a175b95e99CAS | 21271693PubMed |

[18]  O. A. Arikan, L. J. Sikora, W. Mulbry, S. U. Khan, C. Rice, G. D. Foster, The fate and effect of oxytetracycline during the anaerobic digestion of manure from therapeutically treated calves. Process Biochem. 2006, 41, 1637.
The fate and effect of oxytetracycline during the anaerobic digestion of manure from therapeutically treated calves.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XltVKnsrc%3D&md5=8d11522a0692c76975928c05356630c4CAS |

[19]  D. Aga, O. Connor, S. Ensley, J. O. Payero, D. Snow, D. Tarkalson, Determination of the persistence of tetracycline antibiotics and their degradates in manure-amended soil using enzyme-linked immunosorbent assay and liquid chromatography-mass spectrometry. J. Agric. Food Chem. 2005, 53, 7165.
Determination of the persistence of tetracycline antibiotics and their degradates in manure-amended soil using enzyme-linked immunosorbent assay and liquid chromatography-mass spectrometry.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXntVygsr0%3D&md5=698ee1be32cc98d18740027db3376c72CAS | 16131125PubMed |

[20]  F. Ingerslev, B. Halling-Sørensen, Biodegradability of metronidazole, olaquindox, and tylosin and formation of tylosin degradation products in aerobic soil-manure slurries. Ecotoxicol. Environ. Saf. 2001, 48, 311.
Biodegradability of metronidazole, olaquindox, and tylosin and formation of tylosin degradation products in aerobic soil-manure slurries.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXhtlSqt7g%3D&md5=8e62ef882e72d5a2dc37dd4532799502CAS | 11222042PubMed |

[21]  S. O’Connor, D. S. Aga, Analysis of tetracycline antibiotics in soil: advances in extraction, clean-up, and quantification. Trends Analyt. Chem. 2007, 26, 456.
Analysis of tetracycline antibiotics in soil: advances in extraction, clean-up, and quantification.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXmsFajsbw%3D&md5=e12921c005d2e02b32a22b0d040ac09fCAS |

[22]  N. S. Simon, Loosely bound oxytetracycline in riverine sediments from two tributaries of the Chesapeake Bay. Environ. Sci. Technol. 2005, 39, 3480.
Loosely bound oxytetracycline in riverine sediments from two tributaries of the Chesapeake Bay.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXjtVCqtrg%3D&md5=3d690a7535acade4f6fd7f8300130bd3CAS | 15952351PubMed |

[23]  P. E. Rose, J. A. Pedersen, Fate of oxytetracycline in streams receiving aquaculture discharges model simulations. Environ. Toxicol. Chem. 2005, 24, 40.
Fate of oxytetracycline in streams receiving aquaculture discharges model simulations.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXivVGgu7Y%3D&md5=6549b1ff467d95065dcebf17f25105c5CAS | 15683166PubMed |

[24]  P. S. Choo, Degradation of oxytetracycline hydrochloride in fresh and sea water. Asian Fish. Sci. 1994, 7, 195.

[25]  O. B. Samuelsen, Degradation of oxytetracycline in seawater at two different temperatures and light intensities, and the persistence of oxytetracycline in the sediment from a fish farm. Aquaculture 1989, 83, 7.
Degradation of oxytetracycline in seawater at two different temperatures and light intensities, and the persistence of oxytetracycline in the sediment from a fish farm.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3cXkvVCnurY%3D&md5=796c59ff80aadf55af4c753d166ab68eCAS |

[26]  B. Halling-Sørensen, G. Sengeløv, F. Ingerslev, L. B. Jensen, Reduced antimicrobial potencies of oxytetracycline, tylosin, sulfadiazin, streptomycin, cip rofloxacin, and olaquindox due to environmental processes. Arch. Environ. Contam. Toxicol. 2003, 44, 7.
Reduced antimicrobial potencies of oxytetracycline, tylosin, sulfadiazin, streptomycin, cip rofloxacin, and olaquindox due to environmental processes.Crossref | GoogleScholarGoogle Scholar | 12434214PubMed |

[27]  H. Björklund, J. Bondestam, G. Bylund, Residues of oxytetracycline in wild fish and sediments from fish farms. Aquaculture 1990, 86, 359.
Residues of oxytetracycline in wild fish and sediments from fish farms.Crossref | GoogleScholarGoogle Scholar |

[28]  E. Zuccato, R. Bagnati, F. Fioretti, M. Natangelo, D. Calamari, R. Fanelli, Environmental Loads And Detection Of Pharmaceuticals In Italy: Pharmaceuticals In The Environment: Sources, Fate, Effects And Risks (Ed. K. Kümmerer) 2001, pp. 19–27 (Springer: Berlin).

[29]  R. Coyne, P. Smith, C. Moriarty, The fate of oxytetracycline in the marine environment of a salmon cage farm. Marine Environment and Health Series 2001, 3, 1.

[30]  IUPAC Quantitative review and analysis of pesticide sorption and its effect on degradation in relation soil and climate. Chemistry International – Newsmagazine for IUPAC 2011, 33, 23.

[31]  G. Wang, O. Dani, Aqueous films limit bacterial cell motility and colony expansion on partially saturated rough surfaces. Environ. Microbiol. 2010, 12, 1363.
Aqueous films limit bacterial cell motility and colony expansion on partially saturated rough surfaces.Crossref | GoogleScholarGoogle Scholar | 20192969PubMed |

[32]  X. Peng, K. Zhang, C. Tang, Q. Huang, Y. Yu, J. Cui, Distribution pattern, behavior, and fate of antibacterials in urban aquatic environments in South China. J. Environ. Monit. 2011, 13, 446.
Distribution pattern, behavior, and fate of antibacterials in urban aquatic environments in South China.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhslGgsro%3D&md5=c3960cff873bc42a374343f949f1d69eCAS | 21161084PubMed |

[33]  J. J. T. I. Boesten, K. Aden, C. Y. Beigel, S. Beulke, M. Dust, J. S. Dyson, I. S. Fomsgaard, R. J. Jones, S. Karlsson, A. M. A. van der Linden, O. Richter, J. O. Magrans, G. Soulas, Guidance document on estimating persistence and degradation kinetics from environmental fate studies on pesticides in EU registration. Report of the FOCUS Work Group on Degradation Kinetics, EC Doc. Ref. Sanco/10058/2005, version 1 2005 (EU Joint Research Centre: Brussels).

[34]  C. Díez, E. Barrado, Soil dissipation kinetics of twelve herbicides used on rain-fed barley crop in Spain. Anal. Bioanal. Chem. 2010, 397, 1617.
Soil dissipation kinetics of twelve herbicides used on rain-fed barley crop in Spain.Crossref | GoogleScholarGoogle Scholar | 20419492PubMed |

[35]  W. A. Jury, H. Flurer, transorpt of chemicals through soil: mechanisms, models and field applications. Adv. Agron. 1992, 47, 141.
transorpt of chemicals through soil: mechanisms, models and field applications.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK38Xks12js7c%3D&md5=92b893406c110b46811b61a2e2184ea5CAS |

[36]  D. I. Gustafson, L. R. Holden, Non-linear pesticide dissipation in soil: a new model based on spatial variability. Environ. Sci. Technol. 1990, 24, 1032.
Non-linear pesticide dissipation in soil: a new model based on spatial variability.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3cXktVWqu7c%3D&md5=02b0589906be7eb23b107d1cf481e13fCAS |

[37]  P. M. Jardine, F. M. Dunnivat, H. M. Selim, M. McCarth, Comparison of models for describing the transport of dissolved organic carbon in aquifer column. Soil Sci. Soc. Am. J. 1992, 56, 393.
Comparison of models for describing the transport of dissolved organic carbon in aquifer column.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK38XktFCjt7s%3D&md5=9e133a1956ed47a616d1e10937ac6726CAS |

[38]  M. T. van Genuchten, R. W. Cleary, Soil Chemistry. B. Physicochemical models. Developments in Soil Science 1982 (Elsevier Scientific Publishing Co: Amsterdam).

[39]  S. W. Benson, Mathematical characterization of simple kinetc systems, in The Foundations of Chemical Kinetics 1960, pp. 11–25 (McGraw-Hill: New York).

[40]  G. W. Castellan, Physical Chemistry, 2nd edn 1971 (Addison-Wesley: Reading, MA).

[41]  J. Maki, H. Hasegawa, H. Kitami, K. Fumoto, Y. Munekage, K. Ueda, Bacterioal degradation of antibiotic residues in marine fish farm sediments of Uranouchi Bay and phylogenetic analysis of antibiotic degrading bacteria using 16S rDNA sequences. Fish. Sci. 2006, 72, 811.
Bacterioal degradation of antibiotic residues in marine fish farm sediments of Uranouchi Bay and phylogenetic analysis of antibiotic degrading bacteria using 16S rDNA sequences.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XovFymtbk%3D&md5=5a6fe2a04e82e8c8ebdc547aff3fea0bCAS |

[42]  X. Wen, Y. Jia, J. Li, Degradation of tetracycline and oxytetracycline by crude lignin peroxidase prepared from Phanerochaete chrysosporium – a white rot fungus. Chemosphere 2009, 75, 1003.
Degradation of tetracycline and oxytetracycline by crude lignin peroxidase prepared from Phanerochaete chrysosporium – a white rot fungus.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXltFWlt7Y%3D&md5=bb43cdf8f066ff3ad00a7002ffd07cf0CAS | 19232429PubMed |

[43]  E. Meyers, D. A. Smith, Microbiological degradation of tetracyclines. J. Bacteriol. 1962, 84, 797.
| 1:CAS:528:DyaF38XkslyhtLY%3D&md5=a6f391a00a1da86a079cd711502ef85eCAS | 13935339PubMed |

[44]  D. T. Sponza, H. Celebi, Removal of oxytetracycline (OTC) in a synthetic pharmaceutical wastewater by sequential anaerobic multi-chamber bed reactor (AMCBR)/completely stirred tank reactor (CSTR) system: Biodegradation and inhibition kinetics. J. Chem. Technol. Biotechnol. 2012, 87, 961.
Removal of oxytetracycline (OTC) in a synthetic pharmaceutical wastewater by sequential anaerobic multi-chamber bed reactor (AMCBR)/completely stirred tank reactor (CSTR) system: Biodegradation and inhibition kinetics.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XkvVSgug%3D%3D&md5=c8eb37f7a681300cb0fab6f422aa1e38CAS |

[45]  M. F. Zaranyika, M. G. Nyandoro, Degradation of glyphosate in the aquatic environment: an enzymatic kinetic model that takes into account microbial degradation of both free and colloidal (or sediment) particle adsorbed glyphosate. J. Agric. Food Chem. 1993, 41, 838.
Degradation of glyphosate in the aquatic environment: an enzymatic kinetic model that takes into account microbial degradation of both free and colloidal (or sediment) particle adsorbed glyphosate.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3sXitVOnsbo%3D&md5=8512a847ab966836a9a00f344a9d0f79CAS |

[46]  M. F. Zaranyika, M. Jovanni, J. Jiri, Degradation of endosulfan I and endosulfan II in the aquatic environment: a proposed enzymatic kinetic model that takes into account adsorption/desorption of the pesticide by colloidal and or sediment particles. S. Afr. J. Chem. 2010, 63, 100.

[47]  M. F. Zaranyika, M. Mlilo, Degradation of fenamiphos, chlorpyrifos and pirimiphos-methyl in the aquatic environment: a proposed enzymatic kinetic model that takes into account adsorption/desorption of the pesticide by colloidal and sediment particles, in Pesticides – Recent Trends in Pesticide Assay, (Ed. P. Soundararajan) 2012, pp. 193–216 (InTech Press: Rijeka, Croatia).

[48]  M. F. Zaranyika, S. Nyoni, Degradation of paraquat in the aquatic environment: a proposed enzymatic kinetic model that takes into account adsorption/desorption of the herbicide by colloidal and sediment particles. Int. J. Res. Chem. Environ. 2013, 3, 26.
| 1:CAS:528:DC%2BC3sXhtF2lt73L&md5=131c5faf83aad9cb998643b7c55f4a58CAS |

[49]  W. C. Tsai, S. D. Huang, Dispersive liquid–liquid micro-extraction with little solvent consumption combined with gas chromatography–mass spectrometry for the pretreatment of organochlorine pesticides in aqueous samples. J. Chromatogr. A 2009, 1216, 5171.
Dispersive liquid–liquid micro-extraction with little solvent consumption combined with gas chromatography–mass spectrometry for the pretreatment of organochlorine pesticides in aqueous samples.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXntVShs7k%3D&md5=c6a63021f5f8414c61538732266c118fCAS | 19481758PubMed |

[50]  M. Cruz-Vera, R. Lucena, S. Cárdenas, M. Valcárcel, Sample treatments based on dispersive (micro) extraction. Analytical methods 2011, 3, 1719.
Sample treatments based on dispersive (micro) extraction.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhtFKqsbjI&md5=ef3ae613e2a567accf5b14106b749daaCAS |

[51]  M. De Liguoro, V. Cibin, F. Capolongo, B. Halling-Sorensen, C. Montesissa, Use of oxytetracycline in intensive calf farming: evaluation of transfer to manure and soil. Chemosphere 2003, 52, 203.
Use of oxytetracycline in intensive calf farming: evaluation of transfer to manure and soil.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXjt1Gqt7w%3D&md5=494295611924586cef4ed6e48b176e67CAS | 12729703PubMed |

[52]  S. Babić, D. Asperger, D. Mutavdzic, A. J. M. Harvat, M. Kastelan-Macan, Solid-phase extraction and HPLC determination of veterinary pharmaceuticals in wastewater. Talanta 2006, 70, 732.
Solid-phase extraction and HPLC determination of veterinary pharmaceuticals in wastewater.Crossref | GoogleScholarGoogle Scholar | 18970832PubMed |

[53]  Method 9215B: pour plate method, Standard Methods for the Examination of Water and Wastewater, 19th edn, 2004 (American Public Health Association, American Water Works Association, Water Environment Federation: Washington DC).

[54]  H. Pouliquen, H. Le Bris, Sorption of oxolinic acid and oxytetracycline to marine sediments. Chemosphere 1996, 33, 801.
Sorption of oxolinic acid and oxytetracycline to marine sediments.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK28XkvF2jurw%3D&md5=e10c3ebdc5f881d928dbfc4cd4e033eeCAS |

[55]  P. Kulshrestha, R. F. Giese, D. S. Aga, Investigating the molecular interactions of oxytetracycline in clay and organic matter: insites on factors affecting mobility in soil. Environ. Sci. Technol. 2004, 38, 4097.
Investigating the molecular interactions of oxytetracycline in clay and organic matter: insites on factors affecting mobility in soil.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXkvVWqsrw%3D&md5=72dcb3a51108df152370011b418967efCAS | 15352447PubMed |

[56]  F. Daniels, R. A. Alberty, Chemical kinetics, in Physical Chemistry, 2nd edn 1961, pp. 294–349 (Wiley: New York).

[57]  W. J. Moore, Chemical kinetics, in Physical Chemistry, 4th edn 1962, pp. 253–322 (Longmans: London).

[58]  J. Jeong, W. Song, W. J. Cooper, J. Jung, Degradation of tetracycline antibiotics: Mechanisms and kinetc studies for advanced oxidation/reduction processes. Chemosphere 2010, 78, 533.
Degradation of tetracycline antibiotics: Mechanisms and kinetc studies for advanced oxidation/reduction processes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXptlSq&md5=edb2e89a2ea935e332f2f5b33873aa44CAS | 20022625PubMed |

[59]  X. Wen, Y. Jia, J. Li, Enzymatic degradation of tetracycline and oxytetracycline by crude manganese peroxidase prepared from Phanerochaete chrysosporium. J. Hazard. Mater. 2010, 177, 924.
Enzymatic degradation of tetracycline and oxytetracycline by crude manganese peroxidase prepared from Phanerochaete chrysosporium.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXisV2rs7s%3D&md5=73f27e81faef70de2f102cb619e12c66CAS | 20117880PubMed |

[60]  H. Pouliquen, M. Larhantec-Verdier, M. Morvan, H. LeBris, Comparative hydrolysis and photolysis of four antibacterial agents (oxytetracycline, oxolinic acid, flumequine and florfenicol) in deionised water, freshwater and seawater under abiotic conditions. Aquaculture 2007, 262, 23.
Comparative hydrolysis and photolysis of four antibacterial agents (oxytetracycline, oxolinic acid, flumequine and florfenicol) in deionised water, freshwater and seawater under abiotic conditions.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXhtVCntLs%3D&md5=63bcf81a973d4e04db900a5330362b94CAS |

[61]  S. Jiao, S. Zheng, D. Yin, L. Wang, L. Chen, Aqueous oxytetracycline degradation and toxicity change of degradation compounds in photoirradiation process. J. Environ. Sci. 2008, 20, 806.
Aqueous oxytetracycline degradation and toxicity change of degradation compounds in photoirradiation process.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXps12ntbk%3D&md5=8f28a547cbf9c9c98dcecc30a7fd54c1CAS |

[62]  C. V. Gómez-Pacheco, M. Sanchez-Polo, J. Rivera-Utrilla, J. J. Lopez-Penalver, Tetracycline degradation in aqueous phase by ultraviolet radiation. Chem. Eng. J. 2012, 187, 89.
Tetracycline degradation in aqueous phase by ultraviolet radiation.Crossref | GoogleScholarGoogle Scholar |

[63]  K. E. Wommack, R. T. Hill, M. Kessel, E. Russek-Cohen, R. R. Colwell, Distribution of viruses in the Chesapeak Bay. Appl. Environ. Microbiol. 1992, 58, 2965.
| 1:STN:280:DyaK3s%2Fntlyquw%3D%3D&md5=23fc3a2fe2215607c1de8d9baccc08a9CAS | 1444409PubMed |

[64]  K. P. Hennes, C. A. Suttle, Direct counts of viruses in natural waters and laboratory cultures by epifluorescence microscopy. Limnol. Oceanogr. 1995, 40, 1050.
Direct counts of viruses in natural waters and laboratory cultures by epifluorescence microscopy.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2MXpsVCrtb0%3D&md5=1bab35c4a1db8c124d43b70090a8a50bCAS |

[65]  U. L. Zweifel, A. Hagstron, Total counts of marine bacteria include a large fraction of non-nucleoid-containing bacteria (ghosts). Appl. Environ. Microbiol. 1995, 61, 2180.
| 1:CAS:528:DyaK2MXlvFOgt78%3D&md5=533333a4965b259fc5b657ae413cc1f5CAS | 16535043PubMed |

[66]  I. G. Graham-Bryce, The behavior of pesticides in soil, in The Chemistry of Soil Processes (Eds D. J. Greenland, M. H. B. Hayes) 1981, pp. 621–670 (Wiley: New York).

[67]  R. J. Hance, Observations on the relationship between the adsorption of diuron and the nature of the adsorbent. Weed Res. 1965, 5, 108.
Observations on the relationship between the adsorption of diuron and the nature of the adsorbent.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaF28Xit1GktA%3D%3D&md5=49b7cf97f9a8268f413106ad720c49fbCAS |

[68]  B. T. Bowman, W. W. Sans, Adsorption of parathion, fenitrothion, methyl parathion, aminoparathion and paraxon by Na+, Ca2+ and Fe3+ montmorillonite suspensions. Soil Sci. Soc. Am. J. 1977, 41, 514.
Adsorption of parathion, fenitrothion, methyl parathion, aminoparathion and paraxon by Na+, Ca2+ and Fe3+ montmorillonite suspensions.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE2sXlvFGnsbY%3D&md5=4d2c2f73852d4c2d97013c96e28be5e3CAS |

[69]  M. F. Zaranyika, N. T. Mandizha, Adsorption of amitraz by a river sediment: apparent thermodynamic properties. J. Environ. Sci. Health B 1998, 33, 235.
Adsorption of amitraz by a river sediment: apparent thermodynamic properties.Crossref | GoogleScholarGoogle Scholar |

[70]  P. W. Atkins, Rates of chemical reactions, in Physical Chemistry 1978, pp. 849–896 (W.H. Freeman & Company: San Francisco, CA).

[71]  R. E. Weston Jr, H. A. Schwarz, Rate constants for elementary reactions, in Chemical Kinetics 1972, pp. 84–116 (Prentice-Hall, Eaglewood Cliffs, NJ, USA).

[72]  P. W. Atkins, Processes at solid surfaces, in Physical Chemistry 1978, pp. 929–957 (W.H. Freeman & Company: San Francisco, CA).

[73]  M. M. Barbooti, K. S. Al-Bassam, B. H. Qasim, Evaluation of Iraqi montmorillonite as adsorbent for the removal of oxytetracycline from water. Iraqi J. Sci. 2012, 53, 479.

[74]  O. P. Bansal, Sorption of tetracycline, oxytetracycline, and chlortetracycline in illite and kaolinite suspensions. ISRN Environ. Chem. 2013, 2013, 1.
Sorption of tetracycline, oxytetracycline, and chlortetracycline in illite and kaolinite suspensions.Crossref | GoogleScholarGoogle Scholar |